# kb

id: planqc-20260505-0
file: data/en.wikipedia.org/wiki/Planqc-0.md
category: reference
title: Planqc
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planqc
date_saved: 2026-05-05T11:08:03.451786+00:00
instance: kb-cron
parent: planqc-20260505-0
summary:
planqc is a quantum computing company based in Garching. Founded in 2022 as a spin-off from the Max Planck Institute of Quantum Optics, the company develops quantum processors that use neutral atoms trapped in optical lattices of light to perform computations. == History == planqc was founded in 2022 by Alexander Glätzle, Sebastian Blatt, and Johannes Zeiher as the first spin-off from the Max Planck Institute of Quantum Optics within the Munich Quantum Valley initiative. The company is part of broader European efforts to develop locally built quantum computing technologies. The company’s founders and leadership include researchers formerly affiliated with the University of Oxford, Harvard University, and the University of California, Berkeley. In the same year, planqc secured seed funding of approximately €4.6 million from UVC Partners and Speedinvest to support the development of its neutral-atom quantum processors. Among the investors were Hermann Hauser, Ann-Kristin Achleitner, and Markus Wagner, who also joined the company's advisory board. planqc’s scientific advisory board includes researchers in quantum physics, such as Immanuel Bloch, J. Ignacio Cirac, Artur Ekert, Dieter Jaksch, and Markus Müller. In 2023, the company was selected by the German Aerospace Center (DLR) to develop a 1,000-qubit quantum computer under a contract


id: qmill-20260505-0
file: data/en.wikipedia.org/wiki/QMill-0.md
category: reference
title: QMill
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/QMill
date_saved: 2026-05-05T11:08:04.681605+00:00
instance: kb-cron
parent: qmill-20260505-0
summary:
QMill is a quantum computing firm based in Finland that was established in 2024, focusing on creating quantum algorithms that offer immediate, practical advantages for industrial uses. Utilizing upcoming quantum technology, QMill strives to tackle intricate optimization challenges and deliver considerable value across multiple industries. The organization is situated in Espoo, Finland. == References == == External links == Official website


id: qpiai-indus-20260505-0
file: data/en.wikipedia.org/wiki/QpiAI-Indus-0.md
category: reference
title: QpiAI-Indus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/QpiAI-Indus
date_saved: 2026-05-05T11:08:05.842605+00:00
instance: kb-cron
parent: qpiai-indus-20260505-0
summary:
QpiAI-Indus is the India's first full stack quantum computer. It is a 25 superconducting qubits quantum computer developed by the Banglore based startup company QpiAI. It was launched on the occasion of the World Quantum Day in the year 2025. The quantum computer QpiAI-Indus was developed under the leadership of the CEO Nagendra Nagaraja of the company. The development program of the quantum computer was assisted and supported by the National Quantum Mission of the Government of India. The success of the development of the QpiAI-Indus quantum computer at the silicon city Bangalore in India is considered as one of major milestone in journey of India's quantum computer. == Etymology == QpiAI-Indus is the codename of the 25 qubits quantum computer developed by the startup company QpiAI. In the term QpiAI which also signifies for the company name, the letter Q stands for quantum, pi stands for the mathematical symbol π and AI means algorithmic intelligence. The term Indus signifies for the ancient civilization valley in the Indian subcontinent. Thus the etymology of the codename of the quantum computer QpiAI-Indus signifies the legacy of the development of quantum computing in India. == Description == The QpiAI-Indus quantum computer features a


id: quantum-algorithm-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_algorithm-0.md
category: reference
title: Quantum algorithm
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_algorithm
date_saved: 2026-05-05T11:08:07.005881+00:00
instance: kb-cron
parent: quantum-algorithm-20260505-0
summary:
In quantum computing, a quantum algorithm is an algorithm that runs on a realistic model of quantum computation, the most commonly used model being the quantum circuit model of computation. A classical (or non-quantum) algorithm is a finite sequence of instructions, or a step-by-step procedure for solving a problem, where each step or instruction can be performed on a classical computer. Similarly, a quantum algorithm is a step-by-step procedure, where each of the steps can be performed on a quantum computer. Although all classical algorithms can also be performed on a quantum computer, the term quantum algorithm is generally reserved for algorithms that seem inherently quantum, or use some essential feature of quantum computation such as quantum superposition or quantum entanglement. Problems that are undecidable using classical computers remain undecidable using quantum computers. What makes quantum algorithms interesting is that they might be able to solve some problems faster than classical algorithms because the quantum superposition and quantum entanglement that quantum algorithms exploit generally cannot be efficiently simulated on classical computers (see Quantum supremacy). The best-known algorithms are Shor's algorithm for factoring and Grover's algorithm for searching an unstructured database or an unordered list. Shor's algorithm would, if implemented, run


id: quantum-algorithm-20260505-1
file: data/en.wikipedia.org/wiki/Quantum_algorithm-1.md
category: reference
title: Quantum algorithm
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_algorithm
date_saved: 2026-05-05T11:08:07.005881+00:00
instance: kb-cron
parent: quantum-algorithm-20260505-0
summary:
| f ~ ( z i ) | ⩾ 2. {\displaystyle |{\tilde {f}}(z_{i})|\geqslant 2.} This can be done in bounded-error quantum polynomial time (BQP). == Algorithms based on amplitude amplification == Amplitude amplification is a technique that allows the amplification of a chosen subspace of a quantum state. Applications of amplitude amplification usually lead to quadratic speedups over the corresponding classical algorithms. It can be considered as a generalization of Grover's algorithm. === Grover's algorithm === Grover's algorithm searches an unstructured database (or an unordered list) with N entries for a marked entry, using only O ( N ) {\displaystyle O({\sqrt {N}})} queries instead of the O ( N ) {\displaystyle O({N})} queries required classically. Classically, O ( N ) {\displaystyle O({N})} queries are required even allowing bounded-error probabilistic algorithms. Theorists have considered a hypothetical generalization of a standard quantum computer that could access the histories of the hidden variables in Bohmian mechanics. (Such a computer is completely hypothetical and would not be a standard quantum computer, or even possible under the standard theory of quantum mechanics.) Such a hypothetical computer could implement a search of an N-item database in at most O ( N 3 ) {\displaystyle O({\sqrt[{3}]{N}})} steps.


id: quantum-algorithm-20260505-2
file: data/en.wikipedia.org/wiki/Quantum_algorithm-2.md
category: reference
title: Quantum algorithm
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_algorithm
date_saved: 2026-05-05T11:08:07.005881+00:00
instance: kb-cron
parent: quantum-algorithm-20260505-0
summary:
=== Formula evaluation === A formula is a tree with a gate at each internal node and an input bit at each leaf node. The problem is to evaluate the formula, which is the output of the root node, given oracle access to the input. A well studied formula is the balanced binary tree with only NAND gates. This type of formula requires Θ ( N c ) {\displaystyle \Theta (N^{c})} queries using randomness, where c = log 2 ⁡ ( 1 + 33 ) / 4 ≈ 0.754 {\displaystyle c=\log _{2}(1+{\sqrt {33}})/4\approx 0.754} . With a quantum algorithm, however, it can be solved in Θ ( N 1 / 2 ) {\displaystyle \Theta (N^{1/2})} queries. No better quantum algorithm for this case was known until one was found for the unconventional Hamiltonian oracle model. The same result for the standard setting soon followed. Fast quantum algorithms for more complicated formulas are also known. === Group commutativity === The problem is to determine if a black-box group, given by k generators, is commutative. A black-box group is a group with an oracle function, which must be used to perform the group operations (multiplication, inversion, and comparison with identity). The interest


id: quantum-artificial-intelligence-lab-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_Artificial_Intelligence_Lab-0.md
category: reference
title: Quantum Artificial Intelligence Lab
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_Artificial_Intelligence_Lab
date_saved: 2026-05-05T11:08:08.332857+00:00
instance: kb-cron
parent: quantum-artificial-intelligence-lab-20260505-0
summary:
The Quantum Artificial Intelligence Lab (also called the Quantum AI Lab or QuAIL) is a joint initiative of NASA, Universities Space Research Association, and Google (specifically, Google Research) whose goal is to pioneer research on how quantum computing might help with machine learning and other difficult computer science problems. The lab is hosted at NASA's Ames Research Center. == History == The Quantum AI Lab was announced by Google Research in a blog post on May 16, 2013. At the time of launch, the Lab was using the most advanced commercially available quantum computer, D-Wave Two from D-Wave Systems. On October 10, 2013, Google released a short film describing the current state of the Quantum AI Lab. On October 18, 2013, Google announced that it had incorporated quantum physics into Minecraft. In January 2014, Google reported results comparing the performance of the D-Wave Two in the lab with that of classical computers. The results were ambiguous and provoked heated discussion on the Internet. On 2 September 2014, it was announced that the Google Quantum AI Lab, in partnership with UC Santa Barbara, would be launching an initiative to create quantum information processors based on superconducting electronics. On the 23rd of


id: quantum-computation-and-quantum-information-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_Computation_and_Quantum_Information-0.md
category: reference
title: Quantum Computation and Quantum Information
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_Computation_and_Quantum_Information
date_saved: 2026-05-05T11:08:09.577704+00:00
instance: kb-cron
parent: quantum-computation-and-quantum-information-20260505-0
summary:
Quantum Computation and Quantum Information is a textbook about quantum information science written by Michael Nielsen and Isaac Chuang, regarded as a standard text on the subject. It is informally known as "Mike and Ike", after the candies of that name. The book assumes minimal prior experience with quantum mechanics and with computer science, aiming instead to be a self-contained introduction to the relevant features of both. (Lov Grover recalls a postdoc disparaging it with the remark, "The book is too elementary – it starts off with the assumption that the reader does not even know quantum mechanics.") The focus of the text is on theory, rather than the experimental implementations of quantum computers, which are discussed more briefly. As of December 2024, the book has been cited over 58,000 times on Google Scholar. In 2019, Nielsen adapted parts of the book for his Quantum Country project. == Table of Contents (Tenth Anniversary Edition) == Chapter 1: Introduction and Overview Chapter 2: Introduction to Quantum Mechanics Chapter 3: Introduction to Computer Science Chapter 4: Quantum Circuits Chapter 5: The Quantum Fourier Transform and its Applications Chapter 6: Quantum Search Algorithms Chapter 7: Quantum Computers: Physical Realization Chapter 8: Quantum Noise


id: quantum-computing-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_computing-0.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
A quantum computer is a real or theoretical computer that exploits quantum phenomena like superposition and entanglement in an essential way. It is widely believed that a quantum computer could perform some calculations exponentially faster than any classical computer. For example, a large-scale quantum computer could break some widely used encryption schemes and aid physicists in performing physical simulations. However, current hardware implementations of quantum computation are largely experimental and only suitable for specialized tasks. The basic unit of information in quantum computing, the qubit (or "quantum bit"), serves the same function as the bit in ordinary or "classical" computing. However, unlike a classical bit, which can be in one of two states (a binary), a qubit can exist in a linear combination of two states known as a quantum superposition. The result of measuring a qubit is one of the two states given by a probabilistic rule. If a quantum computer manipulates the qubit in a particular way, wave interference effects amplify the probability of the desired measurement result. The design of quantum algorithms involves creating procedures that allow a quantum computer to perform this amplification. Quantum computers are not yet practical for real-world applications. Physically engineering high-quality qubits


id: quantum-computing-20260505-1
file: data/en.wikipedia.org/wiki/Quantum_computing-1.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
A classical computer is a quantum computer ... so we shouldn't be asking about "where do quantum speedups come from?" We should say, "Well, all computers are quantum. ... Where do classical slowdowns come from?" === Quantum information === Just as the bit is the basic concept of classical information theory, the qubit is the fundamental unit of quantum information. The same term qubit is used to refer to an abstract mathematical model and to any physical system that is represented by that model. A classical bit, by definition, exists in either of two physical states, which can be denoted 0 and 1. A qubit is also described by a state, and two states, often written | 0 ⟩ {\displaystyle |0\rangle } and | 1 ⟩ {\displaystyle |1\rangle } , serve as the quantum counterparts of the classical states 0 and 1. However, the quantum states | 0 ⟩ {\displaystyle |0\rangle } and | 1 ⟩ {\displaystyle |1\rangle } belong to a vector space, meaning that they can be multiplied by constants and added together, and the result is again a valid quantum state. Such a combination is known as a superposition of | 0 ⟩ {\displaystyle |0\rangle } and


id: quantum-computing-20260505-2
file: data/en.wikipedia.org/wiki/Quantum_computing-2.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
CNOT := ( 1 0 0 0 0 1 0 0 0 0 0 1 0 0 1 0 ) . {\displaystyle \operatorname {CNOT} :={\begin{pmatrix}1&0&0&0\\0&1&0&0\\0&0&0&1\\0&0&1&0\end{pmatrix}}.} As a mathematical consequence of this definition, CNOT ⁡ | 00 ⟩ = | 00 ⟩ {\textstyle \operatorname {CNOT} |00\rangle =|00\rangle } , CNOT ⁡ | 01 ⟩ = | 01 ⟩ {\textstyle \operatorname {CNOT} |01\rangle =|01\rangle } , CNOT ⁡ | 10 ⟩ = | 11 ⟩ {\textstyle \operatorname {CNOT} |10\rangle =|11\rangle } , and CNOT ⁡ | 11 ⟩ = | 10 ⟩ {\textstyle \operatorname {CNOT} |11\rangle =|10\rangle } . In other words, the CNOT applies a NOT gate ( X {\textstyle X} from before) to the second qubit if and only if the first qubit is in the state | 1 ⟩ {\textstyle |1\rangle } . If the first qubit is | 0 ⟩ {\textstyle |0\rangle } , nothing is done to either qubit. In summary, quantum computation can be described as a network of quantum logic gates and measurements. However, any measurement can be deferred to the end of quantum computation, though this deferment may come at a computational cost, so most quantum circuits depict a network consisting only of quantum


id: quantum-computing-20260505-3
file: data/en.wikipedia.org/wiki/Quantum_computing-3.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
Digital cryptography enables communications to remain private, preventing unauthorized parties from accessing them. Conventional encryption, the obscuring of a message with a key through an algorithm, relies on the algorithm being difficult to reverse. Encryption is also the basis for digital signatures and authentication mechanisms. Quantum computing may be sufficiently more powerful that difficult reversals are feasible, allowing messages relying on conventional encryption to be read. Quantum cryptography replaces conventional algorithms with computations based on quantum computing. In principle, quantum encryption would be impossible to decode even with a quantum computer. This advantage comes at a significant cost in terms of elaborate infrastructure, while effectively preventing legitimate decoding of messages by governmental security officials. Ongoing research in quantum and post-quantum cryptography has led to new algorithms for quantum key distribution, initial work on quantum random number generation and to some early technology demonstrations. == Communication == Quantum cryptography enables new ways to transmit data securely; for example, quantum key distribution uses entangled quantum states to establish secure cryptographic keys. When a sender and receiver exchange quantum states, they can guarantee that an adversary does not intercept the message, as any unauthorized eavesdropper would disturb the delicate quantum system and introduce


id: quantum-computing-20260505-4
file: data/en.wikipedia.org/wiki/Quantum_computing-4.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
A notable application of quantum computing is in attacking cryptographic systems that are currently in use. Integer factorization, which underpins the security of public key cryptographic systems, is believed to be computationally infeasible on a classical computer for large integers if they are the product of a few prime numbers (e.g., the product of two 300-digit primes). By contrast, a quantum computer could solve this problem exponentially faster using Shor's algorithm to factor the integer. This ability would allow a quantum computer to break many of the cryptographic systems in use today, in the sense that there would be a polynomial time (in the number of digits of the integer) algorithm for solving the problem. In particular, most of the popular public key ciphers are based on the difficulty of factoring integers or the discrete logarithm problem, both of which can be solved by Shor's algorithm. In particular, the RSA, Diffie–Hellman, and elliptic curve Diffie–Hellman algorithms could be broken. These are used to protect secure Web pages, encrypted email, and many other types of data. Breaking these would have significant ramifications for electronic privacy and security. Identifying cryptographic systems that may be secure against quantum algorithms is an actively researched


id: quantum-computing-20260505-5
file: data/en.wikipedia.org/wiki/Quantum_computing-5.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
Deep generative chemistry models have been explored for potential applications in drug discovery. Early experimental work has explored the use of near-term quantum hardware in molecular generative modeling for drug discovery. In 2023, researchers at Gero reported a hybrid quantum–classical generative model based on a restricted Boltzmann machine, implemented on a commercially available quantum annealing device, to generate novel drug-like small molecules with physicochemical properties comparable to known medicinal compounds. However, the immense size and complexity of the structural space of all possible drug-like molecules pose significant obstacles, which could be overcome in the future by quantum computers. Quantum computers are naturally good for solving complex quantum many-body problems and thus may be instrumental in applications involving quantum chemistry. Therefore, one can expect that quantum-enhanced generative models including quantum GANs may eventually be developed into ultimate generative chemistry algorithms. == Engineering == As of 2023, classical computers outperform quantum computers for all real-world applications. While current quantum computers may speed up solutions to particular mathematical problems, they give no computational advantage for practical tasks. Scientists and engineers are exploring multiple technologies for quantum computing hardware and hope to develop scalable quantum architectures, but serious obstacles remain. In practice, improvements in


id: quantum-computing-20260505-6
file: data/en.wikipedia.org/wiki/Quantum_computing-6.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
==== Decoherence ==== One of the greatest challenges involved in constructing quantum computers is controlling or removing quantum decoherence. This usually means isolating the system from its environment, as interactions with the external world cause the system to decohere. However, other sources of decoherence also exist. Examples include the quantum gates, the lattice vibrations, and the background thermonuclear spin of the physical system used to implement the qubits. Decoherence is irreversible, as it is effectively non-unitary, and is usually something that should be highly controlled, if not avoided. Decoherence times for candidate systems in particular, the transverse relaxation time T2 (for NMR and MRI technology, also called the dephasing time), typically range between nanoseconds and seconds at low temperatures. Currently, some quantum computers require their qubits to be cooled to 20 millikelvin (usually using a dilution refrigerator) in order to prevent significant decoherence. A 2020 study argues that ionizing radiation such as cosmic rays can nevertheless cause certain systems to decohere within milliseconds. As a result, time-consuming tasks may render some quantum algorithms inoperable, as attempting to maintain the state of qubits for a long enough duration will eventually corrupt the superpositions. These issues are more difficult for optical approaches


id: quantum-computing-20260505-7
file: data/en.wikipedia.org/wiki/Quantum_computing-7.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
=== Skepticism === Despite high hopes for quantum computing, significant progress in hardware, and optimism about future applications, a 2023 Nature spotlight article summarized current quantum computers as being "For now, [good for] absolutely nothing". The article elaborated that quantum computers are yet to be more useful or efficient than conventional computers in any case, though it also argued that, in the long term, such computers are likely to be useful. A 2023 Communications of the ACM article found that current quantum computing algorithms are "insufficient for practical quantum advantage without significant improvements across the software/hardware stack". It argues that the most promising candidates for achieving speedup with quantum computers are "small-data problems", for example, in chemistry and materials science. However, the article also concludes that a large range of the potential applications it considered, such as machine learning, "will not achieve quantum advantage with current quantum algorithms in the foreseeable future", and it identified I/O constraints that make speedup unlikely for "big data problems, unstructured linear systems, and database search based on Grover's algorithm". This state of affairs can be traced to several current and long-term considerations. Conventional computer hardware and algorithms are not only optimized for practical tasks,


id: quantum-computing-20260505-8
file: data/en.wikipedia.org/wiki/Quantum_computing-8.md
category: reference
title: Quantum computing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing
date_saved: 2026-05-05T11:08:10.743299+00:00
instance: kb-cron
parent: quantum-computing-20260505-0
summary:
While quantum computers cannot solve any problems that classical computers cannot already solve, it is suspected that they can solve certain problems faster than classical computers. For instance, it is known that quantum computers can efficiently factor integers, while this is not believed to be the case for classical computers. The class of problems that can be efficiently solved by a quantum computer with bounded error is called BQP, for "bounded error, quantum, polynomial time". More formally, BQP is the class of problems that can be solved by a polynomial-time quantum Turing machine with an error probability of at most 1/3. As a class of probabilistic problems, BQP is the quantum counterpart to BPP ("bounded error, probabilistic, polynomial time"), the class of problems that can be solved by polynomial-time probabilistic Turing machines with bounded error. It is known that B P P ⊆ B Q P {\displaystyle {\mathsf {BPP\subseteq BQP}}} but there is no proof B Q P ≠ B P P {\displaystyle {\mathsf {BQP\neq BPP}}} , which intuitively would mean that quantum computers are more powerful than classical computers in terms of time complexity. The exact relationship of BQP to P, NP, and PSPACE is not known. However, it


id: quantum-volume-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_volume-0.md
category: reference
title: Quantum volume
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_volume
date_saved: 2026-05-05T11:08:11.904022+00:00
instance: kb-cron
parent: quantum-volume-20260505-0
summary:
Quantum volume is a metric that measures the capabilities and error rates of a quantum computer. It expresses the maximum size of square quantum circuits that can be implemented successfully by the computer. The form of the circuits is independent from the quantum computer architecture, but compiler can transform and optimize it to take advantage of the computer's features. Thus, quantum volumes for different architectures can be compared. == Introduction == Quantum computers are difficult to compare. Quantum volume is a single number designed to show all around performance. It is a measurement and not a calculation, and takes into account several features of a quantum computer, starting with its number of qubits—other measures used are gate and measurement errors, crosstalk and connectivity. IBM defined its Quantum Volume metric because a classical computer's transistor count and a quantum computer's quantum bit count aren't the same. Qubits decohere with a resulting loss of performance so a few fault tolerant bits are more valuable as a performance measure than a larger number of noisy, error-prone qubits. Generally, the larger the quantum volume, the more complex the problems a quantum computer can solve. Alternative benchmarks include Cross-entropy benchmarking, reliable Quantum Operations per Second


id: quantum-computing-scaling-laws-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_computing_scaling_laws-0.md
category: reference
title: Quantum computing scaling laws
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_computing_scaling_laws
date_saved: 2026-05-05T11:08:13.112711+00:00
instance: kb-cron
parent: quantum-computing-scaling-laws-20260505-0
summary:
Quantum computing scaling laws (sometimes abbreviated as QC scaling laws) are a set of observations describing the exponential growth of various aspects of quantum computer development. The most important scaling laws in quantum computing are Rose's law, Neven's law, and Schoelkopf's law. These laws are named after prominent quantum computing researchers and predict continued improvement in quantum computer performance in the coming years. However, it is important to note that these laws are more empirical rules of thumb and predictions based on observations rather than immutable truths, and technological development may bring unexpected challenges and breakthroughs. == Rose's law == Rose's law observes that the number of qubits on chips doubles roughly every 18 months. The law is often described as the quantum-computing equivalent of Moore's law. The term was coined by Steve Jurvetson after meeting D-Wave founder Geordie Rose. This law attempts to measure rapid processor scaling, though different quantum computing technologies may follow different trajectories depending on their design constraints. == Neven's law == Neven's law states that the computational power of quantum computers appears to be growing at a doubly exponential rate. In other words, not only is computational power increasing exponentially—that exponential growth is itself accelerating


id: quantum-computing-since-democritus-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_Computing_Since_Democritus-0.md
category: reference
title: Quantum Computing Since Democritus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_Computing_Since_Democritus
date_saved: 2026-05-05T11:08:14.294374+00:00
instance: kb-cron
parent: quantum-computing-since-democritus-20260505-0
summary:
Quantum Computing Since Democritus is a 2013 book on quantum information science written by Scott Aaronson. It is loosely based on a course Aaronson taught at the University of Waterloo, Canada, the lecture notes for which are available online. == Contents == Aaronson has stated that he intends the book to be at the same level as Leonard Susskind's The Theoretical Minimum or Roger Penrose's The Road to Reality; Physics Today compared it to George Gamow's One Two Three... Infinity. The book covers everything from computer science to mathematics to quantum mechanics and quantum computing, starting, as the title indicates, with Democritus. === Front cover === The front cover image is an oil canvas painting of Democritus by Hendrik ter Brugghen dated 1628. It depicts Democritus as a young, laughing hedonist who points in the distance, as to where the folly of mankind is found. The image invokes Aaronson's discussions on Democritus' concept of atoms and the void, which forms the foundational understanding of matter at the atomic level, is relevant to quantum computing, where manipulating and controlling individual quantum objects for calculations echoes the early atomic theory's significance. == Author == Scott Aaronson is a professor of theoretical computer


id: quantum-computing-a-gentle-introduction-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_Computing:_A_Gentle_Introduction-0.md
category: reference
title: Quantum Computing: A Gentle Introduction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_Computing:_A_Gentle_Introduction
date_saved: 2026-05-05T11:08:15.435261+00:00
instance: kb-cron
parent: quantum-computing-a-gentle-introduction-20260505-0
summary:
Quantum Computing: A Gentle Introduction is a textbook on quantum computing. It was written by Eleanor Rieffel and Wolfgang Polak, and published in 2011 by the MIT Press. == Topics == Although the book approaches quantum computing through the model of quantum circuits, it is focused more on quantum algorithms than on the construction of quantum computers. It has 13 chapters, divided into three parts: "Quantum building blocks" (chapters 1–6), "Quantum algorithms" (chapters 7–9), and "Entangled subsystems and robust quantum computation" (chapters 10–13). After an introductory chapter overviewing related topics including quantum cryptography, quantum information theory, and quantum game theory, chapter 2 introduces quantum mechanics and quantum superposition using polarized light as an example, also discussing qubits, the Bloch sphere representation of the state of a qubit, and quantum key distribution. Chapter 3 introduces direct sums, tensor products, and quantum entanglement, and chapter 4 includes the EPR paradox, Bell's theorem on the impossibility of local hidden variable theories, as quantified by Bell's inequality. Chapter 5 discusses unitary operators, quantum logic gates, quantum circuits, and functional completeness for systems of quantum gates. Chapter 6, the final chapter of the building block section, discusses (classical) reversible computing, and the conversion of arbitrary


id: quantum-error-correction-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_error_correction-0.md
category: reference
title: Quantum error correction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_error_correction
date_saved: 2026-05-05T11:08:16.683136+00:00
instance: kb-cron
parent: quantum-error-correction-20260505-0
summary:
Quantum error correction (QEC) comprises a set of techniques used in quantum memory and quantum computing to protect quantum information from errors arising from decoherence and other sources of quantum noise. QEC schemes that employ codewords stabilized by a set of commuting operators are known as stabilizer codes, and the corresponding codewords are referred to as quantum error-correcting codes (QECCs). Conceptually, to use a quantum error-correcting code, one can append ancilla qubits to qubits that need protection, and apply a unitary encoding circuit to rotate the global state into a subspace of a larger Hilbert space. This highly entangled, encoded state corrects for local noisy errors. A quantum error-correcting code makes quantum computation and quantum communication practical by providing a way for a sender and receiver to simulate a noiseless qubit channel given a noisy qubit channel whose noise conforms to a particular error model. == Overview == Much of the terminology in QEC is derived from its classical counterpart, the classical error-correcting code. In classical coding theory, a code is commonly denoted by the notation [ n , k , d ] {\displaystyle [n,k,d]} , which represents the encoding of k {\displaystyle k} logical bits into n {\displaystyle n}


id: quantum-error-correction-20260505-1
file: data/en.wikipedia.org/wiki/Quantum_error_correction-1.md
category: reference
title: Quantum error correction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_error_correction
date_saved: 2026-05-05T11:08:16.683136+00:00
instance: kb-cron
parent: quantum-error-correction-20260505-0
summary:
=== More general QEC schemes === The [ [ n , k , d ] ] {\displaystyle [[n,k,d]]} QECCs do not encompass all possible quantum codes. These belong to the class of additive codes, defined within the stabilizer formalism. A more general class, known as non-additive codes, extends beyond this framework. For instance, the ( ( 5 , 6 , 2 ) ) {\displaystyle ((5,6,2))} code encodes more than two qubits ( log 2 ⁡ 6 ≈ 2.585 ) {\displaystyle (\log _{2}6\approx 2.585)} into five physical qubits with code distance two. Non-additive codes can, in principle, achieve higher code rates than additive ones, but their construction and analysis are considerably more challenging. As a result, they remain relatively unexplored, with only limited studies to date. Beyond encoding qubits into qubits, quantum information can also be stored in more general physical systems, such as d {\displaystyle d} -level systems (qudits) or infinite-dimensional oscillators. Encoding a smaller logical system into a larger physical Hilbert space is an active area of research. == Important code families == The first QECC, named after Peter Shor, can be generalized as a [ [ d 2 , 1 , d ] ] {\displaystyle [[d^{2},1,d]]} code, which


id: quantum-error-correction-20260505-2
file: data/en.wikipedia.org/wiki/Quantum_error_correction-2.md
category: reference
title: Quantum error correction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_error_correction
date_saved: 2026-05-05T11:08:16.683136+00:00
instance: kb-cron
parent: quantum-error-correction-20260505-0
summary:
== Classical codes as bias quantum code == Classical error-correcting codes that employ redundancy can be mapped to biased quantum codes that correct either Pauli X (bit-flip) or Pauli Z (phase-flip) errors. The simplest, though inefficient, example is the repetition code. In a repetition code, the logical information is stored as multiple copies of a bit. If these copies are later found to disagree due to errors, the most likely original value is inferred via majority vote. For example, consider a logical bit in the "1" state copied three times. If noise corrupts one of the three bits, leaving the other two unchanged, the most likely scenario is that a single-bit error occurred, and the original logical value was "1." While it is possible that two bits flip, producing three zeros, this outcome is less probable. In this example, the logical information is the single bit, and the three copies are the physical representation. Repetition codes work in classical channels because classical bits can be freely measured and duplicated. In quantum channels, however, the no-cloning theorem prevents copying an unknown qubit, seemingly posing an obstacle to quantum error correction. This challenge is overcome by encoding the logical information of a


id: quantum-error-correction-20260505-3
file: data/en.wikipedia.org/wiki/Quantum_error_correction-3.md
category: reference
title: Quantum error correction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_error_correction
date_saved: 2026-05-05T11:08:16.683136+00:00
instance: kb-cron
parent: quantum-error-correction-20260505-0
summary:
E corr ( ρ ) = P 0 ρ P 0 + ∑ i = 1 3 X i P i ρ P i X i . {\displaystyle {\mathcal {E}}_{\operatorname {corr} }(\rho )=P_{0}\rho P_{0}+\sum _{i=1}^{3}X_{i}P_{i}\rho \,P_{i}X_{i}.} Note that, while this procedure perfectly corrects the output when zero or one flips are introduced by the channel, if more than one qubit is flipped then the output is not properly corrected. For example, if the first and second qubits are flipped, then the syndrome measurement gives the outcome P 3 {\displaystyle P_{3}} , and the third qubit is flipped, instead of the first two. To assess the performance of this error-correcting scheme for a general input we can study the fidelity F ( ψ ′ ) {\displaystyle F(\psi ')} between the input | ψ ′ ⟩ {\displaystyle \vert \psi '\rangle } and the output ρ out ≡ E corr ( E ( | ψ ′ ⟩ ⟨ ψ ′ | ) ) {\displaystyle \rho _{\operatorname {out} }\equiv {\mathcal {E}}_{\operatorname {corr} }({\mathcal {E}}(\vert \psi '\rangle \langle \psi '\vert ))} . Being the output state ρ out {\displaystyle \rho _{\operatorname {out} }} correct when no more than one qubit is flipped, which happens with


id: quantum-error-correction-20260505-4
file: data/en.wikipedia.org/wiki/Quantum_error_correction-4.md
category: reference
title: Quantum error correction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_error_correction
date_saved: 2026-05-05T11:08:16.683136+00:00
instance: kb-cron
parent: quantum-error-correction-20260505-0
summary:
If a bit flip error happens to a qubit, the syndrome analysis will be performed on each block of qubits (1,2,3), (4,5,6), and (7,8,9) to detect and correct at most one bit flip error in each block. If the three bit flip group (1,2,3), (4,5,6), and (7,8,9) are considered as three inputs, then the Shor code circuit can be reduced as a sign flip code. This means that the Shor code can also repair a sign flip error for a single qubit. The Shor code also can correct for any arbitrary errors (both bit flip and sign flip) to a single qubit. If an error is modeled by a unitary transform U, which will act on a qubit | ψ ⟩ {\displaystyle |\psi \rangle } , then U {\displaystyle U} can be described in the form U = c 0 I + c 1 X + c 2 Y + c 3 Z {\displaystyle U=c_{0}I+c_{1}X+c_{2}Y+c_{3}Z} where c 0 {\displaystyle c_{0}} , c 1 {\displaystyle c_{1}} , c 2 {\displaystyle c_{2}} , and c 3 {\displaystyle c_{3}} are complex constants, I is the identity, and the Pauli matrices are given by X = ( 0 1 1 0 ) ; Y


id: quantum-error-correction-20260505-5
file: data/en.wikipedia.org/wiki/Quantum_error_correction-5.md
category: reference
title: Quantum error correction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_error_correction
date_saved: 2026-05-05T11:08:16.683136+00:00
instance: kb-cron
parent: quantum-error-correction-20260505-0
summary:
and it remains maximal. Thus, even without an error correction step, the metrological properties remain the same. (See the Supplement E in Ref., and Ref.) == Experimental realization == There have been several experimental realizations of CSS-based codes. The first demonstration was with nuclear magnetic resonance qubits. Subsequently, demonstrations have been made with linear optics, trapped ions, and superconducting (transmon) qubits. In 2016 for the first time the lifetime of a quantum bit was prolonged by employing a QEC code. The error-correction demonstration was performed on Schrödinger-cat states encoded in a superconducting resonator, and employed a quantum controller capable of performing real-time feedback operations including read-out of the quantum information, its analysis, and the correction of its detected errors. The work demonstrated how the quantum-error-corrected system reaches the break-even point at which the lifetime of a logical qubit exceeds the lifetime of the underlying constituents of the system (the physical qubits). Other error correcting codes have also been implemented, such as one aimed at correcting for photon loss, the dominant error source in photonic qubit schemes. In 2021, an entangling gate between two logical qubits encoded in topological quantum error-correction codes has first been realized using 10 ions in a


id: quantum-experiments-using-satellite-technology-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_Experiments_using_Satellite_Technology-0.md
category: reference
title: Quantum Experiments using Satellite Technology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_Experiments_using_Satellite_Technology
date_saved: 2026-05-05T11:08:17.875461+00:00
instance: kb-cron
parent: quantum-experiments-using-satellite-technology-20260505-0
summary:
Quantum Experiment using Satellite Technology was launched in 2017 by the Raman Research Institute. In February 2021, the project demonstrated quantum communication for 50 m apart, and on 19 March 2021 for 300 m apart inline of sight in the Space Applications Centre, which was done in coordination with the Indian Space Research Organisation, Indian Institute of Science and Tata Institute of Fundamental Research. Quantum Experiment using Satellite Technology is India's first project on satellite based long distance quantum communication. == Technical specifications == Indigenously developed NAVIC receiver for time synchronization Gimbal mechanism system instead of large aperture telescope for optical alignment. Shared quantum secure text. Shared image transmission. Quantum assisted two ways video conferencing at the Space Applications Centre and Physical Research Laboratory It used robust and high brightness entangled photon source, used BBM92 protocol implementation NAVIC enabled synchronization polarization compensation technique. It is hack proof as it uses quantum key distribution. It uses quantum cryptography and carried out by Quantum information and computing (QuIC) lab . == References ==


id: quantum-flagship-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_Flagship-0.md
category: reference
title: Quantum Flagship
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_Flagship
date_saved: 2026-05-05T11:08:35.116311+00:00
instance: kb-cron
parent: quantum-flagship-20260505-0
summary:
The Quantum Technologies Flagship is a European Union scientific research initiative. With a budget of €1 billion, it is one of the large scale initiatives organized by the Future and Emerging Technologies program, along with the Human Brain Project and the Graphene Flagship.The Quantum Flagship funds over 5,000 European researchers over ten years. Its long-term vision is to develop in Europe a quantum web, where quantum computers, simulators and sensors are interconnected via quantum communication networks. The objective being to develop in Europe a competitive quantum industry making research results available as commercial applications and disruptive technologies. == Beginning of the flagship == In 2016, the European Commissioner for digital economy and society Günther Oettinger invited the quantum community to provide a common European strategy on quantum technologies. Endorsed by 3.400 individuals from academia and industry, a “quantum manifesto” was released in May 2016 in the Netherlands The document called for the European Commission to launch an ambitious European initiative in quantum technologies to ensure Europe's leading role in a technological revolution underway. Following this document, the European Commission appointed a High Level Steering Committee, composed of 12 academic members and 12 industry members, to deliver a strategic research agenda,


id: quantum-image-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_image-0.md
category: reference
title: Quantum image
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_image
date_saved: 2026-05-05T11:08:36.236401+00:00
instance: kb-cron
parent: quantum-image-20260505-0
summary:
Quantum computation, which exploits quantum parallelism, is in principle faster than a classical computer for certain problems. Quantum image is encoding the image information in quantum-mechanical systems instead of classical ones and replacing classical with quantum information processing may alleviate some of these challenges. Humans obtain most of their information through their eyes. Accordingly, the analysis of visual data is one of the most important functions of our brain and it has evolved high efficiency in processing visual data. Currently, visual information like images and videos constitutes the largest part of data traffic in the internet. Processing of this information requires ever-larger computational power. The laws of quantum mechanics allow one to reduce the required resources for some tasks by many orders of magnitude if the image data are encoded in the quantum state of a suitable physical system. The researchers discuss a suitable method for encoding image data, and develop a new quantum algorithm that can detect boundaries among parts of an image with a single logical operation. This edge-detection operation is independent of the size of the image. Several other algorithms are also discussed. It is theoretically and experimentally demonstrated that they work in practice. This is the


id: quantum-image-processing-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_image_processing-0.md
category: reference
title: Quantum image processing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_image_processing
date_saved: 2026-05-05T11:08:37.475265+00:00
instance: kb-cron
parent: quantum-image-processing-20260505-0
summary:
Quantum image processing (QIMP) is using quantum computing or quantum information processing to create and work with quantum images. Due to some of the properties inherent to quantum computation, notably entanglement and parallelism, it is hoped that QIMP technologies will offer capabilities and performances that surpass their traditional equivalents, in terms of computing speed, security, and minimum storage requirements. == Background == A. Y. Vlasov's work in 1997 focused on using a quantum system to recognize orthogonal images. This was followed by efforts using quantum algorithms to search specific patterns in binary images and detect the posture of certain targets. Notably, more optics-based interpretations for quantum imaging were initially experimentally demonstrated in and formalized in after seven years. In 2003, Salvador Venegas-Andraca and S. Bose presented Qubit Lattice, the first published general model for storing, processing and retrieving images using quantum systems. Later on, in 2005, Latorre proposed another kind of representation, called the Real Ket, whose purpose was to encode quantum images as a basis for further applications in QIMP. Furthermore, in 2010 Venegas-Andraca and Ball presented a method for storing and retrieving binary geometrical shapes in quantum mechanical systems in which it is shown that maximally entangled qubits


id: quantum-image-processing-20260505-1
file: data/en.wikipedia.org/wiki/Quantum_image_processing-1.md
category: reference
title: Quantum image processing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_image_processing
date_saved: 2026-05-05T11:08:37.475265+00:00
instance: kb-cron
parent: quantum-image-processing-20260505-0
summary:
== Quantum image manipulations == A lot of the effort in QIMP has been focused on designing algorithms to manipulate the position and color information encoded using flexible representation of quantum images (FRQI) and its many variants. For instance, FRQI-based fast geometric transformations including (two-point) swapping, flip, (orthogonal) rotations and restricted geometric transformations to constrain these operations to a specified area of an image were initially proposed. Recently, NEQR-based quantum image translation to map the position of each picture element in an input image into a new position in an output image and quantum image scaling to resize a quantum image were discussed. While FRQI-based general form of color transformations were first proposed by means of the single qubit gates such as X, Z, and H gates. Later, Multi-Channel Quantum Image-based channel of interest (CoI) operator to entail shifting the grayscale value of the preselected color channel and the channel swapping (CS) operator to swap the grayscale values between two channels have been fully discussed. To illustrate the feasibility and capability of QIMP algorithms and application, researchers always prefer to simulate the digital image processing tasks on the basis of the QIRs that we already have. By using the basic


id: quantum-natural-language-processing-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_natural_language_processing-0.md
category: reference
title: Quantum natural language processing
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_natural_language_processing
date_saved: 2026-05-05T11:08:38.718259+00:00
instance: kb-cron
parent: quantum-natural-language-processing-20260505-0
summary:
Quantum natural language processing (QNLP) is the application of quantum computing to natural language processing (NLP). It computes word embeddings as parameterised quantum circuits that can solve NLP tasks faster than any classical computer. It is inspired by categorical quantum mechanics and the DisCoCat framework, making use of string diagrams to translate from grammatical structure to quantum processes. == Theory == The first quantum algorithm for natural language processing used the DisCoCat framework and Grover's algorithm to show a quadratic quantum speedup for a text classification task. It was later shown that quantum language processing is BQP-Complete, i.e. quantum language models are more expressive than their classical counterpart, unless quantum mechanics can be efficiently simulated by classical computers. These two theoretical results assume fault-tolerant quantum computation and a QRAM, i.e. an efficient way to load classical data on a quantum computer. Thus, they are not applicable to the noisy intermediate-scale quantum (NISQ) computers available today. == Experiments == The algorithm of Zeng and Coecke was adapted to the constraints of NISQ computers and implemented on IBM quantum computers to solve binary classification tasks. Instead of loading classical word vectors onto a quantum memory, the word vectors are computed directly as


id: quantum-programming-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_programming-0.md
category: reference
title: Quantum programming
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_programming
date_saved: 2026-05-05T11:08:39.917227+00:00
instance: kb-cron
parent: quantum-programming-20260505-0
summary:
Quantum programming refers to the process of designing and implementing algorithms that operate on quantum systems, typically using quantum circuits composed of quantum gates, measurements, and classical control logic. These circuits are developed to manipulate quantum states for specific computational tasks or experimental outcomes. Quantum programs may be executed on quantum processors, simulated on classical hardware, or implemented through laboratory instrumentation for research purposes. When working with quantum processor-based systems, quantum programming languages provide high-level abstractions to express quantum algorithms efficiently. These languages often integrate with classical programming environments and support hybrid quantum-classical workflows. The development of quantum software has been strongly influenced by the open-source community, with many toolkits and frameworks—such as Qrisp, Qiskit, Cirq, PennyLane, and qBraid SDK—available under open licenses. Quantum programming can also be used to model or control experimental systems through quantum instrumentation and sensor-based platforms. While some quantum computing architectures—such as linear optical quantum computing using the KLM protocol—require specialized hardware, others use gate-based quantum processors accessible through software interfaces. In both cases, quantum programming serves as the bridge between theoretical algorithms and physical implementation. == Quantum instruction sets == Quantum instruction sets are used to turn higher level algorithms into physical instructions that


id: quantum-programming-20260505-1
file: data/en.wikipedia.org/wiki/Quantum_programming-1.md
category: reference
title: Quantum programming
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_programming
date_saved: 2026-05-05T11:08:39.917227+00:00
instance: kb-cron
parent: quantum-programming-20260505-0
summary:
==== qBraid SDK ==== The qBraid SDK is an open-source platform-agnostic quantum runtime framework developed by qBraid. It enables users to write quantum programs once and execute them across various quantum hardware and simulators without modifying the code. The SDK supports multiple quantum programming libraries, including Qiskit, Cirq, PennyLane, PyQuil, and Braket, among others. It features a graph-based transpiler that facilitates conversion between different quantum program types, allowing seamless interoperability between frameworks. The SDK also provides tools for job submission, result retrieval, and circuit visualization. It is integrated with qBraid Lab, offering access to over 20 quantum devices and simulators from providers such as IonQ, Rigetti, QuEra, and IQM. ==== Qibo ==== An open source full-stack API for quantum simulation, quantum hardware control and calibration developed by multiple research laboratories, including QRC, CQT and INFN. Qibo is a modular framework which includes multiple backends for quantum simulation and hardware control. This project aims at providing a platform agnostic quantum hardware control framework with drivers for multiple instruments and tools for quantum calibration, characterization and validation. This framework focuses on self-hosted quantum devices by simplifying the software development required in labs. ==== Qiskit ==== An open source project developed by IBM.


id: quantum-programming-20260505-2
file: data/en.wikipedia.org/wiki/Quantum_programming-2.md
category: reference
title: Quantum programming
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_programming
date_saved: 2026-05-05T11:08:39.917227+00:00
instance: kb-cron
parent: quantum-programming-20260505-0
summary:
==== QMASM ==== Quantum Macro Assembler (QMASM) is a low-level language specific to quantum annealers such as the D-Wave. ==== Qmod ==== Quantum Modeling (Qmod) language is a high-level language that abstracts away the gate-level qubit operation, providing a functional approach to the implementation of quantum algorithms on quantum registers. The language is part of the Classiq platform and can be used directly with its native syntax, through a Python SDK, or with a visual editor, all methods can take advantage of the larger library of algorithms and the efficient circuit optimization. ==== Q|SI> ==== Q|SI> is a platform embedded in .Net language supporting quantum programming in a quantum extension of while-language. This platform includes a compiler of the quantum while-language and a chain of tools for the simulation of quantum computation, optimisation of quantum circuits, termination analysis of quantum programs, and verification of quantum programs. ==== Quantum pseudocode ==== Quantum pseudocode proposed by E. Knill is the first formalized language for description of quantum algorithms. It was introduced and, moreover, was tightly connected with a model of quantum machine called Quantum Random Access Machine (QRAM). ==== Scaffold ==== Scaffold is a C-like language, that compiles to QASM and OpenQASM.


id: quantum-simulator-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_simulator-0.md
category: reference
title: Quantum simulator
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_simulator
date_saved: 2026-05-05T11:08:41.198982+00:00
instance: kb-cron
parent: quantum-simulator-20260505-0
summary:
Quantum simulators permit the study of a quantum system in a programmable fashion. In this instance, simulators are special purpose devices designed to provide insight about specific physics problems. Quantum simulators may be contrasted with generally programmable "digital" quantum computers, which would be capable of solving a wider class of quantum problems. A universal quantum simulator is a quantum computer proposed by Yuri Manin in 1980 and Richard Feynman in 1982. A quantum system may be simulated by either a Turing machine or a quantum Turing machine, as a classical Turing machine is able to simulate a universal quantum computer (and therefore any simpler quantum simulator), meaning they are equivalent from the point of view of computability theory. The simulation of quantum physics by a classical computer has been shown to be inefficient. In other words, quantum computers provide no additional power over classical computers in terms of computability, but it is suspected that they can solve certain problems faster than classical computers, meaning they may be in different complexity classes, which is why quantum Turing machines are useful for simulating quantum systems. This is known as quantum supremacy, the idea that there are problems only quantum Turing machines can


id: quantum-singular-value-transformation-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_singular_value_transformation-0.md
category: reference
title: Quantum singular value transformation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_singular_value_transformation
date_saved: 2026-05-05T11:08:42.425955+00:00
instance: kb-cron
parent: quantum-singular-value-transformation-20260505-0
summary:
Quantum singular value transformation is a framework for designing quantum algorithms. It encompasses a variety of quantum algorithms for problems that can be solved with linear algebra, including Hamiltonian simulation, search problems, and linear system solving. It was introduced in 2018 by András Gilyén, Yuan Su, Guang Hao Low, and Nathan Wiebe, generalizing algorithms for Hamiltonian simulation of Guang Hao Low and Isaac Chuang inspired by signal processing. == High-level description == The basic primitive of quantum singular value transformation is the block-encoding. A quantum circuit is a block-encoding of a matrix A if it implements a unitary matrix U such that U contains A in a specified sub-matrix. For example, if ( ⟨ 0 | ⊗ I ) U ( | 0 ⟩ ⊗ | ϕ ⟩ ) = A | ϕ ⟩ {\displaystyle (\langle 0|\otimes I)U(|0\rangle \otimes |\phi \rangle )=A|\phi \rangle } , then U is a block-encoding of A. The fundamental algorithm of QSVT is one that converts a block-encoding of A to a block-encoding of p ( A , A † ) {\displaystyle p(A,A^{\dagger })} , where p is a polynomial of degree d and A † {\displaystyle A^{\dagger }} denotes the conjugate transpose, with only


id: quantum-state-discrimination-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_state_discrimination-0.md
category: reference
title: Quantum state discrimination
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_state_discrimination
date_saved: 2026-05-05T11:08:43.736302+00:00
instance: kb-cron
parent: quantum-state-discrimination-20260505-0
summary:
The term quantum state discrimination collectively refers to quantum-informatics techniques, with the help of which, by performing a small number of measurements on a physical system, its specific quantum state can be identified . And this is provided that the set of states in which the system can be is known in advance, and we only need to determine which one it is. This assumption distinguishes such techniques from quantum tomography, which does not impose additional requirements on the state of the system, but requires many times more measurements. If the set of states in which the investigated system can be is represented by orthogonal vectors, the situation is particularly simple. To unambiguously determine the state of the system, it is enough to perform a quantum measurement in the basis formed by these vectors. The given quantum state can then be flawlessly identified from the measured value. Moreover, it can be easily shown that if the individual states are not orthogonal to each other, there is no way to tell them apart with certainty. Therefore, in such a case, it is always necessary to take into account the possibility of incorrect or inconclusive determination of the state of the system.


id: quantum-supremacy-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_supremacy-0.md
category: reference
title: Quantum supremacy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_supremacy
date_saved: 2026-05-05T11:08:44.875213+00:00
instance: kb-cron
parent: quantum-supremacy-20260505-0
summary:
In quantum computing, quantum supremacy or quantum advantage is the goal of demonstrating that a programmable quantum computer can solve a problem that no classical computer can solve in any feasible amount of time, irrespective of the usefulness of the problem. The term was coined by John Preskill in 2011, but the concept dates to Yuri Manin's 1980 and Richard Feynman's 1981 proposals of quantum computing. Conceptually, quantum supremacy involves both the engineering task of building a powerful quantum computer and the computational-complexity-theoretic task of finding a problem that can be solved by that quantum computer and has a superpolynomial speedup over the best known or possible classical algorithm for that task. Examples of proposals to demonstrate quantum supremacy include the boson sampling proposal of Aaronson and Arkhipov, and sampling the output of random quantum circuits. The output distributions that are obtained by making measurements in boson sampling or quantum random circuit sampling are flat, but structured in a way so that one cannot classically efficiently sample from a distribution that is close to the distribution generated by the quantum experiment. For this conclusion to be valid, only very mild assumptions in the theory of computational complexity have to be


id: quantum-supremacy-20260505-1
file: data/en.wikipedia.org/wiki/Quantum_supremacy-1.md
category: reference
title: Quantum supremacy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_supremacy
date_saved: 2026-05-05T11:08:44.875213+00:00
instance: kb-cron
parent: quantum-supremacy-20260505-0
summary:
Vast progress toward quantum supremacy was made in the 2000s from the first 5-qubit nuclear magnetic resonance computer (2000), the demonstration of Shor's theorem (2001), and the implementation of Deutsch's algorithm in a clustered quantum computer (2007). In 2011, D-Wave Systems of Burnaby, British Columbia, Canada became the first company to sell a quantum computer commercially. In 2012, physicist Nanyang Xu landed a milestone accomplishment by using an improved adiabatic factoring algorithm to factor 143. However, the methods used by Xu were met with objections. Not long after this accomplishment, Google purchased its first quantum computer. Google had announced plans to demonstrate quantum supremacy before the end of 2017 with an array of 49 superconducting qubits. In early January 2018, Intel announced a similar hardware program. In October 2017, IBM demonstrated the simulation of 56 qubits on a classical supercomputer, thereby increasing the computational power needed to establish quantum supremacy. In November 2018, Google announced a partnership with NASA that would "analyze results from quantum circuits run on Google quantum processors, and ... provide comparisons with classical simulation to both support Google in validating its hardware and establish a baseline for quantum supremacy." Theoretical work published in 2018 suggested that


id: quantum-supremacy-20260505-2
file: data/en.wikipedia.org/wiki/Quantum_supremacy-2.md
category: reference
title: Quantum supremacy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_supremacy
date_saved: 2026-05-05T11:08:44.875213+00:00
instance: kb-cron
parent: quantum-supremacy-20260505-0
summary:
Complexity arguments concern how the amount of some resource needed to solve a problem (generally time or memory) scales with the size of the input. In this setting, a problem consists of an inputted problem instance (a binary string) and returned solution (corresponding output string), while resources refers to designated elementary operations, memory usage, or communication. A collection of local operations allows for the computer to generate the output string. A circuit model and its corresponding operations are useful in describing both classical and quantum problems; the classical circuit model consists of basic operations such as AND gates, OR gates, and NOT gates while the quantum model consists of classical circuits and the application of unitary operations. Unlike the finite set of classical gates, there are an infinite amount of quantum gates due to the continuous nature of unitary operations. In both classical and quantum cases, complexity swells with increasing problem size. As an extension of classical computational complexity theory, quantum complexity theory considers what a theoretical universal quantum computer could accomplish without accounting for the difficulty of building a physical quantum computer or dealing with decoherence and noise. Since quantum information is a generalization of classical information, quantum computers


id: quantum-supremacy-20260505-3
file: data/en.wikipedia.org/wiki/Quantum_supremacy-3.md
category: reference
title: Quantum supremacy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_supremacy
date_saved: 2026-05-05T11:08:44.875213+00:00
instance: kb-cron
parent: quantum-supremacy-20260505-0
summary:
This computing paradigm based upon sending identical photons through a linear-optical network can solve certain sampling and search problems that, assuming a few complexity-theoretical conjectures (that calculating the permanent of Gaussian matrices is #P-Hard and that the polynomial hierarchy does not collapse) are intractable for classical computers. However, it has been shown that boson sampling in a system with large enough loss and noise can be simulated efficiently. The largest experimental implementation of boson sampling to date had 6 modes so could handle up to 6 photons at a time. The best proposed classical algorithm for simulating boson sampling runs in time O ( n 2 n + m n 2 ) {\displaystyle O(n2^{n}+mn^{2})} for a system with n photons and m output modes. The algorithm leads to an estimate of 50 photons required to demonstrate quantum supremacy with boson sampling. === Sampling the output distribution of random quantum circuits === The best known algorithm for simulating an arbitrary random quantum circuit requires an amount of time that scales exponentially with the number of qubits, leading one group to estimate that around 50 qubits could be enough to demonstrate quantum supremacy. Bouland, Fefferman, Nirkhe and Vazirani gave, in 2018, theoretical


id: quantum-teleportation-20260505-0
file: data/en.wikipedia.org/wiki/Quantum_teleportation-0.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
Quantum teleportation is a technique for transferring quantum information from a sender at one location to a receiver some distance away. While teleportation is commonly portrayed in science fiction as a means to transfer physical objects from one location to the next, quantum teleportation only transfers quantum information. The sender does not have to know the particular quantum state being transferred. Moreover, the location of the recipient can be unknown, but to complete the quantum teleportation, classical information needs to be sent from sender to receiver. Because classical information needs to be sent, quantum teleportation cannot occur faster than the speed of light. One of the first scientific articles to investigate quantum teleportation is "Teleporting an Unknown Quantum State via Dual Classical and Einstein–Podolsky–Rosen Channels" published by C. H. Bennett, G. Brassard, C. Crépeau, R. Jozsa, A. Peres, and W. K. Wootters in 1993, in which they proposed using dual communication methods to send/receive quantum information. It was experimentally realized in 1997 by two research groups, led by Sandu Popescu and Anton Zeilinger, respectively. Experimental determinations of quantum teleportation have been made in information content – including photons, atoms, electrons, and superconducting circuits – as well as distance, with 1,400


id: quantum-teleportation-20260505-1
file: data/en.wikipedia.org/wiki/Quantum_teleportation-1.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
For actual teleportation, it is required that an entangled quantum state be created for the qubit to be transferred. Entanglement imposes statistical correlations between otherwise distinct physical systems by creating or placing two or more separate particles into a single, shared quantum state. This intermediate state contains two particles whose quantum states are related to each other: measuring one particle's state provides information about the measurement of the other particle's state. These correlations hold even when measurements are chosen and performed independently, out of causal contact from one another, as verified in Bell test experiments. Thus, an observation resulting from a measurement choice made at one point in spacetime seems to instantaneously affect outcomes in another region, even though light hasn't yet had time to travel the distance, a conclusion seemingly at odds with special relativity. This is known as the EPR paradox. However, such correlations can never be used to transmit any information faster than the speed of light, a statement encapsulated in the no-communication theorem. Thus, teleportation as a whole can never be superluminal, as a qubit cannot be reconstructed until the accompanying classical information arrives. The sender will combine the particle, whose information is teleported, with one


id: quantum-teleportation-20260505-2
file: data/en.wikipedia.org/wiki/Quantum_teleportation-2.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
A Bell state is generated with one qubit sent to location A and the other sent to location B. In the picture the alternative name of EPR pair is used for this. A Bell measurement of the Bell state qubit and the qubit to be teleported ( | ϕ ⟩ {\displaystyle |\phi \rangle } ) is performed at location A. This yields one of four measurement outcomes which can be encoded in two classical bits of information. Both qubits at location A are then discarded. Using the classical channel, the two bits are sent from A to B. (This is the only potentially time-consuming step after step 1 since information transfer is limited by the speed of light.) As a result of the measurement performed at location A, the Bell state qubit at location B is in one of four possible states. Of these four possible states, one is identical to the original quantum state | ϕ ⟩ {\displaystyle |\phi \rangle } , and the other three are closely related. The identity of the state actually obtained is encoded in two classical bits and sent to location B. The Bell state qubit at location B is then modified in one


id: quantum-teleportation-20260505-3
file: data/en.wikipedia.org/wiki/Quantum_teleportation-3.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
First proposed theoretically in 1993, quantum teleportation has since been demonstrated in many different guises. It has been carried out using two-level states of a single photon, a single atom and a trapped ion – among other quantum objects – and also using two photons. In 1997, two groups experimentally achieved quantum teleportation. The first group, led by Sandu Popescu, was based in Italy. An experimental group led by Anton Zeilinger followed a few months later. The results obtained from experiments done by Popescu's group concluded that classical channels alone could not replicate the teleportation of linearly polarized state and an elliptically polarized state. The Bell state measurement distinguished between the four Bell states, which can allow for a 100% success rate of teleportation, in an ideal representation. Zeilinger's group produced a pair of entangled photons by implementing the process of parametric down-conversion. In order to ensure that the two photons cannot be distinguished by their arrival times, the photons were generated using a pulsed pump beam. The photons were then sent through narrow-bandwidth filters to produce a coherence time that is much longer than the length of the pump pulse. They then used a two-photon interferometry for analyzing the


id: quantum-teleportation-20260505-4
file: data/en.wikipedia.org/wiki/Quantum_teleportation-4.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
=== Quantum teleportation across the Danube River === In 2004, a quantum teleportation experiment was conducted across the Danube River in Vienna, a total of 600 meters. An 800-meter-long optical fiber wire was installed in a public sewer system underneath the Danube River, and it was exposed to temperature changes and other environmental influences. Alice must perform a joint Bell state measurement (BSM) on photon b, the input photon, and photon c, her part of the entangled photon pair (photons c and d). Photon d, Bob's receiver photon, will contain all of the information on the input photon b, except for a phase rotation that depends on the state that Alice observed. This experiment implemented an active feed-forward system that sends Alice's measurement results via a classical microwave channel with a fast electro-optical modulator in order to exactly replicate Alice's input photon. The teleportation fidelity obtained from the linear polarization state at 45° varied between 0.84 and 0.90, which is well above the classical fidelity limit of 0.66. === Deterministic quantum teleportation with atoms === Three qubits are required for this process: the source qubit from the sender, the ancillary qubit, and the receiver's target qubit, which is maximally entangled


id: quantum-teleportation-20260505-5
file: data/en.wikipedia.org/wiki/Quantum_teleportation-5.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
| Φ + ⟩ A B = 1 2 ( | 0 ⟩ A ⊗ | 0 ⟩ B + | 1 ⟩ A ⊗ | 1 ⟩ B ) {\displaystyle |\Phi ^{+}\rangle _{AB}={\frac {1}{\sqrt {2}}}(|0\rangle _{A}\otimes |0\rangle _{B}+|1\rangle _{A}\otimes |1\rangle _{B})} , | Ψ + ⟩ A B = 1 2 ( | 0 ⟩ A ⊗ | 1 ⟩ B + | 1 ⟩ A ⊗ | 0 ⟩ B ) {\displaystyle |\Psi ^{+}\rangle _{AB}={\frac {1}{\sqrt {2}}}(|0\rangle _{A}\otimes |1\rangle _{B}+|1\rangle _{A}\otimes |0\rangle _{B})} , | Ψ − ⟩ A B = 1 2 ( | 0 ⟩ A ⊗ | 1 ⟩ B − | 1 ⟩ A ⊗ | 0 ⟩ B ) {\displaystyle |\Psi ^{-}\rangle _{AB}={\frac {1}{\sqrt {2}}}(|0\rangle _{A}\otimes |1\rangle _{B}-|1\rangle _{A}\otimes |0\rangle _{B})} . | Φ − ⟩ A B = 1 2 ( | 0 ⟩ A ⊗ | 0 ⟩ B − | 1 ⟩ A ⊗ | 1 ⟩ B ) {\displaystyle |\Phi ^{-}\rangle _{AB}={\frac {1}{\sqrt {2}}}(|0\rangle _{A}\otimes |0\rangle _{B}-|1\rangle _{A}\otimes |1\rangle _{B})} , In the following, assume that Alice and Bob share the state | Φ + ⟩ A B . {\displaystyle |\Phi ^{+}\rangle _{AB}.} Alice obtains one of the particles


id: quantum-teleportation-20260505-6
file: data/en.wikipedia.org/wiki/Quantum_teleportation-6.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
Equivalently, the measurement may be done in the computational basis, { | 0 ⟩ , | 1 ⟩ } {\displaystyle \{|0\rangle ,|1\rangle \}} , by mapping each Bell state uniquely to one of { | 0 ⟩ ⊗ | 0 ⟩ , | 0 ⟩ ⊗ | 1 ⟩ , | 1 ⟩ ⊗ | 0 ⟩ , | 1 ⟩ ⊗ | 1 ⟩ } {\displaystyle \{|0\rangle \otimes |0\rangle ,|0\rangle \otimes |1\rangle ,|1\rangle \otimes |0\rangle ,|1\rangle \otimes |1\rangle \}} with the quantum circuit in the figure to the right. The result of Alice's (local) measurement is a collection of two classical bits (00, 01, 10 or 11) related to one of the following four states (with equal probability of 1/4), after the three-particle state has collapsed into one of the states: | Φ + ⟩ C A ⊗ ( α | 0 ⟩ B + β | 1 ⟩ B ) {\displaystyle |\Phi ^{+}\rangle _{CA}\otimes (\alpha |0\rangle _{B}+\beta |1\rangle _{B})} | Φ − ⟩ C A ⊗ ( α | 0 ⟩ B − β | 1 ⟩ B ) {\displaystyle |\Phi ^{-}\rangle _{CA}\otimes (\alpha |0\rangle _{B}-\beta |1\rangle _{B})} | Ψ + ⟩ C A ⊗ ( α |


id: quantum-teleportation-20260505-7
file: data/en.wikipedia.org/wiki/Quantum_teleportation-7.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
where the integration is performed over the Haar measure defined by assuming maximal uncertainty over the initial quantum states | ψ ⟩ {\displaystyle |\psi \rangle } , and F ( ρ , ρ i ) = ( Tr ρ ρ i ρ ) 2 {\displaystyle F(\rho ,\rho _{i})=\left({\text{Tr}}{\sqrt {{\sqrt {\rho }}\rho _{i}{\sqrt {\rho }}}}\right)^{2}} is the Uhlmann-Jozsa fidelity. The widely known classical threshold is obtained by optimizing the average fidelity over all classical protocols (i.e. when the sender Alice and the receiver Bob can use just a classical channel to communicate with each other). When teleportation involves qubit states, the maximal classical average fidelity is 2 / 3 {\displaystyle 2/3} . In this way, a particular protocol with average fidelity ⟨ F ¯ ⟩ {\displaystyle \langle {\overline {F}}\rangle } is certified as useful if ⟨ F ¯ ⟩ ≥ 2 / 3 {\displaystyle \langle {\overline {F}}\rangle \geq 2/3} . However, using the Uhlmann-Jozsa fidelity as the unique distance measure for benchmarking teleportation is not justified, and one may choose different distinguishability measures. For example, there may exist reasons depending on the context in which other measures might be more suitable than fidelity. In this way, the average distance of teleportation


id: quantum-teleportation-20260505-8
file: data/en.wikipedia.org/wiki/Quantum_teleportation-8.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
== Generalizations of the teleportation protocol == The basic teleportation protocol for a qubit described above has been generalized in several directions, in particular regarding the dimension of the system teleported and the number of parties involved (either as sender, controller, or receiver). === d-dimensional systems === A generalization to d {\displaystyle d} -level systems (so-called qudits) is straight forward and was already discussed in the original paper by Bennett et al.: the maximally entangled state of two qubits has to be replaced by a maximally entangled state of two qudits and the Bell measurement by a measurement defined by a maximally entangled orthonormal basis. All possible such generalizations were discussed by Werner in 2001. The generalization to infinite-dimensional so-called continuous-variable systems was proposed by Braunstein and Kimble and led to the first teleportation experiment that worked unconditionally. === Multipartite versions === The use of multipartite entangled states instead of a bipartite maximally entangled state allows for several new features: either the sender can teleport information to several receivers either sending the same state to all of them (which allows to reduce the amount of entanglement needed for the process) or teleporting multipartite states or sending a single state in


id: quantum-teleportation-20260505-9
file: data/en.wikipedia.org/wiki/Quantum_teleportation-9.md
category: reference
title: Quantum teleportation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quantum_teleportation
date_saved: 2026-05-05T11:08:46.081087+00:00
instance: kb-cron
parent: quantum-teleportation-20260505-0
summary:
== Local explanation of the phenomenon == A local explanation of quantum teleportation is put forward by David Deutsch and Patrick Hayden, with respect to the many-worlds interpretation of quantum mechanics. Their paper asserts that the two bits that Alice sends Bob contain "locally inaccessible information" resulting in the teleportation of the quantum state. "The ability of quantum information to flow through a classical channel [...], surviving decoherence, is [...] the basis of quantum teleportation." == Recent developments == While quantum teleportation is in an infancy stage, there are many aspects pertaining to teleportation that scientists are working to better understand or improve the process that include: === Higher dimensions === Quantum teleportation can improve the errors associated with fault tolerant quantum computation via an arrangement of logic gates. Experiments by D. Gottesman and I. L. Chuang have determined that a "Clifford hierarchy" gate arrangement which acts to enhance protection against environmental errors. Overall, a higher threshold of error is allowed with the Clifford hierarchy as the sequence of gates requires less resources that are needed for computation. While the more gates that are used in a quantum computer create more noise, the gates arrangement and use of teleportation in


id: qubit-20260505-0
file: data/en.wikipedia.org/wiki/Qubit-0.md
category: reference
title: Qubit
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qubit
date_saved: 2026-05-05T11:08:47.232211+00:00
instance: kb-cron
parent: qubit-20260505-0
summary:
In quantum computing, a qubit () or quantum bit is a basic unit of quantum information, the quantum version of the classic binary bit physically realized with a two-state device. A qubit is a two-state (or two-level) quantum-mechanical system, one of the simplest quantum systems displaying the peculiarity of quantum mechanics. Examples include the spin of the electron in which the two levels can be taken as spin up and spin down; or the polarization of a single photon in which the two spin states (left-handed and the right-handed circular polarization) can also be measured as horizontal and vertical linear polarization. In a classical system, a bit would have to be in one state or the other. However, quantum mechanics allows the qubit to be in a coherent superposition of multiple states simultaneously, a property that is fundamental to quantum mechanics and quantum computing. A qubit can be generalized as a d=2 qudit or a binary qudit. == Etymology == The coining of the term qubit is attributed to Benjamin Schumacher. In the acknowledgments of his 1995 paper, Schumacher states that the term qubit was created in jest during a conversation with William Wootters. == Comparison with classical bits ==


id: qubit-20260505-1
file: data/en.wikipedia.org/wiki/Qubit-1.md
category: reference
title: Qubit
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qubit
date_saved: 2026-05-05T11:08:47.232211+00:00
instance: kb-cron
parent: qubit-20260505-0
summary:
where α and β are the probability amplitudes, and are both complex numbers. When we measure this qubit in the standard basis, according to the Born rule, the probability of outcome | 0 ⟩ {\displaystyle {|0\rangle }} with value "0" is | α | 2 {\displaystyle {|\alpha |}^{2}} and the probability of outcome | 1 ⟩ {\displaystyle {|1\rangle }} with value "1" is | β | 2 {\displaystyle {|\beta |}^{2}} . Because the absolute squares of the amplitudes equate to probabilities, it follows that α {\displaystyle \alpha } and β {\displaystyle \beta } must be constrained according to the second axiom of probability theory by the equation | α | 2 + | β | 2 = 1. {\displaystyle {|\alpha |}^{2}+{|\beta |}^{2}=1.} The probability amplitudes, α {\displaystyle \alpha } and β {\displaystyle \beta } , encode more than just the probabilities of the outcomes of a measurement; the relative phase between α {\displaystyle \alpha } and β {\displaystyle \beta } is, for example, responsible for quantum interference, as seen in the double-slit experiment. === Bloch sphere representation === The probability amplitudes for the superposition state, | ψ ⟩ = α | 0 ⟩ + β | 1 ⟩ , {\displaystyle


id: qubit-20260505-2
file: data/en.wikipedia.org/wiki/Qubit-2.md
category: reference
title: Qubit
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qubit
date_saved: 2026-05-05T11:08:47.232211+00:00
instance: kb-cron
parent: qubit-20260505-0
summary:
== Operations on qubits == Various kinds of physical operations can be performed on qubits. Quantum logic gates, building blocks for a quantum circuit in a quantum computer, operate on a set of qubits (a register); mathematically, the qubits undergo a (reversible) unitary transformation described by multiplying the quantum gates unitary matrix with the quantum state vector. The result from this multiplication is a new quantum state vector. Quantum measurement is an irreversible operation in which information is gained about the state of a single qubit, and coherence is lost. The result of the measurement of a single qubit with the state | ψ ⟩ = α | 0 ⟩ + β | 1 ⟩ {\displaystyle {|\psi \rangle }=\alpha {|0\rangle }+\beta {|1\rangle }} will be either | 0 ⟩ {\displaystyle {|0\rangle }} with probability | α | 2 {\displaystyle {|\alpha |}^{2}} or | 1 ⟩ {\displaystyle {|1\rangle }} with probability | β | 2 {\displaystyle {|\beta |}^{2}} . Measurement of the state of the qubit alters the magnitudes of α and β. For instance, if the result of the measurement is | 1 ⟩ {\displaystyle {|1\rangle }} , α is changed to 0 and β is changed to 1, while


id: qubit-20260505-3
file: data/en.wikipedia.org/wiki/Qubit-3.md
category: reference
title: Qubit
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qubit
date_saved: 2026-05-05T11:08:47.232211+00:00
instance: kb-cron
parent: qubit-20260505-0
summary:
=== Applications === The | Φ + ⟩ {\displaystyle {|\Phi ^{+}\rangle }} Bell state forms part of the setup of the superdense coding, quantum teleportation, and entangled quantum cryptography algorithms. Quantum entanglement also allows multiple states (such as the Bell state mentioned above) to be acted on simultaneously, unlike classical bits that can only have one value at a time. Entanglement is a necessary ingredient of any quantum computation that cannot be done efficiently on a classical computer. Many of the successes of quantum computation and communication, such as quantum teleportation and superdense coding, make use of entanglement, suggesting that entanglement is a resource that is unique to quantum computation. A major hurdle facing quantum computing, as of 2018, in its quest to surpass classical digital computing, is noise in quantum gates that limits the size of quantum circuits that can be executed reliably. == Quantum register == A number of qubits taken together is a qubit register. Quantum computers perform calculations by manipulating qubits within a register. === Qudits and qutrits === The term qudit denotes the unit of quantum information that can be realized in suitable d-level quantum systems. Qudits are similar to the integer types in classical


id: qudit-20260505-0
file: data/en.wikipedia.org/wiki/Qudit-0.md
category: reference
title: Qudit
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qudit
date_saved: 2026-05-05T11:08:48.438297+00:00
instance: kb-cron
parent: qudit-20260505-0
summary:
In quantum computing, a qudit (/ˈkjuː/dɪt/) or quantum dit is the generalized unit of quantum information described by a superposition of states, where the number of states d is an integer equal to or greater than two. == Qudit versus qubit == A qudit, characterized by d = 2 states is a qubit. Qudits with d states greater than 2 can provide a larger Hilbert space, providing more ways to store and process quantum information. d = 1 states corresponds to a one-dimensional Hilbert space and is therefore a trivial quantum system. == Qudit states == Qunit – Qudit with d = 1 states Qubit – Qudit with d = 2 states Qutrit – Qudit with d = 3 states Ququart or Ququat – Qudit with d = 4 states Ququint– Qudit with d = 5 states Quxit – Qudit with d = 6 states Qusit – Qudit with d = 7 states Quoctit – Qudit with d = 8 states Qupit – Qudit with prime number dimensions (commonly used in quantum error correction) == Teleportation == Qudit teleportation is the transfer of qudit information from one particle to another at a distant location without moving the physical particle itself.


id: quil-instruction-set-architecture-20260505-0
file: data/en.wikipedia.org/wiki/Quil_(instruction_set_architecture)-0.md
category: reference
title: Quil (instruction set architecture)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quil_(instruction_set_architecture)
date_saved: 2026-05-05T11:08:49.647070+00:00
instance: kb-cron
parent: quil-instruction-set-architecture-20260505-0
summary:
Quil is a quantum instruction set architecture that first introduced a shared quantum/classical memory model. It was introduced by Robert Smith, Michael Curtis, and William Zeng in A Practical Quantum Instruction Set Architecture. Many quantum algorithms (including quantum teleportation, quantum error correction, simulation, and optimization algorithms) require a shared memory architecture. Quil is being developed for the superconducting quantum processors developed by Rigetti Computing through the Forest quantum programming API. A Python library called pyQuil was introduced to develop Quil programs with higher level constructs. A Quil backend is also supported by other quantum programming environments. == Underlying quantum abstract machine == In the paper presented by Smith, Curtis and Zeng, Quil specifies the instruction set for a Quantum Abstract Machine (QAM,) akin to a Turing machine, yet more practical for accomplishing "real-world" tasks. The state of the QAM can be represented as a 6-tuple ( | Ψ ⟩ , C , G , G ′ , P , κ ) {\displaystyle (|\Psi \rangle ,C,G,G',P,\kappa )} where: | Ψ ⟩ {\displaystyle |\Psi \rangle } is the (quantum) state of a fixed but arbitrary number of qubits N q {\displaystyle N_{q}} indexed using a 0-based indexing. C {\displaystyle C} is a


id: qutrit-20260505-0
file: data/en.wikipedia.org/wiki/Qutrit-0.md
category: reference
title: Qutrit
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Qutrit
date_saved: 2026-05-05T11:08:50.895685+00:00
instance: kb-cron
parent: qutrit-20260505-0
summary:
A qutrit (or quantum trit) is a unit of quantum information that is realized by a 3-level quantum system (qudit with radix 3), that may be in a superposition of three mutually orthogonal quantum states. The qutrit is analogous to the classical radix-3 trit, just as the qubit, a quantum system described by a superposition of two orthogonal states, is analogous to the classical radix-2 bit. There is ongoing work to develop quantum computers using qutrits and qudits in general. == Representation == A qutrit has three orthonormal basis states or vectors, often denoted | 0 ⟩ {\displaystyle |0\rangle } , | 1 ⟩ {\displaystyle |1\rangle } , and | 2 ⟩ {\displaystyle |2\rangle } in Dirac or bra–ket notation. These are used to describe the qutrit as a superposition state vector in the form of a linear combination of the three orthonormal basis states: | ψ ⟩ = α | 0 ⟩ + β | 1 ⟩ + γ | 2 ⟩ {\displaystyle |\psi \rangle =\alpha |0\rangle +\beta |1\rangle +\gamma |2\rangle } , where the coefficients are complex probability amplitudes, such that the sum of their squares is unity (normalization): | α | 2 + | β | 2


id: randomized-benchmarking-20260505-0
file: data/en.wikipedia.org/wiki/Randomized_benchmarking-0.md
category: reference
title: Randomized benchmarking
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Randomized_benchmarking
date_saved: 2026-05-05T11:08:52.089855+00:00
instance: kb-cron
parent: randomized-benchmarking-20260505-0
summary:
Randomized benchmarking is an experimental method for measuring the average error rates of quantum computing hardware platforms. The protocol estimates the average error rates by implementing long sequences of randomly sampled quantum gate operations. Randomized benchmarking is the industry-standard protocol used by quantum hardware developers such as IBM and Google to test the performance of the quantum operations. The original theory of randomized benchmarking, proposed by Joseph Emerson and collaborators, considered the implementation of sequences of Haar-random operations, but this had several practical limitations. The now-standard protocol for randomized benchmarking (RB) relies on uniformly random Clifford operations, as proposed in 2006 by Dankert et al. as an application of the theory of unitary t-designs. In current usage randomized benchmarking sometimes refers to the broader family of generalizations of the 2005 protocol involving different random gate sets that can identify various features of the strength and type of errors affecting the elementary quantum gate operations. Randomized benchmarking protocols are an important means of verifying and validating quantum operations and are also routinely used for the optimization of quantum control procedures. == Overview == Randomized benchmarking offers several key advantages over alternative approaches to error characterization. For example, the number of experimental


id: rqops-20260505-0
file: data/en.wikipedia.org/wiki/RQOPS-0.md
category: reference
title: RQOPS
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/RQOPS
date_saved: 2026-05-05T11:08:53.289666+00:00
instance: kb-cron
parent: rqops-20260505-0
summary:
Reliable Quantum Operations Per Second (rQOPS) is a metric that measures the capabilities and error rates of a quantum computer. It combines several key factors to measure how many reliable operations a computer can execute in a single second: logical error rates, clock speed, and number of reliable qubits. The quantities included in rQOPS can be measured in all quantum computer architectures, allowing different architectures to be compared with one standard metric. A larger rQOPS measurement indicates a faster and more accurate device capable of solving more complex problems. Microsoft suggest that a machine with 1 million rQOPS qualifies as a quantum supercomputer. Alternative benchmarks include quantum volume, cross-entropy benchmarking, Circuit Layer Operations Per Second (CLOPS) proposed by IBM and IonQ's Algorithmic Qubits. However, as opposed to considering qubit performance alone, rQOPS measures how capable a quantum system is at solving tangible problems. == Definition == rQOPS is calculated as rQOPS=Q x f, at a corresponding logical error rate pL., where Q is the number of logical qubits and f is the hardware's logical clock speed. Microsoft has selected this metric for the higher quantum computing implementation levels as it encompasses scale, speed, and reliability. rQOPS =[Q][f] == See also


id: solovay-kitaev-theorem-20260505-0
file: data/en.wikipedia.org/wiki/Solovay–Kitaev_theorem-0.md
category: reference
title: Solovay–Kitaev theorem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Solovay–Kitaev_theorem
date_saved: 2026-05-05T11:08:54.634759+00:00
instance: kb-cron
parent: solovay-kitaev-theorem-20260505-0
summary:
In quantum information and computation, the Solovay–Kitaev theorem says that if a set of single-qubit quantum gates generates a dense subgroup of SU(2), then that set can be used to approximate any desired quantum gate with a short sequence of gates that can also be found efficiently. This theorem is considered one of the most significant results in the field of quantum computation and was first announced by Robert M. Solovay in 1995 and independently proven by Alexei Kitaev in 1997. Michael Nielsen and Christopher M. Dawson have noted its importance in the field. A consequence of this theorem is that a quantum circuit of m {\displaystyle m} constant-qubit gates can be approximated to ε {\displaystyle \varepsilon } error (in operator norm) by a quantum circuit of O ( m log c ⁡ ( m / ε ) ) {\displaystyle O(m\log ^{c}(m/\varepsilon ))} gates from a desired finite universal gate set (where c is a constant). By comparison, just knowing that a gate set is universal only implies that constant-qubit gates can be approximated by a finite circuit from the gate set, with no bound on its length. So, the Solovay–Kitaev theorem shows that this approximation can be made surprisingly


id: solovay-kitaev-theorem-20260505-1
file: data/en.wikipedia.org/wiki/Solovay–Kitaev_theorem-1.md
category: reference
title: Solovay–Kitaev theorem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Solovay–Kitaev_theorem
date_saved: 2026-05-05T11:08:54.634759+00:00
instance: kb-cron
parent: solovay-kitaev-theorem-20260505-0
summary:
where the big O notation hides higher-order terms. One can naively bound the above expression to be O ( δ 2 ) {\displaystyle O(\delta _{2})} , but the group commutator structure creates substantial error cancellation. We can use this observation to approximate U U n − 1 − 1 {\displaystyle UU_{n-1}^{-1}} as a group commutator V n − 1 W n − 1 V n − 1 − 1 W n − 1 − 1 {\displaystyle V_{n-1}W_{n-1}V_{n-1}^{-1}W_{n-1}^{-1}} . This can be done such that both V n − 1 {\displaystyle V_{n-1}} and W n − 1 {\displaystyle W_{n-1}} are close to the identity (since ‖ U U n − 1 − 1 − I ‖ ≤ ε n − 1 {\displaystyle \|UU_{n-1}^{-1}-I\|\leq \varepsilon _{n-1}} ). So, if we recursively compute gate sequences approximating V n − 1 {\displaystyle V_{n-1}} and W n − 1 {\displaystyle W_{n-1}} to ε n − 1 {\displaystyle \varepsilon _{n-1}} error, we get a gate sequence approximating U U n − 1 − 1 {\displaystyle UU_{n-1}^{-1}} to the desired better precision ε n {\displaystyle \varepsilon _{n}} with ε n {\displaystyle \varepsilon _{n}} . We can get a base case approximation with constant ε 0 {\displaystyle \varepsilon


id: solovay-kitaev-theorem-20260505-2
file: data/en.wikipedia.org/wiki/Solovay–Kitaev_theorem-2.md
category: reference
title: Solovay–Kitaev theorem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Solovay–Kitaev_theorem
date_saved: 2026-05-05T11:08:54.634759+00:00
instance: kb-cron
parent: solovay-kitaev-theorem-20260505-0
summary:
L < 5 4 5 k l 0 = 5 4 ( 3 2 ) k c l 0 = 5 4 ( log ( 1 / s 2 ε ) 2 log ( 1 / s ε 0 ) ) c l 0 {\displaystyle L<{\frac {5}{4}}5^{k}l_{0}={\frac {5}{4}}\left({\frac {3}{2}}\right)^{kc}l_{0}={\frac {5}{4}}\left({\frac {{\text{log}}(1/s^{2}\varepsilon )}{2{\text{log}}(1/s\varepsilon _{0})}}\right)^{c}l_{0}} Hence for any U ∈ SU ⁡ ( 2 ) {\displaystyle U\in \operatorname {SU} (2)} there is a sequence of L = O ( log c ( 1 / ε ) ) {\displaystyle L=O({\text{log}}^{c}(1/\varepsilon ))} gates that approximates U {\displaystyle U} to accuracy ε {\displaystyle \varepsilon } . == Solovay-Kitaev algorithm for qubits == Here the main ideas that are used in the SK algorithm have been presented. The SK algorithm may be expressed in nine lines of pseudocode. Each of these lines are explained in detail below, but present it here in its entirety both for the reader's reference, and to stress the conceptual simplicity of the algorithm: function Solovay-Kitaev(Gate U {\displaystyle U} , depth n {\displaystyle n} ) is if ( n {\displaystyle n} == 0) return Basic Approximation to U {\displaystyle U} else set U n − 1 {\displaystyle U_{n-1}} = Solovay-Kitaev( U {\displaystyle


id: solovay-kitaev-theorem-20260505-3
file: data/en.wikipedia.org/wiki/Solovay–Kitaev_theorem-3.md
category: reference
title: Solovay–Kitaev theorem
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Solovay–Kitaev_theorem
date_saved: 2026-05-05T11:08:54.634759+00:00
instance: kb-cron
parent: solovay-kitaev-theorem-20260505-0
summary:
set V , W {\displaystyle V,W} = GC-Decompose( U U n − 1 + {\displaystyle UU_{n-1}^{+}} ) For practical implementations we will see below that it is useful to have c g c {\displaystyle c_{gc}} as small as possible. The next step is to find instruction sequences which are ε n − 1 {\displaystyle \varepsilon _{n-1}} -approximations to V {\displaystyle V} and W {\displaystyle W} : set V n − 1 {\displaystyle V_{n-1}} = Solovay-Kitaev( V , n − 1 {\displaystyle V,n-1} ) set W n − 1 {\displaystyle W_{n-1}} = Solovay-Kitaev( W , n − 1 {\displaystyle W,n-1} ) The group commutator of V n − 1 {\displaystyle V_{n-1}} and W n {\displaystyle W_{n}} turns out to be an ε n − 1 {\displaystyle \varepsilon _{n-1}} ≡ c approx ε n − 1 3 / 2 {\displaystyle c_{\text{approx}}\varepsilon _{n-1}^{3/2}} -approximation to Δ {\displaystyle \Delta } , for some small constant c approx {\displaystyle c_{\text{approx}}} . Provided ε n − 1 < 1 / c approx 2 {\displaystyle \varepsilon _{n-1}<1/c_{\text{approx}}^{2}} , we see that ε n < ε n − 1 {\displaystyle \varepsilon _{n}<\varepsilon _{n-1}} , and this procedure therefore provides an improved approximation to Δ {\displaystyle \Delta } ,


id: stabilizer-code-20260505-0
file: data/en.wikipedia.org/wiki/Stabilizer_code-0.md
category: reference
title: Stabilizer code
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Stabilizer_code
date_saved: 2026-05-05T11:08:55.806528+00:00
instance: kb-cron
parent: stabilizer-code-20260505-0
summary:
In quantum computing and quantum communication, a stabilizer code is a class of quantum codes for performing quantum error correction. The toric code, and surface codes more generally, are types of stabilizer codes considered very important for the practical realization of quantum information processing. In fact, the toric code and surface codes also belong to a special class of stabilizer codes, CSS codes. An example of a stabilizer code that is not a CSS code is the five-qubit error correcting code. Stabilizer codes are strikingly similar to classical linear block codes in their operation and performance. Just as a classical linear block code can be defined by its parity-check matrix, a quantum stabilizer code also has a "parity check" structure defined by its stabilizers. However, stabilizers for a n-qubit code are n-qubit Pauli operators instead of classical n-bit strings, and they must all commute with each other for the code to be valid. The theory of stabilizer codes allows one to import some classical binary or quaternary codes for use as a quantum code. However, when importing the classical code, it must satisfy the dual-containing (or self-orthogonality) constraint. Researchers have found many examples of classical codes satisfying this constraint, but


id: stabilizer-code-20260505-1
file: data/en.wikipedia.org/wiki/Stabilizer_code-1.md
category: reference
title: Stabilizer code
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Stabilizer_code
date_saved: 2026-05-05T11:08:55.806528+00:00
instance: kb-cron
parent: stabilizer-code-20260505-0
summary:
Span ( | 000 ⟩ , | 111 ⟩ ) {\displaystyle {\text{Span}}(|000\rangle ,|111\rangle )} . Usually, the physical state | 000 ⟩ {\displaystyle |000\rangle } and | 111 ⟩ {\displaystyle |111\rangle } are identified with the | 0 ⟩ {\displaystyle |0\rangle } and | 1 ⟩ {\displaystyle |1\rangle } states of the logical qubit respectively (often written as | 0 ¯ ⟩ {\displaystyle |{\overline {0}}\rangle } and | 1 ¯ ⟩ {\displaystyle |{\overline {1}}\rangle } to distinguish them from physical states). As a quantum code, the codespace also includes superpositions of | 0 ¯ ⟩ {\displaystyle |{\overline {0}}\rangle } and | 1 ¯ ⟩ {\displaystyle |{\overline {1}}\rangle } , such as | + ¯ ⟩ = | 000 ⟩ + | 111 ⟩ {\displaystyle |{\overline {+}}\rangle =|000\rangle +|111\rangle } and | − ¯ ⟩ = | 000 ⟩ − | 111 ⟩ {\displaystyle |{\overline {-}}\rangle =|000\rangle -|111\rangle } . Note that a phase-flip error Zi on any one physical qubit will change | + ¯ ⟩ {\displaystyle |{\overline {+}}\rangle } to | − ¯ ⟩ {\displaystyle |{\overline {-}}\rangle } , and vice versa. === Five-qubit code === An example of a stabilizer code is the five qubit [[5, 1, 3]]


id: stabilizer-code-20260505-2
file: data/en.wikipedia.org/wiki/Stabilizer_code-2.md
category: reference
title: Stabilizer code
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Stabilizer_code
date_saved: 2026-05-05T11:08:55.806528+00:00
instance: kb-cron
parent: stabilizer-code-20260505-0
summary:
Note, however, that these are not the logical operator representative candidates with the lowest weight (number of non-I Pauli factors). For example, Zg1 = −YIIYZ has weight 3. == Stabilizer error-correction conditions == One of the fundamental notions in quantum error correction theory is that it suffices to correct a discrete error set with support in the Pauli group Π n {\displaystyle \Pi ^{n}} . Suppose that the errors affecting an encoded quantum state are a subset E {\displaystyle {\mathcal {E}}} of the Pauli group Π n {\displaystyle \Pi ^{n}} : E ⊂ Π n . {\displaystyle {\mathcal {E}}\subset \Pi ^{n}.} Because E {\displaystyle {\mathcal {E}}} and S {\displaystyle {\mathcal {S}}} are both subsets of Π n {\displaystyle \Pi ^{n}} , an error E ∈ E {\displaystyle E\in {\mathcal {E}}} either commutes or anti-commutes with any particular element S ∈ S {\displaystyle S\in {\mathcal {S}}} . If E anti-commutes with an element S, then S E | ψ ⟩ = − E S | ψ ⟩ = − E | ψ ⟩ {\displaystyle SE|\psi \rangle =-ES|\psi \rangle =-E|\psi \rangle } which means that E | ψ ⟩ {\displaystyle E|\psi \rangle } is in the −1-eigenspace of S rather than the


id: stabilizer-code-20260505-3
file: data/en.wikipedia.org/wiki/Stabilizer_code-3.md
category: reference
title: Stabilizer code
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Stabilizer_code
date_saved: 2026-05-05T11:08:55.806528+00:00
instance: kb-cron
parent: stabilizer-code-20260505-0
summary:
⁠ I → 00 , X → 01 , Y → 11 , Z → 10. {\displaystyle I\to 00,\;X\to 01,\;Y\to 11,\;Z\to 10.} ⁠ This mapping maps ⁠ Π n {\displaystyle \Pi ^{n}} ⁠ to vectors in ⁠ ( Z 2 ) 2 n {\displaystyle (\mathbb {Z} _{2})^{2n}} ⁠, such that multiplication of Pauli operators is equivalent to addition of binary vectors up to a global phase. Furthermore, ⁠ ( Z 2 ) 2 n {\displaystyle (\mathbb {Z} _{2})^{2n}} ⁠ can be equipped with a symplectic algebra, such that the symplectic product of two binary vectors indicate whether the corresponding Pauli operators commute. The above binary representation and symplectic algebra are especially useful in making the relation between classical linear error correction and quantum stabilizer codes more explicit. In the language of symplectic vector spaces, a symplectic subspace corresponds to a direct sum of Pauli algebras (i.e., encoded qubits), while an isotropic subspace corresponds to a set of stabilizers. == Notes == == References == D. Gottesman, "Stabilizer codes and quantum error correction," quant-ph/9705052, Caltech Ph.D. thesis. https://arxiv.org/abs/quant-ph/9705052 Shor, Peter W. (1995-10-01). "Scheme for reducing decoherence in quantum computer memory". Physical Review A. 52 (4). American Physical Society (APS): R2493–R2496. Bibcode:1995PhRvA..52.2493S.


id: sycamore-processor-20260505-0
file: data/en.wikipedia.org/wiki/Sycamore_(processor)-0.md
category: reference
title: Sycamore (processor)
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Sycamore_(processor)
date_saved: 2026-05-05T11:08:56.962909+00:00
instance: kb-cron
parent: sycamore-processor-20260505-0
summary:
Sycamore is a transmon superconducting quantum processor created by Google's Artificial Intelligence division. It has 53 qubits. In 2019, Google claimed alleged first evidence of quantum supremacy by running a randomized benchmarking on the Sycamore. == History == === Speed of processing === In 2019, Sycamore completed a task in 200 seconds that Google claimed, in a Nature paper, would take a state-of-the-art supercomputer 10,000 years to finish. Thus, Google claimed to have achieved quantum supremacy. To estimate the time that would be taken by a classical supercomputer, Google ran portions of the quantum circuit simulation on Summit, one of the most powerful classical computers in the world. Later, IBM made a counter-argument, claiming that the task would take only 2.5 days on a classical system like Summit. If Google's claims are upheld, then it would represent a huge leap in computing power. === Simulations === In August 2020, quantum engineers working for Google reported the largest chemical simulation on a quantum computer – a Hartree–Fock approximation with Sycamore paired with a classical computer that analyzed results to provide new parameters for the 12-qubit system. In April 2021, researchers working with Sycamore reported that they were able to realize the


id: timeline-of-quantum-computing-and-communication-20260505-0
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-0.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
This is a timeline of quantum computing and communication. == 1930s == === 1936 === Erwin Schrödinger publishes a theorem setting the basis for quantum steering and the limits of quantum state purification. The theorem remained uncredited even after multiple expansions and rediscoveries. == 1960s == === 1968/69/70 === Stephen Wiesner invents conjugate coding. === 1969 === 13 June – James L. Park (Washington State University, Pullman)'s paper is received by Foundations of Physics, in which he describes the non-possibility of disturbance in a quantum transition state in the context of a disproof of quantum jumps in the Bohr model of the atom. == 1970s == === 1973 === Alexander Holevo's paper is published. The Holevo bound describes a limit of the quantity of classical information which is possible to quanta encode. Charles H. Bennett shows that computation can be done reversibly. === 1975 === R. P. Poplavskii publishes "Thermodynamical models of information processing" (in Russian) which shows the computational infeasibility of simulating quantum systems on classical computers, due to the superposition principle. Roman Stanisław Ingarden, a Polish mathematical physicist, submits the paper "Quantum Information Theory" in Reports on Mathematical Physics, vol. 10, pp. 43–72, published 1976. It is one


id: timeline-of-quantum-computing-and-communication-20260505-1
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-1.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
=== 1994 === Peter Shor, at AT&T's Bell Labs in New Jersey, publishes Shor's algorithm. It would allow a quantum computer to factor large integers quickly. It solves both the factoring problem and the discrete log problem. The algorithm can theoretically break many of the cryptosystems in use today. Its invention sparked tremendous interest in quantum computers. The first United States Government workshop on quantum computing is organized by NIST in Gaithersburg, Maryland, in autumn. Isaac Chuang and Yoshihisa Yamamoto propose a quantum-optical realization of a quantum computer to implement Deutsch's algorithm. Their work introduced dual-rail encoding for photonic qubits. In December, Ignacio Cirac, at University of Castilla–La Mancha at Ciudad Real, and Peter Zoller at the University of Innsbruck propose an experimental realization of the controlled NOT gate with cold trapped ions. === 1995 === The first United States Department of Defense workshop on quantum computing and quantum cryptography is organized by United States Army physicists Charles M. Bowden, Jonathan Dowling, and Henry O. Everitt; it took place in February at the University of Arizona in Tucson. Peter Shor proposes the first schemes for quantum error correction. Christopher Monroe and David J. Wineland at NIST (Boulder, Colorado) experimentally realize


id: timeline-of-quantum-computing-and-communication-20260505-2
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-2.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
=== 2002 === The Quantum Information Science and Technology Roadmapping Project, involving some of the main participants in the field, lays out the Quantum computation roadmap. The Institute for Quantum Computing is established at the University of Waterloo in Waterloo, Ontario by Mike Lazaridis, Raymond Laflamme and Michele Mosca. A group led by Gerhard Birkl (now at TU Darmstadt) demonstrates the first 2D array of optical tweezers with trapped atoms for quantum computation with atomic qubits. === 2003 === Implementation of the Deutsch–Jozsa algorithm on an ion-trap quantum computer at the University of Innsbruck is reported. Todd D. Pittman and collaborators at Johns Hopkins University, Applied Physics Laboratory, and independently Jeremy O'Brien and collaborators at the University of Queensland, demonstrate quantum controlled NOT gates using only linear optical elements. The first implementation of a CNOT quantum gate, according to the Cirac–Zoller proposal, is reported by a team at the University of Innsbruck led by Rainer Blatt. The United States government DARPA Quantum Network becomes fully operational on October 23, 2003. The Institute for Quantum Optics and Quantum Information (IQOQI) is established in Innsbruck and Vienna, Austria, by the founding directors Rainer Blatt, Hans Jürgen Briegel, Rudolf Grimm, Anton Zeilinger and


id: timeline-of-quantum-computing-and-communication-20260505-3
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-3.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
=== 2007 === Subwavelength waveguide is developed for light. A single-photon emitter for optical fibers is developed. The first one-way quantum computers are built, where measurement (collapse) of an entangled cluster state is the main driving force of computation, and shown to perform simple computations, such as Deutsch's algorithm. A new material is proposed for quantum computing. A single-atom single-photon server is devised. The University of Cambridge, England, develops an electron quantum pump. A superior method of qubit coupling is developed. A successful demonstration of controllably coupled qubits is reported. A breakthrough in applying spin-based electronics to silicon is reported. Scientists demonstrate a quantum state exchange between light and matter. A diamond quantum register is developed. Controlled NOT quantum gates on a pair of superconducting quantum bits are realized. Scientists contain and study hundreds of individual atoms in 3D array. Nitrogen in a buckyball molecule is used in quantum computing. A large number of electrons are quantum coupled. Spin–orbit interaction of electrons are measured. Atoms are quantum manipulated in laser light. Light pulses are used to control electron spins. Quantum effects are demonstrated across tens of nanometers. Light pulses are used to accelerate quantum computing development. A quantum random access


id: timeline-of-quantum-computing-and-communication-20260505-4
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-4.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
=== 2011 === Entanglement in a solid-state spin ensemble is reported NOON photons in a superconducting quantum integrated circuit are reported. A quantum antenna is described. Multimode quantum interference is documented. Magnetic Resonance applied to quantum computing is reported. The quantum pen for single atoms is documented. Atomic "Racing Dual" is reported. A 14-qubit register is reported. D-Wave claims to have developed quantum annealing and introduces their product called D-Wave One. The company claims this is the first commercially available quantum computer. Repetitive error correction is demonstrated in a quantum processor. Diamond quantum computer memory is demonstrated. Qmodes are developed. Decoherence is demonstrated as suppressed. Simplification of controlled operations is reported. Ions entangled using microwaves are documented. Practical error rates are achieved. A quantum computer employing Von Neumann architecture is described. A quantum spin Hall topological insulator is reported. The concept of two diamonds linked by quantum entanglement could help develop photonic processors is described. === 2012 === D-Wave claims a quantum computation using 84 qubits. Physicists create a working transistor from a single atom. A method for manipulating the charge of nitrogen vacancy-centres in diamond is reported. Creation of a 300 qubit/particle quantum simulator is reported. Demonstration of topologically


id: timeline-of-quantum-computing-and-communication-20260505-5
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-5.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
20 April – UNSW Sydney develops a way of producing 'hot qubits' – quantum devices that operate at 1.5 kelvin. 11 March – UNSW perform electric nuclear resonance to control single atoms in electronic devices. 23 April – University of Tokyo and Australian scientists create and successfully test a solution to the quantum wiring problem, creating a 2D structure for qubits. Such structure can be built using existing integrated circuit technology and has considerably lower cross-talk. 16 January – Quantum physicists report the first direct splitting of one photon into three using spontaneous parametric down-conversion which may have applications in quantum technology. 11 February – Quantum engineers report that they created artificial atoms in silicon quantum dots for quantum computing and that artificial atoms with a higher number of electrons can be more stable qubits than previously thought possible. Enabling silicon-based quantum computers may make it possible to reuse the manufacturing technology of "classical" modern-day computer chips among other advantages. 14 February – Quantum physicists develop a novel single-photon source which may allow bridging of semiconductor-based quantum-computers that use photons by converting the state of an electron spin to the polarisation of a photon. They showed that they can generate


id: timeline-of-quantum-computing-and-communication-20260505-6
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-6.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
12 December – At the IEEE International Electron Devices Meeting (IEDM), IMEC shows an RF multiplexer chip that operates at temperatures as low as a few millikelvins, designed for quantum computers. Researchers from the Chalmers University of Technology report the development of a cryogenic low-noise amplifier (LNA) for amplifying signals from qubits, made of indium phosphide (InP) high-electron-mobility transistors (HEMTs). 21 December – Publication of research of "counterfactual quantum communication" – whose first achievement was reported in 2017 – by which information can be exchanged without any physical particle traveling between observers and without quantum teleportation. The research suggests that this is based on some form of relation between the properties of modular angular momentum.


id: timeline-of-quantum-computing-and-communication-20260505-7
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-7.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
=== 2021 === 6 January – Chinese researchers report that they have built the world's largest integrated quantum communication network, combining over 700 optical fibers with two QKD-ground-to-satellite links for a total distance between nodes of the network of up to ~4,600 km. 13 January – Austrian researchers report the first realization of an entangling gate between two logical qubits encoded in topological quantum error-correction codes using a trapped-ion quantum computer with 10 ions. 15 January – Researchers in China report the successful transmission of entangled photons between drones, used as nodes for the development of mobile quantum networks or flexible network extensions, marking the first work in which entangled particles were sent between two moving devices. 27 January – BMW announces the use of a quantum computer for the optimization of supply chains. 28 January – Swiss and German researchers report the development of a highly efficient single-photon source for quantum information technology with a system of gated quantum dots in a tunable microcavity which captures photons released from excited "artificial atoms". 3 February – Microsoft starts offering a cloud quantum computing service, called Azure Quantum. 5 February – Researchers demonstrate a first prototype of quantum-logic gates for distributed


id: timeline-of-quantum-computing-and-communication-20260505-8
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-8.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
=== 2023 === 3 February – At the University of Innsbruck, researchers entangle two ions over a distance of 230 meters. 8 February – Alpine Quantum Technologies (AQT) demonstrates a quantum volume of 128 on its 19-inch rack-compatible quantum computer system PINE – a new record in Europe. 17 February – Fusion-based quantum computation is proposed. 27 March – India's first quantum computing-based telecom network link is inaugurated. 14 June – IBM computer scientists report that a quantum computer produced better results for a physics problem than a conventional supercomputer. 21 June – Microsoft declares that it is working on a topological quantum computer based on Majorana fermions, with the aim of arriving within 10 years at a computer capable of carrying out at least one million operations per second with an error rate of one operation every 1,000 billion (corresponding to 11 uninterrupted days of calculation). 13 October – Researchers at TU Darmstadt publish the first experimental demonstration of a qubit array with more than 1,000 qubits: A 3,000-site atomic array based on a 2D configuration of optical tweezers holds up to 1,305 atomic qubits. 24 October – Atom Computing announces that it has "created a 1,225-site atomic array,


id: timeline-of-quantum-computing-and-communication-20260505-9
file: data/en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication-9.md
category: reference
title: Timeline of quantum computing and communication
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Timeline_of_quantum_computing_and_communication
date_saved: 2026-05-05T11:08:58.171458+00:00
instance: kb-cron
parent: timeline-of-quantum-computing-and-communication-20260505-0
summary:
=== 2025 === 7 January – Researchers at Osaka Metropolitan University derived a simplified formula for quantum entanglement entropy, allowing for easier analysis of entanglement in strongly correlated electron systems. Their study identified unexpected quantum behaviors in nanoscale artificial magnetic materials and highlighted the role of quantum relative entropy in the Kondo effect. 14 February – Researchers (Björkman et al.) used transmon qubits to demonstrate a virtual-state process of the Landau-Zener-Stückelberg-Majorana (LZSM) transition. Their experiment significantly suppressed the AC Stark shift, improving control over quantum state transitions. 19 February – Microsoft announced Majorana 1, claiming to be the first qubit architecture based on a topological superconductor. 27 February – Amazon announced a quantum computing processor prototype, nicknamed "Ocelot", that uses concatenation of encoded bosonic cat qubits for bosonic quantum error correction. 26 March – Researchers at JPMorganChase and Quantinuum announced the realization of certified randomness, generating publicly certifiable bits using a trapped-ion quantum processor. 26 May – Researchers across several institutions, especially Google Research, present an experimental demonstration of a color code for both distances 3 and 5. 5 August – Researchers at the University of Southern California discover that combining two kinds of anyons from topological quantum field theory,


id: topological-quantum-computer-20260505-0
file: data/en.wikipedia.org/wiki/Topological_quantum_computer-0.md
category: reference
title: Topological quantum computer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Topological_quantum_computer
date_saved: 2026-05-05T11:08:59.387929+00:00
instance: kb-cron
parent: topological-quantum-computer-20260505-0
summary:
A topological quantum computer is a type of quantum computer. It utilizes anyons, a type of quasiparticle that occurs in two-dimensional systems. The anyons' world lines intertwine to form braids in a three-dimensional spacetime (one temporal and two spatial dimensions). The braids act as the logic gates of the computer. The primary advantage of using quantum braids over trapped quantum particles is in their stability. While small but cumulative perturbations can cause quantum states to decohere and introduce errors in traditional quantum computations, such perturbations do not alter the topological properties of the braids. This stability is akin to the difference between cutting and reattaching a string to form a different braid versus a ball (representing an ordinary quantum particle in four-dimensional spacetime) colliding with a wall. It was proposed by Russian-American physicist Alexei Kitaev in 1997. While the elements of a topological quantum computer originate in a purely mathematical realm, experiments in fractional quantum Hall systems indicate that these elements may be created in the real world by using semiconductors made of gallium arsenide at a temperature of nearly absolute zero and subject to strong magnetic fields. == Introduction == Anyons are quasiparticles in a two-dimensional space. Anyons are


id: topological-quantum-computer-20260505-1
file: data/en.wikipedia.org/wiki/Topological_quantum_computer-1.md
category: reference
title: Topological quantum computer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Topological_quantum_computer
date_saved: 2026-05-05T11:08:59.387929+00:00
instance: kb-cron
parent: topological-quantum-computer-20260505-0
summary:
== Example: Computing with Fibonacci anyons == One of the prominent examples in topological quantum computing is with a system of Fibonacci anyons. A Fibonacci anyon has been described as "an emergent particle with the property that as you add more particles to the system, the number of quantum states grows like the Fibonacci sequence, 1, 2, 3, 5, 8, etc." In the context of conformal field theory, fibonacci anyons are described by the Yang–Lee model, the SU(2) special case of the Chern–Simons theory and Wess–Zumino–Witten models. These anyons can be used to create generic gates for topological quantum computing. There are three main steps for creating a model: Choose our basis and restrict our Hilbert space Braid the anyons together Fuse the anyons at the end and detect how they fuse in order to read the output of the system. === State preparation === Fibonacci anyons are defined by three qualities: They have a topological charge of τ {\displaystyle \tau } . In this discussion, we consider another charge called 1 {\displaystyle 1} which is the 'vacuum' charge if anyons are annihilated with each-other. Each of these anyons are their own antiparticle. τ = τ ∗ {\displaystyle \tau =\tau


id: topological-quantum-computer-20260505-2
file: data/en.wikipedia.org/wiki/Topological_quantum_computer-2.md
category: reference
title: Topological quantum computer
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Topological_quantum_computer
date_saved: 2026-05-05T11:08:59.387929+00:00
instance: kb-cron
parent: topological-quantum-computer-20260505-0
summary:
== Experimental efforts == In 2018, Leo Kouwenhoven working for Microsoft published a paper in Nature indicating to have found firm evidence of "zero-bias peaks" indicating Majorana quasiparticles. In 2020, the paper got an editorial note of concern. In 2021, in a follow-up paper it was indicated that the data in the 2018 paper was incomplete and misrepresented the results. In 2023, Microsoft Quantum researchers published a paper in Physical Review that described a new device that can represent a logical qubit with hardware stability, measuring a phase of matter consistent with the observation of topological superconductivity and Majorana zero modes. The scientists reported that "such devices have demonstrated low enough disorder to pass the topological gap protocol, proving the technology is viable". This publication has been criticized by other scientists for not providing sufficient evidence for Majorana modes as in previous papers. In a 2025 press release, Microsoft unveiled the Majorana 1 chip, claiming partial evidence of topological behaviour. == See also == Topological order Symmetry-protected topological order Ginzburg–Landau theory Husimi Q representation Random matrix Majorana 1 == References == == Further reading == Collins, Graham P. (April 2006). "Computing with Quantum Knots" (PDF). Scientific American. Sarma, Sankar Das;


id: topological-superconductor-20260505-0
file: data/en.wikipedia.org/wiki/Topological_superconductor-0.md
category: reference
title: Topological superconductor
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Topological_superconductor
date_saved: 2026-05-05T11:09:00.596228+00:00
instance: kb-cron
parent: topological-superconductor-20260505-0
summary:
In condensed matter physics and materials chemistry, a topological superconductor is a material that conducts electricity with zero electrical resistivity, and has non-trivial topology which gives it certain unique properties. These materials behave as superconductors that feature exotic edge states, known as Majorana zero modes. == Classification and examples == Topological superconductors are characterized by the topological order related to their electronic band structure. These materials can be classified using the periodic table of topological superconductors, which categorizes topological phases based on time-reversal symmetry, particle-hole symmetry, and chiral symmetry. An example of a simple topological superconductor in one-dimension is the Kitaev chain. == Experimental evidence == In 2015, uranium ditelluride (UTe2) was found to be a candidate topological superconductor. == Applications == A notable application of topological superconductors is in the realm of topological quantum computing, where Majorana zero modes can be used to implement fault-tolerant quantum gates via braiding operations. This approach leverages the non-Abelian statistics of Majorana modes to perform computations that are protected from local sources of decoherence. == See also == Topological insulator Majorana fermion Kitaev chain Topological quantum computer Cooper pair == References ==


id: uk-national-quantum-technologies-programme-20260505-0
file: data/en.wikipedia.org/wiki/UK_National_Quantum_Technologies_Programme-0.md
category: reference
title: UK National Quantum Technologies Programme
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/UK_National_Quantum_Technologies_Programme
date_saved: 2026-05-05T11:09:01.774508+00:00
instance: kb-cron
parent: uk-national-quantum-technologies-programme-20260505-0
summary:
The UK National Quantum Technologies Programme (UKNQTP) is a programme set up by the UK government to translate academic work on quantum mechanics, and the effects of quantum superposition and quantum entanglement into new products and services. It brings UK physicists and engineers together with companies and entrepreneurs who have an interest in commercialising the technology. == The "second quantum revolution" == The "second quantum revolution", or "quantum 2.0" is a term that is often used to describe quantum technologies based on superposition and entanglement. Originally described in a 1997 book by Gerard J. Milburn, which was then followed by a 2003 article by Jonathan P. Dowling and Gerard J. Milburn, as well as a 2003 article by David Deutsch. These technologies use equipment such as highly stabilised laser systems, magneto-optical traps, cryogenic cooled solid state devices, ion traps and vacuum systems to create, manipulate and then use quantum effects for a number of different purposes. These include: quantum information processing, such as quantum computing, quantum simulation, quantum secure communications, quantum sensing and metrology and quantum imaging, and are widely believed to offer capabilities that will out-perform existing and future classical technologies. The programme has contributed to the vast number


id: zhenghan-wang-20260505-0
file: data/en.wikipedia.org/wiki/Zhenghan_Wang-0.md
category: reference
title: Zhenghan Wang
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Zhenghan_Wang
date_saved: 2026-05-05T11:09:02.983072+00:00
instance: kb-cron
parent: zhenghan-wang-20260505-0
summary:
Zhenghan Wang (Chinese: 王正汉; born April 26, 1965) is a Chinese-American mathematician. He is a principal researcher at Microsoft Station Q, as well as a professor of mathematics at the University of California, Santa Barbara. == Education and career == Wang graduated with a B.S. and M.S. from the University of Science and Technology of China in 1989 and obtained his Ph.D. in 1993 from UC San Diego under the supervision of Michael Freedman. From 1993 to 1996 Wang taught as an assistant professor at the University of Michigan and from 1996 to 2007 Wang taught at Indiana University Bloomington. For the majority of this time, Wang specialized in the topology of 4-manifolds. In 2005, Wang moved to Santa Barbara to serve as a lead scientist in the newly founded research institute Microsoft Station Q. At Station Q, Wang worked with Michael Freedman (the station's director and his former Ph.D. advisor) on the foundations of topological quantum computing. Since 2012 Wang has served as a full professor at UC Santa Barbara. From 2013 to 2020 Wang served as a distinguished visiting research chair at the Perimeter Institute for Theoretical Physics as well. Wang was included in the 2019 class of


id: willow-processor-20260505-0
file: data/en.wikipedia.org/wiki/Willow_processor-0.md
category: reference
title: Willow processor
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Willow_processor
date_saved: 2026-05-05T11:09:04.147921+00:00
instance: kb-cron
parent: willow-processor-20260505-0
summary:
The Willow processor is a 105-qubit superconducting quantum computing processor developed by Google Quantum AI and manufactured in Santa Barbara, California. == Overview == On December 9, 2024, Google Quantum AI announced Willow in a Nature paper and company blogpost, and claiming two accomplishments: First, that Willow can reduce errors exponentially as the number of qubits is scaled, achieving below threshold quantum error correction. Second, that Willow completed a Random Circuit Sampling (RCS) benchmark task in 5 minutes that would take today's fastest supercomputers 10 septillion (1025) years. Willow is constructed with a square grid of superconducting transmon physical qubits. Improvements over past work were attributed to improved fabrication techniques, participation ratio engineering, and circuit parameter optimization. Willow prompted optimism in accelerating applications in pharmaceuticals, material science, logistics, drug discovery, and energy grid allocation. Popular media responses discussed its risk in breaking cryptographic systems, but a Google spokesman said that they were still at least 10 years out from breaking RSA. Hartmut Neven, founder and lead of Google Quantum AI, told the BBC that Willow would be used in practical applications, and in the announcement blogpost expressed the belief that advanced artificial intelligence will benefit from quantum computing. Willow follows


id: xanadu-quantum-technologies-20260505-0
file: data/en.wikipedia.org/wiki/Xanadu_Quantum_Technologies-0.md
category: reference
title: Xanadu Quantum Technologies
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Xanadu_Quantum_Technologies
date_saved: 2026-05-05T11:09:05.325541+00:00
instance: kb-cron
parent: xanadu-quantum-technologies-20260505-0
summary:
Xanadu Quantum Technologies is a Canadian quantum computing hardware and software company headquartered in Toronto, Ontario. The company develops cloud accessible photonic quantum computers and develops open-source software for quantum machine learning and simulating quantum photonic devices. == History == Xanadu was founded in 2016 by Christian Weedbrook and was a participant in the Creative Destruction Lab's accelerator program. Since then, Xanadu has raised a total of US$245M in funding with venture capital financing from Bessemer Venture Partners, Capricorn Investment Group, Tiger Global Management, In-Q-Tel, Business Development Bank of Canada, OMERS Ventures, Georgian, Real Ventures, Golden Ventures and Radical Ventures and innovation grants from Sustainable Development Technology Canada and DARPA. == Technology == Xanadu's hardware efforts have focused on developing programmable Gaussian boson sampling (GBS) devices. GBS is a generalization of boson sampling, which traditionally uses single photons as input; GBS instead employs squeezed states of light. In 2020, Xanadu published a blueprint for building a fault-tolerant quantum computer using photonic technology. In June 2022, Xanadu reported a boson sampling experiment comparable to those of Google and the University of Science and Technology of China. Their setup used loops of optical fiber and multiplexing to replace a network of beam


id: zx-calculus-20260505-0
file: data/en.wikipedia.org/wiki/ZX-calculus-0.md
category: reference
title: ZX-calculus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/ZX-calculus
date_saved: 2026-05-05T11:09:06.582482+00:00
instance: kb-cron
parent: zx-calculus-20260505-0
summary:
The ZX-calculus is a graphical language. It was conceived for reasoning about linear maps between qubits, which are represented as string diagrams called ZX-diagrams. A ZX-diagram consists of a set of generators called spiders that represent specific tensors. These are connected together to form a tensor network similar to Penrose graphical notation. Due to the symmetries of the spiders and the properties of the underlying category, topologically deforming a ZX-diagram (i.e. moving the generators without changing their connections) does not affect the linear map it represents. In addition to the equalities between ZX-diagrams that are generated by topological deformations, the calculus also has a set of graphical rewrite rules for transforming diagrams into one another. The ZX-calculus is universal in the sense that any linear map between qubits can be represented as a diagram, and different sets of graphical rewrite rules are complete for different families of linear maps. ZX-diagrams can be seen as a generalisation of quantum circuit notation, and they form a strict subset of tensor networks which represent general fusion categories and wavefunctions of quantum spin systems. == History == The ZX-calculus was first introduced by Bob Coecke and Ross Duncan in 2008 as an extension of


id: zx-calculus-20260505-1
file: data/en.wikipedia.org/wiki/ZX-calculus-1.md
category: reference
title: ZX-calculus
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/ZX-calculus
date_saved: 2026-05-05T11:09:06.582482+00:00
instance: kb-cron
parent: zx-calculus-20260505-0
summary:
== Formal definition == The category of ZX-diagrams is a dagger compact category, which means that it has symmetric monoidal structure (a tensor product), is compact closed (it has cups and caps) and comes equipped with a dagger, such that all these structures suitably interact. The objects of the category are the natural numbers, with the tensor product given by addition (the category is a PROP). The morphisms of this category are ZX-diagrams. Two ZX-diagrams compose by juxtaposing them horizontally and connecting the outputs of the left-hand diagram to the inputs of the right-hand diagram. The monoidal product of two diagrams is represented by placing one diagram above the other. Indeed, all ZX-diagrams are built freely from a set of generators via composition and monoidal product, modulo the equalities induced by the compact structure and the rules of the ZX-calculus given below. For instance, the identity of the object n {\displaystyle n} is depicted as n {\displaystyle n} parallel wires from left to right, with the special case n = 0 {\displaystyle n=0} being the empty diagram. The following table gives the generators together with their standard interpretations as linear maps, expressed in Dirac notation. The computational basis states are


id: cryonics-20260505-0
file: data/en.wikipedia.org/wiki/Cryonics-0.md
category: reference
title: Cryonics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryonics
date_saved: 2026-05-05T11:09:08.188767+00:00
instance: kb-cron
parent: cryonics-20260505-0
summary:
Cryonics (from Greek: κρύος kryos, meaning "cold") is the low-temperature freezing (usually at −196 °C or −320.8 °F or 77.1 K) and storage of human remains in the hope that resurrection may be possible in the future. Cryonics is regarded with skepticism by the mainstream scientific community. It is generally viewed as a pseudoscience, and its practice has been characterized as quackery. Cryonics procedures can begin only after the "patients" are clinically and legally dead. Procedures may begin within minutes of death, and use cryoprotectants to try to prevent ice formation during cryopreservation. It is not possible to reanimate a corpse that has undergone vitrification (ultra-rapid cooling), as this damages the brain, including its neural circuits. The first corpse to be frozen was that of James Bedford, in 1967. As of 2014, remains from about 250 bodies had been cryopreserved in the United States, and 1,500 people had made arrangements for cryopreservation of theirs. Even if the resurrection promised by cryonics were possible, economic considerations make it unlikely cryonics corporations could remain in business long enough to deliver. The "patients", being dead, cannot continue to pay for their own preservation. Early attempts at cryonic preservation were made in the 1960s


id: cryonics-20260505-1
file: data/en.wikipedia.org/wiki/Cryonics-1.md
category: reference
title: Cryonics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryonics
date_saved: 2026-05-05T11:09:08.188767+00:00
instance: kb-cron
parent: cryonics-20260505-0
summary:
=== Revival === Revival would require repairing damage from lack of oxygen, cryoprotectant toxicity, thermal stress (fracturing), and freezing in tissues that do not successfully vitrify, followed by reversing the cause of death. In many cases, extensive tissue regeneration would be necessary. This revival technology remains speculative. === Legal issues === Historically, people had little control over how their bodies were treated after death, as religion held jurisdiction over the matter. Later, secular courts began to exercise jurisdiction over corpses and use discretion in carrying out deceased people's wishes. Most countries legally treat preserved bodies as deceased persons because of laws that forbid vitrifying someone who is medically alive. In France, cryonics is not considered a legal mode of body disposal; only burial, cremation, and formal body donation to science are allowed, though bodies may legally be shipped to other countries for cryonic freezing. As of 2015, British Columbia prohibits the sale of arrangements for cryonic body preservation. In Russia, cryonics falls outside both the medical industry and the funeral services industry, making it easier than in the U.S. to get hospitals and morgues to release cryonics candidates. In 2016, the English High Court ruled in favor of a mother's


id: cryonics-20260505-2
file: data/en.wikipedia.org/wiki/Cryonics-2.md
category: reference
title: Cryonics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryonics
date_saved: 2026-05-05T11:09:08.188767+00:00
instance: kb-cron
parent: cryonics-20260505-0
summary:
== Reception == Cryonics is generally regarded as a fringe pseudoscience. Between 1982 and November 2018, the Society for Cryobiology rejected members who practiced cryonics, and issued a public statement saying that cryonics "is an act of speculation or hope, not science", and as such outside the scope of the Society. Russian company KrioRus is the first non-U.S. vendor of cryonics services. Yevgeny Alexandrov, chair of the Russian Academy of Sciences commission against pseudoscience, said there was "no scientific basis" for cryonics, and that the company was based on "unfounded speculation". Scientists have expressed skepticism about cryonics in media sources, and the Norwegian philosopher Ole Martin Moen has written that the topic receives a "minuscule" amount of attention in academia. While some neuroscientists contend that all the subtleties of a human mind are contained in its anatomical structure, few will comment directly on cryonics due to its speculative nature. People who intend to be frozen are often "looked at as a bunch of kooks". Cryobiologist Kenneth B. Storey said in 2004 that cryonics is impossible and will never be possible, as cryonics proponents are proposing to "overturn the laws of physics, chemistry, and molecular science". Neurobiologist Michael Hendricks has said,


id: list-of-people-who-arranged-for-cryonics-20260505-0
file: data/en.wikipedia.org/wiki/List_of_people_who_arranged_for_cryonics-0.md
category: reference
title: List of people who arranged for cryonics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/List_of_people_who_arranged_for_cryonics
date_saved: 2026-05-05T11:09:09.400243+00:00
instance: kb-cron
parent: list-of-people-who-arranged-for-cryonics-20260505-0
summary:
This list contains notable people who plan to be or have been cryopreserved after legal death. == Living people who plan to be cryopreserved == == Deceased people who have been cryopreserved == == References ==


id: 21st-century-medicine-20260505-0
file: data/en.wikipedia.org/wiki/21st_Century_Medicine-0.md
category: reference
title: 21st Century Medicine
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/21st_Century_Medicine
date_saved: 2026-05-05T11:09:10.550892+00:00
instance: kb-cron
parent: 21st-century-medicine-20260505-0
summary:
21st Century Medicine (21CM) is a California cryobiological research company which has as its primary focus the development of perfusates and protocols for viable long-term cryopreservation of human organs, tissues and cells at temperatures below −100 °C through the use of vitrification. 21CM was founded in 1993. In 2004 21CM received a $900,000 grant from the U.S. National Institutes of Health (NIH) to study a preservation solution developed by the University of Rochester in New York for extending simple cold storage time of human hearts removed for transplant. At the July 2005 annual conference of the Society for Cryobiology, 21st Century Medicine announced the vitrification of a rabbit kidney to −135 °C with their vitrification mixture. The kidney was successfully transplanted upon rewarming to a rabbit, the rabbit being euthanized on the 48th day for histological follow-up. On February 9, 2016, 21st Century Medicine won the Small Mammal Brain Preservation Prize. On March 13, 2018, they won the Large Mammal Brain Preservation Prize. == References == == External links == Official website


id: aldehyde-stabilized-cryopreservation-20260505-0
file: data/en.wikipedia.org/wiki/Aldehyde-stabilized_cryopreservation-0.md
category: reference
title: Aldehyde-stabilized cryopreservation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Aldehyde-stabilized_cryopreservation
date_saved: 2026-05-05T11:09:11.729305+00:00
instance: kb-cron
parent: aldehyde-stabilized-cryopreservation-20260505-0
summary:
Aldehyde-stabilized cryopreservation is a new technique for cryopreservation first demonstrated in 2016 by Robert L. McIntyre and Gregory Fahy at the cryobiology research company 21st Century Medicine, Inc. This technique uses a particular implementation of fixation and vitrification that can successfully preserve a rabbit brain in "near perfect" condition at −135 °C, with the cell membranes, synapses, and intracellular structures intact in electron micrographs. In 2016, McIntyre and Fahy were awarded the first portion of the Brain Preservation Technology Prize, the Small Animal Brain Preservation Prize, by the Brain Preservation Foundation for the successful cryopreservation of a whole mouse brain. The cryopreserved brain was rewarmed and no serious degradation was found to have occurred; the brain structure under electron microscopic evaluation after rewarming remained well-preserved. Although this technique has not yet led to a successful revival of a cryopreserved brain, some researchers see this technique as providing promising directions for future research. == See also == Cryonics == References ==


id: james-bedford-20260505-0
file: data/en.wikipedia.org/wiki/James_Bedford-0.md
category: reference
title: James Bedford
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/James_Bedford
date_saved: 2026-05-05T11:09:12.917561+00:00
instance: kb-cron
parent: james-bedford-20260505-0
summary:
James Hiram Bedford (April 20, 1893 – January 12, 1967) was an American psychology professor at the University of California who wrote several books on occupational counseling. He is the first person whose body was cryopreserved after legal death, and remains preserved at the Alcor Life Extension Foundation. == Cryonic preservation == In June 1965, Ev Cooper's Life Extension Society (LES) offered the opportunity to preserve one person free of charge, stating that "the Life Extension Society now has primitive facilities for emergency short term freezing and storing our friend the large homeotherm (man). LES offers to freeze free of charge the first person desirous and in need of cryogenic suspension." Bedford did not take this opportunity, however, but later used his own funds. Bedford suffered from kidney cancer that had later metastasized into his lungs, a condition that was untreatable at the time. Bedford died in 1967 at 73 years old. Bedford left $100,000 to cryonics research in his will, but even more was utilized by Bedford's wife and son in court defending both his will and his cryopreservation against arguments created by other relatives. Bedford's body was frozen with the hope of future revival, claimed by Alcor's Mike


id: cryo-20260505-0
file: data/en.wikipedia.org/wiki/Cryo-0.md
category: reference
title: Cryo
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryo
date_saved: 2026-05-05T11:09:14.071820+00:00
instance: kb-cron
parent: cryo-20260505-0
summary:
Cryo- is from the Ancient Greek κρύος (krúos, “ice, icy cold, chill, frost”). Uses of the prefix Cryo- include: == Physics and geology == Cryogenics, the study of the production and behaviour of materials at very low temperatures and the study of producing extremely low temperatures Cryoelectronics, the study of superconductivity under cryogenic conditions and its applications Cryosphere, those portions of Earth's surface where water ice naturally occurs Cryotron, a switch that uses superconductivity Cryovolcano, a type of volcano that erupts volatiles instead of molten rock == Biology and medicine == Cryobiology, the branch of biology that studies the effects of low temperatures on living things Cryonics, the low-temperature preservation of people who cannot be sustained by contemporary medicine Cryoprecipitate, a blood-derived protein product used to treat some bleeding disorders Cryotherapy, medical treatment using cold Cryoablation, tissue removal using cold Cryosurgery, surgery using cold Cryo-electron microscopy (cryoEM), a technique that fires beams of electrons at proteins that have been frozen in solution, to deduce the biomolecules’ structure == Other uses == Cryo Interactive, a video game company Cryos, a planet in the video game Darkspore "Cryo", a song from the album R Plus Seven by Oneohtrix Point Never == See


id: cryobiology-20260505-0
file: data/en.wikipedia.org/wiki/Cryobiology-0.md
category: reference
title: Cryobiology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryobiology
date_saved: 2026-05-05T11:09:15.259833+00:00
instance: kb-cron
parent: cryobiology-20260505-0
summary:
Cryobiology is the branch of biology that studies the effects of low temperatures on living things within Earth's cryosphere or in science. The word cryobiology is derived from the Greek words κρῧος [kryos], "cold", βίος [bios], "life", and λόγος [logos], "word". In practice, cryobiology is the study of biological material or systems at temperatures below normal. Materials or systems studied may include proteins, cells, tissues, organs, or whole organisms. Temperatures may range from moderately hypothermic conditions to cryogenic temperatures. == Areas of study == At least six major areas of cryobiology can be identified: 1) study of cold-adaptation of microorganisms, plants (cold hardiness), and animals, both invertebrates and vertebrates (including hibernation), 2) cryopreservation of cells, tissues, gametes, and embryos of animal and human origin for (medical) purposes of long-term storage by cooling to temperatures below the freezing point of water. This usually requires the addition of substances which protect the cells during freezing and thawing (cryoprotectants), 3) preservation of organs under hypothermic conditions for transplantation, 4) lyophilization (freeze-drying) of pharmaceuticals, 5) cryosurgery, a (minimally) invasive approach for the destruction of unhealthy tissue using cryogenic gases/fluids, and 6) physics of supercooling, ice nucleation/growth and mechanical engineering aspects of heat transfer during


id: cryobiology-20260505-1
file: data/en.wikipedia.org/wiki/Cryobiology-1.md
category: reference
title: Cryobiology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryobiology
date_saved: 2026-05-05T11:09:15.259833+00:00
instance: kb-cron
parent: cryobiology-20260505-0
summary:
=== Historical background === Cryobiology history can be traced back to antiquity. As early as in 2500 BC, low temperatures were used in Egypt in medicine. The use of cold was recommended by Hippocrates to stop bleeding and swelling. With the emergence of modern science, Robert Boyle studied the effects of low temperatures on animals. In 1949, bull semen was cryopreserved for the first time by a team of scientists led by Christopher Polge. This led to a much wider use of cryopreservation today, with many organs, tissues and cells routinely stored at low temperatures. Large organs such as hearts are usually stored and transported, for short times only, at cool but not freezing temperatures for transplantation. Cell suspensions (like blood and semen) and thin tissue sections can sometimes be stored almost indefinitely in liquid nitrogen temperature (cryopreservation). Human sperm, eggs, and embryos are routinely stored in fertility research and treatments. Controlled-rate and slow freezing are well established techniques pioneered in the early 1970s which enabled the first human embryo frozen birth (Zoe Leyland) in 1984. Since then, machines that freeze biological samples using programmable steps, or controlled rates, have been used all over the world for human, animal, and


id: cryobiology-20260505-2
file: data/en.wikipedia.org/wiki/Cryobiology-2.md
category: reference
title: Cryobiology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryobiology
date_saved: 2026-05-05T11:09:15.259833+00:00
instance: kb-cron
parent: cryobiology-20260505-0
summary:
== Scientific societies == The Society for Cryobiology was founded in 1964 to bring together those from the biological, medical, and physical sciences who have a common interest in the effects of low temperatures on biological systems. As of 2007, the Society for Cryobiology had about 280 members from around the world, and one-half of them are US-based. The purpose of the Society is to promote scientific research in low temperature biology, to improve scientific understanding in this field, and to disseminate and apply this knowledge to the benefit of mankind. The Society requires of all its members the highest ethical and scientific standards in the performance of their professional activities. According to the Society's bylaws, membership may be refused to applicants whose conduct is deemed detrimental to the Society; in 1982, the bylaws were amended explicitly to exclude "any practice or application of freezing deceased persons in the anticipation of their reanimation", over the objections of some members who were cryonicists, such as Jerry Leaf. The Society organizes an annual scientific meeting dedicated to all aspects of low-temperature biology. This international meeting offers opportunities for presentation and discussion of the most up-to-date research in cryobiology, as well as reviewing


id: cryonics-freeze-me-20260505-0
file: data/en.wikipedia.org/wiki/Cryonics_–_Freeze_Me-0.md
category: reference
title: Cryonics – Freeze Me
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Cryonics_–_Freeze_Me
date_saved: 2026-05-05T11:09:16.445131+00:00
instance: kb-cron
parent: cryonics-freeze-me-20260505-0
summary:
Cryonics – Freeze Me (originally titled Death in the Deep Freeze) is a television documentary programme created by ZigZag Production for Five in 2006 for in their Stranger than Fiction series. The program's main topic is cryonics and mainly features interviews with Alcor Life Extension Foundation staff or Alcor members. The documentary is narrated by Michael Lumsden. Directed by Virginia Quinn [1]. Interviews with the following people are featured (in order of appearance): Tanya Jones, Chief Operating Officer, Alcor Michael Riskin, Ph.D., Alcor Board of Directors and Member Anita Riskin, Alcor Member Dr Arthur W. Rowe, Ph.D., Professor of Forensic Medicine, New York University Medical School Terry Katz, Alcor Member Aubrey de Grey, Ph.D., Biomedical Gerontologist Gregory Fahy, Ph.D. Vice President and Chief Scientific Officer, 21st Century Medicine Regina Pancake, Head of Alcor Stabilisation Team, South California Tilly Nydes Robin Nydes, Alcor Member Professor Ralph Merkle, Ph.D., Georgia Tech College of Computing Dr James R. Baker MD, Director Michigan Nanotechnology Institute == See also == Gerontology Cryobiology Life extension == External links == ZigZag Productions page about the program


id: hope-frozen-20260505-0
file: data/en.wikipedia.org/wiki/Hope_Frozen-0.md
category: reference
title: Hope Frozen
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Hope_Frozen
date_saved: 2026-05-05T11:09:17.688888+00:00
instance: kb-cron
parent: hope-frozen-20260505-0
summary:
Hope Frozen is a 2019 Thai documentary film directed and co-written by Pailin Wedel, together with Nina Ijäs, and released by 2050 Productions. It follows a Thai couple who, after their three-year-old daughter dies of brain cancer in 2015, decide to have her body cryogenically preserved. Hope Frozen premiered at the Hot Docs Canadian International Documentary Festival 2019, where it won the Best International Feature Documentary award, and was shown at several documentary film festivals. The documentary was picked up for distribution by Netflix under the title Hope Frozen: A Quest to Live Twice, and was released on the platform on September 15, 2020. It won the 49th International Emmy Award for Best Documentary in 2021, becoming the first Thai production to win an International Emmy. == Cast == Max More Matrix Naovaratpong Nareerat Naovaratpong Sahatorn Naovaratpong == References == == External links == Hope Frozen on Netflix Hope Frozen at IMDb


id: information-theoretic-death-20260505-0
file: data/en.wikipedia.org/wiki/Information-theoretic_death-0.md
category: reference
title: Information-theoretic death
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Information-theoretic_death
date_saved: 2026-05-05T11:09:18.875629+00:00
instance: kb-cron
parent: information-theoretic-death-20260505-0
summary:
Information-theoretic death is a term of art used in cryonics to define death in a way that is permanent and independent of any future medical advances, no matter how distant or improbable that may be. Because detailed reading or restoration of information-storing brain structures is beyond current technology, the term lacks practical importance in contemporary medicine. == References ==


id: raymond-and-monique-martinot-20260505-0
file: data/en.wikipedia.org/wiki/Raymond_and_Monique_Martinot-0.md
category: reference
title: Raymond and Monique Martinot
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Raymond_and_Monique_Martinot
date_saved: 2026-05-05T11:09:20.087065+00:00
instance: kb-cron
parent: raymond-and-monique-martinot-20260505-0
summary:
Raymond and Monique (née Leroy) Martinot were a French couple whose quest for cryonic preservation came to an end after a freezer malfunction in 2006. After Madame Martinot died from ovarian cancer in 1984, her widower, a doctor who once taught medicine in Paris, preserved her body in the cellar of their home, sparking a legal battle due to French legal restrictions on the disposal of corpses. Dr. Martinot also spent decades preparing for his own death. He held to the idea that if he were frozen and preserved, eventually he could be brought back to life by 2050 with the help of expanded scientific knowledge. In the 1970s, he bought a château near Saumur in the Loire Valley and began preparing a steel freezer unit in the chateau's freezer for himself. The legal battle extended to encompass Raymond's corpse after he died following a stroke in 2002, with a court ruling that the bodies must be buried. Their bodies were cremated by their son Remy after a malfunction saw their body temperatures rise to -20 °C from -65 °C for a period of several days. == References ==


id: robert-prehoda-20260505-0
file: data/en.wikipedia.org/wiki/Robert_Prehoda-0.md
category: reference
title: Robert Prehoda
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Robert_Prehoda
date_saved: 2026-05-05T11:09:21.238414+00:00
instance: kb-cron
parent: robert-prehoda-20260505-0
summary:
Robert Wayne Prehoda (July 7, 1931 – June 11, 2009) was an American chemist and futurist. He participated in the first cryonic suspension of a human being, that of James Bedford. He had a wife, Aline. == Works == What are the effects of current automation trends in the oil industry on management, unions and the employees?, University of Tulsa, 1957 Technological forecasting methodology, 1966 Designing the future: the role of technological forecasting, Chilton Book Co., 1967 Extended youth: the promise of gerontology, Putnam, 1968 Suspended animation: the research possibility that may allow man to conquer the limiting chains of time, Chilton Book Co., 1969 Your Next Fifty Years, Penguin Group (USA) Incorporated, 1980 (ISBN 9780441952212) == References == == External links == Interview with Prehoda Archived 2010-11-29 at the Wayback Machine, Cryonics Reports, Vol. 4, No. 1, January 1969 "Alcohol as Fuel" (letter to the editor), Science News, Vol. 100, No. 6 (Aug. 7, 1971), p. 88


id: suspended-animation-20260505-0
file: data/en.wikipedia.org/wiki/Suspended_animation-0.md
category: reference
title: Suspended animation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Suspended_animation
date_saved: 2026-05-05T11:09:22.387562+00:00
instance: kb-cron
parent: suspended-animation-20260505-0
summary:
Suspended animation is the slowing or stopping of biological function so that physiological capabilities are preserved. States of suspended animation are common in micro-organisms and some plant tissue, such as seeds. Many animals, including large ones, may undergo hibernation, and most plants have periods of dormancy. This article focuses primarily on the potential of large animals, especially humans, to undergo suspended animation. In animals, suspended animation may be either hypometabolic or ametabolic in nature. It may be induced by either endogenous, natural or artificial biological, chemical or physical means. In its natural form, it may be spontaneously reversible as in the case of species demonstrating hypometabolic states of hibernation. When applied with therapeutic intent, as in deep hypothermic circulatory arrest (DHCA), usually technologically mediated revival is required. == Basic principles == Suspended animation is understood as the pausing of life processes by external or internal means without terminating life itself. Breathing, heartbeat and other involuntary functions may still occur, but they can only be detected by artificial means. For this reason, this procedure has been associated with a lethargic state in nature when animals or plants appear, over a period, to be dead but then can wake up or prevail


id: suspended-animation-20260505-1
file: data/en.wikipedia.org/wiki/Suspended_animation-1.md
category: reference
title: Suspended animation
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Suspended_animation
date_saved: 2026-05-05T11:09:22.387562+00:00
instance: kb-cron
parent: suspended-animation-20260505-0
summary:
==== Emergency Preservation and Resuscitation ==== Emergency Preservation and Resuscitation (EPR) is a way to slow the bodily processes that would lead to death in cases of severe injury. This involves lowering the body's temperature below 34 °C (93 °F), which is the current standard for therapeutic hypothermia. ==== Hypothermic experiments on animals ==== In June 2005, scientists at the University of Pittsburgh's Safar Center for Resuscitation Research announced they had managed to place dogs in suspended animation and bring them back to life, most of them without brain damage, by draining the blood out of the dogs' bodies and injecting a low temperature solution into their circulatory systems, which in turn keeps the bodies alive in stasis. After three hours of being clinically dead, the dogs' blood was returned to their circulatory systems, and the animals were revived by delivering an electric shock to their hearts. The heart started pumping the blood around the body, and the dogs were brought back to life. On 20 January 2006, doctors from the Massachusetts General Hospital in Boston announced they had placed pigs in suspended animation with a similar technique. The pigs were anaesthetized and major blood loss was induced, along with


id: extraterrestrial-life-20260505-0
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-0.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
Extraterrestrial life, or alien life (colloquially aliens), is life that originates from another world rather than on Earth. No extraterrestrial life has yet been scientifically or conclusively detected. Such life might range from simple forms such as prokaryotes to intelligent beings, possibly bringing forth civilizations that might be far more, or far less, advanced than humans. The Drake equation speculates about the existence of sapient life elsewhere in the universe. The science of extraterrestrial life is known as astrobiology. Speculation about inhabited worlds beyond Earth dates back to antiquity. Early Christian writers, including Augustine, discussed ideas from thinkers like Democritus and Epicurus about countless worlds in the vast universe. Pre-modern writers typically assumed extraterrestrial "worlds" were inhabited by living beings. William Vorilong, in the 15th century, acknowledged the possibility Jesus could have visited extraterrestrial worlds to redeem their inhabitants. In 1440, Nicholas of Cusa suggested Earth is a "brilliant star"; he theorized that all celestial bodies, even the Sun, could host life. Descartes wrote that there were no means to prove the stars were not inhabited by "intelligent creatures", but their existence was a matter of speculation. In comparison to the life-abundant Earth, the vast majority of intrasolar and extrasolar


id: extraterrestrial-life-20260505-1
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-1.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
Using Big Bang models for the timeline of the universe, it was too hot for life for the first 15 million years and the elements of organic life, created through stellar fusion, did not exist until at least 50 million years. The first organic compounds may have formed in the protoplanetary disk of dust grains that would eventually create rocky planets like Earth. Although Earth was in a molten state after its birth and may have burned any organics that fell on it, it would have been more receptive once it cooled down. Once the right conditions on Earth were met, life started by a chemical process known as abiogenesis. During most of its stellar evolution, stars combine hydrogen nuclei to make helium nuclei by stellar fusion, and the comparatively lighter weight of helium allows the star to release the extra energy. The process continues until the star uses all of its available fuel, with the speed of consumption being related to the size of the star. During its last stages, stars start combining helium nuclei to form carbon nuclei. The larger stars can further combine carbon nuclei to create oxygen and silicon, oxygen into neon and sulfur, and so


id: extraterrestrial-life-20260505-2
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-2.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
Life in the cosmos beyond Earth has never been observed, but it is expected. The hypothesis of ubiquitous extraterrestrial life relies on three main ideas. The first one, the size of the universe, allows for plenty of planets to have a similar habitability to Earth, and the age of the universe gives enough time for a long process analog to the history of Earth to happen there. The second is that the substances that make life, such as carbon and water, are ubiquitous in the universe. The third is that the physical laws are universal, which means that the forces that would facilitate or prevent the existence of life would be the same ones as on Earth. According to this argument, made by scientists such as Carl Sagan and Stephen Hawking, it would be improbable for life not to exist somewhere else other than Earth. This argument is embodied in the Copernican principle, which states that Earth does not occupy a unique position in the Universe, and the mediocrity principle, which states that there is nothing special about life on Earth. Other authors consider instead that life in the cosmos, or at least multicellular life, may actually be rare. The


id: extraterrestrial-life-20260505-3
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-3.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
If extraterrestrial life exists, it could range from simple microorganisms and multicellular organisms similar to animals or plants, to complex alien intelligences akin to humans. When scientists talk about extraterrestrial life, they consider all those types. Although it is possible that extraterrestrial life may have other configurations, scientists use the hierarchy of lifeforms from Earth for simplicity, as it is the only one known to exist. The first basic requirement for life is an environment with non-equilibrium thermodynamics, which means that the thermodynamic equilibrium must be broken by a source of energy. The traditional sources of energy in the cosmos are the stars, such as for life on Earth, which depends on the energy of the sun. However, there are other alternative energy sources, such as volcanoes, plate tectonics, and hydrothermal vents. There are ecosystems on Earth in deep areas of the ocean that do not receive sunlight, and take energy from black smokers instead. Magnetic fields and radioactivity have also been proposed as sources of energy, although they would be less efficient ones. Life on Earth requires water in a liquid state as a solvent in which biochemical reactions take place. It is highly unlikely that an abiogenesis process


id: extraterrestrial-life-20260505-4
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-4.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
=== Harsh environmental conditions on Earth harboring life === It is common knowledge that the conditions on other planets in the solar system, in addition to the many galaxies outside of the Milky Way galaxy, are very harsh and seem to be too extreme to harbor any life. The environmental conditions on these planets can have intense UV radiation paired with extreme temperatures, lack of water, and much more that can lead to conditions that don't seem to favor the creation or maintenance of extraterrestrial life. However, there has been much historical evidence that some of the earliest and most basic forms of life on Earth originated in some extreme environments that seem unlikely to have harbored life at least at one point in Earth's history. Fossil evidence as well as many historical theories backed up by years of research and studies have marked environments like hydrothermal vents or acidic hot springs as some of the first places that life could have originated on Earth. These environments can be considered extreme when compared to the typical ecosystems that the majority of life on Earth now inhabit, as hydrothermal vents are scorching hot due to the magma escaping from the Earth's


id: extraterrestrial-life-20260505-5
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-5.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
The Solar System has a wide variety of planets, dwarf planets, and moons, and each one is studied for its potential to host life. Each one has its own specific conditions that may benefit or harm life. So far, the only lifeforms found are those from Earth. No extraterrestrial intelligence other than humans exists or has ever existed within the Solar System. Astrobiologist Mary Voytek points out that it would be unlikely to find large ecosystems, as they would have already been detected by now. The inner Solar System is likely devoid of life. However, Venus is still of interest to astrobiologists, as it is a terrestrial planet that was likely similar to Earth in its early stages and developed in a different way. There is a greenhouse effect, the surface is the hottest in the Solar System, sulfuric acid clouds, all surface liquid water is lost, and it has a thick carbon-dioxide atmosphere with huge pressure. Comparing both helps to understand the precise differences that lead to beneficial or harmful conditions for life. And despite the conditions against life on Venus, there are suspicions that microbial life-forms may still survive in high-altitude clouds. Mars is a cold and almost


id: extraterrestrial-life-20260505-6
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-6.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
Scientists search for biosignatures within the Solar System by studying planetary surfaces and examining meteorites. Some claim to have identified evidence that microbial life has existed on Mars. In 1996, a controversial report stated that structures resembling nanobacteria were discovered in a meteorite, ALH84001, formed of rock ejected from Mars. Although all the unusual properties of the meteorite were eventually explained as the result of inorganic processes, the controversy over its discovery laid the groundwork for the development of astrobiology. An experiment on the two Viking Mars landers reported gas emissions from heated Martian soil samples that some scientists argue are consistent with the presence of living microorganisms. Lack of corroborating evidence from other experiments on the same samples suggests that a non-biological reaction is a more likely hypothesis. In February 2005 NASA scientists reported they may have found some evidence of extraterrestrial life on Mars. The two scientists, Carol Stoker and Larry Lemke of NASA's Ames Research Center, based their claim on methane signatures found in Mars's atmosphere resembling the methane production of some forms of primitive life on Earth, as well as on their own study of primitive life near the Rio Tinto river in Spain. NASA officials


id: extraterrestrial-life-20260505-7
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-7.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
Although most searches are focused on the biology of extraterrestrial life, an extraterrestrial intelligence capable enough to develop a civilization may be detectable by other means as well. Technology may generate technosignatures, effects on the native planet that may not be caused by natural causes. There are three main types of techno-signatures considered: interstellar communications, effects on the atmosphere, and planetary-sized structures such as Dyson spheres. Organizations such as the SETI Institute search the cosmos for potential forms of communication. They started with radio waves, and now search for laser pulses as well. The challenge for this search is that there are natural sources of such signals as well, such as gamma-ray bursts and supernovae, and the difference between a natural signal and an artificial one would be in its specific patterns. Astronomers intend to use artificial intelligence for this, as it can manage large amounts of data and is devoid of biases and preconceptions. Besides, even if there is an advanced extraterrestrial civilization, there is no guarantee that it is transmitting radio communications in the direction of Earth. The length of time required for a signal to travel across space means that a potential answer may arrive decades or


id: extraterrestrial-life-20260505-8
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-8.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
The modern concept of extraterrestrial life is based on assumptions that were not commonplace during the early days of astronomy. The first explanations for the celestial objects seen in the night sky were based on mythology. Scholars from Ancient Greece were the first to consider that the universe is inherently understandable and rejected explanations based on supernatural incomprehensible forces, such as the myth of the Sun being pulled across the sky in the chariot of Apollo. They had not developed the scientific method yet and based their ideas on pure thought and speculation, but they developed precursor ideas to it, such as that explanations had to be discarded if they contradict observable facts. The discussions of those Greek scholars established many of the pillars that would eventually lead to the idea of extraterrestrial life, such as Earth being round and not flat. The cosmos was first structured in a geocentric model that considered that the sun and all other celestial bodies revolve around Earth. However, they did not consider them as worlds. In Greek understanding, the world was composed by both Earth and the celestial objects with noticeable movements. Anaximander thought that the cosmos was made from apeiron, a substance


id: extraterrestrial-life-20260505-9
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-9.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
By the time of the late Middle Ages there were many known inaccuracies in the geocentric model, but it was kept in use because naked eye observations provided limited data. Nicolaus Copernicus started the Copernican Revolution by proposing that the planets revolve around the sun rather than Earth. His proposal had little acceptance at first because, as he kept the assumption that orbits were perfect circles, his model led to as many inaccuracies as the geocentric one. Tycho Brahe improved the available data with naked-eye observatories, which worked with highly complex sextants and quadrants. Tycho could not make sense of his observations, but Johannes Kepler did: orbits were not perfect circles, but ellipses. This knowledge benefited the Copernican model, which worked now almost perfectly. The invention of the telescope a short time later, perfected by Galileo Galilei, clarified the final doubts, and the paradigm shift was completed. Under this new understanding, the notion of extraterrestrial life became feasible: if Earth is but just a planet orbiting around a star, there may be planets similar to Earth elsewhere. The astronomical study of distant bodies also proved that physical laws are the same elsewhere in the universe as on Earth, with nothing


id: extraterrestrial-life-20260505-10
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-10.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
The search and study of extraterrestrial life became a science of its own, astrobiology. Also known as exobiology, this discipline is studied by the NASA, the ESA, the INAF, and others. Astrobiology studies life from Earth as well, but with a cosmic perspective. For example, abiogenesis is of interest to astrobiology, not because of the origin of life on Earth, but for the chances of a similar process taking place in other celestial bodies. Many aspects of life, from its definition to its chemistry, are analyzed as either likely to be similar in all forms of life across the cosmos or only native to Earth. Astrobiology, however, remains constrained by the current lack of extraterrestrial life-forms to study, as all life on Earth comes from the same ancestor, and it is hard to infer general characteristics from a group with a single example to analyse. The 20th century came with great technological advances, speculations about future hypothetical technologies, and an increased basic knowledge of science by the general population thanks to science divulgation through the mass media. The public interest in extraterrestrial life and the lack of discoveries by mainstream science led to the emergence of pseudosciences that provided affirmative,


id: extraterrestrial-life-20260505-11
file: data/en.wikipedia.org/wiki/Extraterrestrial_life-11.md
category: reference
title: Extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_life
date_saved: 2026-05-05T11:09:24.121788+00:00
instance: kb-cron
parent: extraterrestrial-life-20260505-0
summary:
The 1967 Outer Space Treaty and the 1979 Moon Agreement define rules of planetary protection against potentially hazardous extraterrestrial life. COSPAR also provides guidelines for planetary protection. A committee of the United Nations Office for Outer Space Affairs had in 1977 discussed for a year strategies for interacting with extraterrestrial life or intelligence. The discussion ended without any conclusions. As of 2010, the UN lacks response mechanisms for the case of an extraterrestrial contact. One of the NASA divisions is the Office of Safety and Mission Assurance (OSMA), also known as the Planetary Protection Office. A part of its mission is to "rigorously preclude backward contamination of Earth by extraterrestrial life." In 2016, the Chinese Government released a white paper detailing its space program. According to the document, one of the research objectives of the program is the search for extraterrestrial life. It is also one of the objectives of the Chinese Five-hundred-meter Aperture Spherical Telescope (FAST) program. In 2020, Dmitry Rogozin, the head of the Russian space agency, said the search for extraterrestrial life is one of the main goals of deep space research. He also acknowledged the possibility of existence of primitive life on other planets of the


id: outline-of-extraterrestrial-life-20260505-0
file: data/en.wikipedia.org/wiki/Outline_of_extraterrestrial_life-0.md
category: reference
title: Outline of extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Outline_of_extraterrestrial_life
date_saved: 2026-05-05T11:09:25.329611+00:00
instance: kb-cron
parent: outline-of-extraterrestrial-life-20260505-0
summary:
The following outline is provided as an overview of and topical guide to extraterrestrial life: Extraterrestrial life – is any type of lifeform, from prokaryotes to intelligent beings, that is neither native of Earth or transplanted from it. So far, no extraterrestrial life has ever been found. == Search == Astrobiology Mars Viking lander biological experiments Meteorites Allan Hills 77005 Allan Hills 84001 Murchison meteorite Nakhla meteorite Shergotty meteorite Yamato 000593 Biosignatures Red edge Search for extraterrestrial intelligence Active SETI Allen Telescope Array Pioneer plaque Project Phoenix (SETI) SERENDIP Technosignature Xenoarchaeology Communication with extraterrestrial intelligence Arecibo message Astrolinguistics Wow! signal == Likely requirements == Circumstellar habitable zone Extraterrestrial liquid water Planetary habitability == Potential locations == Colonization of Europa Habitability of K-type main-sequence star systems Habitability of natural satellites Habitability of red dwarf systems Habitable exoplanet Earth analog Superhabitable planet Life on Mars Life on Titan Life on Venus Life origination beyond planets Catalogs Catalog of Nearby Habitable Systems == Possible traits == Extraterrestrial intelligence Alien language Hypothetical types of biochemistry Carbon-based life CHON Extremophile == Ideas == Anthropocentrism Carbon chauvinism Copernican principle Cosmic pluralism Drake equation Extraterrestrials in Meitei culture Fermi paradox Aestivation hypothesis Great Filter Rare Earth hypothesis


id: aestivation-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Aestivation_hypothesis-0.md
category: reference
title: Aestivation hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Aestivation_hypothesis
date_saved: 2026-05-05T11:09:26.552201+00:00
instance: kb-cron
parent: aestivation-hypothesis-20260505-0
summary:
The aestivation hypothesis is a hypothesized solution to the Fermi paradox conceived in 2017 by Anders Sandberg, Stuart Armstrong and Milan M. Ćirković. The hypothesis, published on 27 April 2017, suggests advanced alien civilizations may be storing energy and aestivating (hibernating in times of heat instead of cold), until the universe cools to better make use of the stored energy to perform tasks. As the universe cools, the potential work producible by stored energy can increase by a multiplier of 1030 per Landauer's principle. If the goal of an advanced civilization is to maximize the number of calculations done, to generate information processing for tasks like mass-producing simulations, then aestivation would be purposeful to achieve this end. == Fermi paradox == There is no reliable or reproducible evidence that aliens have visited Earth. No transmissions or evidence of intelligent extraterrestrial life have been detected or observed anywhere other than Earth in the Universe. This runs counter to the knowledge that the Universe is filled with a very large number of planets, some of which likely hold the conditions hospitable for life. Life typically expands until it fills all available niches. These contradictory facts form the basis for the Fermi paradox,


id: assembly-theory-20260505-0
file: data/en.wikipedia.org/wiki/Assembly_theory-0.md
category: reference
title: Assembly theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Assembly_theory
date_saved: 2026-05-05T11:09:27.671855+00:00
instance: kb-cron
parent: assembly-theory-20260505-0
summary:
Assembly theory is a framework developed to quantify the complexity of molecules and objects by assessing the minimal number of steps required to assemble them from fundamental building blocks. Proposed by chemist Lee Cronin and his team, the theory assigns an assembly index to molecules, which serves as a measurable indicator of their structural complexity. Cronin and colleagues argue that this approach allows for experimental verification and has applications in understanding selection processes, evolution, and the identification of biosignatures in astrobiology. However, the usefulness of the approach has been disputed. == Background == The hypothesis was proposed by chemist Leroy Cronin in 2017 and developed by the team he leads at the University of Glasgow, then extended in collaboration with a team at Arizona State University led by astrobiologist Sara Imari Walker, in a paper released in 2021. Assembly theory conceptualizes objects not as point particles, but as entities defined by their possible formation histories. This allows objects to show evidence of selection, within well-defined boundaries of individuals or selected units. Combinatorial objects are important in chemistry, biology and technology, in which most objects of interest (if not all) are hierarchical modular structures. For any object an 'assembly space' can


id: assembly-theory-20260505-1
file: data/en.wikipedia.org/wiki/Assembly_theory-1.md
category: reference
title: Assembly theory
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Assembly_theory
date_saved: 2026-05-05T11:09:27.671855+00:00
instance: kb-cron
parent: assembly-theory-20260505-0
summary:
== Critical views == Chemist Steven A. Benner has publicly criticized various aspects of assembly theory. Benner argues that it is transparently false that non-living systems, and with no life intervention, cannot contain molecules that are complex but people would be misled in thinking that because it was published in Nature journals after peer review, these papers must be right. A paper published in the Journal of Molecular Evolution concludes that "the hype around Assembly Theory reflects rather unfavorably both on the authors and the scientific publication system in general". The author concludes that what "assembly theory really does is to detect and quantify bias caused by higher-level constraints in some well-defined rule-based worlds"; one "can use assembly theory to check whether something unexpected is going on in a very broad range of computational model worlds or universes". Another paper authored by a group of chemists and planetary scientists published in the Journal of the Royal Society Interface demonstrated that abiotic chemical processes have the potential to form crystal structures of great complexity – values exceeding the proposed abiotic/biotic divide of MA index = 15. They conclude that "while the proposal of a biosignature based on a molecular assembly index


id: astrolinguistics-20260505-0
file: data/en.wikipedia.org/wiki/Astrolinguistics-0.md
category: reference
title: Astrolinguistics
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Astrolinguistics
date_saved: 2026-05-05T11:09:28.904392+00:00
instance: kb-cron
parent: astrolinguistics-20260505-0
summary:
Astrolinguistics is a field of linguistics connected with the search for extraterrestrial intelligence (SETI). == Early Soviet experiments == Arguably the first attempt to construct a language for interplanetary communication was the AO language created by the anarchist philosopher Wolf Gordin (brother of Abba Gordin) in his books Grammar of the Language of the Mankind AO (1920) and Grammar of the Language AO (1924), was presented as a language for interplanetary communication at the First International Exhibition of Interplanetary Machines and Mechanisms (dedicated to the 10th anniversary of the Russian Revolution and the 70th anniversary of the birth of Tsiolkovsky) in Moscow, 1927. The declared goal of Gordin was to construct a language which would be non-"fetishizing", non-"sociomorphic", non-gender based and non-classist. The design of the language was inspired by Russian Futurist poetry, the Gordin brothers' pan-anarchist philosophy, and Tsiolkovsky's early remarks on possible cosmic messaging (which were in accord with Hans Freudenthal's later insights). However, Sergei N. Kuznetsov notes that "Gordin nowhere defines his language as intended for space use," and that "in none of his works does he deal with problems of space communication, only mentioning 'Interplanetary Communication' in passing among other technical areas." == Freudenthal's LINCOS ==


id: byurakan-conference-20260505-0
file: data/en.wikipedia.org/wiki/Byurakan_Conference-0.md
category: reference
title: Byurakan Conference
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Byurakan_Conference
date_saved: 2026-05-05T11:09:30.074559+00:00
instance: kb-cron
parent: byurakan-conference-20260505-0
summary:
The Byurakan Conference was held at the Byurakan Astrophysical Observatory in Armenia in 1964, at the initiative of the young scientist Nikolai Kardashev. It brought together a large number of Soviet astronomers and astrophysicists to take stock of knowledge and results in the search for traces of extraterrestrial life. The possibility of detecting extraterrestrial civilizations with the instruments available at the time was also discussed, as well as the criteria for communication with extraterrestrial intelligence. == Goals of the conference == Since 1962, Nikolai Kardashev has been a member of a SETI research group at the Sternberg Astronomical Institute in Moscow. In 1964, he organized the first Soviet conference on the possibility of extraterrestrial civilizations, held at the Byurakan Astrophysical Observatory in Armenia. This national conference was a response to the 1961 Green Bank Conference, held at the Green Bank Observatory in the USA. Bringing together radio astronomers, its goal was to "arrive at rational technical and linguistic solutions to the problem of communication with an extraterrestrial civilization that is more advanced than Earth's civilization". == Presentations and speakers == Nikolai Kardashev presented his classification, while Troitskii announced that it was possible to detect signals from other galaxies. Kardashev's work


id: communication-with-extraterrestrial-intelligence-20260505-0
file: data/en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence-0.md
category: reference
title: Communication with extraterrestrial intelligence
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence
date_saved: 2026-05-05T11:09:31.304973+00:00
instance: kb-cron
parent: communication-with-extraterrestrial-intelligence-20260505-0
summary:
The communication with extraterrestrial intelligence (CETI) is a branch of the search for extraterrestrial intelligence (SETI) that focuses on composing and deciphering interstellar messages that theoretically could be understood by another technological civilization. The best-known CETI experiment of its kind was the 1974 Arecibo message composed by Frank Drake. There are multiple independent organizations and individuals engaged in CETI research; the generic application of abbreviations CETI and SETI (search for extraterrestrial intelligence) in this article should not be taken as referring to any particular organization (such as the SETI Institute). CETI research has focused on four broad areas: mathematical languages, pictorial systems such as the Arecibo message, algorithmic communication systems (ACETI), and computational approaches to detecting and deciphering "natural" language communication. There remain many undeciphered writing systems in human communication, such as Linear A, discovered by archeologists. Much of the research effort is directed at how to overcome similar problems of decipherment that arise in many scenarios of interplanetary communication. On 13 February 2015, scientists (including Douglas Vakoch, David Grinspoon, Seth Shostak, and David Brin) at an annual meeting of the American Association for the Advancement of Science, discussed active SETI and whether transmitting a message to possible intelligent extraterrestrials


id: communication-with-extraterrestrial-intelligence-20260505-1
file: data/en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence-1.md
category: reference
title: Communication with extraterrestrial intelligence
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence
date_saved: 2026-05-05T11:09:31.304973+00:00
instance: kb-cron
parent: communication-with-extraterrestrial-intelligence-20260505-0
summary:
=== A language based on the fundamental facts of science === Published in 1992 by Carl Devito and Richard Oehrle, A language based on the fundamental facts of science is a paper describing a language similar in syntax to Astraglossa and Lincos, but which builds its vocabulary around known physical properties. === Busch general-purpose binary language used in Lone Signal transmissions === In 2010, Michael W. Busch created a general-purpose binary language later used in the Lone Signal project to transmit crowdsourced messages to extraterrestrial intelligence (METI). This was followed by an attempt to extend the syntax used in the Lone Signal hailing message to communicate in a way that, while neither mathematical nor strictly logical, was nonetheless understandable given the prior definition of terms and concepts in the Lone Signal hailing message. == Pictorial messages == Pictorial communication systems seek to describe fundamental mathematical or physical concepts via simplified diagrams sent as bitmaps. These messages necessarily assume that the recipient has similar visual capabilities and can understand basic mathematics and geometry. A common critique of pictorial systems is that they presume a shared understanding of special shapes, which may not be the case with a species with substantially different


id: communication-with-extraterrestrial-intelligence-20260505-2
file: data/en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence-2.md
category: reference
title: Communication with extraterrestrial intelligence
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Communication_with_extraterrestrial_intelligence
date_saved: 2026-05-05T11:09:31.304973+00:00
instance: kb-cron
parent: communication-with-extraterrestrial-intelligence-20260505-0
summary:
== Algorithmic messages == Algorithmic communication systems are a relatively new field within CETI. In these systems, which build upon early work on mathematical languages, the sender describes a small set of mathematic and logic symbols that form the basis for a rudimentary programming language that the recipient can run on a virtual machine. Algorithmic communication has a number of advantages over static pictorial and mathematical messages, including: localized communication (the recipient can probe and interact with the programs within a message, without transmitting a reply to the sender and then waiting years for a response), forward error correction (the message might contain algorithms that process data elsewhere in the message), and the ability to embed proxy agents within the message. In principle, a sophisticated program when run on a fast enough computing substrate, may exhibit complex behavior and perhaps, intelligence. === CosmicOS === CosmicOS, designed by Paul Fitzpatrick at MIT, describes a virtual machine that is derived from lambda calculus. === Logic Gate Matrices === Logic Gate Matrices (a.k.a. LGM), developed by Brian McConnell, describes a universal virtual machine that is constructed by connecting coordinates in an n-dimensional space via mathematics and logic operations, for example: (1,0,0) <-- (OR


id: the-critical-eye-20260505-0
file: data/en.wikipedia.org/wiki/The_Critical_Eye-0.md
category: reference
title: The Critical Eye
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/The_Critical_Eye
date_saved: 2026-05-05T11:09:32.551171+00:00
instance: kb-cron
parent: the-critical-eye-20260505-0
summary:
The Critical Eye is a Discovery Science Channel documentary series examining pseudoscientific and paranormal phenomena. The eight-part documentary series aired from October 2002 through February 2003 and was hosted by actor and scientific skeptic William B. Davis. == Series description == The Critical Eye, alternately labeled as just Critical Eye, was produced by the Discovery Science Channel, and was produced in association with Skeptical Inquirer Magazine. The show was described by cosmolearning.org as "William B. Davis hosts this programme bringing to the viewers the science behind the paranormal and the unexplained." == Historical event references == The series discusses several notable events: The 1990 civil trial brought against Judas Priest alleging subliminal messaging in their music The Stargate Project The Phoenix Lights The Roswell UFO incident Project Blue Book The Heaven's Gate mass suicide == Episodes == Each episode of the series consists of four or five segments focused specifically on one pseudoscientific or paranormal phenomenon. Each segment begins by explaining the phenomenon in question, discusses it with both scientists/skeptics and proponents/believers, and concludes with street interviews regarding the legitimacy of the phenomenon in question. == References ==


id: demonic-ufo-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Demonic_UFO_hypothesis-0.md
category: reference
title: Demonic UFO hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Demonic_UFO_hypothesis
date_saved: 2026-05-05T11:09:33.877103+00:00
instance: kb-cron
parent: demonic-ufo-hypothesis-20260505-0
summary:
The demonic UFO hypothesis is the proposal that unidentified flying object (UFO) sightings are the result of a satanic influence, or are themselves demons. Psychologist Tim Lomas and theologian Brendan Case from the Harvard Human Flourishing Program argue that interpretations of anomalous aerial phenomena are shaped by the cultural and religious frameworks available to witnesses, with earlier “angelic” readings giving way in modern times to “alien” ones, and that such labels function as interpretive categories for making anomalous experiences intelligible rather than as definitive claims about the phenomenon’s nature. == Chronology == Occultist Marjorie Cameron connected the 1952 Washington, D.C. UFO incident to the recent death of her partner Jack Parsons, a rocketry expert and disciple of Aleister Crowley. In 1954, faith healer and evangelist Walter Vinson "W.V." Grant Sr published the booklet "Men in Flying Saucers Identified: Not a Mystery!" suggesting UFOs were demonic. In the end of the 1960s, British UFO author Gordon Creighton endorsed the theory. In the wake of the 1973 Pascagoula incident, Rev. Bill Riddick preached a sermon suggesting UFOs were demonic. In 1974, Clifford Wilson authored UFOs and their Mission Impossible which popularized the demonic hypothesis. In the 1975 book UFOs: What on Earth


id: exotheology-20260505-0
file: data/en.wikipedia.org/wiki/Exotheology-0.md
category: reference
title: Exotheology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Exotheology
date_saved: 2026-05-05T11:09:35.037511+00:00
instance: kb-cron
parent: exotheology-20260505-0
summary:
The term "exotheology" was coined in the 1960s or early 1970s for the examination of theological issues as they pertain to extraterrestrial intelligence. It is primarily concerned with either conjecture about possible theological beliefs that extraterrestrials might have, or how our own theologies would be influenced by evidence of and/or interaction with extraterrestrials. One of the main themes of exotheology is applying the concept of extraterrestrials who are sentient, and more to the point, endowed with a soul, as a thought experiment to the examination of a given theology, mostly Christian theology, occasionally also Jewish theology. == General == Exotheologian Joel L. Parkyn, in his book Exotheology: Theological Explorations of Intelligent Extraterrestrial Life (2021), examined the conjunction of human religion and a putative intelligent extraterrestrial civilizational contact or disclosure scenario as advanced by proponents of ufology. A summary of some of his fundamental theses regarding contact/disclosure is as follows: Consequences for human religions depend heavily on the mode, means, and proximity of extraterrestrial contact; whether via radio interferometer, alien artifacts discovered on nearby planets or their satellites in our solar system, extraterrestrial probes encountered on Earth or in space, direct contact in space or in Earth orbit, or contact on


id: exotheology-20260505-1
file: data/en.wikipedia.org/wiki/Exotheology-1.md
category: reference
title: Exotheology
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Exotheology
date_saved: 2026-05-05T11:09:35.037511+00:00
instance: kb-cron
parent: exotheology-20260505-0
summary:
In 1951, Los Angeles-based Science Fiction writer Ray Bradbury wrote a short story entitled "The Fire Balloons" as part of short story collection from the Illustrated Man, and ultimately believed that space travel and the discovery of new species and genera of life would - as earthly exploration once did - ultimately serve and expand God's kingdom. He felt that space travel with the same terrestrial laws and moral principles would also apply in outer space. As two clergymen are arguing about extraterrestrial life and outer space, one priest asks:Learn what? That most of the things we’ve taught in the past on earth don’t fit out there in Mars or Venus… [To] Drive Adam and Eve out of some new Garden, on Jupiter, with our very own rocket fires? Or worse, find out there is no Eden, no Adam, no Eve, no damned serpent, no Fall, no original sin, no Annunciation, no Birth, no Son, you go on with the list, no nothing at all? Is that what we must learn, pastor? If need be, yes, said Pastor Sheldon. It’s the Lord’s space and the Lord’s world in space, Father. We must try not to take our cathedrals with us,


id: extra-terrestrial-exposure-law-20260505-0
file: data/en.wikipedia.org/wiki/Extra-Terrestrial_Exposure_Law-0.md
category: reference
title: Extra-Terrestrial Exposure Law
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extra-Terrestrial_Exposure_Law
date_saved: 2026-05-05T11:09:36.188442+00:00
instance: kb-cron
parent: extra-terrestrial-exposure-law-20260505-0
summary:
The Extra-Terrestrial Exposure Law (14 CFR 1211 of the Code of Federal Regulations) — in force from 1969 to 1977 — was the popular name for regulations adopted by the National Aeronautics and Space Administration (NASA) in 1969 to formalize its "policy, responsibility and authority to guard the Earth against any harmful contamination … resulting from personnel, spacecraft and other property returning to the Earth after landing on or coming within the atmospheric envelope of a celestial body". Implemented before the Apollo 11 mission, it provided the legal authority for a quarantine period for the returning astronauts. The regulation defined "extraterrestrially exposed" as ...the state or condition of any person, property, animal or other form of life or matter whatever, who or which has (1) Touched directly or come within the atmospheric envelope of any other celestial body; or (2) Touched directly or been in close proximity (or been exposed indirectly to) any person, property, animal or other form of life or matter who or which has been extraterrestrially exposed by virtue of subparagraph (1) of this paragraph. Quarantining of astronauts on the first lunar missions was mandated in 1969 to prepare for "the remote possibility that they are harboring


id: extraterrestrial-intelligence-20260505-0
file: data/en.wikipedia.org/wiki/Extraterrestrial_intelligence-0.md
category: reference
title: Extraterrestrial intelligence
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrial_intelligence
date_saved: 2026-05-05T11:09:37.452117+00:00
instance: kb-cron
parent: extraterrestrial-intelligence-20260505-0
summary:
Extraterrestrial intelligence (ETI) refers to hypothetical beings – extraterrestrial life or more artificial beings – having the intelligence to perform similar cognitive abilities as humans. No such life has ever been verifiably observed to exist. The question of whether other inhabited worlds might exist has been debated since ancient history. The modern form of the concept emerged when the Copernican Revolution demonstrated that the Earth was a planet revolving around the Sun, and other planets were, conversely, other worlds. The question of whether other inhabited planets or moons exist was a natural consequence of this new understanding. It has become one of the most speculative questions in science and is a central theme of both science fiction and popular culture. An alternative name for it is "Extraterrestrial Technological Instantiations" (ETI). The term was coined to avoid the use of terms such as "civilizations", "species", and "intelligence", as those may prove to be ambiguous and open to interpretation, or simply inapplicable in its local context. The search for extraterrestrial intelligence relies on technosignatures, the detectable effects of alien technological civilizations. == Intelligence == Intelligence is, along with the more precise concept of sapience, used to describe extraterrestrial life with similar cognitive


id: extraterrestrials-in-meitei-culture-20260505-0
file: data/en.wikipedia.org/wiki/Extraterrestrials_in_Meitei_culture-0.md
category: reference
title: Extraterrestrials in Meitei culture
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Extraterrestrials_in_Meitei_culture
date_saved: 2026-05-05T11:09:38.634742+00:00
instance: kb-cron
parent: extraterrestrials-in-meitei-culture-20260505-0
summary:
The Meitei language PuYas, ancient scriptures of the Meitei civilization, describe the origin of Earth and life in ways that suggest the influence of extraterrestrial beings, referred to as the Laiyam (ꯂꯥꯏꯌꯥꯝ). Classical texts such as the Wakoklon Heelel Thilel Salai Amailon Pukok Puya and the Khamnung Ingal Leisaba describe the Earth as once being entirely covered in water, with life introduced through intervention from beings from the sky or outer space. == Concept of extraterrestrial intervention == According to the puyas, Sitapa Mapu descended from the sky and played a central role in shaping life on Earth. The Lai race, believed to have originated from outer space, is said to have spread on Earth prior to the creation of human beings. This narrative aligns with the concept of directed panspermia, wherein life is seeded on Earth by advanced extraterrestrial beings. The puyas mention terms such as “Aatinga Koilou Sitapa” and “Talang Aatingpapu Eepung Loinapa Aapakpana talang malangna Im oina haina humna asumna leilingeita”, describing a cosmic being residing in infinite space-time, who orchestrated the emergence of terrestrial life. Life on Earth, including plants, animals, and humans, is depicted as being purposefully created to preserve and propagate the Lai race's


id: firstborn-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Firstborn_hypothesis-0.md
category: reference
title: Firstborn hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Firstborn_hypothesis
date_saved: 2026-05-05T11:09:39.796915+00:00
instance: kb-cron
parent: firstborn-hypothesis-20260505-0
summary:
The firstborn hypothesis is a proposed solution to the Fermi paradox which states that no extraterrestrial intelligent life has been discovered because humanity is the first form of intelligent life in the universe. Thus, since it posits that there is no intelligent life outside of the solar system, it can be considered to be under the aegis of the Hart-Tipler conjecture. == Background == There is no reliable or reproducible evidence that aliens have visited Earth. No transmissions or evidence of intelligent extraterrestrial life have been observed anywhere other than Earth in the universe. This runs counter to the knowledge that the universe is filled with a very large number of planets, some of which likely hold the conditions hospitable for life. Life typically expands until it fills all available niches. These contradictory facts form the basis for the Fermi paradox, of which the firstborn hypothesis is one proposed solution. Avi Loeb, an astrophysicist and cosmologist, has suggested that Earth may be a very early example of a life-bearing planet and that life-bearing planets may be more likely trillions of years from now. He has put forward the view that the Universe has only recently reached a state in which


id: great-filter-20260505-0
file: data/en.wikipedia.org/wiki/Great_Filter-0.md
category: reference
title: Great Filter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Great_Filter
date_saved: 2026-05-05T11:09:40.994799+00:00
instance: kb-cron
parent: great-filter-20260505-0
summary:
The Great Filter is the idea that, in the development of life from the earliest stages of abiogenesis to reaching the highest levels of development on the Kardashev scale, there is a barrier to development that makes detectable extraterrestrial life exceedingly rare. The Great Filter is one possible resolution of the Fermi paradox. The main conclusion of the Great Filter is that there is an inverse correlation between the probability that other life could evolve to the present stage in which humanity is, and the chances of humanity to survive in the future. The concept originates in Robin Hanson's argument that the failure to find any extraterrestrial civilizations in the observable universe implies that something is wrong with one or more of the arguments (from various scientific disciplines) that the appearance of advanced intelligent life is probable; this observation is conceptualized in terms of a "Great Filter" which acts to reduce the great number of sites where intelligent life might arise to the tiny number of intelligent species with advanced civilizations actually observed (currently just one: human). This probability threshold, which could lie in the past or following human extinction, might work as a barrier to the evolution of intelligent


id: great-filter-20260505-1
file: data/en.wikipedia.org/wiki/Great_Filter-1.md
category: reference
title: Great Filter
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Great_Filter
date_saved: 2026-05-05T11:09:40.994799+00:00
instance: kb-cron
parent: great-filter-20260505-0
summary:
The right star system (including organics and potentially habitable planets) Reproductive molecules (e.g. RNA) Simple (prokaryotic) single-cell life Complex (eukaryotic) single-cell life Sexual reproduction Multi-cell life Tool-using animals with intelligence A civilization advancing toward the potential for a colonization explosion Colonization explosion According to the Great Filter hypothesis, at least one of these steps—if the list were complete—must be improbable. If it is not an early step (i.e., in the past), then the implication is that the improbable step lies in the future and humanity's prospects of reaching step 9 (interstellar colonization) are still bleak. If the past steps are likely, then many civilizations would have developed to the current level of the human species. However, none appear to have made it to step 9, or the Milky Way would be full of colonies. So perhaps step 9 is the unlikely one, and the only things that appear likely to keep humanity from step 9 are some sort of catastrophe, an underestimation of the impact of procrastination as technology increasingly unburdens existence, or resource exhaustion leading to the impossibility of making the step due to consumption of the available resources (for example highly constrained energy resources). So by this argument,


id: habitable-zone-20260505-0
file: data/en.wikipedia.org/wiki/Habitable_zone-0.md
category: reference
title: Habitable zone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone
date_saved: 2026-05-05T11:09:42.148987+00:00
instance: kb-cron
parent: habitable-zone-20260505-0
summary:
In astronomy and astrobiology, the habitable zone (HZ), also known as the circumstellar habitable zone (CHZ), or as the Goldilocks zone, is the range of orbits around a star within which a planetary surface could potentially support liquid water. Liquid water is considered by many scientists as necessary for a planet to be habitable. The range depends upon the brightness of the star interacting with a planet's atmosphere. At the inner edge the star's light, trapped by greenhouse gases in a planet's atmosphere, boils off the planet's water. At the outer edge light from the star is insufficient even with help from atmospheric gas and the planet's water freezes. Many other factors are added in various habitable zone models. The habitable zone has become a key tool in the search for habitable planets because discoveries of exoplanets yield approximate orbital radii. The alternative name, Goldilocks zone, is a metaphor, allusion and antonomasia of the children's fairy tale of "Goldilocks and the Three Bears", in which a little girl chooses from sets of three items, rejecting the ones that are too extreme (large or small, hot or cold, etc.), and settling on the one in the middle, which is "just right".


id: habitable-zone-20260505-1
file: data/en.wikipedia.org/wiki/Habitable_zone-1.md
category: reference
title: Habitable zone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone
date_saved: 2026-05-05T11:09:42.148987+00:00
instance: kb-cron
parent: habitable-zone-20260505-0
summary:
=== Extensions of the concept === In 1999, Guillermo Gonzalez and other noted that metals have important impact on planet formation and the development of life. Together with paleontologist Peter Ward and fellow astronomer Donald Brownlee Gonzalez introduced the idea of the "galactic habitable zone". The galactic habitable zone, defined as the region where life is most likely to emerge in a galaxy, encompasses those regions close enough to a galactic center that stars there are enriched with heavier elements, but not so close that star systems, planetary orbits, and the emergence of life would be frequently disrupted by the intense radiation and enormous gravitational forces commonly found at galactic centers. The discovery of exoplanets unlike any in the Solar System led to suggestions that life might emerge even in conditions outside of currently defined habitable zones. Subsequently, some astrobiologists propose that the concept be extended to other solvents, including dihydrogen, sulfuric acid, dinitrogen, formamide, and methane, among others, which would support hypothetical life forms that use an alternative biochemistry. In 2013, further developments in habitable zone concepts were made with the proposal of a circum- planetary habitable zone, also known as the "habitable edge", to encompass the region around


id: habitable-zone-20260505-2
file: data/en.wikipedia.org/wiki/Habitable_zone-2.md
category: reference
title: Habitable zone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone
date_saved: 2026-05-05T11:09:42.148987+00:00
instance: kb-cron
parent: habitable-zone-20260505-0
summary:
A planet cannot have a hydrosphere—a key ingredient for the formation of carbon-based life—unless there is a source for water within its stellar system. The origin of water on Earth is still not completely understood; possible sources include the result of impacts with icy bodies, outgassing, mineralization, leakage from hydrous minerals from the lithosphere, and photolysis. For an extrasolar system, an icy body from beyond the frost line could migrate into the habitable zone of its star, creating an ocean planet with seas hundreds of kilometers deep such as GJ 1214 b or Kepler-22b may be. Maintenance of liquid surface water also requires a sufficiently thick atmosphere. Possible origins of terrestrial atmospheres are currently theorized to outgassing, impact degassing, and ingassing. Atmospheres are thought to be maintained through similar processes along with biogeochemical cycles and the mitigation of atmospheric escape. In a 2013 study led by Italian astronomer Giovanni Vladilo, it was shown that the size of the circumstellar habitable zone increased with greater atmospheric pressure. Below an atmospheric pressure of about 15 millibars, it was found that habitability could not be maintained because even a small shift in pressure or temperature could render water unable to form as a


id: habitable-zone-20260505-3
file: data/en.wikipedia.org/wiki/Habitable_zone-3.md
category: reference
title: Habitable zone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone
date_saved: 2026-05-05T11:09:42.148987+00:00
instance: kb-cron
parent: habitable-zone-20260505-0
summary:
Some scientists argue that the concept of a circumstellar habitable zone is actually limited to stars in certain types of systems or of certain spectral types. Binary systems, for example, have circumstellar habitable zones that differ from those of single-star planetary systems, in addition to the orbital stability concerns inherent with a three-body configuration. Studying ultraviolet emissions, Andrea Buccino found that only 40% of stars studied (including the Sun) had overlapping liquid water and ultraviolet habitable zones. Stars smaller than the Sun, on the other hand, have distinct impediments to habitability. For example, Michael Hart proposed that only main-sequence stars of spectral class K0 or brighter could offer habitable zones, an idea which has evolved in modern times into the concept of a tidal locking radius for red dwarfs. Within this radius, which is coincidental with the red-dwarf habitable zone, it has been suggested that the volcanism caused by tidal heating could cause a "tidal Venus" planet with high temperatures and no hospitable environment for life. Others maintain that circumstellar habitable zones are more common and that it is indeed possible for water to exist on planets orbiting cooler stars. Climate modeling from 2013 supports the idea that red dwarf


id: habitable-zone-20260505-4
file: data/en.wikipedia.org/wiki/Habitable_zone-4.md
category: reference
title: Habitable zone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone
date_saved: 2026-05-05T11:09:42.148987+00:00
instance: kb-cron
parent: habitable-zone-20260505-0
summary:
A 2015 review concluded that the exoplanets Kepler-62f, Kepler-186f and Kepler-442b were likely the best candidates for being potentially habitable. These are at a distance of 990, 490 and 1,120 light-years away, respectively. Of these, Kepler-186f is closest in size to Earth with 1.2 times Earth's radius, and it is located towards the outer edge of the habitable zone around its red dwarf star. Among nearest terrestrial exoplanet candidates, Tau Ceti e is 11.9 light-years away. It is in the inner edge of its planetary system's habitable zone, giving it an estimated average surface temperature of 68 °C (154 °F). === Early findings === The first discoveries of extrasolar planets in the HZ occurred just a few years after the first extrasolar planets were discovered. However, these early detections were all gas giant-sized, and many were in eccentric orbits. Despite this, studies indicate the possibility of large, Earth-like moons around these planets supporting liquid water. One of the first discoveries was 70 Virginis b, a gas giant initially nicknamed "Goldilocks" due to it being neither "too hot" nor "too cold". Later study revealed temperatures analogous to Venus, ruling out any potential for liquid water. 16 Cygni Bb, also discovered in


id: habitable-zone-20260505-5
file: data/en.wikipedia.org/wiki/Habitable_zone-5.md
category: reference
title: Habitable zone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone
date_saved: 2026-05-05T11:09:42.148987+00:00
instance: kb-cron
parent: habitable-zone-20260505-0
summary:
Recent discoveries have uncovered planets that are thought to be similar in size or mass to Earth. "Earth-sized" ranges are typically defined by mass. The lower range used in many definitions of the super-Earth class is 1.9 Earth masses; likewise, sub-Earths range up to the size of Venus (~0.815 Earth masses). An upper limit of 1.5 Earth radii is also considered, given that above 1.5 R🜨 the average planet density rapidly decreases with increasing radius, indicating these planets have a significant fraction of volatiles by volume overlying a rocky core. A genuinely Earth-like planet – an Earth analog or "Earth twin" – would need to meet many conditions beyond size and mass; such properties are not observable using current technology. A solar analog (or "solar twin") is a star that resembles the Sun. No solar twin with an exact match as that of the Sun has been found. However, some stars are nearly identical to the Sun and are considered solar twins. An exact solar twin would be a G2V star with a 5,778 K temperature, be 4.6 billion years old, with the correct metallicity and a 0.1% solar luminosity variation. Stars with an age of 4.6 billion years are


id: habitable-zone-20260505-6
file: data/en.wikipedia.org/wiki/Habitable_zone-6.md
category: reference
title: Habitable zone
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone
date_saved: 2026-05-05T11:09:42.148987+00:00
instance: kb-cron
parent: habitable-zone-20260505-0
summary:
In the case of planets orbiting in the HZs of red dwarf stars, the extremely close distances to the stars cause tidal locking, an important factor in habitability. For a tidally locked planet, the sidereal day is as long as the orbital period, causing one side to permanently face the host star and the other side to face away. In the past, such tidal locking was thought to cause extreme heat on the star-facing side and bitter cold on the opposite side, making many red dwarf planets uninhabitable; however, three-dimensional climate models in 2013 showed that the side of a red dwarf planet facing the host star could have extensive cloud cover, increasing its bond albedo and reducing significantly temperature differences between the two sides. === Moons === Planetary mass natural satellites have the potential to be habitable as well. However, these bodies need to fulfill additional parameters, in particular being located within the circumplanetary habitable zones of their host planets. More specifically, moons need to be far enough from their host giant planets that they are not transformed by tidal heating into volcanic worlds like Io, but must remain within the Hill radius of the planet so that they


id: habitable-zone-for-complex-life-20260505-0
file: data/en.wikipedia.org/wiki/Habitable_zone_for_complex_life-0.md
category: reference
title: Habitable zone for complex life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone_for_complex_life
date_saved: 2026-05-05T11:09:43.295260+00:00
instance: kb-cron
parent: habitable-zone-for-complex-life-20260505-0
summary:
A Habitable Zone for Complex Life (HZCL) is a range of distances from a star suitable for complex aerobic life. Conventional habitable zones are based on compatibility with water required for bacterial life. Aerobic organism have additional requirements. Different types of limitations preventing complex life give rise to different zones. A planet would need to orbit inside the boundaries of this zone. With multiple zonal constraints, the zones would need to overlap for the planet to support complex life. == Exoplanets == The first confirmed exoplanets were discovered in 1992, orbiting the pulsar PSR B1257+12. Several hundred candidate exoplanets have been identified within convention habitable zones. Most exoplanets are hot Jupiter planets, that orbit very close the star. Many exoplanets are super-Earths, that could be a gas dwarf or large rocky planet, like Kepler-442b at a mass 2.36 times Earths. == Star == Unstable stars are young or old stars, or very large or small stars. Since they are unstable, they have varying solar luminosity, which changes the size of the life habitable zones. These stars also produce extreme solar flares and coronal mass ejections. Thus, life habitable zones require a very stable star like the Sun, at ±0.1% solar


id: habitable-zone-for-complex-life-20260505-1
file: data/en.wikipedia.org/wiki/Habitable_zone_for_complex_life-1.md
category: reference
title: Habitable zone for complex life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone_for_complex_life
date_saved: 2026-05-05T11:09:43.295260+00:00
instance: kb-cron
parent: habitable-zone-for-complex-life-20260505-0
summary:
Ultraviolet habitable zone: a zone where the ultraviolet (UV) radiation from a star is neither too weak nor too strong for life to exist. Life needs the correct amount of ultraviolet for synthesis of biochemicals. The extent of the zone depends on the amount of ultraviolet radiation from the star, the range of UV wavelengths, the age of the star, and the atmosphere of the planet. In humans UV is used to produce vitamin D. Extreme ultraviolet (EUV) can cause atmospheric loss. Photosynthetic habitable zone: a zone where both long-term liquid water and oxygenic photosynthesis can occur. Tropospheric habitable zone, or ozone habitable zone: a zone where the planet would have the correct amount of ozone needed for life. Inhaling too much ozone causes inflammation and irritation, whereas too little troposphere ozone would produce biochemical smog. On Earth, the troposphere ozone is part of the ground-level ozone protection. Tropospheric ozone is formed by the interaction of ultraviolet light with hydrocarbons and nitrogen oxides. Planet rotation rate habitable zone: the zone where a planet's rotation rate is best for life. If the rotation is too slow, the day/night temperature difference is too great. The rotation rate also changes the planet's reflectivity


id: habitable-zone-for-complex-life-20260505-2
file: data/en.wikipedia.org/wiki/Habitable_zone_for_complex_life-2.md
category: reference
title: Habitable zone for complex life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone_for_complex_life
date_saved: 2026-05-05T11:09:43.295260+00:00
instance: kb-cron
parent: habitable-zone-for-complex-life-20260505-0
summary:
The Milky Way is a barred spiral galaxy, the bar is important to star formation and metallicity of the galaxy's stars and planets. A barred spiral galaxy must have stable arms with the just right star formation. Barred spiral galaxies make up about 65% of spiral galaxies, but most have too much star formation. Peculiar galaxies lack stable spiral arms, while irregular galaxies contain too many new stars and lack heavy elements. Unbarred spiral galaxies do not correct star formation and metallicity for a galactic Goldilocks zone. For long term life on a planet, the spiral arms must be stable for a long period of time, as in the Milky Way. The spiral arms must not be too close to each other, or there will be too much ultraviolet radiation. If the planet moves into or across a spiral arm, the orbits of the planets could change from gravitational disturbances. Movement across a spiral arms also would cause deadly asteroid impacts and high radiation. The planet must be in the correct place in the spiral galaxy: near the galactic center, radiation and gravitational forces are too great for life, whereas the outskirts of a spiral galaxy are metal-poor. The Sun


id: habitable-zone-for-complex-life-20260505-3
file: data/en.wikipedia.org/wiki/Habitable_zone_for_complex_life-3.md
category: reference
title: Habitable zone for complex life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Habitable_zone_for_complex_life
date_saved: 2026-05-05T11:09:43.295260+00:00
instance: kb-cron
parent: habitable-zone-for-complex-life-20260505-0
summary:
== Other orbital-distance related factors == Some factors that depend on planetary distance and may limit complex aerobic life have not been given zone names. These include: Milankovitch cycle The Milankovitch cycle and ice age have been key is shaping Earth. Life on Earth today is using water melting from the last ice age. The ice ages cannot be too long or too cold for life to survive. Milankovitch cycle has an impact on the planet's obliquity also. == Life == Life on Earth is carbon-based. However, some theories suggest that life could be based on other elements in the periodic table. Other elements proposed have been silicon, boron, arsenic, ammonia, methane and others. As more research has been done on life on Earth, it has been found that only carbon's organic molecules have the complexity and stability to form life. Carbon's properties allows for complex chemical bonding that produces covalent bonds needed for organic chemistry. Carbon molecules are lightweight and relatively small in size. Carbon's ability to bond to oxygen, hydrogen, nitrogen, phosphorus, and sulfur (called CHNOPS) is key to life. == Gallery == == See also == Extraterrestrial intelligence Exoplanet orbital and physical parameters Habitability of natural satellites


id: history-of-the-extraterrestrial-life-debate-20260505-0
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-0.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T11:09:44.567164+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
The existence of extraterrestrial life is a scientific idea that has been debated for centuries. Initially, the question was purely speculative; in modern times a limited amount of scientific evidence provides some answers. The idea was first proposed in Ancient Greece, where it was supported by atomists and rejected by Aristotelians. The debate continued during the Middle Ages, when the discussion centered upon whether the notion of extraterrestrial life was compatible with the doctrines of Christianity. The Copernican Revolution radically altered mankind's image of the architecture of the cosmos by removing Earth from the center of the universe, which made the concept of extraterrestrial life more plausible. Today we have no conclusive evidence of extraterrestrial life, but experts in many different disciplines gather to study the idea under the scientific umbrella of astrobiology. == Ancient Greece == During the early days of the history of astronomy the things seen in the night sky were explained as the actions of mythological deities. However, it soon became evident that celestial objects move and behave in regular and predictable patterns, which helped in keeping track of time, tides, and seasons, crucial for ancient agriculture. Most ancient civilizations had great knowledge of astronomy but


id: history-of-the-extraterrestrial-life-debate-20260505-1
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-1.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T11:09:44.567164+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
The Greeks discussed as well the possible existence of other worlds, but did not consider the planets as such. In their view, the celestial sphere was a part of Earth and other potential worlds would have their own ones. There was consensus that the world was made of the four classical elements, earth, water, fire and air. From there, they had two opposite ideas: Atomists thought that all existence was composed by atoms, small and indivisible pieces of the four elements, and Aristotelians thought that the four elements were exclusive to Earth and that the universe was made of a fifth one, the Aether. The atomist view would allow the existence of other worlds, as the processes that created Earth may happen elsewhere as well. Although very few of their writings were preserved, it is known that early atomists Leucippus and Democritus thought that atoms should create other worlds the same way Earth was created. Epicurus said in his "Letter to Herodotus" that "There are infinite worlds both like and unlike this world of ours... we must believe that in all worlds there are living creatures and plants and other things we see in this world". Aristotle and Plato opposed


id: history-of-the-extraterrestrial-life-debate-20260505-2
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-2.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T11:09:44.567164+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
Nicolaus Copernicus published De revolutionibus orbium coelestium in 1543, kickstarting the Copernican Revolution. This book restored and updated the old idea of Aristarchus that Earth spins around the sun. The new version was written with so much mathematical detail that it could contest the Ptolemaic model. By this time, scientists noticed several inaccuracies in the Ptolemaic model. They were more open to revising it, but largely kept using it because of the huge work involved in changing the tables. Copernicus thought that Earth spinning around the sun could provide a simpler explanation for the retrograde motion of the planets, and calculated the distance of the planets to the Sun. However, he kept the idea of circular orbits, and added several composite orbits to explain the errors caused by it. Although he correctly displaced the center of the Solar System, this first model turned out to be as inaccurate and as complex as the Ptolematic one, and did not get much supporters in the first decades. A recurring problem for both models was the lack of quality data, as the telescope had not been invented yet and naked eye observations are highly inaccurate. The Danish Tycho Brahe sought to gather such


id: history-of-the-extraterrestrial-life-debate-20260505-3
file: data/en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate-3.md
category: reference
title: History of the extraterrestrial life debate
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/History_of_the_extraterrestrial_life_debate
date_saved: 2026-05-05T11:09:44.567164+00:00
instance: kb-cron
parent: history-of-the-extraterrestrial-life-debate-20260505-0
summary:
However, some scientists had concerns over the new model. Aristotle had once stated that Earth could not move because, if it did so, birds, clouds, and falling objects would be left behind. Orbits had to be circular because the heavens had to be perfect and unchanging. And if Earth moved, the stars should leave a stellar parallax. Those concerns were addressed by Galileo Galilei. First, he explained that an object in motion stays in motion unless a force stops it; a principle nowadays included in the first of Newton's laws of motion. The idea of heavenly perfection was already being challenged by Tycho's observations. Tycho had observed a supernova, which proved that sometimes the heavens do change. The newly invented telescope also revealed "imperfections" in celestial bodies: the sun was shown with sunspots, and the Moon has many features such as craters and mountain ranges. If the heavens were not as perfect as originally considered, then the idea that orbits are not perfect circles was not so questionable. Galileo also discovered the Galilean moons of Jupiter, celestial bodies orbiting another planet, and the phases of Venus. The existence of the Galilean moons refuted the common argument that the Moon would


id: interdimensional-ufo-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Interdimensional_UFO_hypothesis-0.md
category: reference
title: Interdimensional UFO hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Interdimensional_UFO_hypothesis
date_saved: 2026-05-05T11:09:45.833611+00:00
instance: kb-cron
parent: interdimensional-ufo-hypothesis-20260505-0
summary:
The interdimensional UFO hypothesis (IUH) is the proposal that unidentified flying object (UFO) sightings are the result of experiencing other "dimensions" or "portals" that coexist separately alongside our own. The hypothesis has been advanced by ufologists such as Meade Layne, John Keel, J. Allen Hynek, and Jacques Vallée. Proponents of the interdimensional hypothesis argue that UFOs are a modern manifestation of a phenomenon that has occurred throughout recorded human history, which in prior ages was ascribed to mythological or supernatural creatures. Jeffrey J. Kripal, Chair in Philosophy and Religious Thought at Rice University, writes: "this interdimensional reading, long a staple of Spiritualism through the famous 'fourth dimension', would have a very long life within ufology and is still very much with us today". == History == === Pre-modern history === Concepts similar to ”other dimensions” exist amongst various religious and mystical traditions, such as Islamic mysticism known as Sufism. In this tradition, the concept al-ghayb refers to the hidden, unseen, and invisible, and encompasses a range of important phenomena in Islam and in the everyday lives of Muslims. Within this mystical tradition, there is a concept of a hidden multilayered reality or world known as 'ālam al-mithāl, or “the world


id: kardashev-scale-20260505-0
file: data/en.wikipedia.org/wiki/Kardashev_scale-0.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
The Kardashev scale (Russian: шкала Кардашёва, romanized: shkala Kardashova) is a method of measuring a civilization's level of technological advancement based on the amount of energy it is capable of harnessing and using. The measure was proposed by Soviet astronomer Nikolai Kardashev in 1964, and was named after him. Kardashev first outlined his scale in a paper presented at the 1964 conference that communicated findings on BS-29-76, Byurakan Conference in the Armenian SSR, which he initiated, a scientific meeting that reviewed the Soviet radio astronomy space listening program. The paper was titled "Передача информации внеземными цивилизациями" ("Transmission of Information by Extraterrestrial Civilizations"). Starting from a functional definition of civilization, based on the immutability of physical laws and using human civilization as a model for extrapolation, Kardashev's initial model was developed. He proposed a classification of civilizations into three types, based on the axiom of exponential growth: A Type I civilization (planetary) is able to access all the energy available on its planet and store it for consumption. A Type II civilization (stellar) can directly consume a star's energy, most likely through the use of a Dyson sphere. A Type III civilization (galactic) is able to capture all the energy emitted


id: kardashev-scale-20260505-1
file: data/en.wikipedia.org/wiki/Kardashev_scale-1.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
According to the Soviet astronomer, the Earth's civilization would be too young to be able to contact another civilization that would certainly be more advanced; the Solar System is too young with its five billion years, and the first ancestors of today's man appeared only 6 million years ago at the earliest; the oldest celestial objects are between 10 and 14 billion years old; it is clear that the other civilizations are incomparably older than the human civilization. Therefore, the knowledge of these civilizations must be greater than Earth's, and, he reasoned, they must surely be aware of what humans are doing. Kardashev believed it is probable that the present state of Earth's civilization is only one of the stages through which civilizations pass during their evolution. It is thus possible to define civilization on the basis of this universal characteristic, which allowed Aleksandr Lyapunov to define life as "a highly stable state of matter, which uses information encoded by the states of individual molecules to produce maintaining reactions", which Kardashev calls the "functional definition of civilization". He therefore suggests thinking of civilization as a "highly stable state of matter capable of acquiring, making abstract analysis of, and utilizing information


id: kardashev-scale-20260505-2
file: data/en.wikipedia.org/wiki/Kardashev_scale-2.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
==== Two strategies for searching for intelligent signals ==== Kardashev then analyzed various models and hypotheses of the evolution of civilization. Answering the question of the Russian astronomer Iosif Shklovsky, who in an article published in 1977 entitled Possibility of the Intelligent Life in the Universe Being Unique found it strange that the "shock wave of intelligence" of a supercivilization had not yet reached the limits of the whole Universe, Kardashev put forward two explanatory hypotheses. In the first, he postulated that it would not be useful for a supercivilization to expand the space it occupies in order to maintain its activity, and in the second, it is possible that a civilization, instead of dispersing itself in space, would rather continue its activities of information analysis in order to discover new fundamental laws (such as the exploration of the microcosm, or black holes for example). However, such civilization activities require the use of abundant energy. According to the laws of thermodynamics, an important part of this consumed energy must be converted into radiation of a bolometric magnitude approximately equal to that of the radiation background surrounding the source. The spectral distribution of this intensity must be close to that of


id: kardashev-scale-20260505-3
file: data/en.wikipedia.org/wiki/Kardashev_scale-3.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
==== Possible scenarios for the evolution of supercivilizations ==== Kardashev believes that it is very likely that a supercivilization has already detected and observed humanity through cosmic-sized telescopes. He discusses this in a 1997 article on the subject, entitled Radioastron – a Radio Telescope Much Greater than the Earth. For this supercivilization, the science of "cosmic ethnography" must be highly developed. However, the fact that no contact has been made so far could be explained by ethical considerations of these civilizations. Based on this principle, Kardashev sees only two possible evolutionary scenarios for a supercivilization: natural evolution and evolution after contact with other extraterrestrial civilizations. He considers more likely the scenario based on contact between two highly developed, technologically and culturally advanced civilizations; this scenario, which he calls the "Urbanization Hypothesis", would result in the regrouping and unification of several civilizations within a few compact regions of the Universe. Kardashev lists, in the form of investigative tools, six possible scenarios (summarized in a table at the end of his 1997 article) that explain the evolution of a civilization. Each of the scenarios corresponds to a probability, one or more objects to be observed, an adapted procedure, and, finally the possible


id: kardashev-scale-20260505-4
file: data/en.wikipedia.org/wiki/Kardashev_scale-4.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
In the article Cosmology and Civilizations published in 1997, Kardashev reiterates the need to carefully observe astronomical objects with strong radiation in order to detect supercivilizations. However, the discovery of a civilization at a stage of development similar to ours is unlikely. The existence of such supercivilizations is made possible by the fact that life on Earth is recent compared to the age of the Universe (8 × 109 years before the formation of the Solar System). He then examines the conditions for the appearance of life on cosmological time scales. Assuming the rate of evolution of life on Earth and considering the age of the Universe, it is reasonable to assume that a civilization could have reached our level of technological development in 6 × 109 years. Such civilizations can be observed in nearby regions, since the farther away we observe, the younger the objects are. Recent discoveries of sources of intense radiation deadly to life show that life could have flourished under cover for the time necessary for its appearance and maintenance. Another argument for the possibility of a very old supercivilization is that most of the objects that could be megastructures have not yet been discovered and


id: kardashev-scale-20260505-5
file: data/en.wikipedia.org/wiki/Kardashev_scale-5.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
=== Type II === A civilization capable of harnessing the energy radiated by its own large star – for example, by successfully completing a Dyson sphere or Matrioshka brain – with an energy consumption of ≈4×1033 erg/sec. Lemarchand defined such civilizations as being able to harness and channel the entire radiation output of their star. The energy consumption would then be comparable to the luminosity of the Sun, about 4×1033 erg/sec (4×1026 watts). === Type III === A civilization with energy on the scale of its own galaxy, with an energy consumption of ≈4×1044 erg/sec. Lemarchand defined civilizations of this type as having access to energy comparable to the luminosity of the entire Milky Way galaxy, about 4×1044 erg/sec (4×1037 watts). In accordance with the data available at the time, Kardashev did not go beyond a Type III civilization. However, new types (0, IV, V, and VI) have been proposed. == Reassessments of the Kardashev scale == === Sagan's finer classification === In 1973, Carl Sagan discovered Kardashev's work on the classification of civilizations. He found that the differences between the types Kardashev identified were so great that they did not allow for the best possible modeling of the evolution


id: kardashev-scale-20260505-6
file: data/en.wikipedia.org/wiki/Kardashev_scale-6.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
=== Kaku and the knowledge economy === In Physics of the Future (2011), American physicist Michio Kaku examines the conditions for humanity to converge on a Type I planetary civilization. This convergence is based primarily on the knowledge economy. Kaku uses the Kardashev scale, but develops it by adding an additional stage: a Type IV civilization would be able to draw the energy it needs from extragalactic radiation. By studying the evolution of technologies that have changed history (paper, the integrated circuit), Kaku believes that humanity is moving toward a civilization of planetary dimensions, the "starting point" of which is the Internet. A Type I civilization consumes power on the order of thousands to millions of times our current planetary output, about 100 trillion trillion watts. It would have enough energy to manipulate the occurrence of certain natural phenomena, such as earthquakes or volcanoes, and could build cities on the oceans. We can see the beginnings of a Type I civilization in the fact that a global language is developing (English), a global communication system is emerging (the Internet), a global economic system is in the making (the establishment of the European Union), and even a globalized culture is standardizing


id: kardashev-scale-20260505-7
file: data/en.wikipedia.org/wiki/Kardashev_scale-7.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
Zoltan Galántai recognizes the important role that Kardashev's classification has played in the SETI program, but he believes that another scale is possible, without using energy consumption, by resorting to miniaturization. The hypothesis of Donald Tarter, researcher at SETI, is that a civilization based on nanotechnology would not need an ever-increasing amount of energy. A Type I civilization that masters local space travel could colonize its planetary system and even the Oort cloud without needing an amount of energy that would make it Type II. This scale loses its meaning beyond Type II, since it is impossible to predict the evolution of civilizations over long distances in a galactic colonization process. Finally, the Kardashev scale is the product of an era of insufficient scientific knowledge, which considered the possibility of stellar object CTA-102 as an artificial Type III source, whereas today we know that it is a galactic nucleus. In another article, Zoltan Galántai suggests considering another scale, no longer based on energy consumption, but on a civilization's ability to survive natural and cosmic disasters. Type I would describe a civilization capable of surviving a local natural disaster, like the Anasazi. A Type II civilization would have the means to


id: kardashev-scale-20260505-8
file: data/en.wikipedia.org/wiki/Kardashev_scale-8.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
=== Towards type II === Viorel Badescu and Richard Cathcart have studied the possibility that a Type II civilization could use a 450 million kilometer device to direct solar radiation and thus be able to impart a kinetic motion to its star that deviates it from its usual trajectory by about 35 to 40 parsecs, allowing it, among other things, to capture its energy and navigate the galaxy. For Claude Semay, "a Type II civilization could be detected at great distances (by what is called "astro-technical leakage"), provided that it is not located in a region of the galaxy that is too distant from us, or that it does not occupy a location that is obscured from us by clouds of gas or dust". === Towards type III === A Type III civilization should be detectable because of the large amount of radiation captured on a galaxy-wide scale. Calissendorff suggests using 75% of the total light emitted by a galaxy to determine that a Type III civilization uses many Dyson spheres. If only three or four of these spheres occupy the galaxy, it does not necessarily mean that the civilization has reached Type III, and it may still be in


id: kardashev-scale-20260505-9
file: data/en.wikipedia.org/wiki/Kardashev_scale-9.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
=== The technology === This parameter is one of the most undetectable in the Universe due to the fact that solid matter structures are at low temperatures and emit weak radiation. Their luminosity, which is difficult to observe, also makes it impossible to observe them with telescopes. Likewise, we cannot detect them by their gravitational effects. However their existence can be detected by analyzing wavelengths between 8 and 13 microns, corresponding to surface temperatures of 300 K. A hypothetical Dyson sphere could thus be detected, provided that the observation is made from space. Locally, the significant dip in luminosity that would result from a giant Dyson sphere (or "Fermi bubble") would allow the detection of a Type III civilization. A megastructure like a Dyson sphere could be the result of a technology based on self-replicating probes, as those imagined by von Neumann. A Type III civilization would have the means to disperse a significant number of these spheres throughout the galaxy, which would have the effect of attenuating the light emitted by the galaxy. Kaku also considers this to be the most efficient method of colonizing space. For example, a galaxy 100,000 light years in diameter would be explored in


id: kardashev-scale-20260505-10
file: data/en.wikipedia.org/wiki/Kardashev_scale-10.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
According to Kardashev, the transmissions of an extraterrestrial civilization (what SERENDIP is looking for) can be divided into two types. On the one hand, there can be an exchange of information between highly developed civilizations or civilizations at similar stages of evolution. On the other hand, the transmission of information can be aimed at raising the level of other less developed civilizations. If supercivilizations do exist, the transmissions of the first type must remain inaccessible to our observation because they must be unidirectional and not be directed toward the Solar System. Conversely, those of the second type must be easily detectable by our listening devices. A signal of artificial origin should contain more than 10 and less than 100 bits. The latter would be of two types: transient and stable. Several criteria allow us to distinguish a signal of artificial origin from others. First, the optimal region of the spectrum to host artificial signals is the one where the temperature of the cosmic microwave background is the lowest. Second, artificial sources must have a minimum angular size. The presence of suspicious data in other regions of the spectrum (such as circular polarization, radio and optical frequencies, or X-ray emissions) can


id: kardashev-scale-20260505-11
file: data/en.wikipedia.org/wiki/Kardashev_scale-11.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
=== Towards a "physical eschatology" === The knowledge of these hypothetical supercivilizations must fit into a wide range of physical laws that contain the entirety of our current knowledge, since the technical and scientific developments of mankind can be considered as an inevitable and necessary stage in the process of the evolution of a civilization. Based on this principle, Kardashev proposes to define several concepts applicable to extraterrestrial civilizations. The physical laws, which are universal, can be used as a common basis for understanding other civilizations and, in particular, allow us to develop an objective research program. Michio Kaku also believes that the evolution of civilizations obeys the "iron laws of physics" and in particular the laws of thermodynamics, those of stable matter (baryonic matter) and those of planetary evolution (probability of occurrence of natural or cosmic catastrophes). The anthropic principle also makes it possible to predict the sociological characteristics at the basis of any civilization. However, these universal laws are not the only parameters to consider. Zoltan Galántai explains that "it is impossible to calculate the future of the Universe over long periods of time without including the effects of life and intelligence", a position close to that of


id: kardashev-scale-20260505-12
file: data/en.wikipedia.org/wiki/Kardashev_scale-12.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
=== Research conducted === In 1963, Nikolai Kardashev and Gennady Borissovich Sholomitskii studied the CTA 102 radio source on the 920 MHz band from the Crimea Deep Space Station, looking for signs of a Type III civilization. CTA 102 had been discovered by Sholomitskii a year earlier, and Kardashev quickly saw it as a possible artificial source to study in order to validate his classification. The observation lasted until February 1965, and on April 12, Sholomitskii announced to the press (via the Russian ITAR-TASS) that Soviet astronomers had discovered a signal that could be of extraterrestrial origin. On April 14, he gave a conference in Moscow where he repeated his announcement; but by November 1964, two American astronomers had identified CTA 102 as a quasar, and their publication definitively closed the "CTA 102 case". It was the study of this source that had led to the Byurakan conference in 1964. In 1975 and 1976, the American astronomers Frank Drake and Carl Sagan searched at Arecibo for signs of Type II civilizations in four galaxies of the Local Group: M33, M49, Leo I and Leo II. The year before, the two men had sent mankind's first message to M13. The results


id: kardashev-scale-20260505-13
file: data/en.wikipedia.org/wiki/Kardashev_scale-13.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
==== Kardashev's point of view ==== According to Kardashev, humanity's ignorance of the physical possibilities of communication through space is great. Only a negligible fraction of the electromagnetic spectrum as an existing source of information in the universe is known. Thus, of the 89% of information that humans lack, 42% concerns the range from 109 to 1014 Hz (centimetric, millimetric, submillimetric and infrared waves) and 25% concerns the range from 1015 to 1018 Hz (ultraviolet radiation and X-rays). Kardashev distinguishes two categories of listening areas: objects emitting in a broad frequency spectrum and objects emitting on the contrary in a narrow spectral line, the second category posing much more theoretical problems than the first, while being central, both for astrophysics and for the search for extraterrestrial civilizations. Despite advances in astrophysics, the available information is still insufficient to prove the absence of supercivilizations, based on the inability to observe signs of activity. However, because of the possibility that there are planetary systems much older than the Solar System, and considering that cosmic objects such as quasars could be products of supercivilization activity, a detailed program of listening and searching for intelligent signs remains valid. This program includes: Monitoring the sky


id: kardashev-scale-20260505-14
file: data/en.wikipedia.org/wiki/Kardashev_scale-14.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
The quasar 3C 9 is cited by Kardashev as early as 1971. The study of the quasar 3C 273 shows that it has a solid structure. Other quasars (3C 279, 3C 345, 3C 84) have properties close to those expected from an artificial source, especially since the emissions are powerful in the intermediate region of the spectrum (between radio and optical frequencies). Quasars are potential artificial sources, especially since their age corresponds to the technical possibilities of supercivilizations. Radio sources at the center of galaxies can also be artificial sources, according to Kardashev, even if in 2013 they were proven to be supermassive black holes. In 1971, Kardashev believed that the objects most likely to be artificial sources could be discovered in the [then] next few years. The extraordinary periodicity of pulsar emissions was already considered an artificial source in 1968 by Antony Hewish, the discoverer of the first pulsar (CP 19019). The press of the time nicknamed this object "LGM-1" (for "little green men"), following the clumsiness of Hewish, who did not wait for the necessary verifications. Kaplan, in 1971, removed the pulsar from the list of objects that could be a source of artificial origin. In 2011, James


id: kardashev-scale-20260505-15
file: data/en.wikipedia.org/wiki/Kardashev_scale-15.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
Long range omnidirectional transmitters would be very energy intensive. Using directional or intermittent devices, each pointing in a different direction, would require much less energy. Type II or III civilizations might therefore be defined by something other than exponential energy consumption. The assumption of exponential energy consumption is certainly wrong, because if we analyze per capita energy consumption throughout human history, it forms a series of logistic curves with a saturation point for each technological innovation. Therefore, a steady state or limited growth is more likely. According to the principle of mediocrity, applied to the search for extraterrestrial civilizations by Sagan and Shklovskii in 1966 on the basis of John Richard Gott's calculations, civilizations more important than ours must be so rare that they do not have the possibility to dominate and be visible. Finally, research and listening programs in Harvard University and Buenos Aires (Horowitz and Sagan in 1993 or Lemarchand et al. in 1997) have not provided any scientific proof of the existence of artificial sources, neither in the Milky Way nor in nearby galaxies (M33, M81, the Whirlpool Galaxy or Centaurus A), or even in the Virgo cluster. For the British meteorologist Lewis Fry Richardson, author of


id: kardashev-scale-20260505-16
file: data/en.wikipedia.org/wiki/Kardashev_scale-16.md
category: reference
title: Kardashev scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Kardashev_scale
date_saved: 2026-05-05T11:09:47.104746+00:00
instance: kb-cron
parent: kardashev-scale-20260505-0
summary:
=== Type I civilization methods === Large-scale application of fusion power: In terms of mass–energy equivalence, Type I implies the conversion of about 2 kg of matter to energy per second. An equivalent energy release could theoretically be achieved by fusing about 280 kg of hydrogen into helium per second, a rate roughly equivalent to 8.9×109 kg/year. One cubic kilometer of water contains about 1011 kg of hydrogen, and the Earth's oceans contain about 1.3×109 cubic kilometers of water, meaning that humans on Earth could sustain this rate of consumption over geological time scales, in terms of available hydrogen. Antimatter in large quantities would provide a mechanism to produce power on a scale several orders of magnitude beyond the current level of technology. In antimatter-matter collisions, all of the rest mass of the particles is converted to radiant energy. Their energy density (energy released per mass) is about four orders of magnitude greater than that from using nuclear fission, and about two orders of magnitude greater than the best possible yield from fusion. The reaction of 1 kg of antimatter with 1 kg of matter would produce 1.8×1017 J (180 petajoules) of energy. Although antimatter is sometimes proposed as a


id: little-green-men-20260505-0
file: data/en.wikipedia.org/wiki/Little_green_men-0.md
category: reference
title: Little green men
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Little_green_men
date_saved: 2026-05-05T11:09:48.295549+00:00
instance: kb-cron
parent: little-green-men-20260505-0
summary:
Little green men are stereotypical portrayals of extraterrestrials as little humanoids with green skin and sometimes antennae on their heads. The term "little green men" came into popular usage in reference to aliens during the reports of flying saucers in the 1950s. In one classic case, the Kelly-Hopkinsville sighting in 1955, two rural Kentucky men described a supposed encounter with metallic-silver, somewhat humanoid-looking aliens no more than 4 feet (1.2 m) in height. Employing journalistic licence and deviating from the witnesses' accounts, The Evansville Courier used the term "little green men" in writing up the story. Other media then followed suit. == History of the term == Usage of the term clearly predates the 1955 incident; for example, in England reference to little green men or children dates back to the 12th century green children of Woolpit, although exactly when the term was first applied to extraterrestrial aliens has been difficult to pin down. In his historical satire A History of New York (1809), American author Washington Irving described Lunatics (or men from the Moon) as "pea green", in contrast to the "white" inhabitants of Earth. Science fiction scholar Adam Roberts writes that these may be the first green aliens


id: little-green-men-20260505-1
file: data/en.wikipedia.org/wiki/Little_green_men-1.md
category: reference
title: Little green men
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Little_green_men
date_saved: 2026-05-05T11:09:48.295549+00:00
instance: kb-cron
parent: little-green-men-20260505-0
summary:
== Origins and other uses == The term also shows up much earlier in other contexts. Film gossip columnist Hedda Hopper used it in 1939 referring to small cast members of The Wizard of Oz (1939), and admonished against drinking on the set. In 1942, The Los Angeles Times used the term in a pictorial on Marines training for jungle combat. In this case, "little green men" referred to camouflaged Japanese soldiers. The Washington Post in 1942 likewise used the term "little green man" in reference to a camouflaged Japanese sniper who nearly killed one of their war correspondents. Before its more modern application to aliens, little green men was commonly used to describe various supernatural beings in old legends and folklore and in later fairy tales and children's books such as goblins. Aubeck noted several examples of the latter in 19th and early 20th century literature. As an example, Rudyard Kipling had a "little green man" in Puck of Pook's Hill from 1906. Another example, and the earliest use of little green man in The New York Times and the Chicago Tribune, dates from 1902, in a review of a children's book called The Gift of the Magic Staff,


id: metalaw-20260505-0
file: data/en.wikipedia.org/wiki/Metalaw-0.md
category: reference
title: Metalaw
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Metalaw
date_saved: 2026-05-05T11:09:49.474589+00:00
instance: kb-cron
parent: metalaw-20260505-0
summary:
Metalaw is “the entire sum of legal rules regulating relationships between different races in the universe.” It is a concept of space law closely related to the scientific Search for Extraterrestrial Intelligence (SETI). The idea is an elaboration of Immanuel Kant's Categorical imperative "Act only according to that maxim whereby you can at the same time will that it should become a universal law." == Andrew Haley and the origin of Metalaw == First articulated by attorney Andrew G. Haley in 1956, Metalaw was the term Haley coined to refer to his hypothesis regarding the proposed existence of fundamental legal precepts of theoretically universal application to all intelligences, both human and hypothesized intelligent extraterrestrial life. Writer Frank G. Anderson proposed that the definition be expanded to cover all intelligent species, extraterrestrial and terrestrial - which would include any/all intelligent animal life. In 1956, Haley first published an article entitled “Space Law and Metalaw – A Synoptic View”, in which Haley first proposed what he called an “Interstellar Golden Rule”: Do unto others as they would have you do unto them. According to Haley, humans can project only one principle of human law onto our possible future relations with extraterrestrial intelligence:


id: the-millennial-project-20260505-0
file: data/en.wikipedia.org/wiki/The_Millennial_Project-0.md
category: reference
title: The Millennial Project
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/The_Millennial_Project
date_saved: 2026-05-05T11:09:50.707695+00:00
instance: kb-cron
parent: the-millennial-project-20260505-0
summary:
The Millennial Project: Colonizing the Galaxy in Eight Easy Steps by Marshall T. Savage is a book (published in 1992 and reprinted in 1994 with an introduction by Arthur C. Clarke) in the field of exploratory engineering that gives a series of concrete stages the author believes will lead to interstellar colonization. Many specific scientific and engineering details are presented, as are numerous issues involved in space colonization. == The book's thesis == Savage takes a Malthusian view of the exponential growth of human population and life in general, and also recommends the exponential growth of blue-green algae for sustenance. He states that it is humanity's destiny to colonize every star in the galaxy. He draws heavily on the Fermi paradox (briefly stated as, "If there is intelligent life in space, why haven't we found it yet?") to support his position that it is humanity's burden alone to ignite the universe with the "spark of Life." In The Millennial Project, he calls for the creation of an international foundation to realize these goals. Originally known as the First Millennial Foundation (founded by Savage in 1987), the organization changed its name to the Living Universe Foundation. == The steps of the


id: paracoccus-denitrificans-20260505-0
file: data/en.wikipedia.org/wiki/Paracoccus_denitrificans-0.md
category: reference
title: Paracoccus denitrificans
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Paracoccus_denitrificans
date_saved: 2026-05-05T11:09:53.098668+00:00
instance: kb-cron
parent: paracoccus-denitrificans-20260505-0
summary:
Paracoccus denitrificans, is a coccoid bacterium known for its nitrate reducing properties, its ability to replicate under conditions of hypergravity and for being a relative of the eukaryotic mitochondrion (endosymbiotic theory). == Description == Paracoccus denitrificans, is a gram-negative, coccus, non-motile, denitrifying (nitrate-reducing) bacterium. It is typically a rod-shaped bacterium but assumes spherical shapes during the stationary phase. Like all gram-negative bacteria, it has a double membrane with a cell wall. Formerly known as Micrococcus denitrificans, it was first isolated in 1910 by Martinus Beijerinck, a Dutch microbiologist. The bacterium was reclassified in 1969 to Paracoccus denitrificans by D.H. Davis. The genome of P. denitrificans was sequenced in 2004. == Ecology and ecological applications == Metabolically Paracoccus denitrificans is very flexible and has been recorded in soil in both aerobic or anaerobic environments. The microbe also has the ability to live in many different kinds of media and environments and is known to be an extremophile. The bacteria are able to obtain energy both from organic compounds, such as methanol and methylamine, and from inorganic compounds, such as hydrogen and sulfur. The ability to metabolise compounds of hydrogen and sulfur, such as thiosulfate has led to the microbe being exploited


id: pioneer-10-20260505-0
file: data/en.wikipedia.org/wiki/Pioneer_10-0.md
category: reference
title: Pioneer 10
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_10
date_saved: 2026-05-05T11:09:54.283817+00:00
instance: kb-cron
parent: pioneer-10-20260505-0
summary:
Pioneer 10 (originally designated Pioneer F) is a NASA space probe launched in 1972 that completed the first mission to the planet Jupiter. Pioneer 10 became the first of five artificial objects to achieve the escape velocity needed to leave the Solar System. This space exploration project was conducted by the NASA Ames Research Center in California. The space probe was manufactured by TRW Inc. Pioneer 10 was assembled around a hexagonal bus with a 2.74-meter (9 ft 0 in) diameter parabolic dish high-gain antenna, and the spacecraft was spin stabilized around the axis of the antenna. Its electric power was supplied by four radioisotope thermoelectric generators that provided a combined 155 watts at launch. It was launched on March 3, 1972, at 01:49:00 UTC (March 2 local time), by an Atlas-Centaur rocket from Cape Canaveral, Florida. Between July 15, 1972, and February 15, 1973, it became the first spacecraft to traverse the asteroid belt. Photography of Jupiter began on November 6, 1973, at a range of 25 million kilometers (16 million miles), and about 500 images were transmitted. The closest approach to the planet was on December 3, 1973, at a range of 132,252 kilometers (82,178 mi). During the


id: pioneer-10-20260505-1
file: data/en.wikipedia.org/wiki/Pioneer_10-1.md
category: reference
title: Pioneer 10
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_10
date_saved: 2026-05-05T11:09:54.283817+00:00
instance: kb-cron
parent: pioneer-10-20260505-0
summary:
=== History === In the 1960s, American aerospace engineer Gary Flandro of the NASA Jet Propulsion Laboratory conceived of a mission, known as the Planetary Grand Tour, that would exploit a rare alignment of the outer planets of the Solar System. This mission would ultimately be accomplished in the late 1970s by the two Voyager probes, but in order to prepare for it, NASA decided in 1964 to experiment with launching a pair of probes to the outer Solar System. An advocacy group named the Outer Space Panel and chaired by American space scientist James A. Van Allen, worked out the scientific rationale for exploring the outer planets. NASA Goddard Spaceflight Center put together a proposal for a pair of "Galactic Jupiter Probes" that would pass through the asteroid belt and visit Jupiter. These were to be launched in 1972 and 1973 during favorable windows that occurred only a few weeks every 13 months. Launch during other time intervals would have been more costly in terms of propellant requirements. Approved by NASA in February 1969, the twin spacecraft were designated Pioneer F and Pioneer G before launch; later, they were named Pioneer 10 and Pioneer 11 respectively. They formed part


id: pioneer-10-20260505-2
file: data/en.wikipedia.org/wiki/Pioneer_10-2.md
category: reference
title: Pioneer 10
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_10
date_saved: 2026-05-05T11:09:54.283817+00:00
instance: kb-cron
parent: pioneer-10-20260505-0
summary:
Pioneer 10 uses four SNAP-19 radioisotope thermoelectric generators (RTGs). They are positioned on two three-rod trusses, each 3 meters (9.8 ft) in length and 120 degrees apart. This was expected to be a safe distance from the sensitive scientific experiments carried on board. Combined, the RTGs provided 155 W at launch, and decayed to 140 W in transit to Jupiter. The spacecraft required 100 W to power all systems. The generators are powered by the radioisotope fuel plutonium-238, which is housed in a multi-layer capsule protected by a graphite heat shield. The pre-launch requirement for the SNAP-19 was to provide power for two years in space; this was greatly exceeded during the mission. The plutonium-238 has a half-life of 87.74 years, so that after 29 years the radiation being generated by the RTGs was at 80% of its intensity at launch. However, steady deterioration of the thermocouple junctions led to a more rapid decay in electrical power generation, and by 2001 the total power output was 65 W. As a result, later in the mission only selected instruments could be operated at any one time. The space probe includes a redundant system of transceivers, one attached to the narrow-beam, high-gain


id: pioneer-10-20260505-3
file: data/en.wikipedia.org/wiki/Pioneer_10-3.md
category: reference
title: Pioneer 10
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_10
date_saved: 2026-05-05T11:09:54.283817+00:00
instance: kb-cron
parent: pioneer-10-20260505-0
summary:
Pioneer 10 was launched on March 3, 1972, at 01:49:00 UTC (8:49 p.m. Eastern Standard Time on March 2) by the National Aeronautics and Space Administration from Space Launch Complex 36A in Florida, aboard an Atlas-Centaur. The third stage of the expendable vehicle consisted of a solid fuel Star-37E stage (TE-M-364-4) developed specifically for the Pioneer missions. This stage provided about 67 kilonewtons (15,000 lbf) of thrust and spun up the spacecraft. The spacecraft had an initial spin rate of 30 rpm. Twenty minutes following the launch, the vehicle's three booms were extended, which slowed the rotation rate to 4.8 rpm. This rate was maintained throughout the voyage. The launch vehicle accelerated the probe for a net interval of 17 minutes, reaching a velocity of 51,682 km/h (32,114 mph). After the high-gain antenna was contacted, several of the instruments were activated for testing while the spacecraft was moving through the Earth's radiation belts. Ninety minutes after launch, the spacecraft reached interplanetary space. Pioneer 10 passed by the Moon in 11 hours, and became the fastest human-made object at that time. Two days after launch, the scientific instruments were turned on, beginning with the cosmic ray telescope. After ten days, all


id: pioneer-10-20260505-4
file: data/en.wikipedia.org/wiki/Pioneer_10-4.md
category: reference
title: Pioneer 10
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_10
date_saved: 2026-05-05T11:09:54.283817+00:00
instance: kb-cron
parent: pioneer-10-20260505-0
summary:
=== Encounter with Jupiter === On November 6, 1973, the Pioneer 10 spacecraft was at a distance of 25 million km (16 million mi) from Jupiter. Testing of the imaging system began, and the data were successfully received back at the Deep Space Network. A series of 16,000 commands were then uploaded to the spacecraft to control the flyby operations during the next sixty days. The orbit of the outer moon Sinope was crossed on November 8. The bow shock of Jupiter's magnetosphere was reached on November 16, as indicated by a drop in the velocity of the solar wind from 451 km/s (280 mi/s) to 225 km/s (140 mi/s). The magnetopause was passed through a day later. The spacecraft instruments confirmed that the magnetic field of Jupiter was inverted compared to that of Earth. By the 29th, the orbits of all of the outermost moons had been passed, and the spacecraft was operating flawlessly. Red and blue pictures of Jupiter were being generated by the imaging photopolarimeter as the rotation of the spacecraft carried the instrument's field of view past the planet. These red and blue colors were combined to produce a synthetic green image, allowing a three-color combination


id: pioneer-10-20260505-5
file: data/en.wikipedia.org/wiki/Pioneer_10-5.md
category: reference
title: Pioneer 10
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_10
date_saved: 2026-05-05T11:09:54.283817+00:00
instance: kb-cron
parent: pioneer-10-20260505-0
summary:
=== Deep space === Pioneer 10 crossed the orbit of Saturn in 1976 and the orbit of Uranus in 1979. On June 13, 1983, the craft crossed the orbit of Neptune, and so became the first human-made object to leave the proximity of the major planets of the Solar System. The mission came to an official end on March 31, 1997, when it had reached a distance of 67 AU (10.0 billion km; 6.2 billion mi) from the Sun, though the spacecraft was still able to transmit coherent data after this date. After March 31, 1997, Pioneer 10's weak signal continued to be tracked by the Deep Space Network to aid the training of flight controllers in the process of acquiring deep-space radio signals. There was an Advanced Concepts study applying chaos theory to extract coherent data from the fading signal. The last successful reception of telemetry was received from Pioneer 10 on April 27, 2002; subsequent signals were barely strong enough to detect and provided no usable data. The final, very weak signal from Pioneer 10 was received on January 23, 2003, when it was 12 billion km (80 AU; 7.5 billion mi) from Earth. Further attempts to contact


id: pioneer-plaque-20260505-0
file: data/en.wikipedia.org/wiki/Pioneer_plaque-0.md
category: reference
title: Pioneer plaque
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_plaque
date_saved: 2026-05-05T11:09:55.546082+00:00
instance: kb-cron
parent: pioneer-plaque-20260505-0
summary:
The Pioneer plaques are a pair of gold-anodized aluminium plaques that were placed on board the 1972 Pioneer 10 and 1973 Pioneer 11 spacecraft, featuring a pictorial message, in case either Pioneer 10 or 11 is intercepted by intelligent extraterrestrial life. The plaques show the nude figures of a human male and female along with several symbols that are designed to provide information about the origin of the spacecraft. The Pioneer 10 and 11 spacecraft were the first human-built objects to achieve escape velocity from the Solar System. The plaques were attached to the spacecraft's antenna support struts in a position that would shield them from erosion by interstellar dust. == History == The original idea, that the Pioneer spacecraft should carry a message from mankind, was first mentioned by Eric Burgess when he visited the Jet Propulsion Laboratory in Pasadena, California, during the Mariner 9 mission. He approached Carl Sagan, who had lectured about communication with intelligent extraterrestrials at a conference in Crimea. Sagan was enthusiastic about the idea of sending a message with the Pioneer spacecraft. NASA agreed to the plan and gave him three weeks to prepare a message. Together with Frank Drake he designed the plaque,


id: pioneer-plaque-20260505-1
file: data/en.wikipedia.org/wiki/Pioneer_plaque-1.md
category: reference
title: Pioneer plaque
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_plaque
date_saved: 2026-05-05T11:09:55.546082+00:00
instance: kb-cron
parent: pioneer-plaque-20260505-0
summary:
The radial pattern on the left of the plaque shows 15 lines emanating from the same origin. Fourteen of the lines have corresponding long binary numbers, which stand for the periods of pulsars, using the hydrogen spin-flip transition frequency as the unit. Since these periods will change over time, the epoch of the launch can be calculated from these values. The lengths of the lines show the relative distances of the pulsars to the Sun. A tick mark at the end of each line gives the z coordinate perpendicular to the galactic plane. If the plaque is found, only some of the pulsars may be visible from the location of its discovery. Showing the location with as many as 14 pulsars provides redundancy so that the location of the origin can be triangulated even if only some of the pulsars are recognized. The data for one of the pulsars is misleading. When the plaque was designed, the frequency of pulsar "1240" (now known as J1243-6423) was known to only three significant decimal digits: 0.388 second. The map lists the period of this pulsar in binary to much greater precision: 100000110110010110001001111000. Rounding this off at about 10 significant bits (100000110100000000000000000000) would


id: pioneer-plaque-20260505-2
file: data/en.wikipedia.org/wiki/Pioneer_plaque-2.md
category: reference
title: Pioneer plaque
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Pioneer_plaque
date_saved: 2026-05-05T11:09:55.546082+00:00
instance: kb-cron
parent: pioneer-plaque-20260505-0
summary:
== Criticism == One of the parts of the diagram that is among the easiest for humans to understand may be among the hardest for potential extraterrestrial finders to understand: the arrow showing the trajectory of Pioneer. Ernst Gombrich criticized the use of an arrow because arrows are an artifact of hunter-gatherer societies like those on Earth; finders with a different cultural heritage may find the arrow symbol meaningless. Art critic Craig Owens said that sexual bias is exhibited by the decision to have the man in the diagram perform the raised hand gesture to greet the extraterrestrials while the woman in the diagram has her hands at her sides. Feminists also took issue with this choice for the same reason. To appease these criticisms, the Voyager Golden Record contains a "Diagram of vertebrate evolution" with an illustration of a similar couple where the woman raises her hand instead. Carl Sagan regretted that the figures in the finished engraving failed to look "panracial". Although this was the intent, the final figures were criticized for looking too white. In the original drawing, in the attempt to represent "at least three of the major races of mankind", the woman was given eyes


id: planetarium-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Planetarium_hypothesis-0.md
category: reference
title: Planetarium hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planetarium_hypothesis
date_saved: 2026-05-05T11:09:56.785470+00:00
instance: kb-cron
parent: planetarium-hypothesis-20260505-0
summary:
The planetarium hypothesis, conceived in 2001 by Stephen Baxter, attempts to provide a solution to the Fermi paradox by holding that our astronomical observations represent an illusion, created by a Type III civilization capable of manipulating matter and energy on galactic scales. He postulates that we do not see evidence of extraterrestrial life because the universe has been engineered so that it appears empty of other life. == Background == There is no reliable or reproducible evidence that aliens have visited Earth. No transmissions or evidence of intelligent extraterrestrial life have been detected or observed anywhere other than Earth in the Universe. This runs counter to the knowledge that the Universe is filled with a very large number of planets, some of which likely hold the conditions hospitable for life. Life on Earth has shown the tendency to typically expand until it fills all available niches. These contradictory facts form the basis for the Fermi paradox, of which the planetarium hypothesis is one proposed solution. == Criticism == The hypothesis has been considered by some authors as speculative and even next to useless in any practical scientific sense and more related to the theological mode of thinking along with the


id: planetary-habitability-in-the-solar-system-20260505-0
file: data/en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System-0.md
category: reference
title: Planetary habitability in the Solar System
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System
date_saved: 2026-05-05T11:09:58.027696+00:00
instance: kb-cron
parent: planetary-habitability-in-the-solar-system-20260505-0
summary:
Planetary habitability in the Solar System is the study that searches the possible existence of past or present extraterrestrial life in those celestial bodies. As exoplanets are too far away and can only be studied by indirect means, the celestial bodies in the Solar System allow for a much more detailed study: direct telescope observation, space probes, rovers and even human spaceflight. Aside from Earth, no planets in the solar system are known to harbor life. Mars, Europa, and Titan are considered to have once had or currently have conditions permitting the existence of life. Multiple rovers have been sent to Mars, while Europa Clipper is planned to reach Europa in 2030, and the Dragonfly space probe is planned to launch in 2027. == Outer space == The vacuum of outer space is a harsh environment. Besides the vacuum itself, temperatures are extremely low and there is a high amount of radiation from the Sun. Multicellular life cannot endure such conditions. Bacteria can not thrive in the vacuum either, but may be able to survive under special circumstances. An experiment by microbiologist Akihiko Yamagishi held at the International Space Station exposed a group of bacteria to the vacuum, completely unprotected,


id: planetary-habitability-in-the-solar-system-20260505-1
file: data/en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System-1.md
category: reference
title: Planetary habitability in the Solar System
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System
date_saved: 2026-05-05T11:09:58.027696+00:00
instance: kb-cron
parent: planetary-habitability-in-the-solar-system-20260505-0
summary:
Earth is the only celestial body known for sure to have generated living beings, and thus the only current example of a habitable planet. At a distance of 1 AU from the Sun, it is within the circumstellar habitable zone of the Solar system, which means it can have oceans of water in a liquid state. There also exist a great number of elements required by lifeforms, such as carbon, oxygen, nitrogen, hydrogen, and phosphorus. The Sun provides energy for most ecosystems on Earth, processed by vegetals with photosynthesis. However, there are also ecosystems that form in places that never receive sunlight, such as deep areas of Earth's oceans. Organisms in these environments must utilize other forms of energy production. One such example is chemosynthesis, which takes place in isolated environments like Movile Cave. The atmosphere of Earth also plays an important role. The ozone layer protects the planet from the harmful radiations from the Sun, and free oxygen is abundant enough for the breathing needs of terrestrial life. Earth's magnetosphere, generated by its active core, is also important for the long-term habitability of Earth, as it prevents the solar winds from stripping the atmosphere out of the planet. The


id: planetary-habitability-in-the-solar-system-20260505-2
file: data/en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System-2.md
category: reference
title: Planetary habitability in the Solar System
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System
date_saved: 2026-05-05T11:09:58.027696+00:00
instance: kb-cron
parent: planetary-habitability-in-the-solar-system-20260505-0
summary:
Mars is the celestial body in the solar system with the most similarities to Earth. A Mars sol lasts almost the same amount of time as an Earth day, and its axial tilt gives it similar seasons. There is water on Mars, most of it frozen at the Martian polar ice caps, and some of it underground. However, there are many obstacles to its habitability. The surface temperature averages about -60 degrees Celsius (-80 degrees Fahrenheit). There are no permanent bodies of liquid water on the surface. The atmosphere is thin, and more than 96% of it is carbon dioxide, which is toxic. Its atmospheric pressure is below 1% that of Earth. Combined with its lack of a magnetosphere, Mars is open to harmful radiation from the Sun. Although no astronauts have set foot on Mars, the planet has been studied in great detail by rovers. So far, no native lifeforms have been found. The origin of the potential biosignature of methane observed in the atmosphere of Mars is unexplained, although hypotheses not involving life have been proposed. These conditions may have been different in the past. Mars could have had bodies of water, a thicker atmosphere, and a working


id: planetary-habitability-in-the-solar-system-20260505-3
file: data/en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System-3.md
category: reference
title: Planetary habitability in the Solar System
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System
date_saved: 2026-05-05T11:09:58.027696+00:00
instance: kb-cron
parent: planetary-habitability-in-the-solar-system-20260505-0
summary:
Beneath its icy surface, Europa may have a liquid ocean, which could be a habitable environment. This potential ocean was first noticed by the two Voyager spacecraft and later backed by telescope studies from Earth. Current estimations consider that this ocean may contain twice the amount of water of all Earth's oceans combined, despite Europa's smaller size. The ice crust would be between 15 and 25 miles thick and may represent an obstacle to studying this ocean, though it may be probed via possible eruption columns that reach outer space. Life would need liquid water, a number of chemical elements, and a source of energy. Although Europa may have the first two elements, it is unconfirmed whether it has all three of them. A potential source of energy would be a hydrothermal vent, which has not been detected yet. Solar light is not considered a viable energy source, as it is too weak in the Jupiter system and would also have to cross the thick ice surface. Other proposed energy sources, although still speculative, are the magnetosphere of Jupiter and kinetic energy. Unlike the oceans of Earth, the oceans of Europa would be under a permanent thick ice layer, which


id: planetary-habitability-in-the-solar-system-20260505-4
file: data/en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System-4.md
category: reference
title: Planetary habitability in the Solar System
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Planetary_habitability_in_the_Solar_System
date_saved: 2026-05-05T11:09:58.027696+00:00
instance: kb-cron
parent: planetary-habitability-in-the-solar-system-20260505-0
summary:
Titan, the largest moon of Saturn, is the only known moon in the Solar System with a significant atmosphere. Data from the Cassini–Huygens mission refuted the hypothesis of a global hydrocarbon ocean, but later demonstrated the existence of liquid hydrocarbon lakes in the polar regions—the first stable bodies of surface liquid discovered outside Earth. Further data from Cassini have strengthened evidence that Titan likely harbors a layer of liquid water under its ice shell. Analysis of data from the mission has uncovered aspects of atmospheric chemistry near the surface that are consistent with—but do not prove—the hypothesis that organisms there, if present, could be consuming hydrogen, acetylene and ethane, and producing methane. NASA's Dragonfly mission is slated to land on Titan in the mid-2030s with a VTOL-capable rotorcraft with a launch date set for 2027. == Uranus == The planet Uranus, an ice giant, is unlikely to be habitable. The local temperatures and pressures may be too extreme, and the materials too volatile. The only spacecraft to visit, and thus observe, Uranus and its moons in detail is Voyager 2 in 1986. === Uranian moons === The five major moons of Uranus, however, may have been home to tidally heated


id: post-detection-policy-20260505-0
file: data/en.wikipedia.org/wiki/Post-detection_policy-0.md
category: reference
title: Post-detection policy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Post-detection_policy
date_saved: 2026-05-05T11:09:59.271450+00:00
instance: kb-cron
parent: post-detection-policy-20260505-0
summary:
A post-detection policy (PDP), also known as a post-detection protocol, is a set of structured rules, standards, guidelines, or actions that governmental or other organizational entities plan to follow for the "detection, analysis, verification, announcement, and response to" confirmed signals from extraterrestrial civilizations. Though no PDPs have been formally and openly adopted by any governmental entity, there is significant work being done by scientists and nongovernmental organizations to develop cohesive plans of action to utilize in the event of detection. The most popular and well known of these is the "Declaration of Principles Concerning Activities Following the Detection of Extraterrestrial Intelligence", which was developed by the International Academy of Astronautics (IAA), with the support of the International Institute of Space Law. The theories of PDPs constitute a distinct area of research but draw heavily from the fields of SETI (the Search for Extra-Terrestrial Intelligence), METI (Messaging to Extra-Terrestrial Intelligence), and CETI (Communication with Extraterrestrial Intelligence). Scientist Zbigniew Paptrotny has argued that the formulation of post-detection protocols can be guided by three factors: terrestrial society's readiness to accept the news of ET detection, how the news of detection is released, and the comprehensibility of the message in the signal. These three


id: post-detection-policy-20260505-1
file: data/en.wikipedia.org/wiki/Post-detection_policy-1.md
category: reference
title: Post-detection policy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Post-detection_policy
date_saved: 2026-05-05T11:09:59.271450+00:00
instance: kb-cron
parent: post-detection-policy-20260505-0
summary:
Regardless of the nature of a confirmed detection, PDPs also place considerable emphasis on the range of likely reactions from different constituencies, including the press, various religious groups, political leaders, and the general public. The differences in reactions across the range of cultural and religious boundaries would be substantial. One possible strategy for development of more comprehensive PDPs is to undertake carefully planned cross-cultural polls and other empirical studies based on analogues in the humanities and history, the social and behavioral sciences, and even science fiction to determine likely reactions. Shortly after a confirmed detection, the timely application of relevant interdisciplinary data is likely to prove invaluable in implementing the appropriate policy as well as in the delivery of educational and public relations initiatives particular to the situation at hand. Another potential strategy is to explore the capacity of religion as a "resource to absorb the impact of discovery and to maintain beneficial relations with ETI." PDPs also attempt to take into account the political aftermath of a detection and the ways in which both governmental and nongovernmental entities might use information. As Michael Michaud states, "We cannot assume that SETI is immune from the ancient motivations of egoism, power,


id: post-detection-policy-20260505-2
file: data/en.wikipedia.org/wiki/Post-detection_policy-2.md
category: reference
title: Post-detection policy
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Post-detection_policy
date_saved: 2026-05-05T11:09:59.271450+00:00
instance: kb-cron
parent: post-detection-policy-20260505-0
summary:
=== Relative technological capabilities === In considering post-detection courses of action, it is also useful to consider the relative technological capabilities both in relation to signal relay time and in relation to whether or not the ETI is thought to pose a militaristic threat. If the ETI in question is transmitting from outside the Solar System, there will be a significant lag in time between transmission and receipt by either party. The relative sophistication of the communication technology available to each party would play heavily into the feasibility of certain types and content of messaging. In a similar vein, the potential disparities in sophistication of weapons technology hold grave implications for how humankind should react to ETI. Due to the perceived risk of revealing the precise location of the Earth to alien civilizations, METI has been heavily criticized as irresponsible considering the lack of information available about any real or potential ETI threat. Even in the likely scenario that accurate locational coordinates of Earth were available, there is question as to whether humankind should reveal anything more about itself that could be a boon to hostile ETI. Notable among the critics of METI were the (late) British theoretical physicist Stephen


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-0.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
The cultural impact of extraterrestrial contact is the corpus of changes to terrestrial science, technology, religion, politics, and ecosystems resulting from contact with an extraterrestrial civilization. This concept is closely related to the search for extraterrestrial intelligence (SETI), which attempts to locate intelligent life as opposed to analyzing the implications of contact with that life. The potential changes from extraterrestrial contact could vary greatly in magnitude and type, based on the extraterrestrial civilization's level of technological advancement, degree of benevolence or malevolence, and level of mutual comprehension between itself and humanity. The medium through which humanity is contacted, be it electromagnetic radiation, direct physical interaction, extraterrestrial artifact, or otherwise, may also influence the results of contact. Incorporating these factors, various systems have been created to assess the implications of extraterrestrial contact. The implications of extraterrestrial contact, particularly with a technologically superior civilization, have often been likened to the meeting of two vastly different human cultures on Earth, a historical precedent being the Columbian Exchange. Such meetings have generally led to the destruction of the civilization receiving contact (as opposed to the "contactor", which initiates contact), and therefore destruction of human civilization is a possible outcome. Extraterrestrial contact is also analogous


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-1
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-1.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
The implications of extraterrestrial contact depend on the method of discovery, the nature of the extraterrestrial beings, and their location relative to the Earth. Considering these factors, the Rio scale has been devised in order to provide a more quantitative picture of the results of extraterrestrial contact. More specifically, the scale gauges whether communication was conducted through radio, the information content of any messages, and whether discovery arose from a deliberately beamed message (and if so, whether the detection was the result of a specialized SETI effort or through general astronomical observations) or by the detection of occurrences such as radiation leakage from astroengineering installations. The question of whether or not a purported extraterrestrial signal has been confirmed as authentic, and with what degree of confidence, will also influence the impact of the contact. The Rio scale was modified in 2011 to include a consideration of whether contact was achieved through an interstellar message or through a physical extraterrestrial artifact, with a suggestion that the definition of artifact be expanded to include "technosignatures", including all indications of intelligent extraterrestrial life other than the interstellar radio messages sought by traditional SETI programs. A study by astronomer Steven J. Dick at the


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-2
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-2.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
Any person or organization detecting a signal should try to verify that it is likely to be of intelligent origin before announcing it. The discoverer of a signal should, for the purposes of independent verification, communicate with other signatories of the Declaration before making a public announcement, and should also inform their national authorities. Once a given astronomical observation has been determined to be a credible extraterrestrial signal, the astronomical community should be informed through the Central Bureau for Astronomical Telegrams of the IAU. The Secretary-General of the United Nations and various other global scientific unions should also be informed. Following confirmation of an observation's extraterrestrial origin, news of the discovery should be made public. The discoverer has the right to make the first public announcement. All data confirming the discovery should be published to the international scientific community and stored in an accessible form as permanently as possible. Should evidence for extraterrestrial intelligence take the form of electromagnetic signals, the Secretary-General of the International Telecommunication Union (ITU) should be contacted, and may request in the next ITU Weekly Circular to minimize terrestrial use of the electromagnetic frequency bands in which the signal was detected. Neither the discoverer nor anyone


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-3
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-3.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
Futurist Allen Tough suggests that an extremely advanced extraterrestrial civilization, recalling its own past of war and plunder and knowing that it possesses superweapons that could destroy it, would be likely to try to help humans rather than to destroy them. He identifies three approaches that a friendly civilization might take to help humanity: Intervention only to avert catastrophe: this would involve occasional limited intervention to stop events that could destroy human civilization completely, such as nuclear war or asteroid impact. Advice and action with consent: under this approach, the extraterrestrials would be more closely involved in terrestrial affairs, advising world leaders and acting with their consent to protect against danger. Forcible corrective action: the extraterrestrials could require humanity to reduce major risks against its will, intending to help humans advance to the next stage of civilization. Tough considers advising and acting only with consent to be a more likely choice than the forceful option. While coercive aid may be possible, and advanced extraterrestrials would recognize their own practices as superior to those of humanity, it may be unlikely that this method would be used in cultural cooperation. Lemarchand suggests that instruction of a civilization in its "technological adolescence", such


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-4
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-4.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
=== Hostile civilizations === Science fiction often depicts humans successfully repelling alien invasions, but scientists more often take the view that an extraterrestrial civilization with sufficient power to reach the Earth would be able to destroy human civilization or humanity with minimal effort. Operations that are enormous on a human scale, such as destroying all major population centers on a planet, bombarding a planet with deadly neutron radiation, or even traveling to another planetary system in order to lay waste to it, may be important tools for a hostile civilization. Deardorff speculates that a small proportion of the intelligent life forms in the galaxy may be aggressive, but the actual aggressiveness or benevolence of the civilizations would cover a wide spectrum, with some civilizations "policing" others. As among humans, civilizations may not be homogeneous and contain different factions or subgroups. According to Harrison and Dick, hostile extraterrestrial life may indeed be rare in the Universe, just as belligerent and autocratic nations on Earth have been the ones that lasted for the shortest periods of time, and humanity is seeing a shift away from these characteristics in its own sociopolitical systems. In addition, the causes of war may be diminished greatly


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-5
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-5.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
=== Equally advanced and more advanced civilizations === Robert Freitas speculated in 1978 that the technological advancement and energy usage of a civilization, measured either relative to another civilization or in absolute terms by its rating on the Kardashev scale, may play an important role in the result of extraterrestrial contact. Given the infeasibility of interstellar space flight for civilizations at a technological level similar to that of humanity, interactions between such civilizations would have to take place by radio. Because of the long transit times of radio waves between stars, such interactions would not lead to the establishment of diplomatic relations, nor any significant future interaction at all, between the two civilizations. According to Freitas, direct contact with civilizations significantly more advanced than humanity would have to take place within the Solar System, as only the more advanced society would have the resources and technology to cross interstellar space. Consequently, such contact could only be with civilizations rated as Type II or higher on the Kardashev scale, as Type I civilizations would be incapable of regular interstellar travel. Freitas expected that such interactions would be carefully planned by the more advanced civilization to avoid mass societal shock for humanity.


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-6
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-6.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
Given the age of the galaxy, Harrison surmises that "galactic clubs" might exist, groupings of civilizations from across the galaxy. Such clubs could begin as loose confederations or alliances, eventually developing into powerful unions of many civilizations. If humanity could enter into a dialogue with one extraterrestrial civilization, it might be able to join such a galactic club. As more extraterrestrial civilizations, or unions thereof, are found, these could also become assimilated into such a club. Sebastian von Hoerner has suggested that entry into a galactic club may be a way for humanity to handle the culture shock arising from contact with an advanced extraterrestrial civilization. Whether a broad spectrum of civilizations from many places in the galaxy would even be able to cooperate is disputed by Michaud, who states that civilizations with huge differences in the technologies and resources at their command "may not consider themselves even remotely equal". It is unlikely that humanity would meet the basic requirements for membership at its current low level of technological advancement. A galactic club may, William Hamilton speculates, set extremely high entrance requirements that are unlikely to be met by less advanced civilizations. When two Canadian astronomers argued that they potentially


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-7
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-7.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
An extraterrestrial civilization may choose to communicate with humanity by means of artifacts or probes rather than by radio, for various reasons. While probes may take a long time to reach the Solar System, once there they would be able to hold a sustained dialogue that would be impossible using radio from hundreds or thousands of light-years away. Radio would be completely unsuitable for surveillance and continued monitoring of a civilization, and should an extraterrestrial civilization wish to perform these activities on humanity, artifacts may be the only option other than to send large, crewed spacecraft to the Solar System. Although faster-than-light travel has been seriously considered by physicists such as Miguel Alcubierre, Tough speculates that the enormous amount of energy required to achieve such speeds under currently proposed mechanisms means that robotic probes traveling at conventional speeds will still have an advantage for various applications. 2013 research at NASA's Johnson Space Center, however, shows that faster-than-light travel with the Alcubierre drive requires dramatically less energy than previously thought, needing only about 1 tonne of exotic mass-energy to move a spacecraft at 10 times the speed of light, in contrast to previous estimates that stated that only a Jupiter-mass object


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-8
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-8.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
The confirmation of extraterrestrial intelligence could have a profound impact on religious doctrines, potentially causing theologians to reinterpret scriptures to accommodate the new discoveries. However, a survey of people with many different religious beliefs indicated that their faith would not be affected by the discovery of extraterrestrial intelligence, and another study, conducted by Ted Peters of the Pacific Lutheran Theological Seminary, shows that most people would not consider their religious beliefs superseded by it. Surveys of religious leaders indicate that only a small percentage are concerned that the existence of extraterrestrial intelligence might fundamentally contradict the views of the adherents of their religion. Gabriel Funes, the chief astronomer of the Vatican Observatory and a papal adviser on science, has stated that the Catholic Church would be likely to welcome extraterrestrial visitors warmly. There are many UFO religions such as Raëlism. Astronomer David Weintraub suggests unambiguous contact would result in more of these kinds of beliefs and communities, saying "There undoubtedly would be people who would find this as an opportunity or an excuse to call attention to themselves for whatever reason and there would be new religions". Contact with extraterrestrial intelligence would not be completely inconsequential for religion. The Peters


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-9
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-9.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
According to experts such as Niklas Hedman, executive director of UN Office for Outer Space Affairs, there are "no international agreements or mechanisms in place for how humanity would handle an encounter with extraterrestrial intelligence". Tim Folger speculates that news of radio contact with an extraterrestrial civilization would prove impossible to suppress and would travel rapidly, though Cold War scientific literature on the subject contradicts this. Media coverage of the discovery would probably die down quickly, though, as scientists began to decipher the message and learn its true impact. Different branches of government (for example legislative, executive, and judiciary) may pursue their own policies, potentially giving rise to power struggles. Even in the event of a single contact with no follow-up, radio contact may prompt fierce disagreements as to which bodies have the authority to represent humanity as a whole. Michaud hypothesizes that the fear arising from direct contact may cause nation-states to put aside their conflicts and work together for the common defense of humanity. Apart from the question of who would represent the Earth as a whole, contact could create other international problems, such as the degree of involvement of governments foreign to the one whose radio astronomers


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-10
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-10.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
=== Scientific and technological === The scientific and technological impact of extraterrestrial contact through electromagnetic waves would probably be quite small, especially at first. However, if the message contains a large amount of information, deciphering it could give humans access to a galactic heritage perhaps predating the formation of the Solar System, which may greatly advance our technology and science. A possible negative effect could be to demoralize research scientists as they come to know that what they are researching may already be known to another civilization. On the other hand, extraterrestrial civilizations with malicious intent could send (unfiltered) information that could enable or facilitate human civilization to destroy itself, such as powerful computer viruses, knowledge to build an advanced artificial intelligence or information on how to make extremely potent weapons that humans would not yet be able to use responsibly. While the motives for such an action are unknown, it may require minimal energy use on the part of the extraterrestrials. It may also be possible that such is sent without malicious intent. According to Musso, however, computer viruses in particular will be nearly impossible unless extraterrestrials possess detailed knowledge of human computer architectures, which would only happen if


id: potential-cultural-impact-of-extraterrestrial-contact-20260505-11
file: data/en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact-11.md
category: reference
title: Potential cultural impact of extraterrestrial contact
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Potential_cultural_impact_of_extraterrestrial_contact
date_saved: 2026-05-05T11:10:00.533054+00:00
instance: kb-cron
parent: potential-cultural-impact-of-extraterrestrial-contact-20260505-0
summary:
=== Ethics === Astroethics refers to the contemplation and development of ethical standards for a variety of outer space issues, including questions of how to interact remotely or in close encounters and concerns not only humans' ethics but also ethics of non-human intelligences, including whether they all afford us rights (and which each or overall). Lewis White Beck notes that an analysis of the evolution of philosophical thought from ancient times into the modern era suggests that humanity is often comforted during periods of intense cultural transition by subtle archetypal ideas which are derived from firmly held religious, philosophical, ethical and existential belief systems. He includes mankind's search for extraterrestrial life as a manifestation of such beliefs and argues that even if humanity's search for extraterrestrial life proves to be unsuccessful in the short term, it may have longer term beneficial consequences by inspiring humanity to embrace a superior ethical paradigm. === Ecological and biological-warfare impacts === An extraterrestrial civilization might bring to Earth pathogens or invasive life forms that do not harm its own biosphere. Alien pathogens could decimate the human population, which would have no immunity to them, or they might use terrestrial livestock or plants as hosts,


id: project-cyclops-20260505-0
file: data/en.wikipedia.org/wiki/Project_Cyclops-0.md
category: reference
title: Project Cyclops
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Project_Cyclops
date_saved: 2026-05-05T11:10:01.728120+00:00
instance: kb-cron
parent: project-cyclops-20260505-0
summary:
Project Cyclops is a 1971 NASA project that investigated how the search for extraterrestrial intelligence (SETI) should be conducted. As a NASA product the report is in the public domain. The project team created a design for coordinating large numbers of radio telescopes to search for Earth-like radio signals at a distance of up to 1,000 light-years to find intelligent life. The proposed design involving between 1,000 and 2,500 steerable dishes of 100m diameter each was shelved due to costs. However, the report became the basis for much of the SETI work to follow. The approach NASA devised for SETI was to develop a framework with the present understanding of the universe, and then use that as the basis for increasing the probability of discovering extraterrestrials. Making no assumptions, apart from that extraterrestrial radio signals exist, it focused on scanning the skies for signals that could indicate the presence of intelligent life forms. == Original conclusions == The main conclusions, taken verbatim from the report. The italics are in the original, as is the flowery language (see for example conclusion 12): 1. It is vastly less expensive to look for and to send signals than to attempt contact by spaceship


id: project-cyclops-20260505-1
file: data/en.wikipedia.org/wiki/Project_Cyclops-1.md
category: reference
title: Project Cyclops
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Project_Cyclops
date_saved: 2026-05-05T11:10:01.728120+00:00
instance: kb-cron
parent: project-cyclops-20260505-0
summary:
4. The best part of the microwave region is the low frequency end of the "microwave window"- frequencies from about 1 to 2 or 3 GHz. Again, this is because greater absolute frequency stability is possible there, the Doppler rates are lower, beamwidths are broader for a given gain, and collecting area is cheaper than at the high end of the window. 5. Nature has provided us with a rather narrow quiet band in this best part of the spectrum that seems especially marked for interstellar contact. It lies between the spectral lines of hydrogen (1420 MHz) and the hydroxyl radical (1662 MHz). Standing like the Om and the Um on either side of a gate, these two emissions of the disassociation products of water beckon all water-based life to search for its kind at the age-old meeting place of all species: the water hole. 6. It is technologically feasible today to build phased antenna arrays operable in the 1- to 3 GHz region with total collecting areas of 100 or more square kilometers. The Cyclops system is not nearly this large, but we see no technological limits that would prevent its expansion to such a size. 7. With antenna


id: project-cyclops-20260505-2
file: data/en.wikipedia.org/wiki/Project_Cyclops-2.md
category: reference
title: Project Cyclops
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Project_Cyclops
date_saved: 2026-05-05T11:10:01.728120+00:00
instance: kb-cron
parent: project-cyclops-20260505-0
summary:
Points 4 and 5: Cyclops preferred the low end of the microwave band. With technology advances, the disadvantages of higher frequencies are smaller, and they have other advantages. Anything from microwave to optical looks roughly equivalent. Point 6: The highest frequency of such an array can, and should be, much higher. Point 8: Beacons will probably be pointed, and not omnidirectional. Modern processing power makes this possible, and it is much more energy efficient. Point 9: Although not called out in SETI 2020, the point "Beacons ... will surely be highly monochromatic," has suffered substantial criticism. As Earth's communication technology moves toward spread spectrum signals, SETI observations are being augmented with searches for high bandwidth signals. Furthermore, there are now proposals for beacons that are almost as easy to detect as monochromatic signals, but can contain information as well. Point 10: The optical processing of Cyclops should be replaced by digital signal processing. == Current availability == In the 1970s, 10,000 copies of the Cyclops report were distributed by NASA. It is reasonable to assume that most major figures within the current SETI community have seen the document. As of the 1990s, the Cyclops report had long been out of


id: public-opinion-on-extraterrestrial-life-20260505-0
file: data/en.wikipedia.org/wiki/Public_opinion_on_extraterrestrial_life-0.md
category: reference
title: Public opinion on extraterrestrial life
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Public_opinion_on_extraterrestrial_life
date_saved: 2026-05-05T11:10:02.966579+00:00
instance: kb-cron
parent: public-opinion-on-extraterrestrial-life-20260505-0
summary:
Public opinion on extraterrestrial life refers to the collective beliefs, attitudes, and statistical data regarding the existence of extraterrestrial life and extraterrestrial intelligence (ETI). While scientific consensus has historically been cautious, public opinion surveys from the late 20th and early 21st centuries indicate a widespread belief in the existence of intelligent alien civilizations, often exceeding the confidence levels expressed by the scientific community. == Global surveys == Research conducted on an international scale has revealed significant belief in extraterrestrial civilizations across diverse cultures. Glocalities Study (2017): A survey of 26,492 respondents across 24 countries found that 47% of participants believed in "the existence of intelligent alien civilizations in the universe." The study noted substantial cross-national variation, with belief rates ranging from 45% in the United States to 68% in Russia. The researchers categorized a segment of high-engagement believers as "Homo Universalis," a group characterized by unconventional thinking and high interest in science and politics. Western Nations Comparison (2015): A YouGov survey comparing attitudes in the United Kingdom, Germany, and the United States found that more than one in two people in all three nations believed living creatures with communication abilities exist outside Earth. Specifically, 56% of Germans, 54% of Americans,


id: quiet-and-loud-aliens-20260505-0
file: data/en.wikipedia.org/wiki/Quiet_and_loud_aliens-0.md
category: reference
title: Quiet and loud aliens
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Quiet_and_loud_aliens
date_saved: 2026-05-05T11:10:04.164555+00:00
instance: kb-cron
parent: quiet-and-loud-aliens-20260505-0
summary:
The concept of quiet and loud aliens is used in the modelling of hypotheses for the prevalence of extraterrestrial intelligence, particularly in the context of the Fermi Paradox. Hypothetical "loud" aliens expand their sphere of influence rapidly in a highly detectable way; hypothetical "quiet" aliens are hard or impossible to detect. A special type of loud alien civilizations are "grabby aliens" who also inhibit the development of other technological civilizations in their sphere of influence. Walter Barta argues that Robin Hanson's grabby aliens model creates an anthropic dilemma. According to the model, most observers in our reference class should be grabby aliens themselves. This leads to the question of why we do not find ourselves as grabby aliens, but rather as a species confined to a single planet. == See also == Anthropic principle Dark forest hypothesis Search for extraterrestrial intelligence == References ==


id: rio-scale-20260505-0
file: data/en.wikipedia.org/wiki/Rio_scale-0.md
category: reference
title: Rio scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Rio_scale
date_saved: 2026-05-05T11:10:05.379432+00:00
instance: kb-cron
parent: rio-scale-20260505-0
summary:
The Rio scale was proposed in 2000 as a means of quantifying the significance of a SETI detection. The scale was designed by Iván Almár and Jill Tarter to help tell policy-makers how likely, from 0 to 10, it is that an extraterrestrial radio signal has been produced by an intelligent civilization. The scale is inspired by the Torino scale, which is used to determine the impact risk associated with near-Earth objects. Just as the Torino scale takes into account how significant an object's impact on the planet would be, the Rio scale takes into account how much a public announcement of the discovery of extraterrestrial intelligence would probably impact society. The IAA SETI Permanent Study Group officially adopted the Rio scale as a way of bringing perspective to claims of extraterrestrial intelligence (ETI) detection, and as an acknowledgement that even false ETI detections may have disastrous consequences. The scale was modified in 2011 to include a consideration of whether contact was achieved through an interstellar message or a physical extraterrestrial artifact, including all indications of intelligent extraterrestrial life such as technosignatures. A 2.0 version of the scale was proposed in 2018. == Calculation == In its 2.0 version, the


id: san-marino-scale-20260505-0
file: data/en.wikipedia.org/wiki/San_Marino_scale-0.md
category: reference
title: San Marino scale
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/San_Marino_scale
date_saved: 2026-05-05T11:10:06.576362+00:00
instance: kb-cron
parent: san-marino-scale-20260505-0
summary:
The San Marino scale is a suggested scale for assessing risks associated with deliberate transmissions from Earth aimed to possible extraterrestrial intelligent life. The scale evaluates the significance of transmissions from Earth as a function of signal intensity and information content. The scale was suggested by Iván Almár at a conference in San Marino in 2005. The radio output of Jupiter, Saturn and Neptune is not considered in the model. The San Marino Scale was subsequently adopted by the SETI Permanent Study Group of the International Academy of Astronautics at its 2007 meeting in Hyderabad, India. == Calculation == In the original presentation given by Almár, the San Marino index, SMI, of a given event is calculated as the sum of two terms: S M I = I + C . {\displaystyle \mathrm {SMI} =I+C.} The first term, I, is based on the intensity of the signal relative to the background noise in the same frequency band. This term is logarithmic and calculated as I = log 10 ⁡ ( signal intensity background intensity ) . {\displaystyle I=\log _{10}\left({\frac {\text{signal intensity}}{\text{background intensity}}}\right).} For example, a signal which is 100 times more intense than the background noise at the same frequency


id: space-animal-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Space_animal_hypothesis-0.md
category: reference
title: Space animal hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Space_animal_hypothesis
date_saved: 2026-05-05T11:10:07.827954+00:00
instance: kb-cron
parent: space-animal-hypothesis-20260505-0
summary:
The space animal hypothesis proposes that reports of flying saucers or UFOs might be caused not by technological alien spacecraft or mass hysteria, but rather by animal lifeforms ("space critters") that are indigenous to Earth's atmosphere or interplanetary space. == Proponents == Multiple authors independently suggested the space animal hypothesis. In 1923, paranormal author Charles Fort mused, "It seems no more incredible that up in the seemingly unoccupied sky there should be hosts of living things than that the seeming blank of the ocean should swarm with life." During the 1947 flying disc craze, a fan of Fort's writings named John Philip Bessor became the first modern proponent of the hypothesis when he authored a letter to the Air Force suggesting that discs might be "animals bearing very little likeness to human beings". In 1949, he wrote to the Saturday Evening Post to suggest that the discs might be "more like octopuses, in mentality, than humans". In 1957, a saucer group's newsletter credited Bessor with the "space animal" idea, and in 1978 he was called the "grand-daddy" of the "space critter" hypothesis. In 1948, the Saturday Evening Post quoted Luis Walter Alvarez's opinion that the "gizmos" appeared to be "alive".


id: viking-lander-biological-experiments-20260505-0
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-0.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T11:10:10.219552+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
In 1976 two identical Viking program landers each carried four types of biological experiments to the surface of Mars. The first successful Mars landers, Viking 1 and Viking 2, then carried out experiments to look for biosignatures of microbial life on Mars. The landers each used a robotic arm to pick up and place soil samples into sealed test containers on the craft. The two landers carried out the same tests at two places on Mars' surface, Viking 1 near the equator and Viking 2 further north. == The experiments == The four experiments below are presented in the order in which they were carried out by the two Viking landers. The biology team leader for the Viking program was Harold P. Klein (NASA Ames). === Gas chromatograph – mass spectrometer === A gas chromatograph – mass spectrometer (GCMS) is a device that separates vapor components chemically via a gas chromatograph and then feeds the result into a mass spectrometer, which measures the molecular weight of each chemical. As a result, it can separate, identify, and quantify a large number of different chemicals. The GCMS (PI: Klaus Biemann, MIT) was used to analyze the components of untreated Martian soil, and


id: viking-lander-biological-experiments-20260505-1
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-1.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T11:10:10.219552+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
=== Labeled release === The labeled release (LR) experiment (PI: Gilbert Levin, Biospherics Inc.) gave the most promise for exobiologists. In the LR experiment, a sample of Martian soil was inoculated with a drop of very dilute aqueous nutrient solution. The nutrients (7 molecular compounds that were Miller-Urey products) were tagged with radioactive 14C. The air above the soil was monitored for the evolution of radioactive 14CO2 (or other carbon-based) gas as evidence that microorganisms in the soil had metabolized one or more of the nutrients. Such a result was to be followed with the control part of the experiment as described for the PR below. The result was quite a surprise, considering the negative results of the first two tests, with a steady stream of radioactive gases being given off by the soil immediately following the first injection. The experiment was done by both Viking probes, the first using a sample from the surface exposed to sunlight and the second probe taking the sample from underneath a rock; both initial injections came back positive. Sterilization control tests were subsequently carried out by heating various soil samples. Samples heated for 3 hours at 160 °C gave off no radioactive gas


id: viking-lander-biological-experiments-20260505-2
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-2.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T11:10:10.219552+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
Organic compounds seem to be common, for example, on asteroids, meteorites, comets and the icy bodies orbiting the Sun, so detecting no trace of any organic compound on the surface of Mars came as a surprise. The GC-MS was definitely working, because the controls were effective and it was able to detect traces of chlorine, attributed to the cleaning solvents that had been used to sterilize it prior to launch. A reanalysis of the GC-MS data was performed in 2018, suggesting that organic compounds may actually have been detected, corroborating with data from the Curiosity rover. At the time, the total absence of organic material on the surface made the results of the biology experiments moot, since metabolism involving organic compounds were what those experiments were designed to detect. The general scientific community surmises that the Viking's biological tests remain inconclusive, and can be explained by purely chemical processes. Despite the positive result from the Labeled Release experiment, a general assessment is that the results seen in the four experiments are best explained by oxidative chemical reactions with the Martian soil. One of the current conclusions is that the Martian soil, being continuously exposed to UV light from the Sun


id: viking-lander-biological-experiments-20260505-3
file: data/en.wikipedia.org/wiki/Viking_lander_biological_experiments-3.md
category: reference
title: Viking lander biological experiments
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Viking_lander_biological_experiments
date_saved: 2026-05-05T11:10:10.219552+00:00
instance: kb-cron
parent: viking-lander-biological-experiments-20260505-0
summary:
== Controversy == Before the discovery of the oxidizer perchlorate on Mars in 2008, some theories remained opposed to the general scientific conclusion. An investigator suggested that the biological explanation of the lack of detected organics by GC-MS could be that the oxidizing inventory of the H2O2-H2O solvent well exceeded the reducing power of the organic compounds of the organisms. It has also been argued that the Labeled Release (LR) experiment detected so few metabolising organisms in the Martian soil, that it would have been impossible for the gas chromatograph to detect them. This view has been put forward by the designer of the LR experiment, Gilbert Levin, who believes the positive LR results are diagnostic for life on Mars. He and others have conducted ongoing experiments attempting to reproduce the Viking data, either with biological or non-biological materials on Earth. While no experiment has ever precisely duplicated the Mars LR test and control results, experiments with hydrogen peroxide-saturated titanium dioxide have produced similar results. While the majority of astrobiologists still conclude that the Viking biological experiments were inconclusive or negative, Gilbert Levin is not alone in believing otherwise. The current claim for life on Mars is grounded on old


id: xenofiction-20260505-0
file: data/en.wikipedia.org/wiki/Xenofiction-0.md
category: reference
title: Xenofiction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Xenofiction
date_saved: 2026-05-05T11:10:11.427646+00:00
instance: kb-cron
parent: xenofiction-20260505-0
summary:
Xenofiction is a niche genre of speculative fiction centered on stories told from the viewpoint of non-human characters, particularly animal, often focusing heavily on the effects of the characters' species on their lives, and how their lives differ from those of humans. The genre is closely associated with adventure fiction and is common in children's literature. Xenofiction stories often make use of "soft" anthropomorphism that retains most of the characters' animalness, ecological themes, and invented non-human vocabulary. Well-known examples of the genre include The Call of the Wild and Watership Down. == Characteristics == Literature in the genre of xenofiction focuses on the perspectives of non-human entities, most commonly animals, but also non-humanoid aliens, plants, mythical creatures, and monsters. It contrasts from regular stories that use anthropomorphism as set dressing for stories still ultimately about people and human issues, such as fables. Characters in xenofiction works often have human-like levels of intelligence, but their societies, thought processes and senses are completely unfamiliar to a human reader. In xenofiction focused on wild or feral animals, humans are typically treated as plot devices, monsters, or threats, if they are even aware of human society at all. The worldbuilding of these narratives often


id: zoo-hypothesis-20260505-0
file: data/en.wikipedia.org/wiki/Zoo_hypothesis-0.md
category: reference
title: Zoo hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Zoo_hypothesis
date_saved: 2026-05-05T11:10:12.657699+00:00
instance: kb-cron
parent: zoo-hypothesis-20260505-0
summary:
The zoo hypothesis speculates on the assumed behavior and existence of technologically advanced extraterrestrial life and the reasons they refrain from contacting Earth. It is one of many theoretical explanations for the Fermi paradox. The hypothesis states that extraterrestrial life intentionally avoids communication with Earth to allow for natural evolution and sociocultural development, and avoiding interplanetary contamination, similar to people observing animals at a zoo. The hypothesis seeks to explain the apparent absence of extraterrestrial life despite its generally accepted plausibility and hence the reasonable expectation of its existence. Extraterrestrial life forms might, for example, choose to allow contact once the human species has passed certain technological, political, and/or ethical standards. Alternatively, they may withhold contact until humans force contact upon them, possibly by sending a spacecraft to an extraterrestrial-inhabited planet. In this regard, reluctance to initiate contact could reflect a sensible desire to minimize risk. An extraterrestrial society with advanced remote-sensing technologies may conclude that direct contact with neighbors confers added risks to itself without an added benefit. A variant on the zoo hypothesis suggested by former MIT Haystack Observatory scientist John Allen Ball is the "laboratory" hypothesis, in which humanity is being subjected to experiments, with Earth serving


id: zoo-hypothesis-20260505-1
file: data/en.wikipedia.org/wiki/Zoo_hypothesis-1.md
category: reference
title: Zoo hypothesis
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Zoo_hypothesis
date_saved: 2026-05-05T11:10:12.657699+00:00
instance: kb-cron
parent: zoo-hypothesis-20260505-0
summary:
A modified zoo hypothesis is a possible solution to the Fermi paradox. The time between the emergence of the first civilization within the Milky Way and all subsequent civilizations could be enormous. Monte Carlo simulation shows the first few inter-arrival times between emergent civilizations would be similar in length to geologic epochs on Earth. The zoo hypothesis assumes a civilization may have a ten-million, one-hundred-million, or half-billion-year head start on humanity, i.e., it may have the capability to completely negate our best attempts to detect it. The zoo hypothesis relies in part on applying the concept of hegemonic power to the Fermi paradox. Even if a first hegemonic non-interventionist grand civilization (first civilization) is long gone, their initial legacy could persist in the form of a passed-down tradition, or perhaps in an artificial lifeform (artificial superintelligence) dedicated to a non-interventionist hegemonic goal without the risk of death. Thus, the hegemonic power does not even have to be the first civilization, but simply the first to spread its non-interventionist doctrine and control over a large volume of the galaxy. If just one civilization acquired hegemony in the distant past, it could form an unbroken chain of taboo against rapacious colonization in


id: faster-than-light-20260505-0
file: data/en.wikipedia.org/wiki/Faster-than-light-0.md
category: reference
title: Faster-than-light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Faster-than-light
date_saved: 2026-05-05T11:10:14.212907+00:00
instance: kb-cron
parent: faster-than-light-20260505-0
summary:
Faster-than-light (superluminal or supercausal) travel and communication are the conjectural propagation of matter or information faster than the speed of light in vacuum (c). The special theory of relativity implies that only particles with zero rest mass (i.e., photons) may travel at the speed of light, and that nothing may travel faster. Particles whose speed exceeds that of light (tachyons) have been hypothesized, but their existence would violate causality and would imply time travel. The scientific consensus is that they do not exist. According to all observations and current scientific theories, matter travels at slower-than-light (subluminal) speed with respect to the locally distorted spacetime region. Speculative faster-than-light concepts include the Alcubierre drive, Krasnikov tubes, traversable wormholes, and quantum tunneling. Some of these proposals find loopholes around general relativity, such as by expanding or contracting space to make the object appear to be travelling greater than c. Such proposals are still widely believed to be impossible as they still violate current understandings of causality, and they all require fanciful mechanisms to work (such as requiring exotic matter). == Superluminal travel of non-information == In the context of this article, "faster-than-light" means the transmission of information or matter faster than c, a


id: faster-than-light-20260505-1
file: data/en.wikipedia.org/wiki/Faster-than-light-1.md
category: reference
title: Faster-than-light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Faster-than-light
date_saved: 2026-05-05T11:10:14.212907+00:00
instance: kb-cron
parent: faster-than-light-20260505-0
summary:
=== Proper speeds === If a spaceship travels to a planet one light-year (as measured in the Earth's rest frame) away from Earth at high speed, the time taken to reach that planet could be less than one year as measured by the traveller's clock (although it will always be more than one year as measured by a clock on Earth). The value obtained by dividing the distance traveled, as determined in the Earth's frame, by the time taken, measured by the traveller's clock, is known as a proper speed or a proper velocity. There is no limit on the value of a proper speed as a proper speed does not represent a speed measured in a single inertial frame. A light signal that left the Earth at the same time as the traveller would always get to the destination before the traveller would. === Phase velocities above c === The phase velocity of an electromagnetic wave, when traveling through a medium, can routinely exceed c, the vacuum velocity of light. For example, this occurs in most glasses at X-ray frequencies. However, the phase velocity of a wave corresponds to the propagation speed of a theoretical single-frequency (purely monochromatic) component


id: faster-than-light-20260505-2
file: data/en.wikipedia.org/wiki/Faster-than-light-2.md
category: reference
title: Faster-than-light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Faster-than-light
date_saved: 2026-05-05T11:10:14.212907+00:00
instance: kb-cron
parent: faster-than-light-20260505-0
summary:
=== Quantum mechanics === Certain phenomena in quantum mechanics, such as quantum entanglement, might give the superficial impression of allowing communication of information faster than light. According to the no-communication theorem these phenomena do not allow true communication; they only let two observers in different locations see the same system simultaneously, without any way of controlling what either sees. Wavefunction collapse can be viewed as an epiphenomenon of quantum decoherence, which in turn is nothing more than an effect of the underlying local time evolution of the wavefunction of a system and all of its environment. Since the underlying behavior does not violate local causality or allow faster-than-light communication, it follows that neither does the additional effect of wavefunction collapse, whether real or apparent. The uncertainty principle implies that individual photons may travel for short distances at speeds somewhat faster (or slower) than c, even in vacuum; this possibility must be taken into account when enumerating Feynman diagrams for a particle interaction. However, it was shown in 2011 that a single photon may not travel faster than c. There have been various reports in the popular press of experiments on faster-than-light transmission in optics — most often in the context


id: faster-than-light-20260505-3
file: data/en.wikipedia.org/wiki/Faster-than-light-3.md
category: reference
title: Faster-than-light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Faster-than-light
date_saved: 2026-05-05T11:10:14.212907+00:00
instance: kb-cron
parent: faster-than-light-20260505-0
summary:
The relativistic momentum of a massive particle would increase with speed in such a way that at the speed of light an object would have infinite momentum. To accelerate an object of non-zero rest mass to c would require infinite time with any finite acceleration, or infinite acceleration for a finite amount of time. Either way, such acceleration requires infinite energy. Some observers with sub-light relative motion will disagree about which occurs first of any two events that are separated by a space-like interval. In other words, any travel that is faster-than-light will be seen as traveling backwards in time in some other, equally valid, frames of reference, or need to assume the speculative hypothesis of possible Lorentz violations at a presently unobserved scale (for instance the Planck scale). Therefore, any theory which permits "true" FTL also has to cope with time travel and all its associated paradoxes, or else to assume the Lorentz invariance to be a symmetry of thermodynamical statistical nature (hence a symmetry broken at some presently unobserved scale). In special relativity the coordinate speed of light is only guaranteed to be c in an inertial frame; in a non-inertial frame the coordinate speed may be different


id: faster-than-light-20260505-4
file: data/en.wikipedia.org/wiki/Faster-than-light-4.md
category: reference
title: Faster-than-light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Faster-than-light
date_saved: 2026-05-05T11:10:14.212907+00:00
instance: kb-cron
parent: faster-than-light-20260505-0
summary:
=== Spacetime distortion === Although the theory of special relativity forbids objects to have a relative velocity greater than light speed, and general relativity reduces to special relativity in a local sense (in small regions of spacetime where curvature is negligible), general relativity does allow the space between distant objects to expand in such a way that they have a "recession velocity" which exceeds the speed of light, and it is thought that galaxies which are at a distance of more than about 14 billion light-years the Earth today have a recession velocity which is faster than light. Miguel Alcubierre theorized that it would be possible to create a warp drive, in which a ship would be enclosed in a "warp bubble" where the space at the front of the bubble is rapidly contracting and the space at the back is rapidly expanding, with the result that the bubble can reach a distant destination much faster than a light beam moving outside the bubble, but without objects inside the bubble locally traveling faster than light. However, several objections raised against the Alcubierre drive appear to rule out the possibility of actually using it in any practical fashion. Another possibility predicted


id: faster-than-light-20260505-5
file: data/en.wikipedia.org/wiki/Faster-than-light-5.md
category: reference
title: Faster-than-light
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Faster-than-light
date_saved: 2026-05-05T11:10:14.212907+00:00
instance: kb-cron
parent: faster-than-light-20260505-0
summary:
On September 22, 2011, a preprint from the OPERA Collaboration indicated detection of 17 and 28 GeV muon neutrinos, sent 730 kilometers (454 miles) from CERN near Geneva, Switzerland to the Gran Sasso National Laboratory in Italy, traveling faster than light by a relative amount of 2.48×10−5 (approximately 1 in 40,000), a statistic with 6.0-sigma significance. On 17 November 2011, a second follow-up experiment by OPERA scientists confirmed their initial results. However, scientists were skeptical about the results of these experiments, the significance of which was disputed. In March 2012, the ICARUS collaboration failed to reproduce the OPERA results with their equipment, detecting neutrino travel time from CERN to the Gran Sasso National Laboratory indistinguishable from the speed of light. Later the OPERA team reported two flaws in their equipment set-up that had caused errors far outside their original confidence interval: a fiber-optic cable attached improperly, which caused the apparently faster-than-light measurements, and a clock oscillator ticking too fast. == Tachyons == In special relativity, it is impossible to accelerate an object to the speed of light, or for a massive object to move at the speed of light. However, it might be possible for an object to exist which


id: ixs-enterprise-20260505-0
file: data/en.wikipedia.org/wiki/IXS_Enterprise-0.md
category: reference
title: IXS Enterprise
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/IXS_Enterprise
date_saved: 2026-05-05T11:10:16.514864+00:00
instance: kb-cron
parent: ixs-enterprise-20260505-0
summary:
IXS Enterprise is a conceptual interstellar superluminal spacecraft designed by NASA scientist Dr. Harold G. White, revealed at SpaceVision 2013, designed for the goal of achieving warp travel. The conceptual spacecraft would make use of a modified version of the Alcubierre drive. Dr. White is currently running the White–Juday warp-field interferometer experiment in order to develop a proof of concept for Alcubierre-style warp travel, when possible. The Alcubierre drive uses exotic matter (not to be confused with antimatter) to travel faster than light. While the concept had been out since 2013, the design of IXS Enterprise was popularized in June 2014 after a series of media outlets reported on the conceptual artwork done by Dutch artist Mark Rademaker in collaboration with NASA. According to Mark Rademaker, over 1,600 hours have been spent on the conceptual artwork that he created. In 2012, NASA reported that it was experimenting with the concept of warp drive and the loophole within Einstein's theory of relativity. By 2014, it was announced that designer Mark Rademaker had created a CGI representation of a new vessel that would achieve warp velocity. The vessel he designed was the IXS Enterprise, named after the famed ship of the Star


id: 2011-opera-faster-than-light-neutrino-anomaly-20260505-0
file: data/en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly-0.md
category: reference
title: 2011 OPERA faster-than-light neutrino anomaly
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly
date_saved: 2026-05-05T11:10:17.655042+00:00
instance: kb-cron
parent: 2011-opera-faster-than-light-neutrino-anomaly-20260505-0
summary:
In 2011, the Oscillation Project with Emulsion-tRacking Apparatus (OPERA) experiment mistakenly observed neutrinos appearing to travel faster than light. Even before the source of the error was discovered, the result was considered anomalous because speeds higher than that of light in vacuum are generally thought to violate special relativity, a cornerstone of the modern understanding of physics for over a century. On June 8, 2012, after further research and analysis, CERN research director Sergio Bertolucci declared that the speed of neutrinos is consistent with that of light. The press release, made from the 25th International Conference on Neutrino Physics and Astrophysics in Kyoto, states that the original OPERA results were wrong, due to equipment failures. On July 12, 2012, OPERA updated their paper by including the new sources of errors in their calculations. They found agreement of neutrino speed with the speed of light. == Detection == The experiment created a form of neutrinos, muon neutrinos, at CERN's older SPS accelerator, on the Franco–Swiss border, and detected them at the LNGS lab in Gran Sasso, Italy. OPERA researchers used common-view GPS, derived from standard GPS, to measure the times and place coordinates at which the neutrinos were created and detected.


id: 2011-opera-faster-than-light-neutrino-anomaly-20260505-1
file: data/en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly-1.md
category: reference
title: 2011 OPERA faster-than-light neutrino anomaly
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly
date_saved: 2026-05-05T11:10:17.655042+00:00
instance: kb-cron
parent: 2011-opera-faster-than-light-neutrino-anomaly-20260505-0
summary:
=== End results === On July 12, 2012, the OPERA collaboration published the end results of their measurements between 2009 and 2011. The difference between the measured and expected arrival time of neutrinos (compared to the speed of light) was approximately 6.5 ± 15 ns. This is consistent with no difference at all, thus the speed of neutrinos is consistent with the speed of light within the margin of error. Also, the re-analysis of the 2011 bunched beam rerun gave a similar result. == Independent replication == In March 2012, the co-located ICARUS experiment refuted the OPERA results by measuring neutrino velocity to be that of light. ICARUS measured speed for seven neutrinos in the same short-pulse beam OPERA had checked in November 2011, and found them, on average, traveling at the speed of light. The results were from a trial run of neutrino-velocity measurements slated for May. In May 2012, a new bunched beam rerun was initiated by CERN. Then in June 2012, it was announced by CERN that the four Gran Sasso experiments OPERA, ICARUS, LVD, and BOREXINO measured neutrino speeds consistent with the speed of light, indicating that the initial OPERA result was due to equipment errors.


id: 2011-opera-faster-than-light-neutrino-anomaly-20260505-2
file: data/en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly-2.md
category: reference
title: 2011 OPERA faster-than-light neutrino anomaly
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly
date_saved: 2026-05-05T11:10:17.655042+00:00
instance: kb-cron
parent: 2011-opera-faster-than-light-neutrino-anomaly-20260505-0
summary:
=== Measuring distance === Distance was measured by accurately fixing the source and detector points on a global coordinate system (ETRF2000). CERN surveyors used GPS to measure the source location. On the detector side, the OPERA team worked with a geodesy group from the Sapienza University of Rome to locate the detector's center with GPS and standard map-making techniques. To link the surface GPS location to the coordinates of the underground detector, traffic had to be partially stopped on the access road to the lab. Combining the two location measurements, the researchers calculated the distance, to an accuracy of 20 cm within the 730 km path. === Measuring trip time === The travel time of the neutrinos had to be measured by tracking the time they were created, and the time they were detected, and using a common clock to ensure the times were in sync. As Fig. 1 shows, the time measuring system included the neutrino source at CERN, the detector at LNGS (Gran Sasso), and a satellite element common to both. The common clock was the time signal from multiple GPS satellites visible from both CERN and LNGS. CERN's beams-department engineers worked with the OPERA team to provide


id: 2011-opera-faster-than-light-neutrino-anomaly-20260505-3
file: data/en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly-3.md
category: reference
title: 2011 OPERA faster-than-light neutrino anomaly
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly
date_saved: 2026-05-05T11:10:17.655042+00:00
instance: kb-cron
parent: 2011-opera-faster-than-light-neutrino-anomaly-20260505-0
summary:
== The analysis == The OPERA team analyzed the results in different ways and using different experimental methods. Following the initial main analysis released in September, three further analyses were made public in November. In the main November analysis, all the existing data were reanalyzed to allow adjustments for other factors, such as the Sagnac effect in which the Earth's rotation affects the distance traveled by the neutrinos. Then an alternative analysis adopted a different model for the matching of the neutrinos to their creation time. The third analysis of November focused on a different experimental setup ('the rerun') which changed the way the neutrinos were created. In the initial setup, every detected neutrino would have been produced sometime in a 10500 nanoseconds (10.5 microseconds) range, since this was the duration of the proton beam spill generating the neutrinos. It was not possible to isolate neutrino production time further within the spill. Therefore, in their main statistical analyses, the OPERA group generated a model of the proton waveforms at CERN, took the various waveforms together, and plotted the chance of neutrinos being emitted at various times (the global probability density function of the neutrino emission times). They then compared this


id: 2011-opera-faster-than-light-neutrino-anomaly-20260505-4
file: data/en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly-4.md
category: reference
title: 2011 OPERA faster-than-light neutrino anomaly
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/2011_OPERA_faster-than-light_neutrino_anomaly
date_saved: 2026-05-05T11:10:17.655042+00:00
instance: kb-cron
parent: 2011-opera-faster-than-light-neutrino-anomaly-20260505-0
summary:
Physicists affiliated with the experiment had refrained from interpreting the result, stating in their paper: Despite the large significance of the measurement reported here and the stability of the analysis, the potentially great impact of the result motivates the continuation of our studies in order to investigate possible still unknown systematic effects that could explain the observed anomaly. We deliberately do not attempt any theoretical or phenomenological interpretation of the results. Theoretical physicists Gian Giudice, Sergey Sibiryakov, and Alessandro Strumia showed that superluminal neutrinos would imply some anomalies in the velocities of electrons and muons, as a result of quantum-mechanical effects. Such anomalies could be already ruled out from existing data on cosmic rays, thus contradicting the OPERA results. Andrew Cohen and Sheldon Glashow predicted that superluminal neutrinos would radiate electrons and positrons and lose energy through vacuum Cherenkov effects, where a particle traveling faster than light decays continuously into other slower particles. However, this energy attrition was absent both in the OPERA experiment and in the co-located ICARUS experiment, which uses the same CNGS beam as OPERA. This discrepancy was seen by Cohen and Glashow to present "a significant challenge to the superluminal interpretation of the OPERA data". Many


id: scharnhorst-effect-20260505-0
file: data/en.wikipedia.org/wiki/Scharnhorst_effect-0.md
category: reference
title: Scharnhorst effect
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Scharnhorst_effect
date_saved: 2026-05-05T11:10:18.831443+00:00
instance: kb-cron
parent: scharnhorst-effect-20260505-0
summary:
The Scharnhorst effect is a hypothetical phenomenon in which light signals travel slightly faster than c between two closely spaced conducting plates. It was first predicted in a 1990 paper by Klaus Scharnhorst of the Humboldt University of Berlin, Germany. He showed using quantum electrodynamics that the effective refractive index n, at low frequencies, in the space between the plates was less than 1. Gabriel Barton and Scharnhorst in 1993 claimed that either signal velocity can exceed c or that the imaginary part of n is negative. == Explanation == Vacuum fluctuations exist even in a perfect vacuum. The vacuum fluctuations are influenced by conducting plates nearby. As a photon travels through a vacuum its propagation is influenced by these vacuum fluctuations. A prediction made by this assertion is that the speed of a photon will be increased if it travels between two Casimir plates. The ultimate effect would be to increase the apparent speed of that photon. The closer the plates are, the stronger the change in the vacuum fluctuations, and the higher the speed of light. The effect, however, is predicted to be minuscule. A photon traveling between two plates that are 1 micrometer apart would increase the


id: spore-drive-20260505-0
file: data/en.wikipedia.org/wiki/Spore_drive-0.md
category: reference
title: Spore drive
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spore_drive
date_saved: 2026-05-05T11:10:20.022717+00:00
instance: kb-cron
parent: spore-drive-20260505-0
summary:
The spore drive, formally known as the displacement-activated spore hub drive, is a fictional spacecraft propulsion system introduced in the 2017 television series Star Trek: Discovery. It enables instantaneous travel across interstellar and interdimensional space via a subspace network of fungal spores produced by a space-dwelling organism, Prototaxites stellaviatori. This network is depicted as existing simultaneously across all points in space and time, allowing starships to transition between locations or parallel universes without traversing intervening space. In contrast to conventional Star Trek propulsion technologies such as impulse drive and warp drive, the spore drive relies on biologically mediated navigation via a "mycelial network", depicted as a separate space outside of normal reality. It is presented as a classified project developed by Starfleet Intelligence and tested aboard the USS Discovery, but ultimately withheld from broader implementation due to ethical, biological, and strategic constraints. Inspired in part by the work of real-world mycologist Paul Stamets, the spore drive has been analyzed by scholars as a representation of posthuman connectivity, ecological interdependence, and speculative theoretical physics, with conceptual roots in mycology and environmental allegory. == Background == Within Star Trek, a variety of spacecraft propulsion systems have been depicted. The most common are


id: spore-drive-20260505-1
file: data/en.wikipedia.org/wiki/Spore_drive-1.md
category: reference
title: Spore drive
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spore_drive
date_saved: 2026-05-05T11:10:20.022717+00:00
instance: kb-cron
parent: spore-drive-20260505-0
summary:
When controlled by an appropriate navigator, a specially designed starship—such as the USS Discovery—could enter into the "mycelial network", which is composed entirely of P. stellaviatori, emerging instantly anywhere else, regardless of distance. The mycelial network reached any location in all universes, including Star Trek's Mirror Universe, fueled by spores of the fungus. The mycelial network appears as a web-like thread of fibers. According to mycologist Lynne Boddy, the mycelial network visually echoes real-life underground mycorrhizal networks, albeit on a galactic scale. To navigate a spore drive requires "seeing" the connections of the network in ways even future computers cannot handle. Initially, Starfleet is unable to safely use the spore drive for long-range travel, being limited to short jumps. The sister ship of the Discovery, the USS Glenn, is destroyed when first attempting a longer jump due to unproven navigation. Later, Discovery encounters an alien creature visually similar to a large Earth tardigrade, with a natural ability to navigate the mycelial network. Stamets integrates the creature's DNA into himself—similarly to horizontal gene transfer—and gains the same ability, allowing him to safely jump Discovery to any point in the galaxy. Spore jumps were signified by the ship's commander calling for a


id: spore-drive-20260505-2
file: data/en.wikipedia.org/wiki/Spore_drive-2.md
category: reference
title: Spore drive
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spore_drive
date_saved: 2026-05-05T11:10:20.022717+00:00
instance: kb-cron
parent: spore-drive-20260505-0
summary:
Writing in Reactor, Jonathan Alexandratos explores overlaps between the works of both the real-life and fictional Stamets, particularly how mycoremediation concepts are integral to the story mechanics of the mycelial network and factor into the story in several season 2 episodes of Star Trek: Discovery. Alexandratos also raises the concept of using the mycelium to terraform a planet, which Doug Bonderud similarly highlights in an article for aerospace manufacturer Northrop Grumman. He further discusses the implications of the network drawing life into itself, spreading it elsewhere, and its potential to heal or repair harm. The last is seen in similar real-life sciences, such as radiotrophic fungus in the wake of the Chernobyl disaster. Ethan Siegel, an astrophysicist writing for Forbes, examined the theoretical plausibility of the spore drive using concepts from modern physics. He proposed that the drive's effect could be explained by invoking a fourth spatial dimension—allowing a ship to leave three-dimensional space, travel a short distance in this higher dimension, and reenter elsewhere nearly instantaneously. He framed this mechanism as analogous to treating "subspace" in the franchise as a hidden extra dimension, thus giving the spore network a semi-credible scientific analog. However, Siegel was also critical of the


id: spore-drive-20260505-3
file: data/en.wikipedia.org/wiki/Spore_drive-3.md
category: reference
title: Spore drive
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Spore_drive
date_saved: 2026-05-05T11:10:20.022717+00:00
instance: kb-cron
parent: spore-drive-20260505-0
summary:
Bettina Wurche, in a ScienceBlogs article on mycology in Star Trek: Discovery, compared the Discovery's spore-drive navigator to the mutated Navigators of the Spacing Guild in Frank Herbert's Dune series, who "[fold] space" using the spice melange. Herbert's 1965 novel describes melange as originating from a "fungusoid wild growth." Other organic faster-than-light systems depicted in fiction include living ships called Leviathans in the Farscape franchise and Star Trek creator Gene Roddenberry's television series Andromeda, whose "slipstream" drive also required an organic navigator, like the spore drive. Lisa Meinecke in Fighting for the Future: Essays on Star Trek: Discovery interprets Star Trek: Discovery's spore drive arc as a critique of liberal humanism, arguing that the series displaces Star Trek's historical emphasis on autonomous individualism with a vision rooted in posthuman connectivity. She highlights the shift away from human-centered rationality toward an ecological pluralism, in which the mycelial network symbolizes interdependence rather than progress through hierarchy. In this framework, Stamets' fusion with the spore drive marks a narrative break from the franchise's tradition of "enlightened humanism," positioning his transformation as a political gesture toward relational ethics. The University of Warwick's Elizabeth Stanway situates Star Trek: Discovery within a science fiction tradition of


id: superluminal-motion-20260505-0
file: data/en.wikipedia.org/wiki/Superluminal_motion-0.md
category: reference
title: Superluminal motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Superluminal_motion
date_saved: 2026-05-05T11:10:21.209937+00:00
instance: kb-cron
parent: superluminal-motion-20260505-0
summary:
In astronomy, superluminal motion is the apparently faster-than-light motion seen in some radio galaxies, BL Lac objects, quasars, blazars and recently also in some galactic sources called microquasars. Bursts of energy moving out along the relativistic jets emitted from these objects can have a proper motion that appears to have speed greater than the speed of light. All of these sources are thought to contain a black hole, responsible for the ejection of mass at high velocities. Light echoes can also produce apparent superluminal motion. == Explanation == Superluminal motion occurs as a special case of a more general phenomenon arising from the difference between the apparent speed of distant objects moving across the sky and their actual speed as measured at the source. In tracking the movement of such objects across the sky, their speed can be calculated by simply dividing distance by time. If the distance of the object from the Earth is known and the angular speed of the object can be measured, then the speed can be calculated as: But this calculation does not yield the actual speed of the object, as it fails to account for the fact that the speed of light is finite.


id: superluminal-motion-20260505-1
file: data/en.wikipedia.org/wiki/Superluminal_motion-1.md
category: reference
title: Superluminal motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Superluminal_motion
date_saved: 2026-05-05T11:10:21.209937+00:00
instance: kb-cron
parent: superluminal-motion-20260505-0
summary:
A relativistic jet coming out of the center of an active galactic nucleus is moving along AB with a velocity v, and is observed from the point O. At time t 1 {\displaystyle t_{1}} a light ray leaves the jet from point A and another ray leaves at time t 2 = t 1 + δ t {\displaystyle t_{2}=t_{1}+\delta t} from point B. An observer at O receives the rays at time t 1 ′ {\displaystyle t_{1}^{\prime }} and t 2 ′ {\displaystyle t_{2}^{\prime }} respectively. The angle ϕ {\displaystyle \phi } is small enough that the two distances marked D L {\displaystyle D_{L}} can be considered equal. A B = v δ t {\displaystyle AB=v\,\delta t} A C = v δ t cos ⁡ θ {\displaystyle AC=v\,\delta t\cos \theta } B C = v δ t sin ⁡ θ {\displaystyle BC=v\,\delta t\sin \theta } t 2 − t 1 = δ t {\displaystyle t_{2}-t_{1}=\delta t} t 1 ′ = t 1 + D L + v δ t cos ⁡ θ c {\displaystyle t_{1}'=t_{1}+{\frac {D_{L}+v\,\delta t\cos \theta }{c}}} t 2 ′ = t 2 + D L c {\displaystyle t_{2}'=t_{2}+{\frac {D_{L}}{c}}} δ t ′ = t 2 ′ −


id: superluminal-motion-20260505-2
file: data/en.wikipedia.org/wiki/Superluminal_motion-2.md
category: reference
title: Superluminal motion
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Superluminal_motion
date_saved: 2026-05-05T11:10:21.209937+00:00
instance: kb-cron
parent: superluminal-motion-20260505-0
summary:
== History == The apparent superluminal motion in the faint nebula surrounding Nova Persei was first observed in 1901 by Charles Dillon Perrine. "Mr. Perrine's photograph of November 7th and 8th, 1901, secured with the Crossley Reflector, led to the remarkable discovery that the masses of nebulosity were apparently in motion, with a speed perhaps several hundred times as great as hitherto observed." "Using the 36-in. telescope (Crossley), he discovered the apparent superluminal motion of the expanding light bubble around Nova Persei (1901). Thought to be a nebula, the visual appearance was actually caused by light from the nova event reflected from the surrounding interstellar medium as the light moved outward from the star. Perrine studied this phenomenon using photographic, spectroscopic, and polarization techniques." Superluminal motion was first observed in 1902 by Jacobus Kapteyn in the ejecta of the nova GK Persei, which had exploded in 1901. His discovery was published in the German journal Astronomische Nachrichten, and received little attention from English-speaking astronomers until many decades later. Following a 1939 paper by Couderc, in 1966, Martin Rees pointed out that "an object moving relativistically in suitable directions may appear to a distant observer to have a transverse velocity much


id: teleportation-in-fiction-20260505-0
file: data/en.wikipedia.org/wiki/Teleportation_in_fiction-0.md
category: reference
title: Teleportation in fiction
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Teleportation_in_fiction
date_saved: 2026-05-05T11:10:22.375115+00:00
instance: kb-cron
parent: teleportation-in-fiction-20260505-0
summary:
Teleportation is the theoretical transfer of matter or energy from one point to another without traversing the physical space between them. It is a common subject in science fiction and fantasy literature, film, video games, and television. In some situations, teleporting is presented as time traveling across space. The use of matter transmitters in science fiction originated at least as early as the 19th century. An early example of scientific teleportation (as opposed to magical or spiritual teleportation) is found in the 1897 novel To Venus in Five Seconds by Fred T. Jane. Jane's protagonist is transported from a strange-machinery-containing gazebo on Earth to planet Venus. A common fictional device for teleportation is a "wormhole". In video games, the instant teleportation of a player character may be referred to as a warp. == List of fiction containing teleportation == === Multiple media types === Nearly every entry in the Star Trek franchise features a transporter system of some type to various levels of prominence. === Written fiction === William Shakespeare invoked a concept resembling teleportation in The Tempest (1610–1611). Edward Page Mitchell's 1877 story The Man Without a Body details the efforts of a scientist who discovers a method to


id: wormhole-20260505-0
file: data/en.wikipedia.org/wiki/Wormhole-0.md
category: reference
title: Wormhole
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wormhole
date_saved: 2026-05-05T11:10:23.602144+00:00
instance: kb-cron
parent: wormhole-20260505-0
summary:
A wormhole is a hypothetical structure that connects disparate points in spacetime. It can be visualized as a tunnel with two ends at separate points in spacetime (i.e., different locations, different points in time, or both). Wormholes are based on a special solution of the Einstein field equations. Wormholes are consistent with the general theory of relativity, but whether they actually exist is unknown. Many physicists postulate that wormholes are merely projections of a fourth spatial dimension, analogous to how a two-dimensional (2D) being could experience only part of a three-dimensional (3D) object. In 1995, Matt Visser suggested there may be many wormholes in the universe if cosmic strings with negative mass were generated in the early universe. Some physicists, such as Kip Thorne, have suggested how to create wormholes artificially. == Terminology == In 1928, German mathematician, philosopher and theoretical physicist Hermann Weyl proposed a wormhole hypothesis of matter in connection with mass analysis of electromagnetic field energy; however, he did not use the term "wormhole" (he spoke of "one-dimensional tubes" instead). The term "worm-holes" appears in British astronomer Arthur Eddington's 1928 popular exposition The Nature of the Physical World, in which he uses it metaphorically for "worm-holes" (material


id: wormhole-20260505-1
file: data/en.wikipedia.org/wiki/Wormhole-1.md
category: reference
title: Wormhole
tags: science, encyclopedia
source_url: https://en.wikipedia.org/wiki/Wormhole
date_saved: 2026-05-05T11:10:23.602144+00:00
instance: kb-cron
parent: wormhole-20260505-0
summary:
==== Einstein–Rosen bridges ==== Einstein–Rosen bridges (or ER bridges), named after Albert Einstein and Nathan Rosen, are connections between areas of space that can be modeled as vacuum solutions to the Einstein field equations, and that are now understood to be intrinsic parts of the maximally extended version of the Schwarzschild metric describing an eternal black hole with no charge and no rotation. Here, "maximally extended" refers to the idea that the spacetime should not have any "edges": it should be possible to continue this path arbitrarily far into the particle's future or past for any possible trajectory of a free-falling particle (following a geodesic in the spacetime). In order to satisfy this requirement, it turns out that in addition to the black hole interior region that particles enter when they fall through the event horizon from the outside, there must be a separate white hole interior region that allows us to extrapolate the trajectories of particles that an outside observer sees rising up away from the event horizon. And just as there are two separate interior regions of the maximally extended spacetime, there are also two separate exterior regions, sometimes called two different "universes", with the second universe allowing


