6.2 KiB
| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| Dyson sphere | 2/2 | https://en.wikipedia.org/wiki/Dyson_sphere | reference | science, encyclopedia | 2026-05-05T03:39:00.169646+00:00 | kb-cron |
== Feasibility and science-based speculation == Although Dyson spheres in the form of a swarm are theoretically possible, building a stable megastructure around the Sun is currently far beyond humanity's engineering capacity. The number of craft required to obtain, transmit, and maintain a complete Dyson sphere exceeds present-day industrial capabilities. Dyson spheres have prompted speculation into the feasibility of a class of proposed stellar engines, hypothetical megastructures whose purpose is to extract useful energy from a star, sometimes for specific purposes. For example, Matrioshka brains have been proposed to use energy extracted by Dyson spheres for computation, while Shkadov thrusters would extract energy for propulsion. Some proposed stellar engine designs are based on the Dyson sphere. Futurist George Dvorsky has advocated the use of self-replicating robots to overcome the limitation of humanity's engineering capacity in the relatively near term. Some have suggested that Dyson sphere habitats could be built around white dwarfs or pulsars. In 2022 it was suggested that a Dyson swarm around the Sun could be launched from either Mercury or Mars. In order to transmit the energy back, far-field radiative wireless power transfer was proposed, a technology that is not yet fully developed.
== Fictional examples == A precursor to the concept of Dyson spheres was featured in the 1937 novel Star Maker by Olaf Stapledon, in which he described "every solar system... surrounded by a gauze of light-traps, which focused the escaping solar energy for intelligent use"; Dyson got his inspiration from this book and suggested that "Stapledon sphere" would be a more apt name for the concept. Fictional Dyson spheres are typically solid structures forming a continuous shell around the star in question, although Dyson himself considered that prospect to be mechanically impossible. They are sometimes used as the type of plot device known as a Big Dumb Object. Dyson spheres appear as a background element in many works of fiction, including the 1964 novel The Wanderer by Fritz Leiber where aliens enclose multiple stars in this way. Dyson spheres are depicted in the 1975–1983 book series Saga of Cuckoo by Frederik Pohl and Jack Williamson, and one functions as the setting of Bob Shaw's 1975 novel Orbitsville and its sequels. In the 1992 episode "Relics" of the TV show Star Trek: The Next Generation, the USS Enterprise finds itself trapped in an abandoned Dyson sphere; in a 2011 interview, Dyson said that he enjoyed the episode, although he considered the sphere depicted to be "nonsense". Michael Jan Friedman who wrote the novelization observed that in the TV episode itself the Dyson sphere was effectively a MacGuffin, with "just nothing about it" in the story, and decided to flesh out the plot element in his novelization. Other science-fiction story examples include Tony Rothman's The World Is Round, Somtow Sucharitkul's Inquestor series, Timothy Zahn's Spinneret, James White's Federation World, Stephen Baxter's The Time Ships, and Peter F. Hamilton's Pandora's Star. Variations on the Dyson sphere concept include a single circular band in Larry Niven's 1970 novel Ringworld, a half sphere in the 2012 novel Bowl of Heaven by Gregory Benford and Niven, and nested spheres – also known as a Matrioshka brain – in Colin Kapp's 1980s Cageworld series and Brian Stableford's 1979–1990 Asgard trilogy. Stableford observed that Dyson spheres are usually treated as MacGuffins or relegated to the background of narratives, citing examples such as Fritz Leiber’s The Wanderer and Linda Nagata’s Deception Well. Stories in which the concept is explored tend to use variants such as Larry Niven's Ringworld. He identified two reasons for this. First, the sheer scale of a Dyson sphere makes it difficult to address within the constraints of most narratives; Friedman pointed that he had avoided the issue in his novelisation of “Relics” as the book was only four hundred pages long and he had just shy of four weeks to write it. Secondly, particularly in hard science fiction, Dyson spheres present engineering challenges that complicate their use in storytelling. One such difficulty arises from the shell theorem: within a spherical shell, gravitational forces are in equilibrium, so additional mechanisms such as rotation are required to provide effective gravity at the interior surface. This in turn introduces further complications, including a gravity gradient that diminishes to zero at the poles. Authors have addressed these issues through various modifications of the concept, including Stableford’s Cageworld nesting, Dan Alderson’s double-sphere idea, and Niven’s reduced ringworld design.
== See also == Alderson disk – Hypothetical artificial solar megastructure Astronomical engineering – Form of megascale engineering List of hypothetical technologies – Possible future technology Space elevator – Proposed type of space transportation system Stellar engine – Class of hypothetical megastructures Tabby's Star – Star noted for unusual dimming events
== References ==
== Further reading == Gunn, Alastair (December 29, 2022). "Dyson spheres: How humans (and aliens) could capture a star's energy". BBC Science Focus. Archived from the original on March 11, 2024. Retrieved March 20, 2024. Mann, Adam (August 1, 2019). "What is a Dyson sphere?". Space.com. Archived from the original on March 7, 2024. Retrieved March 20, 2024. Schulze-Makuch, Dirk (January 29, 2014). "Dyson Spheres: Still Missing, Maybe Impossible". Smithsonian Magazine. Archived from the original on September 28, 2023. Retrieved March 20, 2024. Stableford, Brian (2004). "Dyson Sphere". Historical Dictionary of Science Fiction Literature. Scarecrow Press. p. 99. ISBN 978-0-8108-4938-9. Stanway, Elizabeth (May 21, 2023). "Megastructures". Warwick University. Cosmic Stories Blog. Archived from the original on May 26, 2023. Retrieved March 25, 2024.
== External links ==
Dyson sphere FAQ FermiLab: IRAS-based whole sky upper limit on Dyson spheres with an appendix on Dyson sphere engineering Dyson sphere at Memory Alpha