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| title | chunk | source | category | tags | date_saved | instance |
|---|---|---|---|---|---|---|
| History of physics | 15/16 | https://en.wikipedia.org/wiki/History_of_physics | reference | science, encyclopedia | 2026-05-05T04:00:08.451736+00:00 | kb-cron |
the invention of the laser (1964 Nobel Prize in Physics); the theoretical and experimental research of superconductivity, especially the invention of a quantum theory of superconductivity by Vitaly Ginzburg and Lev Landau (1962 Nobel Prize in Physics) and, later, its explanation via Cooper pairs (1972 Nobel Prize in Physics). The Cooper pair was an early example of quasiparticles.
=== Unified field theories ===
Einstein deemed that all fundamental interactions in nature can be explained in a single theory. Unified field theories were numerous attempts to "merge" several interactions. One of many formulations of such theories (as well as field theories in general) is a gauge theory, a generalization of the idea of symmetry. Eventually the Standard Model (see below) succeeded in unification of strong, weak, and electromagnetic interactions. All attempts to unify gravitation with something else failed.
=== Particle physics and the Standard Model ===
When parity was broken in weak interactions by Chien-Shiung Wu in her experiment, a series of discoveries were created thereafter. The interaction of these particles by scattering and decay provided a key to new fundamental quantum theories. Murray Gell-Mann and Yuval Ne'eman brought some order to these new particles by classifying them according to certain qualities, beginning with what Gell-Mann referred to as the "Eightfold Way". While its further development, the quark model, at first seemed inadequate to describe strong nuclear forces, allowing the temporary rise of competing theories such as the S-Matrix, the establishment of quantum chromodynamics in the 1970s finalized a set of fundamental and exchange particles, which allowed for the establishment of a "standard model" based on the mathematics of gauge invariance, which successfully described all forces except for gravitation, and which remains generally accepted within its domain of application. The Standard Model, based on the Yang–Mills theory groups the electroweak interaction theory and quantum chromodynamics into a structure denoted by the gauge group SU(3)×SU(2)×U(1). The formulation of the unification of the electromagnetic and weak interactions in the standard model is due to Abdus Salam, Steven Weinberg and, subsequently, Sheldon Glashow. Electroweak theory was later confirmed experimentally (by observation of neutral weak currents), and distinguished by the 1979 Nobel Prize in Physics. Since the 1970s, fundamental particle physics has provided insights into early universe cosmology, particularly the Big Bang theory proposed as a consequence of Einstein's general theory of relativity. However, starting in the 1990s, astronomical observations have also provided new challenges, such as the need for new explanations of galactic stability ("dark matter") and the apparent acceleration in the expansion of the universe ("dark energy"). While accelerators have confirmed most aspects of the Standard Model by detecting expected particle interactions at various collision energies, no theory reconciling general relativity with the Standard Model has yet been found, although supersymmetry and string theory were believed by many theorists to be a promising avenue forward. The Large Hadron Collider, however, which began operating in 2008, has failed to find any evidence that is supportive of supersymmetry and string theory.
=== Cosmology ===
Cosmology may be said to have become a serious research question with the publication of Einstein's General Theory of Relativity in 1915 although it did not enter the scientific mainstream until the period known as the "Golden age of general relativity". About a decade later, in the midst of what was dubbed the "Great Debate", Edwin Hubble and Vesto Slipher discovered the expansion of universe in the 1920s measuring the redshifts of Doppler spectra from galactic nebulae. Using Einstein's general relativity, Georges Lemaître and George Gamow formulated what would become known as the Big Bang theory. A rival, called the steady state theory, was devised by Fred Hoyle, Thomas Gold, Jayant Narlikar and Hermann Bondi. Cosmic microwave background radiation was verified in the 1960s by Arno Allan Penzias and Robert Woodrow Wilson, and this discovery favoured the big bang at the expense of the steady state scenario. Later work was by George Smoot et al. (1989), among other contributors, using data from the Cosmic Background explorer (CoBE) and the Wilkinson Microwave Anisotropy Probe (WMAP) satellites refined these observations. The 1980s (the same decade of the COBE measurements) also saw the proposal of inflation theory by Alan Guth. Recently the problems of dark matter and dark energy have risen to the top of the cosmology agenda.
=== Higgs boson ===
On July 4, 2012, physicists working at CERN's Large Hadron Collider announced that they had discovered a new subatomic particle greatly resembling the Higgs boson, a potential key to an understanding of why elementary particles have mass and indeed to the existence of diversity and life in the universe. For now, some physicists are calling it a "Higgslike" particle. Joe Incandela, of the University of California, Santa Barbara, said, "It's something that may, in the end, be one of the biggest observations of any new phenomena in our field in the last 30 or 40 years, going way back to the discovery of quarks, for example." Michael Turner, a cosmologist at the University of Chicago and the chairman of the physics center board, said: