Portal:Physics
The Physics Portal
Physics is the scientific study of matter, its fundamental constituents, its motion and behavior through space and time, and the related entities of energy and force. It is one of the most fundamental scientific disciplines. A scientist who specializes in the field of physics is called a physicist.
Physics is one of the oldest academic disciplines. Over much of the past two millennia, physics, chemistry, biology, and certain branches of mathematics were a part of natural philosophy, but during the Scientific Revolution in the 17th century, these natural sciences branched into separate research endeavors. Physics intersects with many interdisciplinary areas of research, such as biophysics and quantum chemistry, and the boundaries of physics are not rigidly defined. New ideas in physics often explain the fundamental mechanisms studied by other sciences and suggest new avenues of research in these and other academic disciplines such as mathematics and philosophy.
Advances in physics often enable new technologies. For example, advances in the understanding of electromagnetism, solid-state physics, and nuclear physics led directly to the development of technologies that have transformed modern society, such as television, computers, domestic appliances, and nuclear weapons; advances in thermodynamics led to the development of industrialization; and advances in mechanics inspired the development of calculus. (Full article...)
Featured article -
This is a Featured article, which represents some of the best content on English Wikipedia.
Edward Teller (Hungarian: Teller Ede; January 15, 1908 – September 9, 2003) was a Hungarian and American theoretical physicist and chemical engineer who is known colloquially as "the father of the hydrogen bomb" and one of the creators of the Teller–Ulam design based on Stanisław Ulam's design. He had a volatile personality, and according to Richard Rhodes in his book Dark Sun, was "driven by his megaton ambitions, had a messianic complex, and displayed autocratic behavior." A thermonuclear design he devised was an Alarm Clock model bomb with a yield of 1000 MT (1 GT of TNT) and proposed delivering it by boat or submarine. It would be capable of incinerating an entire continent.
Born in Austria-Hungary in 1908, Teller emigrated to the United States in the 1930s, one of the many so-called "Martians", a group of prominent Hungarian scientist émigrés. He made numerous contributions to nuclear and molecular physics, spectroscopy (in particular the Jahn–Teller and Renner–Teller effects), and surface physics. His extension of Enrico Fermi's theory of beta decay, in the form of Gamow–Teller transitions, provided an important stepping stone in its application, while the Jahn–Teller effect and the Brunauer–Emmett–Teller (BET) theory have retained their original formulation and are still mainstays in physics and chemistry. According to Freeman Dyson, Teller thought about his problems using basic principles of physics and often discussed with other cohorts to make headway through difficult problems. This was seen when he worked with Stanislaw Ulam to get a workable thermonuclear fusion bomb design (a solution to Teller's own classical thermonuclear bomb proposal) but later temperamentally (and with fury) dismissed Ulam's aid. Herbert York stated that Teller utilized Ulam's general idea of compression and heating to start thermonuclear fusion to generate his own sketch of a "Super" bomb that would work. Prior to Ulam's idea, Teller's classical Super was essentially a system for heating (using a fission bomb primary) uncompressed liquid deuterium to the point, Teller hoped, when it would sustain thermonuclear burning. It was, in essence a simple idea from physical principles, which Teller pursued with a ferocious tenacity even if he was wrong or shown that it wouldn't work. To get support from Washington for his Super weapon project, Teller proposed a thermonuclear radiation implosion experiment as the "George" shot of Operation Greenhouse. (Full article...)
Did you know -
- ...that if you ever saw Jupiter's magnetic field from Earth, it would appear five times larger than the full moon?
- ...that the impact of a raindrop would be fatal if not for the property of fluid flow known as terminal velocity?
- ...that transits of Venus occur in a 243-year cycle?
Selected image -
A diagram of the Sun
Related portals
Good articles -
These are Good articles, which meet a core set of high editorial standards.
-
Sir Leslie Harold Martin, CBE, FAA, FRS (21 December 1900 – 1 February 1983) was an Australian physicist. He was one of the 24 Founding Fellows of the Australian Academy of Science and had a significant influence on the structure of higher education in Australia as chairman of the Australian Universities Commission from 1959 until 1966. He was Professor of Physics at the University of Melbourne from 1945 to 1959, and Dean of the Faculty of Military Studies and Professor of Physics at the University of New South Wales at the Royal Military College, Duntroon, in Canberra from 1967 to 1970. He was the Defence Scientific Adviser and chairman of the Defence Research and Development Policy Committee from 1948 to 1968, and a member of the Australian Atomic Energy Commission from 1958 to 1968. In this role he was an official observer at several British nuclear weapons tests in Australia. (Full article...) -
Robert Frederick Christy (May 14, 1916 – October 3, 2012) was a Canadian-American theoretical physicist and later astrophysicist who was one of the last surviving people to have worked on the Manhattan Project during World War II. He briefly served as acting president of California Institute of Technology (Caltech).
A graduate of the University of British Columbia (UBC) in the 1930s where he studied physics, he followed George Volkoff, who was a year ahead of him, to the University of California, Berkeley, where he was accepted as a graduate student by Robert Oppenheimer, the leading theoretical physicist in the United States at that time. Christy received his doctorate in 1941 and joined the physics department of Illinois Institute of Technology. (Full article...) -
Thorntonbank Wind Farm, using 5 MW turbines REpower 5M in the North Sea off the coast of Belgium
A wind turbine is a device that converts the kinetic energy of wind into electrical energy. As of 2020[update], hundreds of thousands of large turbines, in installations known as wind farms, were generating over 650 gigawatts of power, with 60 GW added each year. Wind turbines are an increasingly important source of intermittent renewable energy, and are used in many countries to lower energy costs and reduce reliance on fossil fuels. One study claimed that, as of 2009,[update] wind had the "lowest relative greenhouse gas emissions, the least water consumption demands and the most favorable social impacts" compared to photovoltaic, hydro, geothermal, coal and gas energy sources.
Smaller wind turbines are used for applications such as battery charging and remote devices such as traffic warning signs. Larger turbines can contribute to a domestic power supply while selling unused power back to the utility supplier via the electrical grid. (Full article...) -
Samuel King Allison (November 13, 1900 – September 15, 1965) was an American physicist, most notable for his role in the Manhattan Project, for which he was awarded the Medal for Merit. A professor who studied X-rays, he was director of the Metallurgical Laboratory from 1943 until 1944, and later worked at the Los Alamos Laboratory — where he "rode herd" on the final stages of the project as part of the "Cowpuncher Committee", and read the countdown for the detonation of the Trinity nuclear test. After the war, he returned to the University of Chicago to direct the Institute for Nuclear Studies and was involved in the "scientists' movement", lobbying for civilian control of nuclear weapons. (Full article...) -
Wu Zhonghua (Chinese: 吴仲华; 27 July 1917 – 19 September 1992), also known as Chung-Hua Wu, was a Chinese physicist. He was a National Advisory Committee for Aeronautics (NACA) researcher, Tsinghua University professor, and Founding Director of the Institute of Engineering Thermophysics of the Chinese Academy of Sciences (CAS). He pioneered the general theory of three-dimensional flow for turbomachinery, which has been widely used in aircraft engine designs. Wu and his wife Li Minhua were both academicians of the CAS.
Born in Shanghai, Wu's college education at Tsinghua University was interrupted by the Second Sino-Japanese War. He graduated from the temporary National Southwestern Associated University and was awarded a Boxer Indemnity Scholarship to study at the Massachusetts Institute of Technology in the United States. After earning his Ph.D., he joined the NACA, the predecessor of NASA, where he developed the theory of three-dimensional flow. (Full article...) -
Hans Albrecht Eduard Bethe (/ˈbɛθə/; German: [ˈhans ˈbeːtə] ⓘ; July 2, 1906 – March 6, 2005) was a German-American physicist who made major contributions to nuclear physics, astrophysics, quantum electrodynamics and solid-state physics, and received the Nobel Prize in Physics in 1967 for his work on the theory of stellar nucleosynthesis. For most of his career, Bethe was a professor at Cornell University.
In 1931, Bethe developed the Bethe ansatz, which is a method for finding the exact solutions for the eigenvalues and eigenvectors of certain one-dimensional quantum many-body models. In 1939, Bethe published a paper which established the CNO cycle as the primary energy source for heavier stars in the main sequence classification of stars, which earned him a Nobel Prize in 1967. During World War II, Bethe was head of the Theoretical Division at the secret Los Alamos National Laboratory that developed the first atomic bombs. There he played a key role in calculating the critical mass of the weapons and developing the theory behind the implosion method used in both the Trinity test and the "Fat Man" weapon dropped on Nagasaki in August 1945. (Full article...) -
Joseph Sidney Gelders (November 20, 1898 – March 1, 1950) was an American physicist who later became an antiracist, civil rights activist, labor organizer, and communist. In the mid-1930s, he served as the secretary and southern-U.S. representative of the National Committee for the Defense of Political Prisoners. In September 1936, Gelders was kidnapped, beaten, and nearly killed by members of the Ku Klux Klan for his civil rights and labor organizing activities. After his recovery, Gelders continued his activism and cofounded the Southern Conference for Human Welfare and the National Committee to Abolish the Poll Tax. He collaborated closely with other activists including Lucy Randolph Mason and Virginia Foster Durr. Internal injuries sustained during his kidnapping and assault led to Gelders' death on March 1, 1950. (Full article...) -
George Thomas Reynolds (May 27, 1917 – April 19, 2005) was an American physicist best known for his accomplishments in particle physics, biophysics and environmental science.
Reynolds received his PhD in physics from Princeton in 1943, writing a thesis of the propagation of shock waves. During World War II, he joined the United States Navy, and served with the Manhattan Project. He worked with George Kistiakowsky on the design of the explosive lenses required by the implosion-type nuclear weapon. He was involved in the investigation of the Port Chicago disaster, served with Project Alberta on Tinian, and was part of the Manhattan Project team sent to Hiroshima and Nagasaki to inspect the bomb damage. (Full article...) -
The mobility analogy, also called admittance analogy or Firestone analogy, is a method of representing a mechanical system by an analogous electrical system. The advantage of doing this is that there is a large body of theory and analysis techniques concerning complex electrical systems, especially in the field of filters. By converting to an electrical representation, these tools in the electrical domain can be directly applied to a mechanical system without modification. A further advantage occurs in electromechanical systems: Converting the mechanical part of such a system into the electrical domain allows the entire system to be analysed as a unified whole.
The mathematical behaviour of the simulated electrical system is identical to the mathematical behaviour of the represented mechanical system. Each element in the electrical domain has a corresponding element in the mechanical domain with an analogous constitutive equation. All laws of circuit analysis, such as Kirchhoff's laws, that apply in the electrical domain also apply to the mechanical mobility analogy. (Full article...) -
Henri Coutard (27 August 1876 – 16 March 1950) was a French radiation therapist. He is known for his studies of radiation therapy for the treatment of laryngeal cancer and the development of the "protracted-fractional method" of radiation dosing.
Born in Marolles-les-Braults in the French department of Sarthe, Coutard attended medical school at University of Paris and graduated in 1902. He served in the French Army and lived for several years in the Jura Mountains before returning to Paris to study the medical applications of radium. During World War I, he worked in one of the radiological ambulance units overseen by the Polish-French physicist and chemist Marie Curie. He became the chief of the X-ray department at the Radium Institute of the University of Paris in 1919, working closely with Claudius Regaud and other scientists. Coutard's early work demonstrating the efficacy of radiating patients with laryngeal cancer led to the adoption of radiation therapy as a primary course of cancer treatment. The protracted-fractional method consisted of long durations of radiation applied over several weeks. (Full article...) -
Nikola Tesla (/ˈnɪkələ ˈtɛslə/; Serbian Cyrillic: Никола Тесла [nǐkola têsla]; 10 July 1856 – 7 January 1943) was a Serbian-American engineer, futurist, and inventor. He is known for his contributions to the design of the modern alternating current (AC) electricity supply system.
Born and raised in the Austrian Empire, Tesla first studied engineering and physics in the 1870s without receiving a degree. He then gained practical experience in the early 1880s working in telephony and at Continental Edison in the new electric power industry. In 1884 he immigrated to the United States, where he became a naturalized citizen. He worked for a short time at the Edison Machine Works in New York City before he struck out on his own. With the help of partners to finance and market his ideas, Tesla set up laboratories and companies in New York to develop a range of electrical and mechanical devices. His AC induction motor and related polyphase AC patents, licensed by Westinghouse Electric in 1888, earned him a considerable amount of money and became the cornerstone of the polyphase system which that company eventually marketed. (Full article...) -
Norris Edwin Bradbury (May 30, 1909 – August 20, 1997), was an American physicist who served as director of the Los Alamos National Laboratory for 25 years from 1945 to 1970. He succeeded Robert Oppenheimer, who personally chose Bradbury for the position of director after working closely with him on the Manhattan Project during World War II. Bradbury was in charge of the final assembly of "the Gadget", detonated in July 1945 for the Trinity test.
Bradbury took charge at Los Alamos at a difficult time. Staff were leaving in droves, living conditions were poor and there was a possibility that the laboratory would close. He managed to persuade enough staff to stay and got the University of California to renew the contract to manage the laboratory. He pushed continued development of nuclear weapons, transforming them from laboratory devices to production models. Numerous improvements made them safer, more reliable and easier to store and handle, and made more efficient use of scarce fissionable materiel. (Full article...) -
Charles Louis Critchfield (June 7, 1910 – February 12, 1994) was an American mathematical physicist. A graduate of George Washington University, where he earned his PhD in physics under the direction of Edward Teller in 1939, he conducted research in ballistics at the Institute for Advanced Study in Princeton and the Ballistic Research Laboratory at the Aberdeen Proving Ground, and received three patents for improved sabot designs.
In 1943, Teller and Robert Oppenheimer persuaded Critchfield to come to the Manhattan Project's Los Alamos National Laboratory, where he joined the Ordnance Division under Captain William Parsons on the gun-type fission weapons, Little Boy and Thin Man. After it was discovered that the Thin Man design would not work, he was transferred to Robert Bacher's Gadget Division as the leader of the Initiator group, which was responsible for the design and testing of the "Urchin" neutron initiator that provided the burst of neutrons that kick-started the nuclear detonation of the Fat Man weapon. (Full article...) -
Rendering of the LIFE.1 fusion power plant. The fusion system is in the large cylindrical containment building in the center.
LIFE, short for Laser Inertial Fusion Energy, was a fusion energy effort run at Lawrence Livermore National Laboratory between 2008 and 2013. LIFE aimed to develop the technologies necessary to convert the laser-driven inertial confinement fusion concept being developed in the National Ignition Facility (NIF) into a practical commercial power plant, a concept known generally as inertial fusion energy (IFE). LIFE used the same basic concepts as NIF, but aimed to lower costs using mass-produced fuel elements, simplified maintenance, and diode lasers with higher electrical efficiency.
Two designs were considered, operated as either a pure fusion or hybrid fusion-fission system. In the former, the energy generated by the fusion reactions is used directly. In the latter, the neutrons given off by the fusion reactions are used to cause fission reactions in a surrounding blanket of uranium or other nuclear fuel, and those fission events are responsible for most of the energy release. In both cases, conventional steam turbine systems are used to extract the heat and produce electricity. (Full article...) -
Atomic model of an icosahedral nanoparticle, with red atoms at the five-fold axes
An icosahedral twin is an atomic structure found in atomic clusters and also nanoparticles with some thousands of atoms. Their atomic structure is slightly different from what is found for bulk materials, and contains five-fold symmetries. They have been analyzed in many areas of science including crystal growth, crystallography, chemical physics, surface science and materials science, and are sometimes considered as beautiful due to their high symmetry.
The simplest form of these clusters is twenty interlinked tetrahedral crystals joined along triangular (e.g. cubic-(111)) faces, although more complex variants of the outer surface also occur. A related structure has five units similarly arranged with twinning, which were known as "fivelings" in the 19th century, and more recently as "decahedral multiply twinned particles", "pentagonal particles" or "star particles".: 9–13 A variety of different methods (e.g. condensing metal nanoparticles in argon, deposition on a substrate, wet chemical synthesis) lead to the icosahedral form, and they also occur in virus capsids. (Full article...)
.jpg)
May anniversaries
- May 1, 1960 - U-2 spy plane shot down
- May 6, 1937 - Hindenburg fire
- May 9, 1012 BC – Solar Eclipse seen at Ugarit, 6:09–6:39 PM.
- May 9, 1904 – City of Truro, a steam locomotive exceeds 100 mph (160 km/h).
- May 10, 1946 – V-2 rocket's first successful launch at White Sands Proving Ground
- May 10, 1960 – The nuclear submarine USS Triton completes Operation Sandblast, the first underwater circumnavigation of the earth.
- May 11, 1862 – American Civil War: The ironclad CSS Virginia is scuttled in Virginia.
- May 11, 1995 – In New York City, over 170 countries extend Nuclear Nonproliferation Treaty indefinitely, without conditions.
- May 11, 1998 – India conducts three underground nuclear tests, including a thermonuclear device.
- May 14, 2018 - Ennackal Chandy George Sudarshan died.
- May 16, 1960 - Theodore Maiman operates the first optical laser, at Hughes Research Laboratories in Malibu, California.
- May 16, 1969 – Venera 5, a Soviet spaceprobe, lands on Venus.
- May 17, 1865 – The International Telegraph Union is established.
- May 18, 1974 - India conducts underground nuclear tests, named Smiling Buddha.
- May 18, 1998 - Microsoft sued by US Government
- May 19, 1943 - RAF uses bouncing bombs in combat
- May 20, 1932 - Amelia Earhart crosses Atlantic Ocean
- May 26, 1972 - President Nixon and Leonid Brezhnev sign nuclear weapon non-proliferation pact.
- May 24, 1844 - First official telegraph message is sent by Samuel Morse.
- May 27, 1937 - Grand opening, Golden Gate Bridge
- May 28, 1998 – Pakistan conducts five underground nuclear tests, named Chagai-I.
Births
- May 6, 1872 - Willem de Sitter, physicist, mathematician, and astronomer
- May 9, 1931 – Vance Brand, astronaut
- May 10, 1746 – Gaspard Monge, mathematician
- May 10, 1788 – Augustin-Jean Fresnel physicist
- May 10, 1963 – Lisa Nowak, astronaut
- May 11, 1918 – Richard Feynman, physicist
- May 14, 1686 - Gabriel Fahrenheit, physicist and engineer
- May 21, 1921 - Andrei Sakharov, nuclear physicist
Deaths
- May 10, 1482 – Paolo dal Pozzo Toscanelli, mathematician and astronomer
- May 16, 1830 – Joseph Fourier, French scientist
- May 17, 1916 – Boris Borisovich Galitzine, Russian physicist
General images
The following are images from various physics-related articles on Wikipedia.
-
Richard Feynman's Los Alamos ID badge (from History of physics) -
René Descartes (1596–1650) (from History of physics) -
-
Alessandro Volta (1745–1827) (from History of physics) -
Christiaan Huygens (1629–1695) (from History of physics) -
Chien-Shiung Wu worked on parity violation in 1956 and announced her results in January 1957. (from History of physics) -
Rudolf Clausius (1822–1888) (from History of physics) -
Galileo Galilei (1564–1642), early proponent of the modern scientific worldview and method (from History of physics) -
Classical physics is usually concerned with everyday conditions: speeds are much lower than the speed of light, sizes are much greater than that of atoms, yet very small in astronomical terms. Modern physics, however, is concerned with high velocities, small distances, and very large energies. (from Modern physics) -
Artist's rendition of Kepler-62f, a potentially habitable exoplanet discovered using data transmitted by Kepler space telescope, named for Kepler (from History of physics) -
Gottfried Leibniz (1646–1716) (from History of physics) -
Werner Heisenberg (1901–1976) (from History of physics) -
The quantum Hall effect: Components of the Hall resistivity as a function of the external magnetic field (from Condensed matter physics) -
Daniel Bernoulli (1700–1782) (from History of physics) -
1927 Solvay Conference included prominent physicists Albert Einstein, Werner Heisenberg, Max Planck, Hendrik Lorentz, Niels Bohr, Marie Curie, Erwin Schrödinger, Paul Dirac (from History of physics) -
Marie Skłodowska-Curie
(1867–1934) received Nobel prizes in physics (1903) and chemistry (1911). (from History of physics) -
A Feynman diagram representing (left to right) the production of a photon (blue sine wave) from the annihilation of an electron and its complementary antiparticle, the positron. The photon becomes a quark–antiquark pair and a gluon (green spiral) is released. (from History of physics) -
Albert Einstein (1879–1955), ca. 1905 (from History of physics) -
A magnet levitating above a high-temperature superconductor. Today some physicists are working to understand high-temperature superconductivity using the AdS/CFT correspondence. (from Condensed matter physics) -
Heike Kamerlingh Onnes and Johannes van der Waals with the helium liquefactor at Leiden in 1908 (from Condensed matter physics) -
The Standard Model (from History of physics) -
The first Bose–Einstein condensate observed in a gas of ultracold rubidium atoms. The blue and white areas represent higher density. (from Condensed matter physics) -
Composite montage comparing Jupiter (left) and its four Galilean moons (from top: Io, Europa, Ganymede, Callisto) (from History of physics) -
Star maps by the 11th century Chinese polymath Su Song are the oldest known woodblock-printed star maps to have survived to the present day. This example, dated 1092, employs the cylindricalequirectangular projection. (from History of physics) -
Michael Faraday (1791–1867) (from History of physics) -
The Hindu-Arabic numeral system. The inscriptions on the edicts of Ashoka (3rd century BCE) display this number system being used by the Imperial Mauryas. (from History of physics) -
Einstein proposed that gravitation results from masses (or their equivalent energies) curving ("bending") the spacetime in which they exist, altering the paths they follow within it. (from History of physics) -
Max Planck (1858–1947) (from History of physics) -
Sir Isaac Newton (1642–1727) (from History of physics) -
Computer simulation of nanogears made of fullerene molecules. It is hoped that advances in nanoscience will lead to machines working on the molecular scale. (from Condensed matter physics) -
J.J. Thomson (1856–1940), discoverer of electron and isotopy, and inventor of mass spectrometer, received 1906 Nobel Prize in Physics. (from History of physics) -
Image of X-ray diffraction pattern from a protein crystal (from Condensed matter physics) -
-
The ancient Greek mathematician Archimedes, developer of ideas regarding fluid mechanics and buoyancy. (from History of physics) -
James Clerk Maxwell (1831–1879) (from History of physics) -
Johannes Kepler (1571–1630) (from History of physics) -
-
Ludwig Boltzmann (1844–1906) (from History of physics) -
-
-
Classical physics (Rayleigh–Jeans law, black line) failed to explain black-body radiation – the so-called ultraviolet catastrophe. The quantum description (Planck's law, colored lines) is said to be modern physics. (from Modern physics) -
Nicolaus Copernicus (1473–1543) developed a heliocentric model of the Solar System. (from History of physics) -
William Thomson (Lord Kelvin)
(1824–1907) (from History of physics) -
One possible signature of a Higgs boson from a simulated proton–proton collision. It decays almost immediately into two jets of hadrons and two electrons, visible as lines. (from History of physics)
_in_1958.jpg)
-Portrait-Portr_10971.tif_(cropped).jpg)
Categories
Fundamentals: Concepts in physics | Constants | Physical quantities | Units of measure | Mass | Length | Time | Space | Energy | Matter | Force | Gravity | Electricity | Magnetism | Waves
Basic physics: Mechanics | Electromagnetism | Statistical mechanics | Thermodynamics | Quantum mechanics | Theory of relativity | Optics | Acoustics
Specific fields: Acoustics | Astrophysics | Atomic physics | Molecular physics | Optical physics | Computational physics | Condensed matter physics | Nuclear physics | Particle physics | Plasma physics
Tools: Detectors | Interferometry | Measurement | Radiometry | Spectroscopy | Transducers
Background: Physicists | History of physics | Philosophy of physics | Physics education | Physics journals | Physics organizations
Other: Physics in fiction | Physics lists | Physics software | Physics stubs
Physics topics
Classical physics traditionally includes the fields of mechanics, optics, electricity, magnetism, acoustics and thermodynamics. The term Modern physics is normally used for fields which rely heavily on quantum theory, including quantum mechanics, atomic physics, nuclear physics, particle physics and condensed matter physics. General and special relativity are usually considered to be part of modern physics as well.
More recognized content
Associated Wikimedia
The following Wikimedia Foundation sister projects provide more on this subject:
-
Commons
Free media repository -
Wikibooks
Free textbooks and manuals -
Wikidata
Free knowledge base -
Wikinews
Free-content news -
Wikiquote
Collection of quotations -
Wikisource
Free-content library -
Wikiversity
Free learning tools -
Wikivoyage
Free travel guide -
Wiktionary
Dictionary and thesaurus
Sources
Portals on Wikipedia
