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P. R. Wallace
P. R. (Philip Russell; "Phil") Wallace (April 19, 1915 – March 20, 2006) was a Canadian theoretical physicist and long-time professor at McGill University. He was a Fellow of the Royal Society of Canada and Fellow of the National Academy of Sciences (India). He had a distinguished career as educator, researcher, and activist in science and society, but he is increasingly well known for his pioneering paper in 1947 on the band structure of graphite, and particularly graphene, the subject of the 2010 Nobel Prize in Physics. Early and wartime years Born in Toronto in 1915, Wallace entered the University of Toronto in 1933, achieving a B.A. in mathematics in 1937, an M.A. in 1938, and a Ph.D. in applied mathematics in 1940 under Leopold Infeld with a thesis on electromagnetism in general relativity. Advised by L. J. Synge, then head of the Applied Mathematics Department at Toronto, to hold himself ready for war work in Canada, Wallace took a two-year job at the University of Cincinn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Toronto
Toronto ( ; or ) is the capital city of the Provinces and territories of Canada, Canadian province of Ontario. With a recorded population of 2,794,356 in 2021, it is the List of the largest municipalities in Canada by population, most populous city in Canada and the List of North American cities by population, fourth most populous city in North America. The city is the anchor of the Golden Horseshoe, an urban agglomeration of 9,765,188 people (as of 2021) surrounding the western end of Lake Ontario, while the Greater Toronto Area proper had a 2021 population of 6,712,341. Toronto is an international centre of business, finance, arts, sports and culture, and is recognized as one of the most multiculturalism, multicultural and cosmopolitanism, cosmopolitan cities in the world. Indigenous peoples in Canada, Indigenous peoples have travelled through and inhabited the Toronto area, located on a broad sloping plateau interspersed with Toronto ravine system, rivers, deep ravines, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
General Relativity
General relativity, also known as the general theory of relativity and Einstein's theory of gravity, is the geometric theory of gravitation published by Albert Einstein in 1915 and is the current description of gravitation in modern physics. General relativity generalizes special relativity and refines Newton's law of universal gravitation, providing a unified description of gravity as a geometric property of space and time or four-dimensional spacetime. In particular, the ' is directly related to the energy and momentum of whatever matter and radiation are present. The relation is specified by the Einstein field equations, a system of second order partial differential equations. Newton's law of universal gravitation, which describes classical gravity, can be seen as a prediction of general relativity for the almost flat spacetime geometry around stationary mass distributions. Some predictions of general relativity, however, are beyond Newton's law of universal gr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Physicists
Canadians (french: Canadiens) are people identified with the country of Canada. This connection may be residential, legal, historical or cultural. For most Canadians, many (or all) of these connections exist and are collectively the source of their being ''Canadian''. Canada is a multilingual and multicultural society home to people of groups of many different ethnic, religious, and national origins, with the majority of the population made up of Old World immigrants and their descendants. Following the initial period of French and then the much larger British colonization, different waves (or peaks) of immigration and settlement of non-indigenous peoples took place over the course of nearly two centuries and continue today. Elements of Indigenous, French, British, and more recent immigrant customs, languages, and religions have combined to form the culture of Canada, and thus a Canadian identity. Canada has also been strongly influenced by its linguistic, geographic, and ec ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
2006 Deaths
File:2006 Events Collage V1.png, From top left, clockwise: The 2006 Winter Olympics open in Turin; Twitter is founded and launched by Jack Dorsey; The Nintendo Wii is released; Montenegro votes to declare independence from Serbia; The 2006 FIFA World Cup in Germany is won by Italy; Gol Transportes Aéreos Flight 1907 crashes in the Amazon rainforest after a mid-air collision with an Embraer Legacy 600 business jet; The 2006 Yogyakarta earthquake kills over 5,700 people; The IAU votes on the definition of "planet", which demotes Pluto and other Kuiper belt objects and redefines them as " dwarf planets"., 300x300px, thumb rect 0 0 200 200 2006 Winter Olympics rect 200 0 400 200 Twitter rect 400 0 600 200 Nintendo Wii rect 0 200 300 400 IAU definition of planet rect 300 200 600 400 2006 Montenegrin independence referendum rect 0 400 200 600 2006 Yogyakarta earthquake rect 200 400 400 600 Gol Transportes Aéreos Flight 1907 rect 400 400 600 600 2006 FIFA World Cup 2 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
1915 Births
Events Below, the events of World War I have the "WWI" prefix. January *January – British physicist Sir Joseph Larmor publishes his observations on "The Influence of Local Atmospheric Cooling on Astronomical Refraction". * January 1 ** WWI: British Royal Navy battleship HMS ''Formidable'' is sunk off Lyme Regis, Dorset, England, by an Imperial German Navy U-boat, with the loss of 547 crew. ** Battle of Broken Hill: A train ambush near Broken Hill, New South Wales, Australia, is carried out by two men (claiming to be in support of the Ottoman Empire) who are killed, together with 4 civilians. * January 5 – Joseph E. Carberry sets an altitude record of , carrying Capt. Benjamin Delahauf Foulois as a passenger, in a fixed-wing aircraft. * January 12 ** The United States House of Representatives rejects a proposal to give women the right to vote. ** ''A Fool There Was'' premières in the United States, starring Theda Bara as a ''femme fatale''; she quickly b ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
John David Jackson (physicist)
John David Jackson (January 19, 1925 – May 20, 2016) was a Canadian–American physics professor at the University of California, Berkeley and a faculty senior scientist emeritus at Lawrence Berkeley National Laboratory. A theoretical physicist, he was a member of the National Academy of Sciences, and is well known for numerous publications and summer-school lectures in nuclear and particle physics, as well as his widely used graduate text on classical electrodynamics. Education Born in London, Ontario, Canada, Jackson attended the University of Western Ontario, receiving a B.Sc. in honors physics and mathematics in 1946. He went on to graduate study at MIT, where he worked under Victor Weisskopf, completing his Ph.D. thesis in 1949. Academic career Jackson held academic appointments successively at McGill University, thanks to Philip Russell Wallace, a prominent Canadian theoretical physicist, (January 1950 – 1957); then the University of Illinois at Urbana–Champaign ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Kurt Gottfried
Kurt Gottfried (May 17, 1929 – August 25, 2022) was an Austrian-born American physicist who was professor emeritus of physics at Cornell University. He was known for his work in the areas of quantum mechanics and particle physics and was also a co-founder with Henry Way Kendall of the Union of Concerned Scientists. He wrote extensively in the areas of physics and arms control. Early life and education Gottfried was born in Vienna, First Austrian Republic, on May 17, 1929. In 1939, after their home in Austria was raided on Kristallnacht, his family emigrated to Montreal, Quebec, Canada. Gottfried attended McGill University, studying both theoretical and engineering physics. Gottfried studied with Victor Weisskopf at the Massachusetts Institute of Technology (MIT) from 1952 to 1955, completing his Ph.D. thesis, ''Investigations Based on the Bohr-Mottelson Nuclear Model''. There he studied deformed nuclei, developing models to describe wave functions and energy levels associ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Physics Today
''Physics Today'' is the membership magazine of the American Institute of Physics. First published in May 1948, it is issued on a monthly schedule, and is provided to the members of ten physics societies, including the American Physical Society The American Physical Society (APS) is a not-for-profit membership organization of professionals in physics and related disciplines, comprising nearly fifty divisions, sections, and other units. Its mission is the advancement and diffusion of .... It is also available to non-members as a paid annual subscription. The magazine informs readers about important developments in overview articles written by experts, shorter review articles written internally by staff, and also discusses issues and events of importance to the science community in politics, education, and other fields. The magazine provides a historical resource of events associated with physics. For example it discussed debunking the physics of the Star Wars program of the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Canadian Association Of Physicists
Canadian Association of Physicists (CAP), or in French Association canadienne des physiciens et physiciennes (ACP) is a Canadian professional society that focuses on creating awareness among Canadians and Canadian legislators of physics issues, sponsoring physics related events, physics outreach, and publishes ''Physics in Canada''. It was founded in July 1945. The organization has over 1,600 members and is bilingual, functioning in English and French. P. Phys. professional certification The CAP can appoint an official designation called the P. Phys. which stands for Professional Physicist, similar to the designation of P. Eng. which stands for Professional Engineer. This designation was unveiled at the CAP congress in 1999 and more than 200 people carry this distinction. Physics contests The Canadian Association of Physics hosts several CAP physics contests across Canada each year, aimed at different levels of physics students. The CAP High School Prize exam is offered across ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semimetals
A semimetal is a material with a very small overlap between the bottom of the conduction band and the top of the valence band. According to electronic band theory, solids can be classified as insulators, semiconductors, semimetals, or metals. In insulators and semiconductors the filled valence band is separated from an empty conduction band by a band gap. For insulators, the magnitude of the band gap is larger (e.g., > 4 eV) than that of a semiconductor (e.g., < 4 eV). Because of the slight overlap between the conduction and valence bands, semimetals have no band gap and a negligible at the . A metal, by contrast, has an appreciable density of states at the Fermi level because th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Semiconductors
A semiconductor is a material which has an electrical conductivity value falling between that of a conductor, such as copper, and an insulator, such as glass. Its resistivity falls as its temperature rises; metals behave in the opposite way. Its conducting properties may be altered in useful ways by introducing impurities (" doping") into the crystal structure. When two differently doped regions exist in the same crystal, a semiconductor junction is created. The behavior of charge carriers, which include electrons, ions, and electron holes, at these junctions is the basis of diodes, transistors, and most modern electronics. Some examples of semiconductors are silicon, germanium, gallium arsenide, and elements near the so-called "metalloid staircase" on the periodic table. After silicon, gallium arsenide is the second-most common semiconductor and is used in laser diodes, solar cells, microwave-frequency integrated circuits, and others. Silicon is a critical element for fabricat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Positron Annihilation
The positron or antielectron is the antiparticle or the antimatter counterpart of the electron. It has an electric charge of +1 '' e'', a spin of 1/2 (the same as the electron), and the same mass as an electron. When a positron collides with an electron, annihilation occurs. If this collision occurs at low energies, it results in the production of two or more photons. Positrons can be created by positron emission radioactive decay (through weak interactions), or by pair production from a sufficiently energetic photon which is interacting with an atom in a material. History Theory In 1928, Paul Dirac published a paper proposing that electrons can have both a positive and negative charge. This paper introduced the Dirac equation, a unification of quantum mechanics, special relativity, and the then-new concept of electron spin to explain the Zeeman effect. The paper did not explicitly predict a new particle but did allow for electrons having either positive or negative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
