Carl David Anderson (Anderson Carl David)( American physicist. Nobel Prize in Physics, 1936)
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Biography Carl David Anderson (Anderson Carl David)
genus. September 3, 1905
American physicist Carl David Anderson was born in New York and was the only son of Emma Adolfino (nee Ayyaksson) and Carl David Anderson. After the family moved to California, he attended Los Angeles High School, graduated from the CE in 1924. and enrolled at the California Institute of Technology (Caltech), located in the vicinity of Pasadena.
After receiving a bachelor's degree at Caltech in physics and engineering in 1927, and. began graduate work in physics under the leadership of Robert E. Millikan. In 1930. he brilliantly defended his doctoral dissertation about the spatial distribution of electrons ejected from gases by X-rays. Then A. continued to work researcher at Millikan, who advised him to study cosmic radiation (electromagnetic radiation and atomic particles from extraterrestrial sources). A year later, Millikan decided to entrust a. daily project to identify and measure the energy of various types of cosmic radiation, and together they developed a more efficient variant of the condensing chamber, which was created CH.T.R. Wilson and designed to detect charged particles. When charged particles pass through the vessel, they ionize in its path the gas molecules, and the last act as centers of condensation of water vapor. Each type of particles leaves the characteristic condensation trail that can be photographed, and the positively charged and negatively charged particles are deflected in opposite directions.
. Studying thousands of photographs of condensation tracks left by high-energy particles flying out of an extraterrestrial space, A
. noticed several signs that differed from the traces of the electrons only one: they deviated in the opposite direction. Other researchers have also noticed from time to time such traces, . but, . because the theoretical justification for the existence of a positively charged electron-like particles lacking, . they carried them from the experimental errors, . However, in 1928,
. P.A.M. Dirac predicted the existence of a family of anti-particles - particles that correspond to known, but with opposite charge and magnetic moment. Initially skeptical about the physics of this prediction, and A. not looking antiparticle until until he noticed strange tracks. The discovery, for which he received the Nobel Prize, he said later, was completely random. However, instead of being brushed aside by the observed fact, he tried to determine whether or not these tracks following hypothetical 'antielectron'. Experimentally eliminating all other possible explanations,. concluded that his observations can be explained only by recognizing the existence of a positively charged particle with mass, roughly equal to the mass of the electron. In September 1932. He announced the opening of the particle, which he called a positron.
Opening A. confirmed the existence of antimatter and led to intensive studies of interactions of matter with antimatter, A. and others have found that when an electron meets a positron, both are annihilated, producing a flash of gamma rays (high energy electromagnetic radiation). Conversely, if the gamma rays are high enough energy to stop, then they disappear, leaving only the newly created pair of electron - positron. These transitions are eloquent proof of the equivalence of mass and energy, expressed in the formula of Albert Einstein's E = mc2. Other antiparticles (antiprotons and antineutrons) were not found until 50-ies. But by that time, physicists were convinced that each particle has its antiparticle. Antiparticles reaching the earth from cosmic rays or by gamma rays from the laboratory, quickly eliminated the interaction with ordinary particles. However, physicists are inclined to believe, . that somewhere could be a galaxy, . consisting of antimatter, . in which atomic nuclei contain antiprotons and positrons are surrounded by, . thus providing an inverse relationship between the charges compared with our 'local' atoms.,
. 'For the discovery of the positron' A
. received in 1936. Nobel Prize in Physics. He shared it with Victor F. Hess, who discovered cosmic rays in 1912, and proved their extraterrestrial origin. When presenting the winner Hans Pleyel, a member of the Royal Swedish Academy of Sciences, said, referring to Anderson: 'Using the ingenious devices, you will find one of the building bricks of the universe - positive electron'.
A. was appointed assistant professor of physics at Caltech in 1933, an associate professor in 1937. and full professor in 1939. Two years later, after he discovered the positron, he, together with C. Neddermayerom have discovered yet another previously encountered particles in cosmic rays, . But they waited until 1937, . patiently gathering additional evidence from photographs of tracks, . before they announced the discovery of the particle, . now known as the muon,
. The mass of the particle was approximately 200 times greater than that of the electron.
During the Second World War, A. worked on military projects, including projects to create missiles for the National Committee for the Defense Research and the Office of Research and Development in 1944. He spent a month on the coast of Normandy, to oversee the operation of aircraft missiles in combat conditions. After the war, A. returned to Caltech, where he had a teaching and research work, particularly in the field of cosmic rays and elementary particles, until his resignation in 1976
A. married Lorraine Elvira Bergman in 1946, they raised two sons. In his spare time he likes to play tennis.
In addition to the Nobel Prize, A. received numerous awards and honorary degrees. including the Elliott Cresson Medal Franklinovskogo Institute (1937) and Medal of John Erickson, American Society of Swedish Engineers (1960). He holds honorary degrees Colgate University and Temple. A. is a member of the U.S. National Academy of Sciences, the American Academy of Arts and Sciences. American Physical Society and the American Philosophical Society.