Word: positrons
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Dates: during 1930-1939
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Then, in quick succession, the neutron was discovered by Chadwick in England and the positron by Anderson in California. The neutron was about as heavy as the proton but had no electric charge. The positron had the same mass as the electron but an opposite charge. Physicists then saw that if they could add to their collection a particle heavy like the proton but negatively charged, and a particle light like the electron but not charged at all like the neutron, they would have a neat array of pairs and triplets, as follows...
MASS CHARGE Plus Minus No Charge Heavy Proton (Negative Neutron proton?) Light Positron Electron (Neutrino...
...mathematical "hole" imagined by Dirac. Its life was brief-about a third of a millionth of a second. But Karl Kelchner Darrow of Bell Telephone Laboratories later pronounced it "probably the most famous individual corpuscle in the history of physics." Dr. Anderson called his discovery the positive electron, or positron...
...University of Pisa, has taught and researched at the University of Rome since 1927. Short, wiry, dapper, cheerful, he is married, has a 5-year-old daughter, likes to ski, play tennis. Some years ago he perceived that when a nuclear impact knocks a neutron and a positron out of an electron, there is a mysterious disappearance of energy. He surmised that the excess energy rode away on a little particle which, now generally accepted as theoretically necessary, still eludes observation. It is because of Fermi that this little particle, the neutrino, has an Italian name...
...laboratory experiments which show radiation transformed back into matter. Every physicist under 35, he declared, would agree with him that such demonstrations are valid. What apparently happens is that the quantum of radiation, scoring a hit on an atomic nucleus, vanishes and gives birth to an electron and a positron-i.e., particles of matter. The quantum of radiation is "mathematically irritated" by the atomic nucleus into giving up its existence. Here Dr. Swann ran into the difficulty that in his sea of radiation there would be no atomic nuclei to provide irritation. He wiggled out of it by supposing...