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  • Topic: Electron, Antimatter, Positron
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  • Published : January 2, 2006
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Dec. 1, 2005

Antimatter is a large subject which is covered through all the science fields. Antimatter or antiparticles is often called the "mirror image" of ordinary matter. For every type of ordinary matter particle, an antimatter particle can be created that is identical in characteristics except for an opposite electric charge and some other properties like magnetic moment. While staying with the topic of astronomy, this paper will describe the discovery of antimatter, the origins of antimatter, and antimatter as energy. To describe antimatter we must first look at the history in its discovery. The history of discovering antimatter begins in 1929 by the proposal of an English Physicist named Paul Dirac. In attempting to combine quantum mechanics with special relativity to describe the behavior of an electron, he found that the solutions of the equation which showed that if matter is created from energy then an equal amount of antimatter is also created. For example, the equation, X squared equals four can have two possible solutions (X equals two) or (X equals negative two.) Dirac's equation proves two possible solutions, one for an electron with positive energy, and one for an electron with negative energy. This showed that for every proton in the universe there should be an antiproton or a proton with a negative charge, for every electron there’s a anti-electron or an electron identical in everyway but with a positive charge, and every neutron there’s a antiparticle called an antineutron. The combined theory was called the Quantum field theory. From 1930, the hunt for the mysterious antiparticles began. A scientist named Victor Hess had discovered a natural source of high energy particles called cosmic rays. Cosmic rays are very high energy particles that come from outer space and as they hit the Earth's atmosphere they produce huge showers of lower energy particles that have proved very useful to physicists. In 1932 Carl Anderson, a professor at the California Institute of Technology, was studying showers of cosmic particles in a cloud chamber and saw a track left by a positively charged particle with the same mass as an electron. He concluded that the tracks were actually anti-electrons each produced alongside an electron from the impact of cosmic rays in the cloud chamber. He called the anti-electron a "positron", for its positive charge. This proved the existence of antiparticles as predicted by Dirac. Since an antiproton (or proton) is almost 2000 times heavier than an anti-electron (or electron), it takes a lot more energy to create them. Twenty-three years later technology advanced enough to create enough energy to produce an antiproton. In 1954, a particle accelerator called the Bevatron was built at Lawrence Berkeley Laboratory which possessed sufficient energy to create its own antimatter. The Bevatron could collide two protons together at a energy of 6.2 GeV. This was expected to be the optimum for producing antiprotons. Meanwhile a team of physicists designed and built a special detector to see the antiprotons. In October 1955 the big news hit the front page of the New York Times with the discovery of the antiproton. A year later the Bevatron created the antineutron. So if particles bound together in atoms are the basic units of matter, it is natural to think that antiparticles bound together in anti-atoms are the basic units of antimatter. In 1965 two teams of physicists observed the making of an anti-deuteron, a nucleus of antimatter made out of an antiproton plus an antineutron. In 1995 an anti-electron was combined with an anti-deuteron to create an anti-atom. And finally the Anti-hydrogen atom was created. Acceleration and deceleration of particles are not the only way to study antimatter. Antimatter could exist somewhere in outer-space. Dirac was the first to consider the existence of antimatter in an astronomical scale. It was only after the confirmation of his theory, with the...
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