Antiparticle - Dirac's Hypothesis, Other Antiparticles, Antimatter, Antiparticles And Cosmology

An antiparticle is a subatomic particle identical with more familiar subatomic particles such as electrons or protons, but with the opposite electrical charge or, in the case of uncharged particles, the opposite magnetic moment. For example, an antielectron (also known as a positron) is identical with the more familiar electron, except that the former carries a single unit of positive electrical charge rather than a single unit of negative electrical charge. Antiparticles are not considered to be unusual or abnormal but are as fundamental a part of the natural world as are non-antiparticles. The main difference between the two classes of particles is that the world with which humans normally deal is constituted of protons, neutrons, and electrons rather than antiprotons, antineutrons, and antielectrons. To avoid suggesting that non-antiparticles are more "normal" than antiparticles, the name koinoparticle has been suggested for "ordinary" particles such as the proton, electron, and neutron.