Antimatter

This was written by my friend Ben Weber.

Antimatter is a very close to matter but also the exact opposite of matter. The first idea of antimatter came from an concept created by Paul Dirac which combined forms of quantum mechanics and spacial relativity. This concept predicted the idea of anti-electrons which were later renamed positrons. The idea of positrons eventually lead to discovery of anti-protons and the creation of anti-particles. A complete periodic table of antimatter was created by Charles Janet in 1929, the table lists all the elements in there anti form yet only two of these elements have been created in a lab and are still almost impossible to study. 

Antimatter can be produced naturally or artificially. Positrons are created naturally in β+ decay (beta positive decay), which is the decay of protons to neutrons, decays of naturally occurring radioactive isotopes. This includes Potassium 40, which is found in humans and even bananas. Anti-neutrons are created through natural radioactivity, or β- decay (beta negative decay), and example of this is when the free neutron (10n) decays by β− decay into a proton (p).  Antiparticles are also produced in any environment with a sufficiently high temperature, which means particle energy greater than the pair production threshold. It is hypothesized that during the period of baryogenesis, which is when the universe was extremely hot and dense, matter and antimatter were continually produced and annihilated. Recent observations indicate black holes and neutron stars, which are stars of a very small radius with an extreme amount of mass, produce vast amounts of positron-electron plasma via the jets.

That artificial creation of antimatter is much more complicated then the natural creation so this next part might not make any sense. Positrons are created using a laser to drive electrons through a gold target's nuclei, which causes the incoming electrons to emit energy quanta that decayed into both matter and antimatter. In 1995, CERN announced that they had successfully created 9 hot anti-hydrogen atoms by implementing the SLAC/Fermilab concept during the PS210 experiment, sadly these atoms where extremely energetic and not suitable to study.