The very first proof for the existence of antimatter came in the 1920s through the work of British physicist Paul Dirac. In his attempts to make Einstein’s special relativity principle agree with the rules of quantum mechanics – a mathematical system that pertains to the behavior of small particles – Dirac found himself consistently running into a negative sign he felt didn’t belong there.
His breakthrough came when he ultimately realized that the negative sign wasn’t really a mistake, but rather a revelation. It dawned upon him that in order for the calculations to work, there needed to be an undetected particle similar in weight to a negatively-charged electron, but carrying a positive charge.
This proof was only theoretical in nature though, and it took a further four years for these particles to be actually detected in the laboratory. The man behind the experiment was Carl Anderson, who was able to detect the positively charged electron by observing its trail. He dubbed this newly discovered particle “positron”.
The real innovation in Anderson’s experiments lay in his detection methods. While he may not have been the first to create antimatter in a lab, he was the first to utilize something called a cloud chamber to identify traces of antimatter just before they vanished. For their tremendous contributions, both Dirac and Anderson would later go on to win the Nobel prize in physics.
What makes the detection of antimatter hard is the fact that they are annihilated as soon as they come into contact with matter, releasing a bunch of energy. Therefore, any antimatter that is formed on Earth is lost to this reaction almost immediately.
Antimatter can be understood to be essentially matter with its electrical charge reversed. Since Anderson’s discovery of the positron, scientists have found that there are various other forms of antimatter. Similar to positron, there is also antiproton, a negatively charged proton, and antineutron, for which the theory still holds since although neutrons have no charge, the negative of zero is simply zero. There are also antiparticles other than this which are even smaller in size.
These days, positron, antiprotons and other antiparticles can be routinely created at particle accelerator labs, such as CERN in Europe, where they are often trapped and kept in storage for days, and even weeks at a time. Research at CERN has also led to the creation of the very first antihydrogen particles.
Direct evidence of antimatter occurring naturally on Earth was discovered for the first time as recently as January 2011, when scientists using NASA’s Fermi Gamma-ray Space Telescope detected beams of antimatter produced above thunderstorms on Earth. Scientists believe that these particles were formed inside thunderstorms due to a terrestrial gamma-ray flash (TGF) associated with lightning.
While antimatter has now established itself as more than mere science fiction, its actual use outside of research is thoroughly limited due to the costs associated with its production. At present, it would cost a hundred billion dollars to create just one milligram of antimatter, a price that would have to drop by a factor of ten thousand to make production of antimatter commercially viable.
