1928–1932Reputable sourceWell documented
Dirac, Antimatter, and the Positron
On the timeline · around 1928–1932 ·
What happened
In 1928 the British physicist Paul Dirac wrote an equation uniting quantum mechanics with special relativity to describe the electron. Strangely, it also predicted a mirror-image particle with opposite charge — antimatter. When the 'positron,' an anti-electron, was found in cosmic rays in 1932, Dirac's prediction was spectacularly confirmed.
Why it matters
Dirac's prediction of antimatter was one of the great triumphs of pure theory, revealing a hidden symmetry of nature. Antimatter is now central to particle physics and even used in medical PET scanners.