BEYOND FUSION
Antimatter
Is there anything that lies beyond fusion?
When hydrogen undergoes fusion and becomes helium, only 0.7% of the original mass of the hydrogen is converted to energy. Is it possible to take a quantity of mass and convert all of it, every bit, to energy? Surely that would be the ultimate energy source. Mass for mass, that would deliver 140 times as much energy as hydrogen fusion would; it would be as far beyond hydrogen fusion as hydrogen fusion is beyond uranium fission.
And, as a matter of fact, total annihilation of matter is conceivable under some circumstances.
In 1928 the English physicist Paul Adrien Maurice Dirac (1902- ) presented a treatment of the electron’s properties that made it appear as though there ought also to exist a particle exactly like the electron in every respect except that it would be opposite in charge. It would carry a positive electric charge exactly as large as the electron’s negative one.
If the electron is a particle, this suggested positively charged twin would be an “antiparticle”. (The prefix comes from a Greek word meaning “opposite”.)
P. A. M. Dirac
