THE INVENTION OF ANTIMATTER: DIRAC AND SYMMETRY QUANTUM WORLD

In the spring of 1931 a shy Englishman published a paper containing two predictions, both of them squeezed out of nothing but symmetry. One of them was photographed the following year and won him a share of the Nobel Prize. The other has never been seen at all, despite ninety-five years of increasingly expensive looking. Paul Dirac is remembered as the purest of pure theorists, the man who wrote on a Moscow blackboard that physical laws should possess mathematical beauty. He was also, and first, an electrical engineer who failed to impress the factory that trained him, who learned his trade calculating the stresses in whirling shafts, and who said plainly that engineering had taught him to tolerate approximation. That combination produced the strangest career in modern physics: a thinker who conjured antimatter out of an algebraic sign, and who then spent his final thirty years refusing to accept the theory he himself had founded. This book tells that story as a single sustained argument. Antimatter, it suggests, was not discovered in the way that a continent or a comet is discovered. It was invented, in the way a category is invented, and the invention worked. But the same method, applied twice more by the same hand, produced one prediction that has gone unanswered and one that quietly failed. Mathematical beauty, it turns out, is not a guarantee. It is a wager, and this is the record of what the wager cost. Drawing on Dirac's own recollections and on the long history of a discipline that keeps finding more in its equations than it put there, the book follows a silent boy forbidden to speak English at his father's table all the way to a green slate marker in Westminster Abbey, inscribed not with a sentence but with an equation. Keywords: antimatter, Paul Dirac, quantum mechanics, positron, symmetry, history of physics, philosophy of science