Quantum Legacy by Barry Parker, Prometheus, $29, ISBN 157392993X Reviewed by Marcus Chown
OF THE two great pillars of 20th-century physics 鈥� quantum theory and relativity 鈥� there is no doubt that quantum theory has had the greatest impact on day-to-day life. It has made much of today鈥檚 world possible, giving us transistors, computers and mobile phones, while simultaneously explaining why the ground beneath our feet is solid and how the stars shine. It鈥檚 ironic, then, that relativity, created by a single genius, Einstein, is far better known. In Quantum Legacy, Barry Parker, sets out to try to redress the balance and reinstate quantum theory to its rightful place.
Einstein was one of quantum theory鈥檚 great critics, but ironically it was he who first recognised the mould-breaking nature of quantum theory. In the four papers he published during his 鈥渕iraculous year鈥� of 1905, the one he considered revolutionary was not either of the two papers on relativity, but the one explaining the photoelectric effect in terms of the absorption of 鈥渜uanta鈥� (packets) of radiation. It was an opinion shared by the Nobel judges, who awarded him the 1921 physics prize.
Advertisement
In his remarkably concise and clear book, Parker sets out the whole story of the development of quantum theory, starting with Max Planck鈥檚 epoch-making discovery of the 鈥渜uantum鈥� in 1900. Einstein enters the story with his crucial recognition that the quantum was not only 鈥渞eal鈥� but totally incompatible with every previous notion in physics.
As the peculiar story of quantum theory unfolds 鈥� and Alice in Wonderland has nothing on this 鈥� Parker introduces the key figures in the revolution, from Niels Bohr and Wernher Heisenberg to Richard Feynman.
It鈥檚 a thrilling tale 鈥� not least because it is still unfolding. Much confusion remains about what quantum theory is actually telling us about the 鈥渞eality鈥� that underpins our Universe, and we still have no quantum theory of gravity, the biggest obstacle to a quantum 鈥渢heory of everything鈥�. But if you want to find out where we stand now 鈥� a necessary prerequisite to appreciating the big problems quantum theory still poses 鈥� you could do no better than read this well-written and accessible account.