Einstein locked horns with Niels Bohr and younger physicists over their controversial ideas, as a superb new book, Quantum Drama, explains
Viewers of Christopher Nolan’s Oscar-hoovering biopic about the physicist J Robert Oppenheimer will have learned a lot about the race to build nuclear weapons, but not much about the hero’s involvement in arguably a much more important debate: what science ought to be able to tell us about reality. Oppenheimer has a walk-on part in Quantum Drama, Jim Baggott and John L Heilbron’s account of that epic struggle. Here, he’s introduced as “psychologically tender” and quoted as declaring that Albert Einstein (impersonated in the movie by Tom Conti) had “no understanding of or interest in modern physics”.
It was indeed once the popular history that by the time the Danish genius Niels Bohr and his comrades had built the startling edifice of quantum mechanics Albert Einstein was already too old and set in his ways to accept it, and spent the rest of his life kvetching impotently from the sidelines. In fact, and as this hugely detailed narrative of the 20th-century battle for the meaning of physics emphasises, Einstein’s challenges to the theory were tremendously powerful and inspired decades of fruitful research into questions that still are not definitively settled.
Niels Bohr’s base of theoretical operations lent its name to what became known as the “Copenhagen interpretation” of quantum mechanics, according to which – to put it very crudely – subatomic particles and maybe bigger things don’t exist anywhere in particular until you look at them. Bohr was unperturbed by the implications, trusting in the equations. But Einstein would not accept a style of physics that, as he saw it, abandoned its duty to describe the real world. Nor, completely, would his friend Schrödinger, whose famous cat – which is somehow both alive and dead in its box until someone opens it – was intended as a reductio ad absurdum.
This book is at the crunchily technical end of pop science, but also of its highest-quality peak. It helps to be able to read an equation or three, but the style is humane and interesting, and also blessed with a fantastically dry sense of humour. Among the story’s teeming cast we meet “a cooperative experimentalist who did indeed find the desired result and could have found any result desired, for he faked his experiments”, and a physics-curious English theologian, “author of too many books”. We can no longer stand on the hill where Heisenberg had an important insight, “for the British blew it up, not from opposition to quantum mechanics but because it capped a fortress the Germans had used during World War II”.
Quantum Drama is published by Oxford University Press
First Published at the Telegraph.co.uk