Saturday, 1 January 2011

The Many Worlds of Hugh Everett III

The Many Worlds of Hugh Everett III: Multiple universes, mutual assured destruction, and the meltdown of a nuclear family by Peter Byrne

It’s a sobering fact that the world we live in would be a very different place but for the discovery of quantum mechanics in the 1920s. Yet for the next sixty years most physicists accepted that the theory denied the existence of reality at the atomic and sub-atomic level. This strange state of affairs led the Nobel Prize-winning American physicist Murray Gell-Mann to describe quantum mechanics as ‘that mysterious, confusing discipline which none of us really understands but which we know how to use’. And use it we have, for without it there would be no computers, mobile phones, televisions and numerous other everyday gadgets.

Gell-Mann blamed the celebrated Danish physicist Niels Bohr, accusing him of having ‘brain-washed a whole generation of physicists into believing that the problem had been solved’. The problem being the vexed one that lies at the heart of quantum mechanics – what does the theory tells us about the nature of reality.

Albert Einstein and Bohr spent nearly thirty years locked in a debate over this question. Bohr believed he had the answer. There simply was no objective reality, but only ‘an abstract quantum mechanical description’. For Bohr, Schrödinger’s famous mythical cat trapped in a box with a vial of poison was neither dead nor alive but in a ghostly mixture of quantum states that ranged from being totally dead to completely alive and every conceivable combination in between until the box was opened. It was the act of observation/measurement, i.e. opening the box, that decided the fate of the cat. Einstein thought this was absurd. He believed that the cat was simply either dead or alive and to find out which all one had to do was look in the box.

Hugh Everett III was a twenty-four student at Princeton University when Einstein died in April 1955. By then Bohr’s so-called Copenhagen interpretation had become quantum orthodoxy that few were prepared to challenge. However, Everett did exactly that in his PhD thesis when he demonstrated it was theoretically possible to treat each and every possible outcome of a quantum experiment as actually existing in an alternative parallel reality. According to Everett this meant that the moment the box containing Schrödinger’s cat was opened the universe split in two, one in which the cat was dead and another in which it was still alive and kicking.

H.G. Wells wrote one of the first stories about parallel universes. In his 1922 Men Like Gods there exists an alternate world with ‘no parliament, no politics, no private wealth, no business competition, no police, no prison’. The Utopians who inhibit this world had shared our bloody past until history inexplicably branched. Everett was an avid reader of science fiction and believed that his theory was the simplest explanation of quantum mechanics, but accepting it was ‘a matter of taste’. Bohr and his inner circle rejected Everett’s heretical ‘many worlds’ as unpalatable and it was ignored.

Instead of pursuing an academic career and fighting for his idea, Everest joined the Pentagon in the late 1950s to apply game theory to strategic nuclear war planning. At the time the Pentagon was busy analyzing the cost-benefits of global and limited nuclear wars and calculating nuclear blast and fallout kill ratios. Appropriately for a man whose favourite film was Dr Strangelove, Everett helped bring the world perilously close to the brink of nuclear destruction. His work was instrumental in the development of the no-win scenario of mutual assured destruction (MAD) that defined the Cold War as it became the strategic posture of both the Americans and the Soviets. Peter Byrne in this vivid and thoroughly researched portrayal of a quintessential cold war techno-warrior found no evidence that Everett ever had the slightest doubt about effectively playing God with all life on Earth.

Byrne does an admirable job of weaving together quantum mechanics, nuclear war games and the disintegration of a dysfunctional family in this tale of a talented scientist, but morally compromised man. In pursuing what mattered to him, Everett was indifferent to the feeling of others and cared little what harm is actions caused those closest to him – one of his two children committed suicide. His achievements in physics and for the military were matched by his shortcomings as a husband and father.

Everett, who died of a heart attack aged fifty-one in 1982, did not live to see his many worlds interpretation taken seriously by physicists as they struggled to explain the mystery of how the universe came into being. A poll conducted just over a decade ago revealed that only four out of ninety physicists voted for Bohr’s Copenhagen interpretation, but thirty favoured the modern version of Everett’s many worlds. ‘There is no question that there is an unseen world,’ Woody Allen once said. ‘The problem is how far is it from mid-town and how late is it open’.