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 YOU KNOW IT'S CHRISTMAS when that classic slice of
early-eighties schoolboy humour A Hundred and One Uses for a Dead Cat ('we're still flogging it') re-surfaces in W H Smiths. Erwin Schrodinger's cat-in-the-box isn't featured - its fate probably
wasn't sufficiently macabre - but its fame as the popular face of quantum absurdity guarantees this particular cat its own place in history. Sixty years on, perhaps it's time the cat was finally
laid to rest? Gribbin thinks so, and reporting from the cutting edge of quantum research he explains how physicists are trying to take absurdity out of the equation.
Schrodinger's Cat highlights the consequences of quantum mechanics in laymen's terms and exemplifies the 'Copenhagen Interpretation', which has been the orthodox view of quantum mechanics since the 1930s. The
main thrust of the Copenhagen Interpretation is that alternative outcomes of the experiment exist only as probability waves until an external observer checks the result. This reliance on an observer to
'collapse the wave function' leads to a morass of philosophical debate which serves to emphasise that this is a crutch for interpreting quantum behaviour, not an explanation of it. Gribbin argues that the
Copenhagen Interpretation is what makes quantum mechanics hard to understand, and he leads us through the alternatives that have appeared over the last couple of decades before revealing his own 'best buy'.
The book focuses, as does much of quantum research, on what happens to electrons as they go through 'the experiment with two holes', as Richard Feynman called it. Many of the apparently strange consequences
of quantum behaviour can be attributed to the fact that we still don't really know what electrons are, and it's hard to break away from classical models such as 'waves' and 'particles'. To paraphrase
Feynman, things on a very small scale don't behave like waves, particles, clouds, billiard balls - or like anything we have ever seen. What quantum mechanics shows us is that waves and particles in the
classical sense may be mere shadows that reveal some aspects of a higher order we haven't yet figured out.
Although billed as a sequel to Gribbin's earlier work In Search of Schrodinger's Cat
, this book is complete in its own right. Gribbin updates the cat-in-the-box experiment by shooting the moggie's hypothetical offspring off to opposite ends of the universe in
spaceships, but the kittens provide little more than a cute title, reappearing only briefly in the final chapter where their fate is left an exercise for the reader. I won't spoil the book by revealing its
conclusions, but Gribbin's aim is to reveal the most promising explanation of the mechanics underlying quantum behaviour. 'Most promising' means an explanation that is easily understood, and one that
doesn't carry around any philosophical baggage. To give you a little clue, it does at first appear to involve time travel, but this is a moot point once we've learned about how photons experience time.
This is a challenging book that repays a second reading: the subtleties of some of the experiments Gribbin describes are difficult to impart in laymen's terms and it's easy to miss some of the detail first time
around. Gribbin isn't going to challenge the Dead Cat book (this year anthologised in a bumper edition with its two sequels) as a stocking filler, but if you want something to revive your intellect buds from
the festive torpor, Schrodinger's Kittens is an entertaining and stimulating read. |
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