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A Different Universe: Reinventing Physics from the Bottom Down

25 November 2005

by Robert Laughlin, Basic Books. Hardback ISBN 046503828X, $26 (£15.50).

Despite the fact that the author has a Nobel Prize in Physics, this is rather an easy book to read. While not as funny as Richard Feynman’s jokes, and fortunately not as exquisitely informal (this is an understatement) as João Magueijo’s Faster than the Speed of Light, it is quite nicely written, good humoured and even sprinkled with poetic eloquence. I actually enjoyed reading the innumerable biographical anecdotes (at least the first 50 or so), even though most seemed rather irrelevant for the purpose of the book, which could easily be half as thick without any loss in real content.

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Let me do justice to the book by wandering myself. We often hear at CERN that particle physics deals with the most fundamental level, the “ultimate theory”, from which everything else should, in principle even if not in practice, be derivable. But systems above certain levels of complexity exhibit “emergent” laws that cannot be derived through such a “bottom-up” approach. It is particularly interesting to note that superconductivity cannot be derived from fundamental principles, especially when we see how crucially dependent we are on superconductivity to perform our “fundamental” studies at CERN. A little modesty would not harm some particle physicists. We can’t always learn how a toy works by breaking it to pieces; sometimes all we learn is that the broken toy doesn’t work any longer.

This is the central point of Laughlin’s thought-provoking book: there’s a different universe out there, which we can easily see if we care to look, and where certain things are more than the sum of their parts.

This is surely not a new idea. “More is different” claimed Philip Anderson 33 years ago, at a time when Jacques Monod argued that the higher levels of reality are not necessarily determined by the lower levels.

What I enjoyed most in Laughlin’s “different” book were the descriptions of several eye-opening experimental observations – such as the von Klitzing and Josephson effects – which intrinsically depend on collective behaviour (the effects disappear in very small samples) but provide today’s most accurate measurements of the fundamental constants e and h.

Unfortunately these fascinating issues are not really described in much detail, while too many pages, especially at the end of the book, are devoted to less relevant topics, seemingly motivated by polemic fights with “hard-boiled reductionists” who are accused of believing that nothing fundamental is left undiscovered. However, don’t miss chapter 15, which is about a “cast of characters” trying to define what “emergence” means; this is particularly hilarious if you have read Arthur Koestler’s The Call-Girls (1972).

Laughlin’s book is definitely worth reading, although I was disappointed; there is a lot of talking but in the end not much physics really gets reinvented. It is a pity that Laughlin spends much of his energy fighting reductionism rather than detailing his own new ideas. And a little modesty would also not harm his arguments. Emergence and reductionism are equally important in our quest for understanding the (single) universe around us – as Freud said, on psychology and biology, “Some day the two will meet.” If you are interested in these topics, read Koestler’s The Ghost in the Machine (1967) and Stuart Kauffman’s At Home in the Universe (1995).

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