Continuing my attempts to blog about every book I’ve read for the first time this year, we come to this, which I actually finished about ten days ago, but didn’t get around to writing about because, like everything in my life for the last few weeks, it’s been delayed by repeated bouts of borderline illness (feeling too ill to write but not ill enough to be actually ill), work stuff, home stuff, and coursework. This is also why PEP! still hasn’t come out. (For those who are interested, text-only proof copies were sent to contributors a week ago. I’ve got their changes in, and now it just needs actual typesetting and layout. I *was* going to do that today, but ended up sleeping off a migraine until 2PM).
The Constants Of Nature is a book by physicist John Barrow that seems a bit less focussed than his other works. It reminded me actually of nothing more than a recent pop-science documentary I saw where the comedian Alan Davies tried to find out exactly how long a piece of string was – lumping together several more-or-less unrelated topics under a general theme, rather than having anything specific to say.
Barrow’s book starts with looking at how we measure things – looking at how units of measurement evolved from primitive measurements based on the human body, how first these were standardised to a ‘typical’ human body, and then slowly over centuries our units changed to become steadily more ‘universal’ – mesaurements of length starting as the length of parts of the body, then becoming proportions of the Earth’s circumference, before becoming wavelengths of light emitted by a particular atom.
He then goes on to talk about the effort – primarily in the late nineteenth and early twentieth centuries – to try to find a ‘natural’ system of measurements. There are all sorts of apparently-arbitrary constants like the gravitational constant, the charge on an electron, the speed of light in a vacuum, Planck’s constant, and so on. However, it is possible to get the number of these constants down to a fairly small number by choosing the right units. It was wondered (and still is) if it was possible to get these down to one or even no arbitrary constants – to have the whole of physics drop neatly out of pure mathematics.
(It is entirely possible that if a comprehensible Theory Of Everything were to be discovered, it would reduce these constants down to one or zero – that is one of the intents behind looking for such a theory. This might not be the case, however – Barrow’s former collaborator Frank Tipler (an exceedingly strange man who has done some extremely solid, worthwhile physics and also some stuff that is absolute crackpottery of the first order, as well as some work which is too technical for me safely to say which it is) seems to have shown in The structure of the world from pure numbers [Rep. Prog. Phys. 68 (2005) 897–964] that Richard Feynman came up with a workable theory of quantum gravity in the 60s, but it would require an infinite expansion of arbitrary terms… the parts of Tipler’s paper I can follow (the stuff about logic, Bekenstein bounds, etc) all make sense, but I simply can’t follow a big chunk of the rest well enough yet to say whether his argument holds water)
Barrow talks about various attempts to create some kind of unified theory, and to find some kind of simple mathematical relationship between these various constants, including the rather tragic story of Arthur Eddington – one of the most widely-respected British scientists of the early twentieth century – who wasted the last decades of his life on what amounted to nothing more than the kind of numerology one finds in books like The Bible Code, trying to fit the various constants of nature, plus ‘important’ mathematical numbers like pi, into some convoluted series of equations that would work without any reference to the real world.
Barrow then sidesteps into what one suspects is the real purpose of the book. He and Tipler had previously written a very successful book, The Anthropic Cosmological Principle, which is one of those pop-science books that hard-of-thinking people get hold of and believe says something very different to its actual content.
What Barrow & Tipler’s book actually says – and what Barrow reiterates here – is that the universe we live in seems inordinately fine-tuned for the kind of life that we are. Should the mass of the proton, say, or the charge on an electron, or any of these other constants, be changed by even one part in a million (or some other such tiny fraction), the universe would be so radically different as to render it impossible for life of our kind to exist.
Now, a lot of wooly-minded people (including, one suspects, Tipler at times), have seen this ‘fine-tuning’ as evidence of a creator setting up the universe ‘just so’ for humans. Other, more hard-headed people, have pointed out that this is like a child saying how lucky it is to live in the same house as mummy and daddy – if this weren’t that kind of universe, then, by definition, we wouldn’t be around to say what a shame it is that the universe couldn’t support our kind of life.
Barrow definitely takes the second tack, and the middle part of the book is essentially a reiteration of this view, although he also looks at a variety of options as to how the universe got to be the way it is, including the possibility of other universes with different physical constants.
And then, finally, Barrow swerves yet again as he discusses his own research – and other research that was ongoing at the time – which suggested that the ‘fundamental constants of nature’ weren’t so fundamental and constant after all, but have been slowly changing since the Big Bang, and what the implications of this would be for the long-term future of the universe. This is probably the most interesting part of the book, but also the least reliable, as this was (at the time the book was written, in 2002) bleeding-edge research, and I don’t know enough about cosmology to know if the research Barrow is talking about has since been falsified, or how reliable it seemed at the time.
This book seems to want to be three separate books – a history of measurement throughout history, The Anthropic Cosmological Principle For Dummies and a report on Barrow’s then-current research. Each on their own would probably be slightly more interesting than this book, which is still worth reading but far from its author’s best.