I find this book fascinating, not just as science but as a window into the mind of a scientist. Sir Martin Rees is an astronomer who wrote this book to describe how six particular numbers appear to be "set" so that life will have a chance to emerge from the cosmos. Since he's an astronomer he writes very well about the laws of physics and once the periodic table is set up he assumes that takes care of everything (as a chemist, I start where he ends!). He is not a theist apparently, but he quotes St. Augustine twice and has the good sense to include a "summing up" chapter where he explains the tuning of these six numbers by invoking the multiverse, in which an infinity of possible universes exists, and we happen to see this one because there's no one around to see the others.
To which I say: great! You believe in something infinite. Why is an infinite array of universes preferred to the idea of an infinite creator? You gotta choose your infinity. And an infinite personality creating other personalities is at least logically connected. It comes down to, do you want to believe in someone bigger than you or not? And I suspect that we'll always be left at precisely that point, on the verge of a leap of faith but never forced over it, no matter how much science we know.
The six numbers are (that is, my understanding of the six numbers given my limited physical knowledge is):
-- N, which makes gravity so much weaker than the other physical forces, which allows atoms to form at all.
-- Epsilon, the nuclear efficiency, which is the energy released when matter is converted to energy in the heart of a star. If this was different (0.006 or 0.008 instead of 0.007) we wouldn't have a full periodic table.
-- Omega, the critical density, related to the ratio of dark matter to visible matter. If there weren't a lot of dark matter galaxies wouldn't form.
-- Lambda, the cosmological constant, a cosmic repulsion that pushes things apart (not well understood yet at least in the year 2000!).
-- Q, the number of ripples in the expansion, allowing galaxies to form from unevenness in the universe (1/100000 rather than 1/1000000 or 1/10000).
-- 3 + 1, that is, three dimensions of space and 1 dimension of time, which allows the inverse-square law to work so gravity can actually hold planets in stable orbits.
Needless to say my Weter lecture builds on all this and from a different perspective. But I'm grateful for Rees's forthrightness and clear statements, both for science and philosophy. This is an example of where the discussion of faith and science should be, for those scientists without a faith background.