Rees’ small volume on cosmology is good but not great. He details the origins and fine-tuned-ness of six physical constants: N (10^36 = strength of atomic electrical forces); E (0.007 = nuclear force); Omega (the amount of dark matter in the universe); Lambda (anti-gravitational force); Q (1/100,000 = ratio between fundamental energies); and D (3 = number of dimensions). If any of these numbers were slightly off, we would not have the universe as we recognize it today. While Rees has neither the flare or plain-spoken-ness that Brian Greene possesses, he gets his point across with some competence. I wouldn’t recommend starting with this book, but it is nevertheless a decent source of cosmological wonder. ( )

Essential reading if you want to know why we're here. This book gives a clear understanding of the anthropic principle -- there are many different kinds of separate inflationary universe bubbles, so of course we are in the one that happens to be able to support us. Note that this kind of multiverse is completely different from the multiverse aspect described by Deutsch and Julian Barbour (see my reviews). This book describes and explains the multiverses separated in space, really all in this same Now. The other books deal with the multiplicity of multiverses "arising" in parallel at each moment in time, vastly more multiple than the accepted inflationary bubble universes. Put the two models together and you've got it all, a total theory of objective reality, and ultimately an explanation of why we exist -- the answer: because everything that can exist does exist. Why everything instead of nothing? Why not? This is as far as our answers will ever go. ( )

http://www.skepticalchristian.com/br_... ( )

The way our universe is depends on six numbers, pretty much. Two of those numbers are related to basic forces, two fix the size and texture of the universe and the final two fix the properties of space. The numbers have certain values and even the smallest changes in those numbers would lead to universes very much unlike our own.

That is all rather curious and interesting. Martin Rees, the Astronomer Royal, uses these six numbers as a springboard to explain the current state of knowledge about our universe. This is a fairly short book, but it's packed full of knowledge. While Rees writes for the general public (and he writes well), understanding this book requires certain level of intellectual curiosity. The concepts he covers are so complicated, I think it would be rather hard to explain them with more clarity.

In any case, this is recommended reading for everyone interested in finding out how our universe came to be.

(Original review at my review blog) ( )