Amazon.com (ISBN 0198502540, Hardcover)

The publication over a decade ago of Stephen Hawking's runaway bestseller A Brief History of Time triggered a flood of more or less comprehensible books about the frontiers of physics and mathematics. And to judge by most of their authors, we are on the brink of finding the theory of everything, or the key to the cosmos, or some other Holy Grail of science.

Rarer are authors such as John Barrow, professor of physics at Sussex University, a genuine expert in these fields who writes coolly and clearly about the current state of play. Between Inner Space and Outer Space is a collection of Barrow's writings about the frontiers of science dating back to 1980, and is remarkable for the number of fresh twists and insights it brings to many now-familiar debates. For example, are scientists really close to a theory of everything, uniting all the fundamental forces in the universe and all the particles on which they act? Barrow shows how the quest may be stymied by fundamental limits to knowledge that have emerged from 20th-century mathematics. Are scientists really close to understanding the birth of the universe? Again, Barrow shows that a whole set of limitations--not the least of which is the fact that light travels at a finite speed--forever stops us from knowing for sure if our ideas are right. As in any collection, there is a modicum of repetition and a few ill-judged selections. Even so, any reader seeking thoughtful, sophisticated, and above all original writing about the cutting edge of physics and mathematics need look no further. --Robert Matthews, Amazon.co.uk