The End of Time: The Next Revolution in Physics (Paperback)

Barbour has taken on an especially difficult task in trying to explain these esoteric concepts in a work of popular science. The book doesn't succeed, in my view, and the most I can do here is give him credit for trying. My negative review does not reflect any disagreement with his ideas - it is up to his peers in physics, not me, to decide whether he is on to something or not. I just don't think he's succeeded in putting his ideas across to a general audience. The book is so wordy, and its exposition so plodding and foggy and vague, that it is hard to imagine that most people would get much out of it.

I really don't like to write negative reviews, but sometimes they can be useful in steering readers away from books that are likely to frustrate and turn them off. Barbour is a respected physicist, an original thinker, and an interesting person, whose life trajectory has taken him far from the typical academic career. But I really hope he'll take on a co-writer, somebody who knows how to write clearly and informatively about popular science, on his next book.

Here is a crude summary of his hypothesis. Our universe exists within a configuration space that he calls Platonia, which defines all possible configurations of matter and energy in all possible universes. As the configuration of the universe changes moment-by-moment, it "moves" within Platonia. But the possible configurations are discrete and static (what the author calls Nows), so what appears to an observer as motion and time is actually just infinitesimal leaps within Platonia. Each configuration is dependent on the last, and no other next configuration, outside of those made possible by the vanishingly small variations allowed by the uncertainty principle and the wave functions that govern probability, is likely.

It's certainly a new way of looking at things, and by tossing aside the notion of an absolute time, it might make some of the physical equations that seem to describe the universe easier to apply. It also does a nifty job of explaining why time cannot be manipulated as such, and why it doesn't run backwards every so often. Even if the universe ceases expansion due to gravity and eventually collapses in a Big Crunch (and his theory does not predict anything about that), time will not flow backwards because the discrete configurations during the contraction phase are still dependent on what came before.

However, we still have this little problem of the appearance of time. Just because the universe resides in only the present fleeting moment does not necessarily mean that there was no history leading up to any particular configuration. One must still look back at all of the previous configurations to the beginning of the universe to explain the universe as it is Now.

Just as the Newtonian laws of motion work well at nonrelativistic speeds, the concept of time has enormous usefulness here in the macroscopic world. Barbour may disagree, but it still means something to say that an event happened so many years ago, even if the difference is measured not by time but by the number of discrete configurations of the universe between then and Now.

Barbour's theory of a timeless universe does not make any predictions about how the universe may have come about in the first place. It may yet, but he does not present anything here. Perhaps it was buried in his rambling about the supposedly all-encompassing Wheeler-DeWitt equation, and I just missed it.

Admittedly, I am a layman. I cannot tell whether Barbour's theory has any predictive value. I would think that if it did, Barbour would have at least hinted at what it might be. As it is, I am left with the impression that he considers the implications "intuitively obvious to the casual observer", as they used to say in my college physics courses. That leaves me exactly nowhere. I can't tell that his theory of a timeless universe actually accomplishes anything other than justifying the Wheeler-DeWitt equation and the timeless zero energy Schroedinger equation, neither of which were reproduced in the book.

The epilogue, in which he explores the philosophical implications of a timeless universe, is pretty much useless speculation grouped under section headers like, "Does Free Will Exist?" and "Is There A Role For A Creator In Quantum Cosmology?" and even "Where Is Heaven?" Thankfully, he doesn't seem to conclude the existence of the Judeo-Christian god, but this sort of stuff is out of place here.

The argument for a timeless universe is not laid out terribly well. Granted, this is his attempt at convincing people that are a lot smarter than I am that a different framework for looking at the universe is needed. But the best science popularizations leave you feeling smarter, and I'm not so sure that I do.