How to Build a Time Machine

Rating:
Summary: buy it used, if you can get a cheap one
Review: This book was a very interesting look at what it would take to build a time machine, but it's only 128 pages. Don't expect to go build one after reading this, but at least when you finish you can poke fun at star-trek. It's a quick read, but it's worthwhile.

Rating:
Summary: How to build a quick tour of physical theories.
Review: Well, I hate to ruin it for you, but Davies isn't really telling the reader "how to build a time machine" so much as he is taking advantage of a gee-whiz slice of science fiction fun to build a quick tour of the fundamental theories of modern physics.
"So can it really be done?" asks Davies, one of the most frequently cited mathematical physicists of our day. And away we go, flying through the ideas of Newton, Einstein, Gödel, Hawking, and Penrose, and leaping into wormholes in space-time. As we go, the great modern physical theories come into play one after another. Davies is good at this. Quickly treated are singularities, entropy and the arrow of time, the special and general theories of relativity, exotic matter, antigravity, the topology of space-time, quantum uncertainty, and other stuff including a bevy of time-travel paradoxes.
To be sure, the author describes time machines that 'might' work. "So can it really be done?" Again, I don't want to ruin it for you. But some reviewers seem to have come up with the wrong answer. Here's a hint, "The purpose of science is to provide a consistent picture of reality, so if a scientific theory produces genuinely paradoxical (rather that merely weird or counterintuitive) predictions, that is a very good reason for rejecting the theory" (p 123). This isn't going to be remembered as one of Davies more important books (I recommend 'The Mind of God' and 'The Matter Myth'), but this is aimed at a different audience/readership.
A fun little book.

Rating:
Summary: How to build a quick tour of physical theories.
Review: Well, I hate to ruin it for you, but Davies isn't really telling the reader "how to build a time machine" so much as he is taking advantage of a gee-whiz slice of science fiction fun to build a quick tour of the fundamental theories of modern physics.
"So can it really be done?" asks Davies, one of the most frequently cited mathematical physicists of our day. And away we go, flying through the ideas of Newton, Einstein, Gödel, Hawking, and Penrose, and leaping into wormholes in space-time. As we go, the great modern physical theories come into play one after another. Davies is good at this. Quickly treated are singularities, entropy and the arrow of time, the special and general theories of relativity, exotic matter, antigravity, the topology of space-time, quantum uncertainty, and other stuff including a bevy of time-travel paradoxes.
To be sure, the author describes time machines that 'might' work. "So can it really be done?" Again, I don't want to ruin it for you. But some reviewers seem to have come up with the wrong answer. Here's a hint, "The purpose of science is to provide a consistent picture of reality, so if a scientific theory produces genuinely paradoxical (rather that merely weird or counterintuitive) predictions, that is a very good reason for rejecting the theory" (p 123). This isn't going to be remembered as one of Davies more important books (I recommend 'The Mind of God' and 'The Matter Myth'), but this is aimed at a different audience/readership.
A fun little book.