How to Build a Time Machine

Rating:
Summary: For the curious engineer and the scientific theorist alike.
Review: Those with a theoretical interest in time travel will appreciate Davies' attention to explaining in detail the intricate theory behind the components of time travel. I think the real winner though will be the engineer with a slant toward the practical application side. Davies' presents a potential design (complete with flow diagram!) of the process steps needed to construct a time machine. Theories of black holes, worm holes, gravity, anti-gravity, causality etc. are presented in crisp yet coherent detail.
As a literary style, I at first didn't care for the many cartoon type drawings which decorate nearly a quarter of the book, but as it went on I realized that not only where they illustrative to the the book's finer details, but also a symbol for the fanciful possiblity of time travel. Reader's with further interest will also appreciate the detailed bibliography.

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.