Sci-fi makes it look so easy. Receive a distress call from Alpha Centauri? No problem: punch the warp drive and you're there in minutes. Facing a catastrophe that can't be averted? Just pop back in the timestream and stop it before it starts. But for those of us not lucky enough to live in a science-fictional universe, are these ideas merely flights of fancy – or could it really be possible to travel through time or take shortcuts between stars?
Cutting-edge physics may not be able to answer those questions yet, but it does offer up some tantalizing possibilities. In Time Travel and Warp Drives, Allen Everett and Thomas Roman take readers on a clear, concise tour of our current understanding of the nature of time and space – and whether or not we might be able to bend them to our will. Using no math beyond high school algebra, the authors lay out an approachable explanation of Einstein's special relativity, then move through the fundamental differences between traveling forward and backward in time and the surprising theoretical connection between going back in time and traveling faster than the speed of light. They survey a variety of possible time machines and warp drives, including wormholes and warp bubbles, and, in a dizzyingly creative chapter, imagine the paradoxes that could plague a world where time travel was possible – killing your own grandfather is only one of them!
Written with a light touch and an irrepressible love of the fun of sci-fi scenarios – but firmly rooted in the most up-to-date science, Time Travel and Warp Drives will be a delightful discovery for any science buff or armchair chrononaut.
2. Time, Clocks, and Reference Frames
3. Lorentz Transformations and Special Relativity
4. The Light Cone
5. Forward Time Travel and the Twin “Paradox”
6. “Forward, into the Past”
7. The Arrow of Time
8. General Relativity: Curved Space and Warped Time
9. Wormholes and Warp Bubbles: Beating the Light Barrier and Possible Time Machines
10. Banana Peels and Parallel Worlds
11. “Don’t Be So Negative”: Exotic Matter
12. “To Boldly Go . . .”?
13. Cylinders and Strings
Appendix 1. Derivation of the Galilean Velocity Transformation
Appendix 2. Derivation of the Lorentz Transformations
Appendix 3. Proof of the Invariance of the Spacetime Interval
Appendix 4. Argument to Show the Orientation of the x',t' Axes Relative to the x,t Axes
Appendix 5. Time Dilation via Light Clocks
Appendix 6. Hawking’s Theorem
Appendix 7. Light Pipe in the Mallett Time Machine
Allen Everett is professor emeritus of physics at Tufts University. Thomas Roman is professor in the Mathematical Sciences Department at Central Connecticut State University. Both have taught undergraduate courses in time-travel physics.
"In recent years, a number of books have taken on real science that sounds like science fiction. Unfortunately, most are frothy concoctions that leave the serious reader unsatisfied. This is all the more reason to celebrate the arrival of Time Travel and Warp Drives – a deeply informed, richly detailed yet immensely readable account of science at the frontiers, by two physicists who know the territory. For well over a decade Allen Everett and Thomas Roman have been charting the strange realms of negative energy, twisted spacetime, temporal paradoxes, and travel between universes. In a wonderfully written and especially timely account, they share with us what they've learned. Time Travel and Warp Drives deserves a place on the shelf between Greene's The Elegant Universe and Hawking's A Brief History of Time."
- David Toomey, author of The New Time Travelers: A Journey to the Frontiers of Physics
"There have been plenty of light popularizations of the puzzling physics of time. This book stands out in its depth and range. Written by two who have done the calculations, followed the field, and thought about what it all means, it leads the reader through the byzantine labyrinths of current theory. I found it enlightening and fun to read. If you have time for one book in this field, let it be this one."
- Gregory Benford, author of Timescape
"I have been searching for years for a book like this. With Time Travel and Warp Drives, Everett and Roman have written an illuminating exploration of the physics of time travel. What sets this book apart, however, is that the authors do not rely on analogies or metaphors. They actually explain the underlying science in a clear and accessible way. My search is over: this book is my new guide to a place stranger than science fiction – our universe."
- Charles Yu, author of How to Live Safely in a Science Fictional Universe
"Einstein meets Captain Kirk in this improbable foray into the frontiers of theoretical physics, where readers survey the exciting possibilities for traveling through time and between galaxies [...] Relying only minimally on technical jargon and formulas, the authors open to view the exciting conceptual prospects for designing a time machine capable of slipping backward through the centuries and of riding fast-than-light warp bubbles through the cosmos [...] Armchair scientists share the thrill of peeking into the universe's deepest secrets. Penetrating science illuminates humankind's most audacious dreams."
- Booklist | starred review
"Everett and Roman are physicists who have probed the theoretical possibilities of time travel. Their expertise shines."
- Science News
"Whenever anyone asks me whether time travel is possible, or rapid insterstellar travel via spacewarps is possible, I send them to this book. It is the best source of answers at a level accessible to nonexperts."
- Kip Thorne, author of Black Holes and Time Warps: Einstein's Outrageous Legacy | Feynman Professor of Physics, California Institute of Technology