Getting in a Twist over Time
- http://www.spacedaily.com/news/timetravel-01a.html
- Article on Space Daily about Ron Mallet's attempts to design a time machine using a loop of laser light. By Michael Brooks; also includes a brief history of time travel in relativity, including remarks on wormholes and the chronology protection conjecture.
How Time Travel Will Work
- http://www.howstuffworks.com/time-travel.htm
- Article about time travel from "How Stuff Works"; by Kevin Bonsor. Includes background information about relativity and black holes, and possible time travel scenarios involving wormholes and cosmic strings.
How to Build a Time Machine
- http://www.sciam.com/article.cfm?articleID=0004226A-F77D-1D4A-90FB809EC5880000
- Article in Scientific American, written by Paul Davies. Covers time travel into the future in special and general relativity and a variety of hypothetical mechanisms for time travel into the past, such as cosmic strings and wormholes, including caveats such as the chronology protection conjecture. Images not available in the free version.
NOVA Online: Time Travel
- http://www.pbs.org/wgbh/nova/time/
- Companion site to the NOVA program "Time Travel" (1999); includes a description of the connection with Einstein's theories of relativity, an interview with Carl Sagan, a teacher's guide, and a transcript of the show.
Quantum Time Travel
- http://www.npl.washington.edu/AV/altvw45.html
- Brief description of the work by Yakir Aharonov's group on a "quantum time machine", including parallels with published science-fiction stories. From John G. Cramer's column "The Alternate View", published in Analog Science Fiction & Fact Magazine.
Time Loops
- http://www.edge.org/3rd_culture/davies/davies_index.html
- An interview on Edge with the author and physicist Paul Davies about time travel and the ensuing paradoxes, physical time-travel scenarios from Gödel's universe to wormholes, and the interplay between physics and science-fiction. Includes both a transcript and a video version.
