Account of a hypothetical dual with pistols firing faster-than-light bullets showing how, in special relativity, the ability to travel faster than the speed of light implies the ability to travel into the past. By Wayne Throop.
Brief overview of physics issues related to time travel, including the question of conversation laws, general relativity, possible paradoxes, and the notion of tachyons. From the Physics FAQ; original by Jon J. Thaler.
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.
Article on the site of the Australian Broadcasting Corporation about the physics of time travel, from special relativity and time travel into the future to general relativity, Ron Mallet's time machine, and wormholes. By Elizabeth Warnes.
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 and Fact Magazine.
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.
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.
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.
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.
A collection of brief articles by the renowned non-fiction author John Gribbin. Includes "How to build a time machine", articles about wormholes and time travel, and a discourse on the question whether the laws of physics forbid travel into the past.