Time Travel in Flatland? - Superb pages by Patricia Schwarz, explaining special relativity, general relativity, and the basics of relativistic time travel in a hypothetical world with just two dimensions ("flatland"). - http://www.theory.caltech.edu/people/patricia/lctoc.html
NOVA Online: Time Travel - 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. - http://www.pbs.org/wgbh/nova/time/
Everything You Always Wanted to Know About Time Travel - 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 - http://www.lifesci.sussex.ac.uk/home/John_Gribbin/Time_Travel.html
Evading Quantum Barrier to Time Travel - Science News article about the work by Li-Xin Li and J. Richard Gott III on a counter-example to the "chronology protection conjecture" (which states that quantum effects will always prevent the occurrence of time-travel curves in general relati - http://www.sciencenews.org/pages/sn_arc98/4_11_98/fob3.htm
The Relativistic Asynchronous Machine - Design of a hypothetic machine for travel into the future by Tilmann Schneider. - http://www.tilmannschneider.de/dok_en.html
How to Build a Time Machine - 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 su - http://www.sciam.com/article.cfm?articleID=0004226A-F77D-1D4A-90FB809EC5880000
Time Travel and Modern Physics - Article from the Stanford Encyclopedia of Philosophy about the basis of time travel scenarios in modern physics, including a discussion of mechanisms such as wormholes, and the question of paradoxes. - http://setis.library.usyd.edu.au/stanford/archives/fall2001/entries/time-travel-phys/
Time Travel - Fact or Fiction? - 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. - http://math.ucr.edu/home/baez/physics/Relativity/GR/time_travel.html
Time Loops - 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 - http://www.edge.org/3rd_culture/davies/davies_index.html
Quantum Time Travel - 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 &am - http://www.npl.washington.edu/AV/altvw45.html
Time Travel - Brief text by Neil Johnson (Oxford University) about the connection between gravity, black holes, singularities, the multiple worlds of quantum theory, and time travel. From BBC Science & Nature. - http://www.bbc.co.uk/science/space/exploration/timetravel/index.shtml
Space-Time Physics and the Future of Time Travel - Elementary exposition of Euclidean geometry, Newton vs. Einstein, and the possibility to travel into the future, and see into the past, in relativity. By Alex MacLellan. - http://themaclellans.com/timetravel.html
Rotating Universes and Time Traveling - Brief exposition of time travel in special and general relativity, with a focus on rotating universes (such as Gödel universes). By Egils Sviestins; based on the author's PhD thesis. - http://www.ettnet.se/~egils/essay/essay.html
Getting in a Twist over Time - 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 conjectur - http://www.spacedaily.com/news/timetravel-01a.html
Taking the Cosmic Shortcut - 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. - http://www.abc.net.au/science/slab/wormholes/default.htm
Why Faster-Than-Light Implies Time Travel - 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. - http://sheol.org/throopw/tachyon-pistols.html
How Time Travel Will Work - 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. - http://www.howstuffworks.com/time-travel.htm
Chronos Shrugged: The World of Time Travel - A brief tour of the world of time travel - from the myths and psychology to the science (including relativity). Also includes a bibliography and links. - http://www.umich.edu/~engtt415/menu.html