In This Topic
Scientists are still trying to figure out why we travel through time Tricking time with relativity
Need more time? Considering the possibility of a second time dimension Logical paradoxes: The fun part of time travel
One of the most fascinating concepts in science fiction is the idea of traveling forward or backward in time, as in H. G. Wells’s classic story The Time Machine. Scientists haven’t been able to build a time machine yet, but some physicists believe that it may someday be possible — and some (probably most) believe that it will never be possible.
Time travel exists in physics because of possible solutions to Einstein’s general theory of relativity, mostly resulting in singularities. These singularities would be eliminated by string theory, so in a universe where string theory dictates the laws of the universe, time travel will probably not be allowed — a result that many physicists find quite favorable to the alternative (though far less interesting).
In this topic, I explore the notion of time and our travel through it — both in the normal, day-to-day method and in more unusual, speculative methods. I discuss the scientific meaning of time, in both classical terms and from the standpoint of special relativity. One possible method of time travel involves using cosmic strings. There’s a possibility, which I explore, that there may be more than one time dimension. I also explain one scenario for creating a physically plausible (though probably impossible) time machine using worm-holes. Finally, I look at some of the different logical paradoxes involved with time travel.
