Thursday, April 28, 2016

The Possibilities of Time Travel

Time travel is a phenomenon that has been fascinating the human race for centuries. Since the development of Einstein’s theory of relativity, physicians have especially shown a special interest in this field. Einstein’s special theory of relativity suggests that time passes at different rates to different observers. This development resulted from the discovery that traveling at the speed of light would make time appear slower than to an individual with a lower speed. This breakthrough provided unprecedented insight into the nature of space and time and its interactions with gravity. As a result, scientists found that matter is actually able to distort space such that the rate of time is adjusted. They expected this distortion, now referred to as a “wormhole”, to be shaped like a tunnel with two entrances so that inside, time is stopped.

Since the first mention of wormholes, the scientific community has been investigating whether they actually exist and the implications they may hold. Since wormholes act as passages through space-time, they may potentially create shortcuts for journeys across the universe. Scientist Robert Oppenheimer theorized that a star collapse might give way to a wormhole by leaving a black hole that would warp space into a wormhole. However, these Schwarzschild black holes are found to retain charge and spin, which would require one to travel at a speed greater than that of light. Instead, simpler types of black holes would be more ideal to act as passageways and time machines as they allow for speeds slower than the speed of light.

With more research on the feasibility of time travel, physicists have also looked into the implications of time travel for human life. The most well known conflict they face is the grandfather paradox: can time travelers actually change history? This had led the way to a variety of “what-if” scenarios such as killing a family member or meeting oneself, which also caused wide scale discussion on their potential consequences. A large problem that arises is causality, which refers to when an event occurs only after a driving force. This principle may be violated through time travel into the past if one were to interfere with history.

The discussion on time travel and human interference has given way to multiple models of the events that would unfold after changing the past. One model of time travel by researcher Seth Lloyd suggests that paradoxical events would actually be censored by making unlikely events to happen more frequently. For example, in the grandfather’s death instance, a bullet that was used to kill a time traveler’s grandfather would be more likely to be defective so that he couldn’t be killed. Another model by David Deutsch allows inconsistencies between a time travel’s memories and their actual experiences so that he would remember killing his grandfather without having done it.

Unfortunately, we cannot know the true nature of time travel until humans are able to pass through spacetime differently. As a result, physicists have been further looking into the feasibility of time travel via wormholes. There is no clear answer currently to whether humans are capable of travelling through, developing, or stabilizing a wormhole. However, with the rapid developments of science and technology, we will hopefully gain a much greater understanding of space and time travel that may pay off thousands of years from now.


“Time Travel: Tunnels Through Time” by Barry Parker (1992)
“Time travel gets more plausible, yet weirder too” by Laura Sanders (2016)
- Shreya Punya