Cause and Effect
September 10, 2012 § Leave a comment
I personally find the possibility of time travel, at least to the past, to be very unrealistic. As an aside, I do believe ‘time travel’, if it should be called that, is possible due to the principles of relativity. Just get in a spaceship (timeship?) traveling at the speed of light, and time will stop from your frame of reference while it passes normally for everyone not travelling at the speed of light. While this sort of travel is typically used in the scenario of allowing humans travel vast interstellar distances within a lifetime, I think that it would be very interesting if a spaceship just took off at the speed of light, and just returned to the Earth after a period of time; this would theoretically allow humans to travel to the future on Earth. Some other possible theories to travel to the future would be to cryogenically freeze humans and ‘thaw’ them out in the future, whenever people figure out how they do that (this is what happen in Futurama, if any of you are fans of that show). The greatest caveat in time travelling to the future would be that you couldn’t return to the past; you’d be stuck in the future, displaced in time, a living anachronism. I personally wouldn’t do this because I’d have to leave everything I’ve ever known – my family, my friends, literally my entire world and travel to the truly unknown. It takes a special kind of person to be able to do that. Not that we’re anywhere close to achieving any of this. But I digress.
Returning to the original issue if time travel to the past was somehow possible, I would definitely travel there, just because the implications-for physics, philosophy, and our basic understanding of the universe would just be so much more interesting. The reason why many experts believe that time travel to the past is impossible is because it violates the principle of causality, a fundamental principle governing our perception of the world. Basically, the principle says that for a given event, there is a cause and effect relationship, and cause precedes effect. This principle may seem fairly simple (and it is), but it is essential. I’m sure you have heard of the grandfather paradox; this is an example of the violation of cause and effect and can be expanded to involve any action committed once someone has travelled back in time that negates the possibility of travelling back in time in the first place. However, some theories have been formulated to resolve this paradox. One popular one is that it is impossible for the time traveler to perform any action which would cause him to be unable to travel to the past; the universe would simply forbid it. Another is that changing the course of history could result in the creation of parallel universes, one in which history has been altered, and one in which it has not. A more disquieting one is that the creation of any paradox would destroy the universe, although that possibility is remote. I personally believe that the universe would not respond to a paradox by destroying itself, but rather act preemptively to prevent the paradox from occurring in the first place. However, we have no idea of what would happen if time travel was possible. Therefore, if I had the chance, I would travel to the past, because I want to find out.