Fiction books and movies talk about time travel quite a lot. But, is it possible to build a time machine so we can go backward and forward in time in real life?
It is reasonable to say that we are all time travelers. Why? We move forward in time from one minute to the next. But it is more elusive to go back in time to avoid some mistake or to repeat and fix something we want.
Why does the idea about time travel come up?
It was back to 1905. At that time, Albert Einstein wrote down his theory of relativity. In that theory, it showed space and time are linked. Then, it was in 1916, Einstein in his general theory of relativity showed that space and time are malleable – Warping, bending, expanding, an contracting are what they can do like the response to the presence of matter and energy.
Space is filled with some exotic form of energy (Extension), after that, space and time warp in a way and space, bend back upon themselves like circles. Therefore, one can move forward in the straight line and return to one’s starting point in both space and time.
Even though the topic about time travel is more than a century, no physicists reveal it more. The first person who wrote the mathematical solution about general relativity equations was Kurt Gödel, a Mathematician. He described the exotic type of space-time. Kurt is a close colleague of Einstein’s at the Institute for Advanced Study in Princeton, N.J. He then presented his result in the scientific paper, and he gave it to Einstein as his 70th birthday present.
Even though general relativity allows the configuration of space and time so it is possible to go forward or backward time travel, it does not mean that it is easy to create these configurations. General relativity implies the configuration of space-time is all about the matter and energy within it.
So far, most physicists are working against the possibility of time travel. Not because it is difficult to generate the necessary conditions to allow it. But, it is also because of the implications of time travel if it is possible.
If you see the modern science fiction like Back to the Future, or Star Trek, the common plot is when we go back in time and change the past, it means we can change the future. But, there are some possible paradoxes. Let us say, what would happen if you went back in time and then killed your grandmother before she gave birth to your mother. If your mother was never born, then you would never have been born. So, how did you go back in time and then kill your grandmother?
So, the possible resolution to end this paradox would be the laws of physics that should allow only a kind of time travel, in which you are doomed to repeat the same sequence of events. But, no matter how you would like to alter things around, time would travel in a circle, not in a straight line. So, you would be doomed to repeat events for eternity. Don’t think that traveling forward in time and then returning would not produce problems. In fact, Bill Gates is the richest person in the world argues the presence of a time machine. Even Stephen Hawking presented that if it were possible, then we would be forever be inundated with tourists from the future.
In the end, even though physicists and laypeople alike keep searching for the possibility of time travel, still the odds are against it. If time travel were possible, it would take a greater amount of energy t to create the conditions for time travel than the total energy on Earth. At least at this time, time travel is still the stuff of science fiction.