Is Time Travel possible? This theory opens new window of reality

Is time travel possible? We all have wondered this at least once in our life. And it also remains one of the biggest mysteries for physicists to solve. From popular media to scientific journals, many have tried their hands at understanding and explaining this problem in their own ways. Even Albert Einstein, the great physician, took up the challenge of understanding how time works and wrote his general theory of relativity around it. In short, time travel is the most fascinating yet confusing puzzle that exists. But if you look at the theory of relativity, it does offer a small window into whether time travel is really possible or not. Read on to find out. Also read: Space triumph! Photos of 4 brown dwarfs taken by group of researchers

The challenges with time travel

In short, there are two big challenges in proving whether it is possible or not. The first is technology. Even if a physicist does prove time travel to be real based on a genius equation, we would never really know unless we can build a machine capable of traveling through time based on that equation. But to build the time machine in the first place, we would probably need rare cosmic material and technology that we do not have access to, at present. This is how technology has always grown. Theory comes first, and then once technology catches up, the theories turn into reality. Virtual reality is a good example of it.

The next and probably more significant challenge for time travel is consistency. Consider this. You find a machine that can be used to travel back in time. You used it and went ten minutes back in time. After reaching the past, you killed yourself. But now that you have killed yourself, you could not have found the time machine ten minutes later and traveled to the past to kill yourself. In physics, this is called a paradox. And paradox remains one of the biggest problems to solve in time travel. Also read: This largest ever NASA spacecraft, Europa Clipper, will look for Aliens on Jupiter’s Moon

Einstein shows the way for time travel

The idea of parallel universes has existed for a while now. From physicist Michio Kaku’s string theory to science fiction, we know what multiple dimensions and parallel universes look like. However, from a scientific perspective, taking another hypothetical concept to prove the hypothetical problem of time travel is not fair. That is why we look at the general theory of relativity as a solution to this. Einstein had popularly said that time is relative to the observer’s frame of reference. In a simplified manner, it means that time is not a thing that exists but a point of reference. So, while some things like mass are constant and not dependent on the surroundings, the same does not apply to time.

And here is how this theory can explain the possibility of time travel. According to the theory of relativity, the speed of light is constant whereas time is just a reference. Also, the speed of light is the fastest anything in the universe can move (based on our present knowledge). So, based on this, a person traveling at the speed of light will experience time slower than others and will actually be traveling in the past compared to others.

A good example of this is astronaut Scott Kelly, who was born six minutes after his twin brother Mark. Now, Scott spent 520 days in space aboard the international space station which is moving around the Earth at a speed of 28,160 km/h. This actually resulted in widening of the time between the two brothers. In a panel discussion, Mark said, “So, where[as] I used to be just 6 minutes older, now I am 6 minutes and 5 milliseconds older,” reported Space.com.