There is something about time travel that is so alluring that we just can’t let the idea go. Maybe it’s because of the ability to undo any wrongs that it offers or the ability to foresee everything in advance.

That’s why it has been one of the hottest trends (and kind of overused) in our countless movies, TV shows and novels and we just can’t wait for it to actually happen in reality.

Well technically, we are constantly time travelling into the future, every second, every minute. But that’s not the kind of time travel we’re interested in, are we? We want the good stuff, to be able to travel to any time, forward or back.

So, could time travel ever be possible? Do the laws of physics allow it to happen? Or are we going to always have to satisfy our time travelling cravings watching movies? Well, the answer is: yes, it’s possible. But don’t get excited just yet.

Time Travel To The Future

Let’s look at time travel to the future. While there are many theories as to how it can be done, let me talk about the two most common ones. I will try to keep it as simple as possible.

Travelling Close To The Speed of Light

Einstein’s theory of special relativity states that time passes at different rates for two people who are moving relative to one another. However, this difference only becomes noticeable when the speeds involved are closer to the speed of light.

You might already know that speed of light is the fastest anything can travel in the universe and it is very, very difficult to reach that speed, technologically speaking.

But let’s say, you did manage to build a spaceship that can travel at like, 99.5% speed of light. Then you leave Earth and cruise at that speed for 5 years before returning home. Upon returning, you would notice that, the world has not advanced 5 years but 50 years! And all your friends have become old.

This happens because as you are travelling at speeds closer to the speed of light, time slows down for you considerably relative to the people back home, for whom, it stays the same. Therefore, you experience just 5 years of time while they experience 50 years! This essentially means that you travelled into the future.

Orbiting A Black Hole

If you have watched the movie Interstellar, you must be aware of this already. Basically what happens is that objects in the universe with an extreme gravitational pull also slow down time considerably for any objects that are near to them.

Black holes have some of the strongest gravitational pulls in the universe. The greater the pull, the greater the difference in time. So, in theory, you could use this to travel to the future.

For this, you would need to locate the nearest black hole and head in its direction. Once there, you would need to orbit around it and head back home. Depending on its gravity, that one orbit could be months or years for people on Earth while you would experience only a fraction of that time.

If you wanted to travel even further into the future, all you need to do would be to take more revolutions around the black hole. You would need to be in perfect orbit though or you would get sucked in!

Time Travel To The Past

This one is where things get really tricky. While technically, time travel to the past may not be impossible per say, but for all intents and purposes, it sure looks that it is highly improbable.

Many scientists believe that it is just impossible and that time flows in only one direction. This also explains why we have yet to meet a time traveller from the future because nature just doesn’t let it happen.

There would be all sorts of paradoxes if people could travel to the past, the most famous being the grandfather paradox where if you went to the past and killed your grandfather, you wouldn’t be born and therefore you couldn’t have gone to the past to kill him in the first place.

There is one theory that allows for it but it is a highly speculative one which involves creating a wormhole and accelerating one mouth of that wormhole to the speed of light. That would still not allow you to travel further back in time than the point it was created. So, I see no point. Plus it is just technologically impossible at this point.