For millennia, humans have posed an age-old  question. Is it possible to travel in time? Imagine all the possibilities. You could visit your great-great grandfather that you could never meet or see what humanity looks like in 50 years. Will cities be flooded due to climate change, or thriving due to discovering a new energy source? Will that family heirloom still be in your family after 100 years? Although answering these questions has seemed like a fantasy, there is compelling scientific evidence that time travel exists.

 

If you’ve seen the movie Interstellar, you may know that time travel to the future is quite possible. In the film, a group of astronauts visit a planet near a black hole, an extremely dense region of space that light can’t escape. Due to Einstein's Theory of Relativity, we know that gravity warps time, making it take longer for light to travel around it. This makes time pass more slowly around objects with a lot of gravity.

 

As a result, on this planet, one second is one year on Earth, due to the extreme gravity of the black hole. So, this hypothetically means if you decided to spend a minute on this planet, then immediately teleport back to Earth, then 60 years would have passed. A child who would have been in high school would now be near the end of their life. All in 60 seconds. 

 

If you were to observe this, someone going near a black hole, you would notice something strange. As the passengers on the ship are waving bye to you, their hand and the clock on the spacecraft would move more slowly. Eventually, all movement on the spaceship would freeze and all passengers would slowly turn a deep red until they vanished. If there were somehow a way to get out of a black hole, they could time travel. However, nothing can escape a black hole, not even light.

 

But what about the past? Is it possible to go back in time like in Back to the Future? Well, the past poses many more problems than traveling to the future. For one, it is logically impossible to do so. For example, let's go back to visiting your grandfather in the past before he met his wife. Let's say you didn’t care for him very much, and killed him right then and there. If you decided to kill your grandfather, then you would not be able to be born, meaning that no one could kill your grandfather. This concept that is protecting your poor grandfather’s fate is called the Grandfather paradox (image below). 

 

 

Source : BYJU’S

 

So, to answer this question, is time travel possible? Yes and no. Yes because we can hypothetically travel to the future, and no because we don’t have the resources to travel to said future, and it is impossible to travel to the past. But you never know, maybe someday, one of your ancestors might be on one of those planets we can only look at night, using a black hole as nature’s very own time machine.