hey there!  welcome to the new episode of Curiosity! A series in which we will answer some of the questions that makes us all curious.   

Travelling in time has been one of the biggest dream ever seen by humans. Tons of Movies are released showing time travel. Have you ever thought to go back in time and fix the mistakes that you have made?. Most of us might have seen Interstellar. This movie made us fantasize even more about travelling in time.  Have you ever dreamed of travelling through centuries and see the future or go back in time and fix the mistakes that you have made?. Well, is time travel even possible. That's what we are gonna discuss today . Let's Find out.

Have Anyone traveled in time yet?

Fig : Sergie Krikalev (Credits)

Well, it turns out , time travel is possible and to some extent it's already been done. No, I am not talking about doctor Who . I am talking about Sergei Krikalev a Russian Astronaut. He is considered one of the greatest time traveler in the history. He orbited our planet with the total of 803 days at 17000 miles per hour. At this rate he traveled in his own future by 0.02 seconds. This phenomenon is known as time dilation.

What is Time Dilation?

Although we have based our technology on theories for decades, an experiment finally proved , time dilation is absolutely real. And this phenomenon might allow us to travel in time. To explain this phenomenon we have to see the speed of light. No matter what direction the speed of light is travelling in vacuum , the speed of light always remains the same. And to keep the speed of light constant, if  i am moving relative to you or you are moving relative to me our references for time have to shift to keep the speed of light constant. As I move faster and faster, my time according to you has to slow down and similarly, your time will slow down relative to me. This is what keeps the speed of light constant.

Fig : time dilation (Credits)

Also, Not only motion causes time dilation. As shown in Movie Interstellar, Gravity also causes time dilation. According to Einstein's Theory of Relativity, Gravity is the property of warping of space and time. So if there is the bigger mass , it actually warps space and time around it. So time on Earth slows down a little bit than space due to Earth's gravity. But the change is barely noticeable.

But if There is something very massive like a Black hole, the infinite gravity wraps the space and time slowing down time to its limit as shown in Movie Interstellar. If you orbit around a black hole, your time would slow down tremendously.

So theoretically, it is possible to travel in future but what about travelling back in time?

Can we travel back in time?

Everyone want to see Dinosaurs! so , is there any way , we could go back in time? well, theoretically, some specific types of motion in space might allow to travel back in time, however that might not be true. It would Require Close time like curve(CTC) to travel back in time.

A closed time like curve (CTC) is the closed loop in the space that could allow a object to return to its past. But according to many scientists It is not possible at all. According to the scientists travelling to the past would cause a Paradox. For example : Somehow you time traveled in the past , and killed you grand father, then you wouldn't have ever existed, if you would't have ever existed then you could not go back in time and kill your grand father. That means you never killed you grand father and that would mean you yourself would be alive and the loop goes on. This is called "Grand Father Paradox" . If this is the case then certainly travelling back in time is not possible.

Conclusion

Of course the science of time travel is very vast. But theoretically, we really can move forward in time by moving very fast and though time dilation but travelling through the past is likely impossible. But who knows we might be missing something and still there is lot to be discovered. One day, We might be able to travel in time by all the technological advancement and using the knowledge we already have.

 That's it for this Episode guys, Hope you enjoyed it. If you did, Upvote and comment your thoughts below. Thank you

Stay Curious.

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Last Five Episodes: 

 Curiosity | What would happen if Nuclear War breaks out?

Curiosity | How did life Begin On Earth?

Curiosity | What Happens when you go into Coma? 

Curiosity | Why do some people Sleep Walk? 

Curiosity | What is the possibility of being hit by an Asteroid?