MOVING THROUGH TIME
By: Prashant Rathee
Tags: Black Hole Sun, Space, Time, Tenet 2020, Interstellar

MOVING THROUGH TIME

What if you could go back in time and change a few things?

That one moment you regret and want to change? Past experience that you cherish and wants to re-live??

That one school/college friend you wanted to be in your life? What if you could make that one change to keep them in your life?

Seems like a fantasy right. Something that every sci-fi movie shows us(mostly negative things though).

But what if the future that these movies predict isn't as brutal, lonely, chaotic and unhappy but instead something beautiful.

The thought is worth exploring isn't it.

Well, let's first look at what every movie explore in this area.

Tenet for example, explores the possibility of traveling back through time and giving a little hint of how parallel worlds can exist. In the movie, people in future have discovered how to travel back in time or rather how to move backwards in time. That way they(future humans) want to move backwards and want to change their fate in the future without affecting anything in their own world. The world in their time doesn't have enough resources to feed their own and hence wants to move backwards to overtake ours. Interesting bit is that they are actually the future version of us(present people)

This can be connected in a very interesting way with Nolan's other big hit, Interstellar. In Interstellar, future's world is also deprived of resources, but they are good people and are more forward looking than the "Tenet" ones. Hence, they want to flee the earth and find something else out there and restart(hopefully better this time).

Tenet shows a negative side of things while Interstellar is at the opposite spectrum.

Let's look at time travel a little more technically. I will explore it from my side of understanding. I might be wrong about a few things but the overall concept should be fine. Let me explain the concept a little by this small example.

You are looking at a mirror and can see yourself. Let's look at what all happens when you stand in front of a mirror. Light is reflected from the mirror, travel towards you and you see yourself. You will see the exact same thing but in reverse.

Light travels really fast and is the fastest speed of anything known to us. Around 3 lakh km/sec. To give you the perspective, Sun is 147 million kms away from the Earth and light takes a little more than 8 minutes to reach here. So if sun rays started at T0 reference time from the Sun, it will reach Earth by T0+ 8 minutes. Similarly light that travels to the mirror and back has to cover some distance. Let's say that time is T1, so in theory you are looking at your past self by T1 time. The time T1 however is very very very small and can be ignored here. But, what if the mirror was far far away and light takes enough time, say 5 years to go and come back. That means you will be seeing a 5 years younger version of yourself.

Now what if you can harness this thing and can in fact control it. In simple words, what if you could get to travel to that past version and change things.

How can that happen or when in time it can happen is a much more technical question to be asked. Interstellar has tried giving one kind of explanation. They talk about Gravity being the key in making time travel possible. In that black hole, Cooper along with TARS sends the code to finish his daughter's equation back in time through gravity. I can not comment on how that can happen, but gravity is one of the forces well felt by us but not so well understood. Newton told us how two bodies are attracted towards each other but exactly how it happens is unknown. We don't yet understand which particle is behind gravity force to be generated. We are far far away from harnessing gravity and the only way of doing that would be that we understand it's fundamental particle.

Whether or not we will be able to harness gravity and control time travel is a thing of the future(from our perspective at least! ).

Right now we can all be curious and keep moving through time!!