Time - Arhant Bararia

I was sitting in my physics class. Sir was teaching about magnetism then I thought what could be the reason behind this marvelous force. Why the hell current flowing through the conducting wire generates a magnetic field around it in such a specific direction. Then I went back home scorched the internet for the answer and then I found a video that showed me  that somehow this marvelous force of magnetism is related to the action of special relativity. I am not getting into that now. But that day I learnt that when speed of light and time combines they can do amazing things like length contraction etc.

So, what is time?

Suppose your boss fixes a meeting at some café and orders you to reach there but he forgets to mention time. The first question your brain is gonna put up is “WHEN?” 

 Or your boss tells you to meet him at 10:00 AM, but this time he forgets to mention the place. Then your brain will ask you “WHERE?”

So by this small example you would have understood that time is as important as other 3-coordinates, it is indeed so important that it is accepted as the 4^th coordinate to specify a motion. And when the 3-coordinates of space and one coordinate of time combines, it is called the Space-time.

I have already told you in the earlier article that every motion is relative, to specify your speed, you must specify the reference frame. 

“Time is among the most familiar yet least understood concepts that humanity has ever encountered”-Brian Greene

Is Time Travel Possible?

Time travel, it is something that everyone wants to try. It is indeed a dream of many people to travel back in the past and to correct their mistakes. Or to travel in future and see what it would be like.

I will say that time travel is possible. How am I saying that?  You will get to know in just a few mins.

Suppose you are in a room with a chair (Click a photo of the room). Things outside the room or the things not concerning you and the chair (like air or light) are not important (just ignore them). You are asked to dance with the chair for five minutes (you can do whatever you want). Then you are asked to place the chair where it was 5 mins ago and to stand where you were 5 mins ago, (Click a photo again)

Then go to your friend and ask him are these photos clicked simultaneously or there is time gap of 5 minutes. Your friend (or anyone) would not be able to tell the difference because the photos look exactly similar to each other. So have you rewinded the time by just putting back the chair in the right place?

 The answer is YES, you have undone the action you have done to the chair.

Travelling in time is somewhat similar to travelling in space. To travel back to a place you just have to be there. But to travel back in time you need to move to that place with your reference frame, with whose you have moved ahead in that place that too in exact similar conditions that were before. But the reference frames with whom you have moved ahead, could be anything (like your age, sun etc.).Therefore at 4pm in the evening if you want to go to back at 9 am you need to rotate the earth in opposite direction.

This gives rise to a new question. If we are not moving then time stops too?

Yea it does but now the condition will be the reference frame with whose respect you are stationary. But if there are no reference frames to judge a motion?

I want you to do a thought experiment again, suppose you are in black empty space no reference frames, nothing to judge a motion.  All your motion (neither in space nor in time) will be not be counted. But if you sat for years then you will get aged and you will ask me “If I was not travelling through time, then why would have I got aged?” As I mentioned earlier our age is also a reference frame. I am not getting into the thermodynamic thing because it’s boring.

But What about Future?  

To stop time you need to stop moving or move at a very high speed of 3x10⁸m/s.  But moving at light speed has some of it’s benefits too. Because at such great speed every reference frame in the universe will tell you that you are moving with a constant speed of 3X10⁸m/s as explained in the earlier article. Also every reference frame even your age will tell you that time has stopped and you will stop aging.

Back to the question, Can we travel to the future?

To explain this we need to conduct another thought experiment J :

Suppose You and your friend Barry decided to race  but he is too much faster than you. Still you want to race. You gave your best still can’t win L .

  He will reach the finish line earlier than you.

If we draw a distance time graph for the velocities of both of you:

The symbol ‍Ʌt represents the time difference between you and Barry to reach the same place. Now if we modify our thinking then Barry reached the same place at time t  and you will reach the finish line at t+‍Ʌt . So, can we say that at the finish line Barry is at the future when you were somewhere b/w start and the finsh. Barry is ‍Ʌt times ahead of you .

Let’s create this analogy at a larger scale.

Suppose there is a point P in space that is 3X10⁸ meters away from  earth. You made a ship which can reach the speed of light instantaneously. And you are supposed to reach point P and come back.

  And you did it in just 2 seconds (1 sec for going  and 1 sec for coming back). Since earth was moving at much lower speed (but faster in Time, as the 2 motions are complementary), the time you will land from ship you will notice that your twin brother will be much older than you. This is called TIME DILATION. This case similar to the earlier one but the difference in the speed and distance was very large, so the time dilated will be also large. So, here are at the future you are younger than your twin    

But then you decided to go back to your time but you can’t because this time (future) will be your present now. To return to the time when you decided to move to the point P in space you need to set everything back to its place.  Hence I am saying that you have reached the future by just going through the alternate and faster path than everybody else on the earth.

Time is just a series of events or you can see that every scene is a just a on the film of the projector illuminated by the light of consciousness.

If you  undo the the events, the time will revise itself (to past) or if you skip the events (by some alternate path way) Time will skip them too( the future).

I wanna thank My friend Hritik Talwar for suggesting me this topic and giving me the idea about the time dilation.       

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