We know that time flows in one direction because we can’t remember the future. Why is the future, “the future” and why is the past, “the past”. And why is the future yet to happen and why has the past already happened?
Entropy, the degree of randomness is increasing with time. That’s what the second law of thermodynamics states. You can see a glass break but you can’t see broken pieces of glass integrate together. That’s how our psychological arrow of time works.
But what if time is not actually flowing in a certain way? What if it is also random? In fact, when we say entropy is increasing with time, how do we know what state the time is in, is it moving at all?
All the laws that govern nature do not take into consideration the direction of time and are not based on the fact that the past has already happened and the future is yet to happen. As a simple example, if I am given an object with a velocity moving with constant acceleration, I can very easily tell you what the velocity was 5 seconds earlier and what it will be 5 seconds later. Funnily enough, the words “earlier” and “later” are not even distinguishable here.
Entropy is a physical quantity. How can it possibly distinguish between the past and the future. For example, if I am standing at A. B is to my right where I perceive the future to be. C is on my left: my past and what I remember. I travel towards B and throw glass. It breaks. Cool, entropy increased with time. I travelled to C , I throw glass. It has to break because laws of physics say so. What happened to entropy now? IT HAS TO INCREASE.
Also, when we talk of increasing entropy, we prove it by saying that the universe is expanding. What’s ironical is that no person on this planet has yet proved that when the universe was just a speck (and it might still be), i.e, before what people call the “Big Bang”, it was in a low entropy state.
It all comes down to our psychological perception. We function because of an “arrow of time” which we think has a single direction. But us moving in that direction is not guaranteed at all. The only way we can feel time is because we remember stuff. And as far as entropy is concerned, we will always find is increasing, from what we remember (also called the past) to what we don’t (also called the future)
One possibility is that time moves randomly and we move randomly in time. The only thing that is certain is our psychologically perceived arrow of time.
To explain simply, let Jack be a normally functioning creature. Today is January 21 2017 A.D. on Jack’s calendar. He remembers everything from his birthdate till this date in perfect order. He throws glass and it breaks. Entropy works normally because he threw the glass from some height and gravitational force made the glass fall. Even if the glass would have been thrown on January 21 2017 B.C. gravity would have pulled it to the ground because gravity doesn’t differentiate between 2017 A.D and B.C. .
The next day Jack wakes up and the calendar shows that today is January 20 2017. But Jack only remember things from his birthdate till this date. He throws glass. It breaks. Entropy increases because gravity will still make the glass fall down. How would Jack know his life is not going perfectly? How can he possibly get to know that January 20 is actually “yesterday”? He can’t. Because for a yesterday there has to be a today. For Jack today is January 20 and January 21 is yet to come so he doesn’t remember it.
We all are Jack. We have no possible way to find out what “today” is and so we believe what we remember is “yesterday”, what we can’t is “tomorrow” and what we are undergoing is “today”. We don’t think that what we remember can also change depending on where in the web of time we are. We might be shifting every second but don’t get to know it because we are constantly forgetting the past or knowing the future.
It is quite possible that we don’t flow with time but our psychological arrow of time knows how to adjust with our position is the “time” part of “spacetime”.
Fun fact: Time passes faster for your face than for your feet (assuming you’re standing up). Einstein’s theory of relativity dictates that the closer you are to the centre of the Earth, the slower time goes.
Made you think? Let me know in the comments!
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