Existence
Don’t Google the title. What I want to contemplate in my bold letters is that a watch is just a physical representation of the passing of time. So, if chiming clocks can’t define time, then what does? Time is a dimension because we can show different positions in space at different times. It is also called measurement, and we all can relate to it.
For instance, think about how we can celebrate our birthday because we measured years by time. Yet, time is the most unknown of all unknown things, as once said by Aristotle. Perhaps for understanding it, we should start with our existence. We must have originated somewhere. Since the Big Bang (the creation of the Universe) happened, time has been like an arrow.
Time is like an ‘arrow’ because it is unidirectional, and the second law of thermodynamics can explain that. The second law of thermodynamics states that entropy in a closed system can either increase or remain constant. And the universe started at a very low entropy point (the measurement of randomness). Therefore, by the law, it has been moving to a higher Entropy situation since then, giving rise to galaxies, planets, stars, and us. If we think, what if the universe started at high entropy? Then we wouldn’t have been discussing the universe because there would have been no us and no time.
Now we can see how we are interlinked with time.
Entropy
I believe that while thinking of this interlink, most of you would have thought about the past and future. So, I have a question: why do we think they are different while scientists consider them identical? Is it because we can remember the past and not the future? Yes, I suppose, and perhaps we develop an illusion that time is moving. It can be explained using the only law that perceives the past and the future differently – the second law of thermodynamics.
To grasp it, think of something you broke like, a glass. Initially, the glass was at low entropy, that is, a state of order and less randomness, and when you broke it. It smashed into many pieces, which is a state of high disorder or high entropy compared to the former situation. Once broken, you cannot fix the glass into what it was before.
In short, a physical system has changed from a low entropy configuration to a high entropy configuration, and it is irreversible. That is what creates an effect on the passing of time for us. And, that’s how we think that the past is different and the future is yet to come.
Relativity
But, what if the person next to you says that a particular situation happened before the other and you contradict it. The thing is, you both would be right.
Because it is possible that the thing that has happened in the other person’s past is yet to happen in your future or maybe, it is not present anywhere for you. What I want to deduce here is that time is relative. The rate at which it passes may vary according to the observer (frame of reference). Einstein gave the theory of relativity, which introduced time dilation that means as speed increases, the time slows down.
Also, time runs slower wherever gravity is strongest. So, if your twin is traveling in a spaceship with nearly the speed of light and comes back after some years, you will notice that they would have aged less in comparison to you.
In an observable manner, let’s take an example of you traveling in a train, moving at a high velocity. You will notice that the watch on the platform would seem to be moving slowly and then as if its hands have come to a halt. And so, the watch ceases to tell you what time is.
Time is a dimension that every one of us deals with daily, yet when asked to explain, very few can actually do. It is neither a thing nor an event. There is debate on whether time is a feeling or a judgment. Some even doubt if time is real.
Over so many centuries that man has lived, they have been able to make some sense of time. As more time passes, we are sure to understand well, time better.