Time is a concept which hasn’t been grasped completely by scientists till today. While there is a lot left to understand about time, we have made a clock for mankind that helps us distinguish between past, present and future, and makes sure that everyone on Earth is on the same page. Humans created time zones on Earth to keep the whole world on the same schedule. But this is not the absolute reality. In fact, there is no absolute time. Time is always relative to something. Even our time on Earth is relative to our Sun and the position of Earth with respect to it. So, what is time exactly? Is it an illusion? Let us address this question today.
Firstly, it is important to understand the direction of time. We know that time is moving in a place with respect to another place. Being on Earth, time moves faster with respect to an astronaut in the space station. He ages slower as compared to us on Earth. This is because of something called time dilation. So that means if among a set of twins, one is an astronaut who has returned to Earth after having spent two years on the space station, he would be about twenty milliseconds younger than his twin on Earth. While this isn’t much difference, my point is that someone farther, say on Pluto, would have aged even slower due to this concept. But, does that mean time is still moving forward for everyone, at different speeds?
According to Einstein’s theory, as fast as we move, time moves slower. So if we were to accelerate to the speed of light, time would have almost stopped. Is it possible then to have time move in the reverse direction? Now you may come up with an explanation that when we look at the stars, we are actually looking at the past because the light from those stars has come to us after so many years. While it is partially true, I don’t think we are looking at the past. We are looking at the present in the star’s time. It is just that we got to see the star a little later and hence is our past. This topic is still debatable because nobody has been able to come up with a definitive idea about how time passes. Ultimately, I see time as an illusion, as it is enabling us to measure change in our space. The reality we see is only the change in space around us. This does not give us a direction of time.
There is a theory of mirror universe going around the scientific discussions for a while now, where it is suggested that the Big Bang resulted into two universes where time moves in opposite directions, i.e. if we move from past to future, the mirror universe moves from future to past from our perspective. But from their perspective, we are moving from their future to past, i.e. an anti-universe. Another discussion that came up in recent times is that this anti-universe existed before the Big Bang, which collapsed later. Then the Big Bang happened and it expanded into our current universe. While these theories are up for debate and are equally likely to be wrong, we can agree that they provide interesting perspectives for research. Although popular media like comic books and the Star Trek series have explored the concept of mirror universe extensively, because despite the absence of physical proof yet, it does make for a spectacular treat for the imagination. These however, still don’t explain the concept of time, although we understand passage of time.
There is yet another concept given by none other than Isaac Newton. He explained the concept of absolute time, which is independent of everything. According to him, absolute time is understood mathematically and progresses at a consistent pace in the entire universe. So if we put this concept in a simple language very vaguely, we are looking at a clock in the universe that is essentially micromanaging every event in the universe, including local time at every point in the universe. This directly contradicts Einstein’s theory of time being relative. But if we were to include the concept of frame of reference, where we look at events happening from a particular perspective, we will end up with time being relative if we change our frame of reference. Even if we somehow solve this puzzle, this theory implies that the universal time started from zero. It essentially means that there was an inception of the universe in some form at time zero. However, it flies in the face of the law of conservation of energy, which states that energy can neither be created nor destroyed. Hence this also fails to answer our question.
Let us take a different route to understanding the concept of time. We may be able to create a definition of time if we can understand its origin or end. But does time have an origin at all, or did it always exist? Assuming that the Big Bang was the way our universe was created, universe existed within an infinitesimally small point which was extremely dense. This is known as a singularity. Then the big bang happened and the universe started expanding. It is theorized that as you approach a singularity, space and time lose meaning as time approaches zero. However, time itself does not approach zero. It appears to be zero to an observer outside of the singularity. In simple terms, if I were to fall into a singularity while continuously send you signals, you would see my signals slowing down to a stop. Going by this theory, did time exist before the Big Bang? It is a concept hard to put into simple words, but in a very crude way, it would appear that there was no time before Big Bang. But if that was the case, then there should be an absolute time of the universe, which isn’t the case. So, it leads us to the answer that time always existed, but in a different frame of reference having different intervals. Again, these are theories and nobody has lived 13.8 billion years to give an eye witness account!
Moving ahead with this knowledge, this is an interesting fact to consider. Let’s say you are walking to a place you have to reach. You look up and see your friend going past you in a car to reach the same place. So the time that has passed is different for both of you because of the different speeds. However, the time after which we will be able to see the current event happening in Proxima Centauri (the star closest to Earth after our Sun) will be the same as the time if we were to put a bright torch light near Proxima Centauri and see it from the Earth. This is because light travels at the same speed everywhere in the universe. Hence, time is only an illusion that enables us to measure ourselves in our surroundings. Before I push you into an existential crisis, I point to one perspective that might help us look at our lives in a promising way. Your life is only a sequence of events being placed one after the other. The period of time in which this happens is not important to note in the absolute sense because it won’t be a logical way of measurement. If you picked up a book from your table and placed it on your nightstand, this sequence of events may have happened 10 times slower compared to Earth time to an observer in the Andromeda galaxy because their time moves 10 seconds for every passing second on the Earth. But from their perspective, our time moves 0.1 seconds for every passing second on their planet in the Andromeda galaxy. Who is fast, or who is slow in this case? Actually no one is fast or slow. It is a matter of perspective.
So, time is neither a reality, nor an illusion. It is basically a perspective. It is only an indicator of the sequence of events happening in our lives, so that we can place them in order and create a “timeline”. While this timeline enables you to look at your life objectively from the perspective of your environment, it is not the absolute reality. Point to ponder?
