TIME: REALITY OR HUMAN ILLUSION?

By: Aalia Garg

William Shakespeare once said, “Make use of time, let not advantage slip”. We understand the importance of time for all of us and the value it holds. Since childhood, we’ve been writing numerous essays about the importance of time management or using time wisely, but ever wondered what time is?  Does it even exist, or is it just an infatuation or maybe something made up by clock-selling companies? The concept of time originates from classical physics, and that might apply only to Earth. Well, the 17^th and 18^th century views about time are quite different from those given by modern physicists in the 19^th century. One after another, several physicists offered interpretations of time, but the one that really fascinates me is the cosmological arrow of time, characterised by the expansion of space. 

Currently, there is a major problem with the time that lies between quantum mechanics and general relativity. 

That’s probably because general relativity measures time at the cosmic scale, whereas classical interpretations, such as the Copenhagen interpretation, treat time as an external parameter. Einstein’s interpretation of time has really blown my mind. As a kid, I wouldn’t have thought of time as a relative phenomenon; now this seems complicated, but we can understand it with an example. For instance, let’s take two identical clocks showing the same time, let’s say 2 pm, clock A that stays on earth, and clock B that we’ve put in a spaceship and have sent it around the universe at the ‘SPEED OF LIGHT’, now clock B is moving quite fast. Imagine yourself in that spaceship, travelling through the universe on a tour and returning after about an hour. Meanwhile, I’m here on Earth with clock A, chilling out in a Pizza Hut, perhaps. Now I know it’d seem like nothing happened at all, and if I ask you the time in clock B after returning to earth, you’d say 3 pm; and no doubt that’d be the most logical answer based on the facts we’re aware of. However, this is not the case; you’ll see that clock A would be ahead of clock B, clearly indicating that clock B slowed down over time. 

This is exactly what the theory of general relativity is, and this was just a small-scale example of what is actually happening in the universe, in real life.

Not only this, but the gravitational pull of the heavy planets or black holes can also alter the spacetime. Now I’d want y’all to recall the interstellar, this is exactly what happened in there. We saw a group of astronauts who went to space in search of a new place to live, and they travelled to a wormhole near Saturn. Now, according to their watches, they were there for about a month, but when they returned, the main lead saw that his daughter had grown really old, older than him. Most of us wondered what just happened. This leads to time dilation, which is when time seems to slow down around heavier objects. Wormholes, being a billion times more massive, slow down the time around them. Massive bodies in the space bend the spacetime curvature, and their gravitational pull allows the time to pass more slowly around them compared to the bodies with weaker gravity. 

Moving on from this, I’d like to talk about time travel, another interesting aspect of spacetime. For now, the ability to time-travel is alien to us, and numerous research projects are underway. It must involve a way to connect the past to the present or the future to the present. It is, in fact, very essential to do this. If we somehow just travel in the past with no means to come back and make even a slight change, then the universe would collapse…