By: Radhika Bhambi

Sitting by Pebble Beach, New York City, awestruck by the mesmerizing beauty of nature, I wonder about a mysterious place, a parallel Earth-like planet yet to be discovered. I look deeper and see a place of my imagination—a place filled with people like you and me, people with heads full of dreams. In that perfectly strange space, we witness the wonders of the Universe, just as we witness those marvels here on Earth. In that sphere, the fabrications of space-time are such that the Universe gives us an opportunity to cherish the hallucinations of the past. Each day, we get to revisit the exact same moment in our past and get a chance to relive our elapsed time and be present in the bygones. 

Well, we don’t have to go far away to experience this peculiar fascination. You’d be amazed to know that we witness something similar here on Earth every single day through a process that I call the sunset illusion, a phenomenon based on how refraction and our atmosphere impact the notion of sunrise and sunset. 

Over 500 years ago, in the pre-Copernicus era, humans believed that the Earth was the center of the Universe, and that all the planets revolved around the Earth. Nicolaus Copernicus and Galileo identified that the Earth was a part of the heliocentric system; that is, the Sun was at the center of the Universe and all the planets, including the Earth, revolved around the Sun. 

However, to make things simpler, we constructed terminologies such that we, at least in our notion, kept ourselves at the center of everything. Hence, words such as sunrise and sunset emerged.

This brings us to the principles of science—physics, to be precise—that explain the theory of everything. Sunlight, generated at the center of the Sun, is assumed to hit the Earth in a fraction of seconds. In fact, it takes sunlight 8 minutes and 20 seconds to reach our eyes. Refraction, or the change in the direction of a wave (or light) moving from one medium into another due to a change in speed, explains why it takes the Sun more than 8 minutes to travel. As the sunlight moves through the vacuum of space, it moves at the speed of light - 3x108 m/s. However, when it goes through the Earth’s atmosphere (a different medium), it no longer moves at the speed of light. Instead, it slows down, taking more than 8 minutes to reach us.

A sunset is derived from a similar concept. When the Sun approaches the horizon, it moves faster than we see. This happens because the Earth’s atmosphere takes the light and bends it in such a manner that what we see is not the Sun, but the mere image of the Sun. We see “the Sun” for a few extra minutes after it has already set.  Astounding, isn’t it?

These are the marvels of the Universe that compel us to question the very essentials of our existence and make us wonder if we indeed are just a speck of dust within the galaxy. So, the next time you watch that Sunset on the horizon, do not forget to appreciate the few extra minutes that the Universe gives us to cherish the hallucinations of the past.

Speaking of illusions of the past, if I were given a chance to relive one moment from my past, I would want to lay down on that luscious green lawn in my Nani’s house and look at my Nani (grandmother in Hindi) and my doggo (Rexc) tittle tattle about me.

Which moment would you want to live again? Always remember: Keep looking up.