To understand the size of the universe we have to use light years. Because light is the fastest thing we know of. So fast that it can travel around Earth seven times in a second. And a light year is the distance that light can travel in one year.
Alpha Centauri, our nearest star system roughly 4.3 light years away from us. If we could travel at the speed of light, we could reach the nearest star system within 4.5 years. Not so far, right? But it’s nothing when compared to the size of the Milky Way Galaxy. Our Galaxy is over 100,000 light years across. That means it would take 100,000 years to travel from one side to the other at the speed of light. That’s also mean we’ll never know what’s actually there on the other side of our galaxy.
And that’s not all. There are 2 trillion galaxies in the observable universe, according to the scientists’ estimates. The observable universe is what we can see and it’s 93 billion light years across. Yes, travel to edge of the observable universe would take 93 billion years at the speed of light!
Unobservable part of the universe is a complete mystery. It may be millions of times bigger than the observable universe. We don’t know exactly how large the whole universe is. What we know is we’re so small in the universe.
But don’t feel worthless. We’re not the smallest thing here. Think of atoms. There are around 1,000,000,000,000,000,000 atoms in just a single grain of salt. And, what’s more, they are made up of particles that are even smaller. These particles called protons, neutrons, and electrons. If an atom was the size of a football stadium, the nucleus would the size of a pea in the center of the stadium.
The scale of the universe is hard to imagine. It’s so complex in our perception. We’re either too small or too big to understand the size of something. We must be in the middle of somewhere in the universe.