879,873,000,000,000,000,000,000 kilometers. Take a moment and try to imagine this number. If you can’t, that’s totally fine. The human brain simply isn’t built to understand values this enormous. And just so you know, this is roughly the size of the observable universe in kilometers.
So the thing that truly amazes me is the sheer scale of the observable universe.
The fastest speed we know is the speed of light, around 300,000 kilometers per second, or about 1.08 billion kilometers per hour. If humans could travel that fast, we would reach the Moon in about 1.3 seconds, the Sun in nearly 8 minutes, and Pluto in around 6.5 hours. Sounds incredible, right?
But even at that speed, it would still take about 93 billion years to cross the observable universe. That is almost 7 times longer than the age of the universe itself, which is around 13.8 billion years. And it gets even more mind blowing. The universe is not static. It is expanding, and that expansion is speeding up. Because of this, nearly 94 percent of the observable universe is already permanently out of our reach.
And here is the most fascinating part. Everything we are talking about is only the observable universe. No one really knows what lies beyond it. The actual universe could be far larger, maybe even infinite, making that already massive number seem small in comparison.
And yet here we are, humans, a species only about 300,000 years old, living on a tiny planet called Earth, somehow able to understand all of this.
That is what truly blows my mind.