Why Is The Night Sky Dark When There Are Billions Of Stars Shining?
Hi there, dear friends! It's the Business Guy, and I'm back again with an awesome blog about the mysteries of the Universe.
There's a really awkward realization about space or the universe that makes people ask this particular question:
How come space looks pitch black if it's really true that space is made up of billions of stars shining all the time?
The light from our sun alone is able to create daytime on our planet and the other planets in our solar system.
There are literally billions of stars far bigger than our own sun, and they're all shining bright.
There are also supernova activities going on constantly. A supernova is the name we give to the explosion of a star.
Imagine our sun exploding. The kind of light it would produce cannot even be seen with the visible eye without going totally blind, and in fact, the energy from that explosion can destroy planets and end up creating what we call a black hole.
So if all these stars are shining, and supernova activities are happening constantly, why is space dark?
Well, guys, I'm going to share briefly an explanation of this concept.
There are hundreds of billions of stars in the Milky Way alone, and they're everywhere, so wouldn't it make more sense that their light would take up the entire sky?
That's a question I would love to answer.
This condition of space being dark while there exist billions of super bright stars is indeed a paradox and is known as Olber's paradox, named after a German astronomer of the same name who asked that very question: If the universe was static and infinite, why isn't space bright?
And the answer lies in the fact that the universe is actually finite and expanding due to dark energy, which causes the light from stars outside our immediate vicinity to be stretched and weakened, making them invisible to the naked eye.
Now another thing is that because the speed of light is also finite, light from distant stars billions of light years away hasn't actually reached us yet, making them outside of our observable universe.
This is what causes our Universe to seem dark, although there are billions of bright stars. The light from the stars is being stretched and weakened as space itself stretches.
So we only see a weakened version of the stars.
I hope this explains everything, guys. If you're still confused, definitely let me know through the comments, and I'll further explain.