The vacuum is nothingness. To remove nothingness, you add something. When you add molecules, then you might be able to hear sound.

So, the trick is that sound needs something to travel through to reach your ears so you can hear it. When you talk, you make vibrations in the air, and those vibrations will move through the air and hit someone else's ears, and they can hear it.

It doesn't need to be air, sound can travel through things like walls or water, just not the same way as it would through the air.

But space doesn't have enough of anything between planets and stars and asteroids for sound to work. The vibrations can't go anywhere, they need something to travel through.

So, in order to make sound work in space, you would need to fill up all the space between stars and planets and asteroids with something. Like air or water, something that sound can move through.

How sound would work now would depend on what you chose, but also this is such a gigantic change to space that it's hard to figure out what would happen next.

Do you want that quote explained or do you want it answered?

If the vacuum of space would suddenly be filled with something like the air on our planet we could hear some things. The sun would be loud as a jackhammer 24/7. I'm actually uncertain if you'd be able to hear anything else with the sound of the sun there. Maybe relatively close supernovae, but the sun would definitely drown out most other sounds like space rocks colliding & similar.

Ok well first, you can't "remove" a vacuum because a vacuum is already nothing. You can't "remove" nothing. Second, if the vacuum of space were suddenly filled with some material that was dense enough to propagate sound, we would all instantly die and everything we know would be instantly destroyed, so you wouldn't hear anything.

Please read this entire message

Your submission has been removed for the following reason(s):

Hypotheticals questions, or questions about hypothetical situations, are not allowed on ELI5.

If you would like this removal reviewed, please read the detailed rules first. If you believe this submission was removed erroneously, please use this form and we will review your submission.

I understand your question and will answer it, but to remove space is the same as taking an empty bag and remove the emptiness. To let sound move in space do you have to add air or something like that, but it would be so much air that all dust, planets and stars you can see would not be near enough to make any change at all.

If we say it somehow was possible to add air between the sun and the earth, then would we hear a constant random humming, it would not be particular laud but if you got near to the sun, would the audio level be enough to tear all planets apart.