# Sound and Space

## Main Question or Discussion Point

Hello again To my understanding, sound is vibrating particles in the air. Does that mean that in Space you can't hear anything because its mainly a vacuum?

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In space, no one can hear you scream!

In space, no one can hear you scream!
That is fascinating! scary too

Well, in one sense it's true but in another it's not.

For example, if you were outside a spaceship and rang a simple bell, that sound would not propagate.

However, if while outside you set-off a gaseous explosion, the expanding gases would provide a medium for sound waves.
In other words, if 2 spacecraft were relatively close to each other and one exploded, the violently expanding gases and materials impacting the second craft would most definitly be "heard" by those inside when the vibrational impact affects the hull and then the air inside the second craft.

Well, in one sense it's true but in another it's not.

For example, if you were outside a spaceship and rang a simple bell, that sound would not propagate.

However, if while outside you set-off a gaseous explosion, the expanding gases would provide a medium for sound waves.
In other words, if 2 spacecraft were relatively close to each other and one exploded, the violently expanding gases and materials impacting the second craft would most definitly be "heard" by those inside when the vibrational impact affects the hull and then the air inside the second craft.
That makes sense. If there was an atmosphere that extended from earth to the sun so there was no vacuum between us, would we hear the sun boiling or is the sun just to far away to hear regardless?

Yes, we would hear it!

The variations would take a very long time(many years I suppose) and would likely degrade/integrate into some sort of low-level "hum"

Yes, we would hear it!

The variations would take a very long time(many years I suppose) and would likely degrade/integrate into some sort of low-level "hum"
That's weird. Then again what isn't?

Now my brain is hurting. Are vibrations in particles caused by other particles banging in to them? Does sound genterate every time a particle vibrates?

russ_watters
Mentor
Now my brain is hurting. Are vibrations in particles caused by other particles banging in to them? Does sound genterate every time a particle vibrates?
Yes, but there isn't enough coordinated/coherent energy in those collisions to create audible sounds. The vibrations have to be in phase to cause your eardrum to vibrate.

In a way, though, the phenomena of sound and static air pressure are similar...

Yes, we would hear it!

The variations would take a very long time(many years I suppose) and would likely degrade/integrate into some sort of low-level "hum"
But would the vibrations stop after a few minutes to where the atoms can't collide to make a sound?

But would the vibrations stop after a few minutes to where the atoms can't collide to make a sound?
Sure. That's certainly possible. And, given the distance between our earth and our sun, even with some type of atmosphere in-between many sounds would not reach us.

However, on the sun there are really BIG explosions, many times the size of our earth!!
So, with senstive instruments, under those conditions one "might" be able to hear a low-level hum.

But with such distances involved, even with an atmosphere in-between, I don't have the math skills to validate my comment.