Ok, this is a question that has been bugging me for quite some time.
We all know there really is NO sound in space, because obviously there is no air in space and such.

But we do know of radio waves that can be converted into sound, right? And because of this, there

has been some peculiar and somewhat creepy sounds produced by NASA. They do this by interpreting the

best that they can the waves into sound.

 

https://www.youtube.com/watch?v=gO9hx0x68lk - this video explains some things and also shows examples of

freaky sounds in space. But here's the question that the video failed to ask. If radiowaves can be converted into

sound - does this mean there really is sound in space? - however the sound we know as radio waves (which are

actually light waves, I believe) are simply disguised as light? Like if you think about it that way, there really is sound

in space, right? It's a hard question, much like many of the questions asked in science.

 

Opinions?

No, it is not sound in space. It's people taking some liberties to (unfortunately, IMO) sensationalize some results.

I think from a strict scientific viewpoint, there do have some sound in space. We know that sound can`t travel through vacuum. But you have to remember that in space there are still Interstellar Medium or ISM. They are dust and gas or plasma particles. Sound can be heard strictly speaking but too faint to be detected by our ears.

Edited May 31, 201411 yr by Nicholas Kang

Sound is a wave. Waves require a medium in which to oscillate. Sound oscillates in gasses, liquids, and solids. Space isn't comprised of any of those so sound can't oscillate in space, therefore sound doesn't exist in space. Light waves are able to travel through space because they are able to oscillate in electromagnetic fields. Sound however, can't. That is my understanding anyway.

I think from a strict scientific viewpoint, there do have some sound in space. We know that sound can`t travel through vacuum. But you have to remember that in space there are still Interstellar Medium or ISM. They are dust and gas or plasma particles. Sound can be heard strictly speaking but too faint to be detected by our ears.

The particles in space are too thinly spread out to carry "sound". For example, in air, the molecules are still tightly packed together enough that if you disturb some, they don't have to travel far before bumping into their neighbors and disturbing them. This is what allows sound waves to travel. In space however, the particles are so spread out that a disturbed particle can travel long distances before ever meeting up with another particle while missing particles that are nearer to it. It just adds to the already random motion of the particles without the "movement as a group" you need for sound propagation.

How can you be so sure that particles are too far apart? What about if a supernova occurs and compresses gases and dust particles? Do you have any references? Can you share with me some of them? Thanks.

 

Regards,

 

Nicholas Kang

How can you be so sure that particles are too far apart?

We have been into space and can verify that generally space is quite empty. However there are regions of concentrated matter obviously. So, for example if you stuck your head into Jupiter's atmosphere you will hear something...but not for long.

 

Molecular clouds can also be dense enough for sound to propagate. Though this is outside my area of expertise, I recall sound waves and their propagation speed being important in Jeans instability. I am sure google will reveal all.

Edited June 14, 201411 yr by ajb

You can hear something means there is sound. So?

You can hear something means there is sound. So?

This depends on your definition of sound. As a physicist as long as there are sound waves (pressure wave) there is sound, we may detect these with our ears or any other suitable device. A philosopher or maybe even a biologist would say there is only sound if there is someone to hear it as sound is our brain's interpretation of the pressure wave.

 

Anyway, there are certainly regions of space (not including the Earth) where pressure waves can propagate and so we have sound. However this sound cannot propagate without some material. Thus we cannot directly detect these pressure waves as they just don't propagate through the near empty void of space.

 

In regards to the opening post, it is clear that we can detect radio waves from many different sources in space and translate these signals into sound. Great, but that is all that has been done. It is akin to false colour images, they are not what is really there, but can give us useful information.

Then there would be ambiguity, which is correct? How can I accept and why? Arguments would have to be done, wouldn`t it? textbooks in school just simply ignore this fact and state sound can`t be heard in space, but now we have the evidences.

...textbooks in school just simply ignore this fact and state sound can`t be heard in space, but now we have the evidences.

By space they of course mean the near empty void in between heavenly bodies. There is no sound propagating in this near void. They do not mean that sound or pressure waves are particular to the Earth, just that sound waves cannot propagate through near empty space.

ok, I got what you mean. Thanks.

If the human ear could recognize particles in space traveling at the speed of light yes. Otherwise no.

There is sound in "outer space" because "outer space" is not a full vacuum.

A full vacuum, however, will prevent any sound from passing through.

Conclusion:
There is Sound in "Outer Space" because it is not a full vacuum.

The end.

Edited October 1, 201411 yr by Tzurain

But I am worried that if the density of the particles is not sufficient then sound will effectively propagate at zero speed.

But I am worried that if the density of the particles is not sufficient then sound will effectively propagate at zero speed.

 

And with an exceedingly low frequency cutoff. I don't see how you could possibly transmit a frequency higher than (mean time between collisions)^-1