Sound in Space

[Seeka]

It's been a while since I have asked a silly and easily explained question so here goes another...

If you were to play a musical instrument on Mercury it wouldn't be heard right? Why not? I take it not having an atmosphere has alot to do with it but what part does an atmosphere play when it comes to sound?

Also, i listened recently to 'sounds of space' and one clip was a random recording of the planets Jupiter and Saturn 'talking', (not to each other) I thought in space there was no sound so, how was there a recording made? How was it heard in the first place?

Regards

Steffanie.

[antoniseb]

Sound is carried by acoustic vibrations. When you hear music from a stringed instrument, the sound comes from molecules (mostly Nitrogen and Oxygen) being forced into motion when the vibrating strings (or sound board) hit them, and then those atoms recoil off of other molecules, and progressing at about 700 miles an hour away from the string.

On Mercury, there is a very thin atmosphere, and sound waves can happen there, but they would carry a lot less energy, and not be something your human ear could detect.

Concerning the "sounds of space", these are usually radio signals that have been translated into the acoustic spectrum. They aren't actually sound waves that you'd hear if you were there.

[danscope]

Well said, Sir. You need a 'medium' to transmit sound. Water, air, wood, steel, rock. Sound travels through all of these. Vaccuum? No.
The speed of sound changes ...depending on the medium. It is much faster in water and steel than in air.
Best regards,
Dan

[DrWho]

Concerning the "sounds of space", these are usually radio signals that have been translated into the acoustic spectrum. They aren't actually sound waves that you'd hear if you were there.

That is true, however you can have sound in space provided you're in a dense enough medium. A cool example of this is the sound of the big bang itself.

About 400,000 years after the big bang, the universe had expanded and cooled enough for electrons and protons to start combining into neutral hydrogen. That freed both the photons and the trapped sound waves to travel unimpeded through space. The expanding sound wave originates from all points in the universe. The outward ripple from each sound wave grew to be 500 million light years in length due to the expansion of the universe. The birth of galaxies tended to occur at the leading edge of the ripple, where matter was slightly denser and gravitational forces slightly stronger.

What did the big bang sound like? Have a listen here.

(The simulation lasts 100 seconds representing the first 760 thousand years of evolution of the universe, and varies the sound intensity to match the cosmic microwave which, according to WMAP, peaked at 379 thousand years and dropped to 60% intensity in 110 thousand years before and after the peak time. The sound frequencies used in the simulation must be boosted upward by a huge factor (about 10^26 power) to match the response of the human ear, because the actual big bang frequencies, which had wavelengths on the order of a fraction of the size of the universe, were far too low to be heard by the human ear).

[George]

Since space is not a complete vacuum, there are sound waves in space, but they are very, very low frequency. Here is something about black holes that appear to be creating sound waves. I also recall a B-flat note propogating out through a galaxy, but also at dozens of octaves below our audible range.

[WayneFrancis]

personally with only 1 atom per cubic cm I fail to see how "sound" would travel through this medium very far. Surely there is a formula that given a certain density of a medium you could calculate how far "sound" would travel given the initial power of the vibration.

[mugaliens]

Surely there is a formula that given a certain density of a medium you could calculate how far "sound" would travel given the initial power of the vibration.

There surely is! It's here, Wayne.

However, the distance is infinite. It's just that the signal drops well below the random noise floor, so as to no longer be distinguisheable. The pressure of the last atom, carried atom to atom, will eventually push on forever, just as matter has pushed outward since the Big Bang.

[DrRocket]

There surely is! It's here, Wayne.

However, the distance is infinite. It's just that the signal drops well below the random noise floor, so as to no longer be distinguisheable. The pressure of the last atom, carried atom to atom, will eventually push on forever, just as matter has pushed outward since the Big Bang.

That formula is based on continuum mechanics. It ceases to be valid when the continuum model ceases to be valid. That happens a bit sooner than when you start considering the behavior of individual atoms.

[astromark]

wow that's a deep tone... thanks for the link 'mugaliens'
So the answer is NO. Sound as we know it does not transmit through a vacuum.
It needs a substance in order to resonate it. As the density increases so to the velocity of transmission.
As to other sounds in space. Yes electromagnetic forces and waves of energy... some can be recorded, some not. I recall that the 'Cassinie' probe on arrival at Saturn had to go through the rings plain. The sound of those tiny particles impacting the crafts body was recorded... another question beckons.. was the microphone on the Hygens probe to record sound from the only moon with a atmosphere ?

[Seeka]

Thank you all for your replies. The links were pretty awesome also, especially the sound of the Big Bang! I can't think why i didn't realise sound needs a medium to travel, seems pretty obvious now.

Thanks again,

Steffanie.

[trinitree88]

Thank you all for your replies. The links were pretty awesome also, especially the sound of the Big Bang! I can't think why i didn't realise sound needs a medium to travel, seems pretty obvious now.

Thanks again,

Steffanie.

Steffanie. It was a good question.Most people think sound propagates through space because of movies,".like Star Wars", TV series, video games with shoot-em up effects...leading one to think you'd hear it. They contemplated doing them "right"....tried it out on a test audience, and found people thought it was too boring without the "booms"...so like so many other things in the world, it's fake to make money. pete

[rommel543]

I liked the Firefly movie Serenity, during a space scene another ship was destroyed and it imploded, then exploded (happening very rapidly) but no sound. Even the gun they were using had no sound. I believe Joss Wendon wanted the show and subsequent movie to be "somewhat" scientificlly accurate.

[DrWho]

I liked the Firefly movie Serenity, during a space scene another ship was destroyed and it imploded, then exploded (happening very rapidly) but no sound. Even the gun they were using had no sound. I believe Joss Wendon wanted the show and subsequent movie to be "somewhat" scientificlly accurate.

Yeah, 'somewhat'. Of course, there was one landmark film which went to great lengths to get this right - 2001: A Space Odyssey. Much of the film is in dead silence (depicting the absence of sound in space), or with the sound of human breathing inside a spacesuit.

[WayneFrancis]

There surely is! It's here, Wayne.

However, the distance is infinite. It's just that the signal drops well below the random noise floor, so as to no longer be distinguisheable. The pressure of the last atom, carried atom to atom, will eventually push on forever, just as matter has pushed outward since the Big Bang.

Thanks for that. What you said makes perfect sense.

[WayneFrancis]

Thank you all for your replies. The links were pretty awesome also, especially the sound of the Big Bang! I can't think why i didn't realise sound needs a medium to travel, seems pretty obvious now.

Thanks again,

Steffanie.

Don't feel bad. Many people think that they can see in a room with no light if they have enough time to adjust their eyes too even though the room might be light tight.

[SkyZesus]

There are "sounds in space" we just can't hear them. Sound travels as vibration. Sound can travel through liquids, solids, and gases. But it travels at different speeds and frequences. Now if you were to yell into outer space, your voice wouldn't travel very far.

[danscope]

Sir: There is no continuous medium to transmit a vibration.
ie .... if I strike a steel rail a mile long ( for instance) the speed in which this medium will travel is 5,490 meters per second. It is a continuous medium, unbroken, and will conduct the vibrations we call sound to it's end.
Space is NO SUCH MEDIUM , and represents distance without material.
The odd molecule of hydrogen here and there does not constitute anything
that would conduct sound. No. There is no sound in space.

[ShinAce]

Sir: There is no continuous medium to transmit a vibration.
ie .... if I strike a steel rail a mile long ( for instance) the speed in which this medium will travel is 5,490 meters per second. It is a continuous medium, unbroken, and will conduct the vibrations we call sound to it's end.
Space is NO SUCH MEDIUM , and represents distance without material.
The odd molecule of hydrogen here and there does not constitute anything
that would conduct sound. No. There is no sound in space.

Agreed. The medium is so thin that the energy given by 'sound' will likely be trumped by solar radiation.

I guess space does have a sound...I call it static.