Why can't sound travel through space?
924840
sound is the vibration of the air and it's relationship to the ear drum.....no air.......no sound
534293
To hear a noise you need to have something for the noise to propagate through. The sun and Mercury exist in the vacuum of space. There is nothing in a vacuum, hence no sound can travel. So no, we can't hear the noise the sun or mercury make. Sound won't travel through the vacuum of space.\n\nBut the sun certainly makes a noise, it is after all a massive fusion reactor. If you could stand within the atmosphere of the sun without being vaporised or crushed you would be deafened by the noise it makes.\n\nBut once you left the Sun's atmosphere the noise would stop. All of space is a vacuum and totally silent.
49424
Not neccessarily.  But it is not because the sound waves are being affected by gravity.  It is because the medium that the sound travels through is affected by gravity.  The air is thicker at the 1st floor and thinner at the 10th floor.  To make an extreme example it would be like passing sound through water at the 1st floor and air at the 10th.  So yes it will be different sounds but because of the effect of gravity on the medium not the waves.
864873
Not on any realistic scale.  The particles in matter move according th the net of all the forces acting on them, including gravity.  Sound is a disturbance to the position of those particles, which propagates as a compression wavefront.  Gravity affects the steady-state behavior of each particle.  Sound just creates a short-term displacement.
539308
The vibration of a particle at one place is transmitted to the adjacent particle.\n \nThe transmission of vibration energy from one point to another is sound transmission. \n\nThe transmission is not instantaneous. There is a time delay.\n\nThe delayed transmission of energy from one point to another makes the sound to travel with a particular speed. \n\nWhat makes this delay? That is your question. \n\nEvery body is elastic to one or another degree.\n\nLet a body be distorted by a force for a short duration. The body restores itself to its original form. Every body has this elastic property.\n\n This property is the reason that any   mechanical action is transmitted with a finite velocity.\n\nImagine a perfectly rigid rod. This rod by definition cannot be deformed.\n\nAn action of a force on such a rod would be able to move the rod as a unit and the energy will dissipate instantaneously.\n\nTherefore a perfectly rigid body cannot transmit sound. (Velocity of sound is zero)\n\nNext consider a perfectly plastic body.  This body by definition will not return to its original form after distortion.\n\nTherefore a perfectly plastic body also cannot transmit sound. (Velocity of sound is zero)\n\nThus the speed of sound depends upon the elastic property of the materials used.\n\nThe air is highly compressible and takes some time to return to its original form when compared to liquid which are not so compressible and take lesser time to return to original form.\n\nTherefore sound travels with less speed in air than in liquid.\n\nThe density of the substance also plays an important role; If the mass is greater the restoring force gives less acceleration to the particle.
283342
Although we can't hear the sound the sun makes in a usual way from earth -- since sound can't travel through the vacuum of space -- we can make measurements of how portions of the sun are rising and falling and deduce what vibrations must be going through the sun because of this.  These vibrations are equivalent to sound, though at a much lower frequency.  For instance, middle C on a musical instrument vibrates the air back and forth 256 times a second.  For one vibration on the sun to go back and forth typically takes 5 minutes.\n\nSo the vibrations are at a frequency far below what human hearing could pick up, but if you multiply the frequencies to bring them into the range of what we can hear, the site below lets us listen to what the sun would then sound like.  Click on the "Hear the Sun Sing" link when you get there.
1041113
If you could hear the sounds of the sun it would mean the void of outer space is not a void but filled with air or an atmosphere.  Sound requires air to travel, i.e. sound generates sound waves or pressure differentials in the atmosphere.  Therefore if all space between here and Earth were filled with an atmosphere, this atmosphere would be superheated by the Sun and there would be no human life on Earth.  the temperature on Earth would be too high to sustain human life.
654732
Sound is a form of energy which is audible that is it can be registered by the ear. It travels in a medium and cannot travel in vaccuum. It is propagated in air as a series of compression and rarefaction (or expansion zones) these zones exist along the line joining the source and observer.\n\nIt is hard to localise sound unlike light because sound travels due to the disturbance of the material particles themselves.\n\nSound travels faster in a denser medium.
929469
Be proud of yourself, you found a mistake that slips past some of the most rabid trekkies.\nBut now I think of it, the parts of the engines themselves might be able to make a whoosing sound that would travel through the walls of the ship and be heard inside. But you're right, you shouldn't be able to hear it from the view of the ship they have in the opening sequence.
135250
When you are sitting in an airplane, the air around you is traveling with you in that "bubble" which is the airplane.  Therefore, sound acts the same as it would on the ground.  Sound is carried in air (and to some degree, other materials), but not in a vacuum.  So the paradoxes which crop up about traveling faster than light do not apply to traveling faster than sound.
997346
See this all depends.... if this were in the philosophy section, then it could be debatable.  But alas- it's in the botany section, so yes- it does make a sound.  Friction is created as it falls through the air and hits the ground, and that friction causes soundwaves.  Whether someone is there or not is irrelevant.  Humans can only pick up on a certain range of decibels anyways.  That doesn't mean just because we can't hear it, it doens't make a sound.  It just means that we can't hear it.  People need to get unstuck from themselves and think outside the human box.  "If humans can't.... must not be possible."  Meh.
629963
Besides the obvious "that's just how the universe and nature is" reason, it might be because sound is the propogation of mechanical waves.  It needs things like air to travel through and disturb the molecules.  Light is just itself (in some wavelength form) and travels that quickly.
137886
Sound travels faster through water because the particles in water are already touching each other (in gases the particles are all spread out). [the other answers have dealt with this in more detail]\n\nHelium is less dense than air becuase helium molecules weigh less than regular air molecules (a molecule of helium is two helium atoms, so its atomic weight is 2x 2 = 4. Air is mostly nitrogen, with molecular weight 2x 14 = 28).\n\nHowever, the molecules in helium are almost exactly as close together as the molcules in air. In fact, in any gas, one mole of molecules takes up the same amount of space - 24 litres at standard temperature and atmospheric pressure.\n\nSo, sound can travel faster through helium because the particles are the same distance apart as air, but they are lighter so it is easier to get them moving.
756089
The question asks nothing about the speed of sound in air compared with water. I believe that the answer is that sound will travel farther through air than water. \n\nMy reasoning is as follows:\n\nSound is a compression wave and its propagation is based upon atoms and/or molecues "bumping into" each-other in order to convey the energy of the sound. Now, with each collision between atoms/molecules, some energy is lost due to heat, so the more collisions there are (eg water), the more energy is lost. The fewer collisions there are (eg air) the less energy is lost. Of course, as everyone has pointed out, water is more dense than air, so there are more collisions per metre in water than in air, and so more energy loss per metre in water than in air.\n\nTherefore sound will travel farther in air than in water. \n\nAnother way to look at it is by taking it to the extreme. Let us imagine for a moment that there is a lonely molecule in outer space and we "bump" it with a spaceship. It will travel through space unimpeded, carrying that energy until it finds another molecule to bump into, maybe millions of kilometres away. So, that energy the spaceship imparted onto that molecule has travelled millions of kilometres. We can't hear a single molecule hitting our eardrums, but the effect is the same.\n\nAnyway, I hope that analogy helps.
1002624
Well actually on thing first: the reason why on a spacecraft or in a spacestation air is sucked out into space, is because gas as being air rises and fills as much room as it can expand, but as space is empty it will try to consume that space. This gets vacuum mixed up with air/gas escaping.\nSo nebulas, dust, gas and other remnants can stay in one place. Although the gas expands and converts dark matter to a larger mass (process=0.000023% conversion). As also the mass expands, the same way as galaxies expand the universe like the particles of the nova gas.\nIf a spaceship or spacestation was to explode it would be a flash of light expanding on the particles that were ejected by the explosive expansion, feeding on the explosion power. Basically the explosion would push out the mass rather than the mass expanding on itself. The term of explosion in space is not yet literally confirmed but some people name it a "nova". Although it means "explosion of gas from gas cloud" to our sense. There may not be air but the dark matter would provide a vibe cushion. Although a smaller sound it will still be a "sound" that probably only certain ears can hear as well as the energy production would create a certain spectrum of sound.\nOnly man-made satellites have been broken and fallen to Earth, but I don't know of any explosions, actually they're 50% explosion proof I think.\nAlso think as if you're in a spaceship and you are travelling at 100 mph all heavier loose matter will be forced down by gravity and weight as liquid and gas and air as heavy loose matter to be heavy and travelling will cause these heavier loose matter to be forced into your face as you are gaining speed this is a vacuum of force "forced matter vacuum". With the door wide open while travelling will cause a pump or "matter pump vacuum". Making loose heavy matter to be forced to the bottom in gravity and backwards by force vacuum "also 'gravitional vacuum' ". This is called the "circulation vacuum". Like liquid you would see heavier elements go to the base and the lightest at the top this is the same physic as that of forcing heavier loose matter back in a spaceship as "circulation vacuum". This force is relative to gravity "relativity".
470235
The previous poster is right.  It's particles in the air "vibrating" (caused by pressure differences) that enables you to hear.  That is why in space, which is a vaccuum, you cannot hear anything.  There is nothing to transmit those pressure differences to your ear.
38101
Because the speed of sound is set by the medium of sound (usually air) and hence your speed relative to the medium will make the speed of sound different if you're moving relative to said medium.\n\nThe speed of light is a constant for all observers, and light does not need a medium to travel through.