A sound is something which needs a medium to travel. The air molecules provide a medium, and we can hear any sound. But there are a few questions about sound in space. Is there sound in space and if it does, can we hear it? If not, then how do astronauts interact? Let’s find out and solve these queries as much as possible about the aspect of sound in space.
There is no air in space, and what we call “sound” is vibrations in the air. But there are indeed light waves and radio waves, but these are not sound, but light. Astronauts do talk to each other since there is plenty of air in spacecraft, so they speak normally. But when they are space walking, they speak by means of radios in their helmets. The radio waves have no problem in space but thats are not sound. Those are radios which are converted into sound by the astronaut’s headset.
Sound can’t be carried in empty vacuum of space since there are no molecules for the audio vibrations to move through, which is true but to an extent. Space isn’t entirely void. The interstellar gas and the dust left by the old stars are sometimes used to create new ones, which does have the potential to carry sound waves, but we are just not able to listen to them. The particles are so much spread out, and the resulting sound waves are of a very low frequency that they are beyond the limit of human hearing.
When a sound wave passes, it causes oscillations in the air pressure and the time difference between these oscillations represent the frequency of the sound which is measured in Hertz, and the distance between the oscillating peaks is called wavelength.
If the distance between the air particles is greater than this wavelength, the sound cannot bridge the gap and stops the ripple. Therefore, sound needs to have a wide wavelength which can come across as a low pitch to our ears to make it from one particle to the next in certain parts of space. Once sound goes below 20 Hz, it becomes infra sound that we cannot hear.
Now when someone says there is no sound in space, since there is no air, interrupt them and say that it’s not so normal. There is actually sound in space, but we just can’t hear it.