An old quote from Ridley Scott says that in space, no one can hear you scream. But actually, whether you can hear something in space or not, this is a matter of technology.
What does sound propagation depend on?
Sound is a mechanical wave, so material is required to propagate it. Hence, it cannot propagate in a vacuum. But while outer space is indeed very empty, it is not really a vacuum. The universe is filled with particles. Yes, there are huge spaces with less than half a proton per cubic meter, but planetary systems and nebulae are condensing and they transmit sounds.
These sounds are not audible within the limited range of the human ear, but they can be measured and converted into something we can all listen to.
Promotional video:
Sound of interstellar plasma waves
Among the well-known (and somewhat terrifying) sounds of space, Voyager's recording of interstellar plasma waves should be recalled. The recording is 12 seconds long but incredibly meaningful. Scientists have sent a man-made object, Voyager-2, as far away from our planet as possible so that it is now capable of detecting particle waves in interstellar space.
The role of mechanical waves
Mechanical waves play an important role in the formation of stars. The decay of a star's gas depends on the speed of sound. And even the beautiful structures seen in supernova remnants have a strong connection. The material pushed out by the star travels at supersonic speed and slams into the interstellar medium, heating it to millions of degrees and ultimately creating spectacles such as the Crab Nebula.
Radio wave conversion
In addition, scientists work with radio waves. They take the frequency of the radio signal (from 300 GHz to 3 kHz) and convert it to sounds (with a frequency reduced by 20 kHz-20 Hz). So, while radio waves are just a type of light, they can be more effectively heard as sound than seen by a radio source map. Thus, you can listen to the sound of radio communications on Earth, lightning on Jupiter, and even radio emission from Saturn.
Cosmic noise
But the same can be done not only with radio waves. Any kind of wave can be converted to sound. Physicists have even turned the signal from gravitational waves discovered last year into sound. And these sounds are used for more than just science. Space noises can also be used in art. Queen Mary University is currently working on a space sound short film competition.
Sometimes we use sounds for fun and sometimes because it is useful. We are heavily dependent on our ears and, thanks to thousands of years of music, we perceive melodies with their patterns well. By listening, we might understand what is not easy to see. And with the right technology, we can listen to music even in space and time.
Anna Pismenna