Since the detectors of the electromagnetic spectrum in which we bathe are receiving the full spectrum of its emissions, and since the visual part of this spectrum (the one we can see with our eyes) is only a small part of its range, we have to “transpose” its data so that we will be able to match our senses. This is usually understood as making it accessible to our eyes, as we are an intensely visual civilization. But the sound spectrum is increasingly being used, and there are several reasons for this development.
Originally the emphasis was to give access of the data to visually impaired by translating images into sounds. The basic principle is to render higher data entries into higher frequencies and the lower ones into lower frequencies, a result resembling sine wave (for example) will be translated in an undulating pitch recalling the sound of an ambulance siren (the European kind).
But in reality when you get a data feed from an observatory, the results are much more complex.
Most of the pretty pictures form space of nebulas and far-flung galaxies are in a good portion made by “transposition of data” that our eyes can’t see, and these can be sonified and the results can be as pleasing to the ears as the pretty picture you see in magazines or online.
But there are some data that is timed, meaning that they develop on a time scale. They are not still and instead of the picture, we need a video. For this kind of data, sound is as good or even better to understand with sonification, in particular to detect patterns. Here’s an example which represents Fast Radio Burst or FRBs for short, these are mysterious events from deep space, and I mean deep- billions of years in the past. They are massive explosions, most of the time one-offs, but some repeat. We have not yet understood what causes them; one of the explanations is that they could be from a rare type of star called a magnetar, which are collapsed stars with a very strong magnetic field. Here are two ways to represent them:
Video of the event
Sonification of the event:
You can judge as to which one conveys the jumps between high and low frequencies.
For another example: let’s look at data that is only usable using sonification:
One of the hardest things to find out about objects in the universe is to assess their distances. There are several methods that work for different distances: parallax, type A supernovas (also known as standard candles), redshifts, etc. I won’t go into details about these, but the farthest the objects are, the less accurate the distances are. Furthermore, it is important to be able to double check the results with at least two modes of investigation.
A new method to get information about these distances has been recently developed and it uses translating data into sounds. it is called asteroseismic parallaxes and it uses asteroseismology (the study of earthquakes in star or star quakes). These calculations were performed on over 12,000 oscillating red giant stars.
The speed with which sound waves propagate across space depends on the temperature and density of the star’s interior. “By analyzing the frequency spectrum of stellar oscillations, we can estimate the size of a star, much like you can identify the size of a musical instrument by the kind of sound it makes – think of the difference in pitch between a violin and a cello,” says Andrea Miglio, a full professor at the University of Bologna’s Department of Physics and Astronomy who is one of the study’s author.
So by translating these frequencies into sound, we, now that we know their sizes, can deduct their luminosity. And by using their luminosity, it allows us to find out how far they are from us.
“In our study, we listened to the ‘music’ of a vast number of stars – some of them 15,000 light-years away!” says Saniya Khan, a scientist in Anderson’s research group and the lead author of a study published in Astronomy & Astrophysics.
you can read about it here:
https://actu.epfl.ch/news/scientists-measure-the-distance-to-stars-by-their-/
I’ll be interested in hearing this sonification. Once again, space is silent, but the symphony that all the electromagnetic spectrum sends to us in the form of photons, once transposed into the visual or auditive spectrum, carries a lot of valuable information. And it might even sound good.