If a Tree Falls in Space...

All of those galactic-horror-flick taglines are right:  in space, nobody can hear you scream...

But if you’re sporting the right kind of “ears,” you can hear Jupiter sing! Sound can’t exist in a vacuum because it is a pressure wave within a medium, not an independent physical force itself. If you unwisely popped your helmet off while in orbit around Jupiter (don’t try) and for some reason your head didn’t blow up like that scene in Total Recall, “hearing” could not occur. At all.

However, say your ears detected not vibrations in the air, but electromagnetic vibrations instead — waves that are are emanated by all active planetary bodies. Like the sound we know, these vibrations are a form of energy emitted by physical objects. Our ears can’t detect them because our survival as a species never depended on it, and so we never evolved the ability to hear them. This "sound" is there in an unhearable form, only our ears can't perceive it. But what if we could translate these other detected vibrations into sound? What would Jupiter sound like if we could “hear” it?

I'll save you time. It would sound exactly like this:

These ghostly echoes are the result of the “sonification” of data. The Voyager I probe recorded and translated them during its fly-by mission in 1979. I find these recordings so striking not just because they sound cool and seem eerily fitting (don’t they sound particularly “Jupitery” to you?), but also because they force me to reconceptualise notions of sound and hearing. Hearing is, after all, a process of translating electrically-transmitted data. Air vibrates, ears detect and produce electrical nerve impulses, the brain translates, and we hear. The key to hearing isn’t necessarily the exact nature of the initial sensory input, rather it is the interpretative process that happens in the brain — a sonification of data.

Data sonification is not new, but it is gaining momentum as an analytical tool. For over 60 years, people have been using Geiger counters to measure radiation levels, devices that rely on translating energy detectionsinput into audible sound. Surgeons have similarly relied on sonified data — in their case, the (hopefully) beeping indicator of their patient’s electrically detected heartbeat — to warn them of bodily reactions during procedures. These are fairly simple technologies, but ones that we've relied on for decades.

With the advent of powerful supercomputers, the full potential of data sonification is only now being realized. For example, researchers are attempting to use sonification to predict solar storms by detecting warning signs and changes in solar wind. Visual analysis of the sun is translated into audio, which reveals a layer of climatic activity invisible to other methods. It’s similar to the concept of a seismograph, only that it “hears the light” of the sun rather than direct vibrations. Such detection is important, since communication satellites are constantly threatened by damaging gales of electromagnetic particles. These storms are troublesome but manageable, if detected beforehand. Data sonification as an analytical tool is a rapidly expanding field, one that promises to shed new light on the universe around us. With it, we are developing the ability to penetrate the overbearing silence of the universe.



Comments

[Nathan Battams]

http://www.physorg.com/news/2011-03-astronomers-echoes-depth-red-giant.html