Cosmic Symphony

by Madeleine Kando


I am obsessed with the stars. Really obsessed. It’s not healthy. How can you love something that doesn’t love you back? Not just that, but stars don’t even know about my existence. It’s like being obsessed with the air, the ocean, the Siberian Tundra. That’s what we do, us humans: we become infatuated with things like that because it makes us feel more important than we are. If Jupiter and Mars are out there for us to see, doesn’t that mean that we somehow are part of it? Part of the vastness of space?

That obsession led to a conversation with my nine-year old grandson, Marshall. I told him that black holes sing. Not only do they sing, but they sing in B flat. It’s true. Go here, if you don’t believe me. Marshall and I had to first figure out what B flat sounded like. It sounds like this.

Black holes can generate enormous sound waves. They spew out vast amounts of material traveling at close to the speed of light. When that material slams into the hot gas that pervades the galaxy it is in, they beat a 'galactic drum'. The jet acts as the "stick," whereas the surface of the gas is the "drum”.

The problem is, that a black hole sings 52 octaves below middle C, or one million, billion times lower than the lowest sound audible to the human ear! But even if there were such a super-duper baritone-detecting creature, it would have to wait 10 million years between each sound wave (tone) to reach it. It would be a very slow symphony in B flat. (For a better explanation, see: Strange but True: Black Holes Sing).

We are so used to looking up at the night sky and marvel at the magic of it all. It is amazing how far our eyes can see. We see the moon at 239,000 miles. We have no trouble seeing the sun, at 93 million miles. Saturn, at 746 million miles, is visible in the night sky, and we can even see the entire Andromeda Galaxy, which is 2.5 million light-years away.

The Hubble Deep Field (HDF) image taken by the Hubble Telescope, shows galaxies so far away, that it allows us to travel back in time. It shows us the universe the way it was in the very beginning. Still, Hubble needs assistance to transpose those parts of the light spectrum that our naked eye can not detect, to give us a full picture of these stellar objects. Even the visual images we see, are always rendered in full color—converted from invisible X-rays or radio waves to visible light so we can see the universe in all its splendor. They might be a lot more boring if we limited ourselves to the visible range.

In fact, how far we can see is basically unlimited, depending on the size and brightness of the observed object. But even light needs time to travel, so by the time light reaches us from the Andromeda Galaxy, we see it as it was when Homo Habilis, an ancestor of ours, was barely walking around on the planes of Africa.

Light travels about a million times faster than sound. Sound needs a medium to travel through (air, water, rocks). If it didn’t, we would be bombarded by a deafening cacophony of stellar sounds, each one piercing our eardrums like a sledge hammer. The sound of a supernova exploding, a meteor crashing into a planet or a red giant blowing up and collapsing. Nature was wise by giving us the right kind of ears and by sucking the air out of space.

Ok, so we cannot touch, smell, taste or hear the cosmos. Until now.

SONIFICATION

The NASA’s Chandra X-ray Observatory, which orbits around the earth, has taken our ability to appreciate the splendor of the Cosmos a step further by converting light waves into sound waves. This process is called sonification. While we are feasting our eyes on the beautiful Crab Nebula, for example, we can also hear what it sounds like. (See: Crab Nebula Sonification).



But this is a trick, you might argue. It’s just a pretend sound. It’s like putting a horn on a horse and call it a unicorn. Sound can not ravel through space, since it’s a vacuum! Until now, we weren’t sure whether sounds from the cosmos were really there.

In fact, sound can travel through space. Because of gravitational waves, i.e. the distortion of space/time. For the first time, scientists detected gravitational waves at the LIGO Observatory. It was a result of 2 black holes colliding a mere 1.3 billion years ago, as they merged into one. Close to the source, it must have been a deafening sound, but like a pebble dropped in a pond, the waves propagated through the fabric of space-time, and when it finally reached us, here on earth it was detected by the super sensitive instruments at LIGO as a faint chirp.

Every planet in the solar system generates radio waves which, when transposed into sound waves, generate a unique sound signature. The muffled sound of thunder on Mars, the raging storms of Saturn, the frigid methane waterfalls of Uranus, the roar of the burning sun, the howling winds of Jupiter. Every planet shrieks, screams and yells at the top of their lungs, but no one is there to hear it. There are a trillion different islands of sound in the universe that does not travel through space. It is not sound that fills the Universe, it is light.

So, if I am correct, there are three ways to eavesdrop on the Cosmos: We can wait until a gravitational wave hits earth and measure it with superfine instruments, we can transpose the extra deep pressure waves that black holes create in their surrounding gas to audible sound, or we can ask some creative musicians to sonify the x-ray images at Chandra.

Either way, it is refreshing to realize how much of our daily existence is puny compared to all of this. Does it matter if I do the dishes or not? Do I worry about the faucet leaking? The laundry piling up? I wonder how scientists manage to do anything mundane, like matching their socks or combing their hair, being constantly confronted with the banality of it all.

I wish we were as good at looking at ourselves from a distance as we are at observing the Cosmos.
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