Who Cares About Gravitational Waves?
If your Facebook feed is anything like mine, then today it is chock full of people pretending they understand quantum mechanics, heralding the arrival of gravitational waves. Yipee! As if any of your friends actually know what they are or why they are significant. So big gravity makes little waves that propagate throughout the universe and a couple of L shaped sensors detected them. So what? Why should I care? What's the practical application of gravitational waves?
Click on any of the articles your stupid friends posted and you'll get something like 'Two Massive Black Holes Merge', 'Confirms Einstein's Theory of Relativity', 'Most Important Discovery of the Century' or 'If You Post This To Your Timeline People Will Think You're Really Smart'. Pretty much every article tells you that gravity makes waves, Einstein predicted them, they're really hard to detect, and it's a really important discovery that you should be excited about...and then here's a cool colorful sciencey picture of something that no one's actually seen.
But what these articles don't really tell you is why it's such an important discovery. What's the big deal about gravitational waves? What do they do? And why should I care? Fortunately for you my friends, you have The Science Curmudgeon!
The short answer to these questions is; Nobody knows. The exciting part is what they might be able to tell us about the universe.
Traditionally we've looked out at the universe with our eyesballs. But our eyeballs can only detect visible light and visible light is only a small portion of the electromagnetic spectrum. Not all objects in the distant universe shine strongly in the visible light portion of the spectrum. Some objects may shine really freakin bright in, for example, radio wavelengths. Using radio telescopes, astronomers have found pulsars, quasars, and other awesome objects that push the limits of our understanding of physics. Observations in the microwave band have opened our eyes to the faint imprints of the Big Bang, as seen in this famously cool colorful sciencey picture:
This image is so cool because it is the oldest known "light" energy that we can see. This is an image of the era of recombination, when the energy from the Big Bang had cooled down enough and the universe had expanded enough for light and matter to coalesce into pretty much the forms we know now. Let me say that again; This is the oldest known "light" in the universe. Pretty freakin cool. This kind of image is only veiwable when we use the microwave band of the electromagnteic spectrum. Similar advances in observations using gamma rays, x-rays, ultraviolet light, and infrared light have also brought new insights to astronomy. As each of these regions of the spectrum has opened up, new discoveries have been made that could not have been made otherwise. Astronomers hope that the same holds true of gravitational waves.
The above image shows what the universe looked like about 380,000 years after the Big Bang. You can't see anything before that because light and matter did not exist as we know them. But what did exist? Gravity! And lots of it. The ability to detect gravitational waves implies that we may be able to look back into the age of our universe before light and matter existed, perhaps all the way back to the Big Bang itself. That's kind of freakin exciting!
Another, more immediate application of being able to detect gravitational waves is the ability to observe and study black holes. Until now no one has ever actually seen a black hole, that's why they're called "black", because astronomers are racist. Their existence has been inferred by looking at the stars and gas swirling around them. The cool thing about gravitational waves is that their gravitational signal comes directly from the holes themselves, no need for the surrounding matter or energy. So an isolated black hole system could theoretically now be observed, even if it isn't surrounded by stars and gas and dust. One of the awesome properties of gravitational waves is that they pass right through any intervening matter, without being absorbed or scattered. We should soon be able to "see" black holes even if there are stars and dust and galaxies blocking the view. The gravity waves just pass right through that shit!
The ability to observe the universe with a new set of eyes has a lot of crazy potential. It is possible that we will discover new types of astronomical bodies, particles and states of matter that we've never even dreamed of.
But not yet. The observation that was made in September was basically just a blip. All we know is that the two black holes that smashed together were each roughly 30 times the mass of the sun and merged some 1.3 billion light years from Earth. We don't know where in the universe it was or what happened after...or any real details for that matter. This is just a confirmation that all of the crap I've been rambling about above should be possible at some point in the future.
So ignore all of your friends stupid posts talking about interstellar space time travel energy wave wormholes and stuff. The fact is there's some things that might be really cool...sometime soon. But really nobody knows. Yet. Stay tuned my fair curmudgeons!
