A dance—a cosmological one, that is.
Two black holes waltzing through the cosmos, swirls of light flaring outward from our dancers like skirt and coattail, gravity the matchmaker. Closer and closer they inch, easing into a delicate embrace until…BOOM! A flash of light and rock and an explosion with the intensity of 100 million supernovas rips into existence, obliterating nearby solar systems in a seething, gaseous cloud and sending gravitational waves hurdling through space in every direction.
Where do we fit into this cosmic performance, you ask? Well, we’re enjoying from the nosebleeds—the 3.5 billion light years away nosebleeds, to be exact. And with 100,000 years till the climax, we’re a safe distance away in space and time.
So why bring it up, then? My answer is two-fold.
Firstly, it’s cool. We, these specks on a speck on a speck on a speck on a speck (and so on and so forth for longer than I can type) somehow have knowledge about this enormous physical anomaly taking place 3.5 BILLION light years away. Billion—with a gigantic, capital “B.” That we even have the capacity to contemplate something so distant and so grand is an unfathomable mystery in itself.
Secondly, these gravitational waves hurdling through space should hurdle right on past us, providing the first observable evidence of ripples in the space-time continuum. See, like a moving ball agitating the surface of a pond, massive objects
in space have a rippling effect on the gravitational status quo (you can think of space-time as the surface of the pond, with floating celestial bodies causing tiny waves as they move). But when two extremely massive objects—say, two black holes—are moving at a significant fraction of the speed of light, these tiny waves get much, much bigger. And when extremely massive, fast-moving bodies collide, oh boy.
The important (and fascinating) thing about these waves is that, according to Einstein in his theory of general relativity, they carry with them information about their origins. This means observing one first hand could offer a wealth of new information about the early universe and provide deep insights into the principles that govern it.
And just to emphasize: that we know anything at all about our universe is absurd. It’s like a proton in your left pinky fingernail having knowledge about behavioral economics; it doesn’t make sense that something as tiny and far-removed from natural cosmic phenomena as we are has knowledge about the mechanisms that underlie said phenomena.
I think that idea is the real takeaway. The science is interesting and necessary and important, but what we’re being reminded here is that, despite our minute-ness, we are still a part of this ginormous thing we call the universe. We persist. In a way, we’re as much players in the performance as we are audience members. This wave 100,000 years down the line is just a nudge from across the universe. A handshake from the dancers. A “thank you for participating.” So when I look up at the stars, all that mystique and beauty and vastness doesn’t stop at the foot of the stage; I’m on the stage, and I can look around and wonder.