Albert Einstein was the first to discuss the fabric of space, and according to his theorems, the curvature of it. We have been discussing gravitational waves ever since. Einstein e claimed that with a planet orbiting on the fabric of space, it would act like the surface of a trampoline, sending out waves and ripples in reaction to the planet’s pressure.
The ripples spanning out through space are gravitational waves, and as these gravitational waves pass by, like birds on the ocean surface bouncing up and down, every object they pass will compress and stretch along with these waves. This includes our planet, stretching and compressing with the waves that hit us.
As gravitational waves behave similar to frequencies, they are perhaps more like sound than a physical phenomenon. The LIGO (Laser Interferometer Gravitational-Wave Observatory) instrument, designed specifically to detect the extremely weak signals of gravity, can measure these waves. With some work, we can translate them to sound, allowing us to actually hear the gravity of the universe.
Despite all these waves, and the force of the Earth’s gravity pulling us down, gravity is a very weak force. So LIGO must be extremely sensitive in order to record these waves. But because it’s so sensitive, and only responds to gravity, it can search out places science hasn’t been able to get to, lacking strong enough telescopes and other appropriate equipment. Gravity isn’t blocked out by light, or cut off by interrupting planets; it keeps going in ways telescopes can’t.
By using LIGO, scientists were able to record two black holes as they came together, one that was twenty-nine times the size of our sun, the other thirty-six. They hit together, becoming a single black hole over sixty times the size of our sun. We know about this because of LIGO, and this is the first time we have information brought to us that wasn’t seen. This is a brand new way to look at the universe — by the form of its gravity waves.
Levin’s newest book is Black Hole Blues and Other Songs from Outer Space
