If, like us, you're still coming down from the high that is the first direct evidence of Einstein's gravitational waves - one of the biggest astrophysical discoveries of the past century - you're gonna want to hear this. This is what the heartbeat of the Universe sounds like - a ripple in space-time as it passes through the Laser Interferometer Gravitational Wave Observatory (LIGO).

"We can hear gravitational waves. We can hear the Universe," physicist Gaby González from the LIGO Scientific Collaboration told the press. "That's one of the beautiful things about this. We are not only going to be seeing the Universe. We are going to be listening to it."

So what exactly are we listening to? As the LIGO team explained, the signs of gravitational waves they picked up on were the result of two black holes colliding, which released 50 times more energy than all the stars in the observable Universe, and lasted only a few fractions of a second. 

The signals recorded by LIGO were converted to sound waves, and in the first part of the video, you hear the sound wave frequencies that exactly match the frequencies of the gravitational waves. In the second part of the video, the sounds have been played at higher frequencies that better fit the human hearing range. 

"What we have done is taken the real signal and shifted it a bit in frequency, but it is still the real signal," said González.

What you want to tune into is the subtle little "blip" that interrupts the signal - believe it or not, that's the actual sound of gravitational waves surging in frequency as the black holes collided. How does anyone even begin to fathom how incredible that is?

"What the observatory picked up was a minute gravitational distortion as the wave tripped the ribbon of laser light within LIGO's vast tunnels," Becky Ferreira explains over at Motherboard. "It only lasted for 20 milliseconds, and the frequencies were measured with a precision equal to the width of a human hair over four light-years."

Excuse us while we go eat a ghost sandwich and lie on the floor for a bit to contemplate our place in the cosmos.

If you're still getting up to speed on all of this, check out our live breakdown of the announcement last night, and watch below for a really easy explainer: