Scientists have managed to capture the sound of a black hole floating deep inside the Perseus galaxy cluster
As Ridley Scott wisely informed us back in 1979, in space no one can hear you scream. Contrary to popular belief, however, that’s not because no sound is emitted outside Earth’s atmosphere – it’s just that space is almost a complete vacuum, meaning that there’s no way for sound waves to travel.
Now, though, NASA has shared an actual space sound, picked up in the Perseus galaxy cluster, where there’s so much gas that soundwaves are able to travel. More specifically, these sound waves emanated from a massive black hole at the cluster’s centre, more than 200 million light years away.
So what does a black hole floating through deep space actually sound like? Weirdly enough, pretty much how you’d expect. Raised 57 octaves above their true pitch, into the range of human hearing, the cosmic groans appear pretty much identical to sci-fi sound effects produced by mere Earthlings, also inviting comparisons to the likes of Brian Eno.
Still, it’s admittedly unnerving that a giant cosmic entity is out there making these sounds by itself, especially since we have basically no idea what goes on inside a black hole. Would it help calm the nerves if we explained the “sonification of Perseus” to the best of our limited abilities? Let’s find out, shall we.
WHAT’S MAKING THE SOUND, ANYWAY?
We’ve known that the black hole at the centre of the Perseus galaxy cluster – one of the most massive objects in the known universe – is the source of a mysterious sound since back in 2003, when NASA’s Chandra X-Ray Observatory picked up one of the deepest notes ever recorded.
Astronomers discovered that pressure waves were being sent out by the black hole, causing circular ripples in the cluster’s cloud of multimillion-degree gas, which could be “translated” into a musical note. However, due to the very long time period between its oscillations (we’re talking about 9.6 million years), the sound couldn’t be picked up by the human ear.
HOW CAN WE HEAR IT?
Unsurprisingly, it’s not easy to record and play back a sound being emitted 200 million light years away. Most of the time, any sounds that we hear “from” space are actually just data points shifted into audio form – like last year’s spooky banger from Jupiter’s moon. The sound from the Perseus black hole is special, though. This time around, it’s not just a “data sonification” – the translation of astronomical data into sound – but a re-sonification, or “remix”, of the actual sound wave that occurred in the depths of space. Eerie.
Yes, NASA has classified the new sound as a “remix”. Scientists aren’t going to be slapping a hardcore drum and bass beat over the top anytime soon – unless that is in the works, in which case go off. But they did have to shift the note – B flat, in case you were wondering – up some 57 octaves to bring it up to a frequency humans would recognise. Think: “Black Hole Sounds (Nightcore Remix)”... times 144 quadrillion.
This remix was pulled off in May, to celebrate NASA’s Black Hole Week, “a celebration of celestial objects with gravity so intense that even light cannot escape them” (put that in your calendars for next year). This week, however, the space agency shared the sound on Twitter, bringing it to our little human ears.
WHY DO PEOPLE CARE?
Besides the sublime terror-slash-wonder of listening to a sound from a distance we can hardly conceive in our tiny minds, via groundbreaking methods? Well, people mostly care because the noise itself sounds a bit like an intergalactic whale. Or the end of the universe. Or souls being dragged through Hell (maybe ask CERN). Or space ghosts. Or the new Björk. More than anything, the internet is in agreement that the black hole sounds exactly what you would expect a black hole to sound like, courtesy of every sci-fi film ever.
Listen for yourself below.
The misconception that there is no sound in space originates because most space is a ~vacuum, providing no way for sound waves to travel. A galaxy cluster has so much gas that we've picked up actual sound. Here it's amplified, and mixed with other data, to hear a black hole! pic.twitter.com/RobcZs7F9e— NASA Exoplanets (@NASAExoplanets) August 21, 2022