It’s Black Hole Week at Nasa and to celebrate, the space agency has released the soundtrack of an actual black hole.
On Wednesday, Nasa gave us a glimpse inside a black hole at the centre of the Perseus galaxy cluster, more than 200 million light-years away from Earth.
Perseus is known to be a 11 million-light-year-wide bundle of hundreds of galaxies shrouded by hot gas.
In 2003, astronomers discovered that the pressure waves sent out by the black hole at the centre of Perseus caused ripples in the hot gas surrounding it that could be translated into a sound note. However, this was not audible to the human ear.
The actual sound waves were discovered in data from Nasa’s Chandra X-ray Observatory. Now, Nasa has translated this astronomical data into sound using a process called sonification.
It sounds exactly like you’d think a black hole sounds like which is not quite Hans Zimmer’s Interstellar version.
There’s a popular misconception that there is no sound in space considering the fact that most of it is essentially a vacuum, meaning there’s no medium for sound waves to propagate through.
That’s where the hot gas surrounding the Perseus galaxy cluster comes in. Turns out that the gas provides the perfect medium for sound waves to travel through, letting us listen in to what that part of space sounds like.
The sonification process involves the signals being resynthesised to be audible to the range of human hearing by scaling them upward by 57 and 58 octaves above their true pitch.
‘Another way to put this is that they are being heard 144 quadrillion and 288 quadrillion times higher than their original frequency,’ said Nasa. (A quadrillion is 1,000,000,000,000,000.)
In addition to the Perseus galaxy cluster’s black hole, Nasa released another sonification of a famous black hole at the centre of the galaxy Messier. This one is famous for being the first-ever black hole to be photographed.
More sonifications of astronomical data, as well as additional information on the process, can be found at the ‘A Universe of Sound’ website: https://chandra.si.edu/sound/