NASA Discovers How Black Holes Sound, Releases Space ‘Remix’

34-second It set social media ablaze, with many outraged that a black hole could escape, let alone an eerie, screeching hum.

But the idea that there is no sound in space is actually a “popular misconception,” the company said. While most of space is empty, with no medium for sound waves to travel through, a galaxy cluster “contains an abundance of gas that includes hundreds or thousands of galaxies, providing a medium for sound waves to travel through,” it explained.

The clip, described by NASA as a “black hole remix,” was first released in early May in conjunction with NASA’s Black Hole Week — but a tweet from the NASA Exoplanets team on Sunday actually saw more than 13 million views. method.

Sound waves were discovered in 2003, when and then Researchers at NASA’s Chandra X-ray Observatory “discovered that pressure waves sent out by the black hole caused ripples in the cluster’s hot gas, which could be specifically translated.”

But according to NASA, humans couldn’t hear that note because its frequency was so low — the equivalent of B-flat, about 57 octaves below the piano’s middle C note. So astronomers on Chandra remixed the sound and increased its frequency by 57 and 58 octaves. “Another way to put it is that they are heard between 144 quadrillion and 288 quadrillion times their original frequency,” NASA said.

When Kimberly Arcand, the sonification project’s principal investigator, first heard the sound in late 2021 — what she described as “a beautiful Hans Zimmer score with a really high mood” — she jumped with excitement.

“It’s a wonderful representation of what I had in mind,” Chandra’s visualization scientist and emerging technology leader told The Washington Post. But it was a “tipping point” for the entire sonification project that “really sparked people’s imagination,” he said.

It also points to future areas of research. “The idea that there are these supermassive black holes all over the universe… belching out incredible compositions is a very awe-inspiring thing,” Arcand added.

Experts warn that if you happen to be standing close to a black hole, the sound in NASA’s remix won’t be exactly what you’re hearing. Human ears “may not be sensitive enough to pick up those sound waves,” Michael Smith, a professor of astronomy at the University of Kent in England, told The Post. “But they’re there, they’re the right frequency, and if we amplify it … we can hear it,” Smith said. He compared it to a radio — “You turn up the volume, the volume is louder, and you can hear it.”

Arcand said the idea was born during the coronavirus pandemic. He was involved in converting X-ray light captured by Chandra’s orbiting telescope into images, creating 3D models and making that data accessible to people with low or no vision. When the pandemic hit, it became difficult to maintain the project remotely.

So, along with other colleagues, he decided to try something new: sonification, or the process of translating astronomical data into sound. Blind experts in the group also encouraged Arcand to “think differently” about the value of translating complex data sets into sound.

Looking at 2003 data from the Perseus galaxy cluster, she and colleagues worked to determine the properties of pressure waves and reduce the sound they make, then boost their frequency.

The decision to release the “re-sonification” of nearly two-decade-old data is part of the agency’s efforts. Scientific discoveries in plain English to millions of followers.

Through a partnership with Twitter, NASA discovered that “while its fans enjoyed stunning photos of space and behind-the-scenes travel, there was also a group that wanted to know what space looks like.” In a news release.

Some experts said the clip was disturbing because the sound was “somehow you would hear if you were there,” said Chris Lindott, a professor of astrophysics at the University of Oxford. on Twitter on Tuesday — as if you had a recording device translating sound directly from the galaxy cluster to Earth.

“Sonification of data is fun and useful — especially for people who can’t see the images. But it can sometimes be used to make things seem ‘deeper’ than they are here,” Lindott added.

But Professor Smith, University of Kent, said: “It is perfectly reasonable to say that there are sound waves. [in the galaxy cluster]If we were there, we could hear them if we had sensitive enough ears.

However, he admitted, “these galaxies are so far away that we have to make a lot of assumptions to make them audible to us if we were there.”

Arcand said he understands the criticism from some quarters that sonification is a complicated process — particularly because the combination of pressure, heat and gas that drives sound waves inside the Perseus galaxy cluster is specific to that environment. But the value of sonification, she said, made her “question it in different ways.”

“It’s a great representation of science, in my opinion, and a haunting sound!” Carol Mundell, chair of the astrophysics department at the University of Bath in England, told The Post via email.

The project, and NASA’s tweets about it, appear to have fulfilled the space agency’s mission of sharing its science and research with a wider public in a conversational way — and not everyone is a fan of the remixed sounds of a black hole.

Online, people seemed both thrilled and horrified by it For the Lord of the Rings and Silent Hill series.

Others had fun with an audio clip, overlaying an image on it or remixing it with a is considered to be very close to .

“I can confirm that the black hole noise made by NASA is the sound of hell,” wrote one darkly humorous Twitter user . Another one : “New Genre Just Dropped: Cosmic Horror.”