What's the Sound of a Black Hole?
By Alexandra Wade - March 26, 2023

Since childhood, we’ve all been familiar with the concept of a black hole in space where everything vanishes. According to scientists, a black hole is a compact object, which usually takes the form of a collapsed star, that has such a strong gravitational pull that nothing can run from its pull, not even light. To give you a reference, if we need to put an object into space, we must launch it at 11 km/s for it to escape Earth’s gravitational pull and get released into orbit. To require escaping the black hole’s gravitational pull, however, the speed has to exceed even the speed of light. However, as it is known, nothing can exceed the speed of light – the ultimate speed – black holes suck in everything, including light, making them pitch dark and consequently invisible.

Getty Images / Science Photo Library / MARK GARLICK/SCIENCE PHOTO LIBRARY

A few days back, on August 21st, NASA revealed what a black hole sounds like through a 34-second clip on Twitter. While the sound may sound incredible, it is equally eerie and spooky to listen to. NASA’s exoplanets Twitter account released this audio captured by a drone in the Perseus galaxy cluster which is around 240 million light years away from earth. This audio clip was specifically “extracted and made audible” for the first time in around two decades, according to NASA. The sound is formed when the black hole sends pressure waves that cause ripples in the cluster’s hot gas that can alternatively be turned into a note. The sound can naturally not be heard by humans as it is about 57 octaves below middle C, so NASA shifted the notes and amplified it using other data on the black hole to make it audible for us.

This news took social media by storm as it was previously misconceived that there is no sound in space, let alone such eerie sounds. NASA released a statement that said, “The misconception that there is no sound in space originates because most space is a vacuum, providing no way forward for sound waves to travel.”