Contrary to the belief that the universe cannot produce sound due to the inability of sound waves to travel in a vacuum, we can actually “hear” the universe in various ways.
The NASA Exoplanets account, which specializes in sharing scientific information about the universe beyond our Solar System, recently published an article explaining how humans can “hear” the sound of black holes.
In May, NASA released a 35-second audio clip capturing the sound of a black hole located at the center of the massive galaxy cluster in the Perseus constellation, approximately 240 million light-years away from Earth.
This cosmic object emits a strange, low-frequency rumble, reminiscent of a creaking door each time it opens and closes.
However, this idea has been challenged. Recently, NASA’s Chandra X-ray Observatory recorded the sound waves of a black hole in the form of astronomical data, which were then converted into a format that humans can hear.
In fact, this data was collected by the Chandra X-ray Observatory over 20 years ago. They are pressure waves (sound waves) that span 30,000 light-years, covering the Perseus galaxy cluster, which is 11 million light-years wide. This also serves as the medium through which the sound waves travel.
“In my first ten years of work, I focused solely on images in the galaxy. But over time, I realized that my work wasn’t beneficial for those who aren’t professionals in astronomy or have vision problems,” shared NASA scientist Kimberly Arcand with NPR.
As a result, she converted the pressure waves from the black hole into sounds audible to the human ear. This process is known as “sonification” of data from the black hole. Additionally, Arcand has captured sounds from various other cosmic objects. Each material, whether from an interstellar cloud or a star, has a distinct sound.
According to NPR, by “sonifying” the collected data, astronomers were able to synthesize the sound waves in the galaxy cluster. These sounds lie 57-58 octaves above middle C (C4). Therefore, to make these waves audible to the human ear, the Chandra Observatory raised the pitch by 57-58 octaves, increasing the frequency by 4 billion times compared to the original.
The Chandra X-ray Observatory has been collecting sound wave data from black holes since 2003. (Image: NASA).
Recording and publishing the sound of the black hole in the Perseus constellation is part of the activities for Black Hole Week 2022.
NASA also released sounds captured during the transition from light data in the energy beams emitted by the black hole of the M87 galaxy, which is 53.5 million light-years away from Earth.
Another “sonification” project has been undertaken by Erin Kara, an astrophysicist at the Massachusetts Institute of Technology. Her research team used signals from X-ray bursts to map the environment around black holes, similar to how bats use sound to catch mosquitoes.
