An eerie audio clip has been captured by NASA that features sound waves originating from a supermassive black hole that is located 250 million light-years away. These acoustic waves emanated from the black hole situated at the centre of the Perseus cluster of galaxies. The sound waves have been modified to go up by 57 and 58 octaves so that they are audible to human listeners. These audio clips were released in 2022, signaling the first time that spatial sound waves have been extracted and transformed into a format which is audible to human ears. The journey began in 2003 when astronomers discovered acoustic waves moving through the vast gas surrounding the supermassive black hole, leading to what is now known for its haunting humming.
Listen to the deepest sound of the universe here:
As perceived by human beings, sound as a wave requires a medium like air or water to travel. Since space is a vacuum, and particles are absent, traditional sound waves cannot propagate. Black holes, however, emanate vibrations due to their massive gravitational forces, which in turn can be detected with the help of sensitive instruments. These vibrations are produced by the turbulent movements of gas and matter whirling around the black hole, resulting in ripples that scientists interpret as sound.
NASA’s Chandra X-ray Observatory identified these vibrations from the center of the Perseus galaxy cluster, located 250 million light years away from Earth, in 2023. The sound waves that were detected belonged to a frequency of 57 octaves below middle C, making it the deepest-ever note heard in universe.
The immense gravitational forces exerted by black holes, especially the supermassive ones that lie at the centers of galaxies, can significantly influence the movement of nearby particles in space. With gas and dust particles spiraling inwards, a massive frictional force and heat is generated, which results in the production of sound waves at frequencies so low, that they are inaudible to the human ears. Through advanced scientific methods, these sound waves can be modified such that they are detected by the human ears. NASA's researchers used data from X-ray emissions—specifically, the way sound waves compress and heat surrounding gas—to translate the cosmic vibrations into sounds we can hear. By converting these frequencies, scientists create a unique auditory experience, likening the sounds of black holes to the deepest bass notes in music.
When a collapsing star leads to the birth of a black hole, it disturbs the surrounding space, creating a gravitational wave that ripples outward. The phenomenon is similar to the science behind throwing a stone into a pond which leads to visible ripples on the surface of the water body. The frequency of sound waves emitted by black holes can provide valuable insights into their characteristics. The pitch and duration of these sounds correlate with the mass and spin of the black hole, offering a new method for astronomers to categorize and study these elusive entities.
The ability to "hear" black holes marks a transformative shift in astrophysics. By studying these sound waves, scientists can extract breakthrough information about the formation and behavior of black holes, nurturing our understanding of dark matter and energy. This approach is similar to how seismologists analyse earthquakes by interpreting the vibrations they produce.
Moreover, the ongoing research into cosmic sound waves may refine our models of galaxy formation and the evolution of the universe. By integrating sound analysis with traditional observational methods, researchers can develop a more comprehensive picture of the cosmos.
Black holes, once perceived as sinister voids, are now unveiled to be complex composers of the universe's deepest sounds. The vibrations they create resonate with the fundamental laws of physics, providing deep insights into the nature of the cosmos.
