Sound

The Perseus galaxy cluster contains a supermassive black hole that generates pressure waves, creating a B-flat note 57 octaves below middle C. This sound is far too low for the human ear to perceive.

The 1883 eruption of Krakatoa produced a sound so immense it was heard 3,000 miles away and generated atmospheric shockwaves that circled the globe multiple times. Close to the volcano, the sound pressure was lethal, instantly rupturing eardrums and lungs, an unimaginable force of nature.

While sound cannot travel in a vacuum, space is filled with electromagnetic waves, including radio emissions from planets, stars, and other cosmic phenomena. NASA has captured and converted these into audible "sounds" that reveal the universe's hidden symphony.

Space is a vacuum, meaning there are no molecules to vibrate and carry sound waves. While explosions in space are depicted with sound in movies, in reality, they would be utterly silent.

Sound waves require a medium, like air or water, to travel. The vacuum of space lacks such a medium, meaning sound cannot propagate, making it utterly silent, regardless of how loud the explosion or scream, a truly eerie silence.

Water is much denser and less compressible than air, allowing sound waves to propagate more efficiently. This is why marine animals rely heavily on sound for communication and navigation over long distances.

While there's no air to transmit sound waves as we know them, space isn't a perfect vacuum. Planets, stars, and other celestial bodies emit electromagnetic vibrations that can be converted into sound, revealing a hidden symphony.