What Does Space Sound Like?
Space is often portrayed as being silent in movies, with the famous tagline from Alien stating, "In space no one can hear you scream." This is true, not just because of the distance from Earth, but also because sound requires molecules to travel through. Space is virtually empty, with as few as 10 atoms in a cubic meter, compared to billions in our own atmosphere. Without this big soup of atoms, sound has no way to travel.
However, billions of years ago, shortly after the Big Bang, the entire universe was a ball of hot plasma thick enough for sound to pass through. Shock waves from the formation of the universe rippled through space, creating a cosmic hum that was deeper than anything our ears could detect.
Today, researchers have decoded these primordial stirrings and pitched them up to a level we can hear, making them the first sounds ever created in the universe.
Space and Sound
Space is vast, empty, and quiet. We should be grateful for this because if sound could travel through space, we would be bombarded by a constant deafening roar of the sun. Fortunately, the void of space protects us, and we get to live in a world of amazing sonic diversity, from sandy deserts to lush forests to the sound of the ocean. Our home planet is a rich soundscape, but there are other worlds of sound out there in the skies, oceans, and rocks of other planets.
What is Sound?
Sound is the vibrations of molecules in the air. It is a pressure wave that takes on many forms but is most familiar to us as pressure waves moving through gas. Sound travels faster through lighter gases, like helium, making our voices sound higher pitched. When the air is colder or made of heavier gases, like sulfur hexafluoride, sound travels more slowly.
