In space, no one can hear you scream - and Hollywood almost always gets this wrong. Sound is a wave of pressure that needs something physical to travel through: air, water, metal, anything with molecules close enough to push against each other. In the vacuum of space, there’s basically nothing for sound waves to push.
If a giant explosion happened in space, you’d see the flash, but no boom. If a planet broke apart, no rumble. If two stars collided, total silence. Spaceships in Star Wars and Star Trek whooshing past each other wouldn’t make a sound to anyone watching from outside.
Astronauts in spacesuits, of course, can hear each other through radios - but that’s because the suits hold an atmosphere inside, where sound waves can travel. Talk to them through the radio and your voice is converted to electromagnetic signals, beamed across space, and converted back to sound in their helmet. Outside any pressurized cabin, the universe is the quietest place there is.
