In space, no one can hear you scream
The title of my post today comes from the Alien movie poster—it's the film's tagline, if you recall. Of course, we all know how many sci-fi series have messed this little fact up by adding explosions and such to satisfy our selfish need for action, no matter how inauthentic. But there are some great examples of Hollywood getting it right. First, a refresher, if you forgot why we wouldn't be able to hear explosions in space:
Simple: Sound waves, just like humans, need air to exist. Space is a vacuum, so the sound waves can't vibrate and reach our ears. If you were in a spaceship when a nearby ship or basestation exploded, you'd only hear the shrapnel bouncing into your ship. That's it. No explosion.
Stanley Kubrick's 2001: a Space Odyssey is probably the best example of Hollywood getting this correct. Whenever a scene cuts to the outside of a spacecraft, there are no sounds at all. Remember the big scene where astronaut David Bowman needs to get inside the spaceship Discovery from his pod without his helmet? We see the explosion and subsequent propulsion of Bowman from the airlock in total, eerie silence. When do we get sound back? When Bowman closes the airlock and lets it fill with air.