Curiosity 6 of 10
6. In space there is no sound
In the void of space, sound does not travel, because there is neither air nor any other material to carry the vibration. The loud explosions in science fiction films are artistic license.
Sound needs something to vibrate
Sound is a vibration wave that passes from particle to particle, through air, water or a solid. When you speak, your vocal cords make the air vibrate, and that vibration reaches the ear of the listener.
The space between planets and stars is almost empty. The particles are so far apart from each other that they cannot pass the vibration along as they do in air. So an explosion in space would make no sound for anyone nearby.
Astronauts talk over the radio, because radio waves, like light, travel through a vacuum. Inside the spacecraft or the space station there is air, and there sound works normally, including the constant noise of fans and equipment.
If two astronauts touch their helmets together, they can hear each other a little, because the sound passes through the material of the helmets. It is the same principle as pressing your ear against a wall to hear what is happening on the other side.
Did you know? In 2022, NASA turned the pressure waves of gas around a black hole in the Perseus cluster into sound. The real waves are too low-pitched for the human ear, about 57 octaves below middle C on the piano, and had to be sped up to be heard.
