Sound in Space

Sound wave requires medium to propagate. There is no air in space, and therefore, sound cannot travel over space. However, in some cases, sound and vibration can still travel over solid objects —like spacecraft or spacesuits— that exist in space.

In some videos taken in space, things that occur in a vacuum can be heard, and flat-Earthers use it to discredit spaceflight. In reality, 1. sound can still travel over solid spacesuits and spacecraft, 2. vibrations can cause noise in microphones, 3. there is air inside spacesuits and many spacecraft, 4. the sound was heard over the radio communication system, and not directly over space.