You’ve probably heard astronauts talking to mission control while they perform operations in space. In these recordings, you can hear the back-and-forth chatter, along with the astronaut’s breathing and the background noise of their spacesuit pumping oxygen into their helmet to keep them alive. Yet, if they removed that helmet and broke the barrier of the suit shielding them from outer space, that conversation would be cut — and all sound would go radio silent.
As astrophysicist Neil DeGrasse Tyson once explained on the podcast StarTalk, astronauts would be able to hear things from within the body itself — like their own heartbeat.
