“In space, no one can hear you scream,” is probably the most iconic movie tagline of the all, and it has the benefit of being true. What we perceive as a sound (or scream) is a pressure wave moving through a medium like air. Space is a vacuum, and so without air, no one will hear you, even if you were yelling in their face. This week’s episode of The Expanse once again showed that it takes science seriously by thinking up a clever way to get around this problem.

At one point in “Paradigm Shift,” (don’t worry, no spoilers here) two characters are in the vacuum of space when their communications drop out at a critical moment. Thinking quickly, the two characters touch helmets and yell orders at each other. A lesser show would probably say this was an attempt to read lips, and that the audience was afforded the luxury of hearing that attempt aloud. The Expanse is smarter than that.

I had a hunch that this helmet-to-helmet technique may be more than what it seemed, so last night I spoke with show runner Naren Shankar at an event hosted by the Science and Entertainment Exchange in Los Angeles. Shankar confirmed that the real reason the characters touched helmets was in order to translate the vibrations from their voices through the helmet and into the air inside the other helmet. It’s the same principle that makes string and can telephones work, and it’s a brilliant work-around for theoretical rock-hoppers.

Touching helmets so that in space someone can hear you scream is a minor detail, but most sci-fi shows discard this science-minded minutia for the sake of time, money, or narrative. Even though The Expanse doesn’t have to include thoughtful moments like this, it is clearly committed to doing so. “The nice thing about The Expanse is that we get to tackle ideas that most fiction has passed over,” Shankar said. “[The Expanse] is an opportunity to make life in space a character.”

Images: Syfy