• Question: Does sound travel faster in space?

    Asked by Mason The Amazing :) to Andrew, Hina, Ian, Kathryn, Leah-Nani, Xu on 14 Jun 2018.
    • Photo: Kathryn Burrows

      Kathryn Burrows answered on 14 Jun 2018:


      No, sound cannot travel through space itself as it needs matter such as a gas to travel through. We can only hear (and quite importantly breathe of course) because of the atmosphere. Inside a space ship where there is air, I can think of no reason why sound would travel faster than in the same conditions on earth.

    • Photo: Leah-Nani Alconcel

      Leah-Nani Alconcel answered on 15 Jun 2018:


      No. It is very difficult for sound to travel in space, because sound relies on lots of particles being around in order to move. In space there are very few particles!

    • Photo: Andrew Margetts-Kelly

      Andrew Margetts-Kelly answered on 20 Jun 2018:


      Sound energy travels through a medium (that’s the fancy word for stuff) at the speed the molecules move.

      In gas this is dictated by the temperature (more thermal energy = faster molecules = faster sound), and the molecular weight of the gas molecules (lighter molecules = faster molecules = faster sound). This is why if you breathe helium you get a higher pitch voice, the sound moves faster in helium than it does air because helium is lighter.

      In space though there is no gas really, the distance between molecules is measured in kilometres (1000m), not like air on Earth which is 10’s of nanometres (0.000000001m). So there is no sound in space,… well, sort of!
      We could get really pedantic and say that “some” sound energy “could” be transmitted through space because there are “some” particles and it is not an absolute vacuum; and in which case because the lonely molecules in space travel way faster than those in the air on earth, sound will travel faster in space…
      …BUT:
      * the amount of energy transferred is that small and
      * the distance between molecules is so vast and
      * the chances of the same molecule hitting you twice is so slim
      …that we consider molecular interactions in space to be ballistic collisions and not sound pressure.

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