I was watching an XKCD “What-If” video recently and Randal off-handedly mentions the title fact as a given. Upon a further Google search I see explanations about why sound moves faster in liquids than gasses but nothing for my specific question. Is there an intuitive explanation for that fact or is it just one of those weird observable facts with no clear explanation

  • Little_mouse@lemmy.ca
    36·
    2 months ago

    Sound is transferred through a medium literally as a wave. When you get right down to the core of it, the wave requires movement within the medium to transmit.

    So it might help to conceptualize it not as “Liquid cannot move faster than the speed of sound in it’s medium” but more like “The speed of sound in a liquid medium is defined by the speed at which energy can propagate in that system, which includes motion.”

    • makeshiftreaper@lemmy.worldOPEnglish
      7·
      2 months ago

      So you’re saying I should view the speed of sound in a medium like the speed of light in a vacuum? That it’s the “speed-limit” of how a wave propagates and so trying to exceed it is impossible for a physical wave?

      • halcyoncmdr@lemmy.worldEnglish
        4·
        2 months ago

        Badically. “Liquid/fluid” and “gas” don’t necessarily mean the same thing scientifically as they do colloquially, they’re actually very close to the same thing.

        Fluid dynamics covers the study of liquids, gasses, and plasmas because they’re effectively the same.

        Note that the speed of sound isn’t a constant across various media. Just like the speed of light isn’t a constant on different media. The “speed of light” we usually refer to is specifically in a vacuum. Light travelling through a media like water or a prism actually changes speed, however slight.

        The same happens to sound. The speed of sound at altitude is different from sea level for instance, because of the atmospheric pressure difference. And sound doesn’t propagate at all in a vacuum because it requires the wave to move molecules, which don’t exist in a vacuum.