makeshiftreaperJul 20, 2025

Why can't a liquid move faster than the speed of sound in that medium?

https://lemmy.world/post/33238087

Why can't a liquid move faster than the speed of sound in that medium? - Lemmy.World

I was watching an XKCD “What-If” [https://youtu.be/pfbzrrcQZjs] 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

Show threadℕ𝕖𝕞𝕠
So, sound is vibration, right? And it’s going to vibrate as fast as it can, at the fastest rate that liquid can move. So it’s not that the rate of movement comes from the speed of sound; if anything, it’s the reverse.
Jul 20, 2025 at 7:01pmWeb
Show threadZwuzelmausJul 20, 2025

it’s going to vibrate as fast as it can, at the fastest rate that liquid can move.

Not quite logical unless there’s a reason why it should vibrate as fast as it can