29 ms·
Well, given that with non-variable air density altitude doesn't matter, it should seem that if air density [actually, temperature] did matter (that is, it cause
by photon_off 16y ago
Well, given that with non-variable air density altitude doesn't matter, it should seem that if air density [actually, temperature] did matter (that is, it caused the sound to travel slower), then the higher the altitude, the higher the "plane to speed of sound" ratio would be, and the higher the angle between hearing the plane and observing it. So, I'd answer with infinite altitude. Eventually, the plane would travel from horizon to horizon without the sound ever reaching you.
Or, you're going to say that curvature is now a parameter, or the air temperature is some weird function of altitude, etc, etc.
- DanielBMarkham 16y agoNo, I'm not just trying to over-complicate things for the sake of it. My first though was eye-level, then, after thinking about air density, it was infinity. But the problem with distance is that *as things get farther away, they appear to move slower". So although some pulsar in the crab nebula might be moving millions of miles an hour, and there is no sound, there is also no movement, therefore the angle of the sound source to the light source is nothing. No sound. So the only other (natural) constraint I would mention would be that the sound has to be able to reach the observer.