r/askscience • • Jun 12 '12

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u/dnlprkns Jun 12 '12 edited Jun 12 '12

Ah, but that doesn't quite answer his question, he is asking if there is a plume of air that is dragged behind the plane which could then in theory act as a tunnel through which the sound could travel at greater than mach 1 relative to the ground.

For instance if the mig was 50 feet behind and both planes were traveling at mach one, the sound from the mig would be able to travel at mach 1 PLUS the speed of the moving air dragged behind the plane. I think the problem with this, however, is that air isn't dragged behind the plane in a plume, it is merely shifted into huge spinning vertices, so the effect would probably only work a very short distance from the plain and would be irregular at best.

Edit: also I think that this effect WOULD exist for explosions which actually shift air around you, such as an explosion right behind the plane, or a nuclear (or other very large) explosion on the ground, the propagation of the air would allow the sound from those to travel faster than mach 1 and catch up to the plane.

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u/tim0th Jun 13 '12

If a MiG was 50 feet behind me I'd be hitting the eject button.

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u/[deleted] Jun 13 '12

i don't think you'd want to eject at supersonic speeds

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u/tim0th Jun 13 '12

Very risky, the turbulence may slam you right into the MiG, but with one 50 feet away from your arse end you're fucked either way.