Sonic Boom

[mytg8]

A man-sized object flying at an altitude of 10000 feet exceeds Mach 1. Would there be a loud boom on the ground?

[wildwood]

Maybe not a loud boom like a plane would make but certainly audible with the naked ear.
You don't need to fly through the air to make a sonic boom. Clapping your hands forces the air out from between your hands just before impact at a speed faster than sound and so produces a small sonic boom. The same principle applies to cracking a whip or flicking a towel (ouch). Even cracking your knuckles involves a mini sonic boom as the gas bubble bursts.

[mytg8]

That's interesting. Say you're Superman and can do such things; and want to avoid it when sneaking up on some supervillain. I read somewhere that if you flew upright--as opposed to horizontally like in the comics--you would make less of a boom.

[chakka35]

Certainly cracking a whip or towel produces a sonic boom because the end of the whip/towel is travelling supersonically.
But there is no supersonic travel involved in bursting a gas bubble in a joint so I'm not convinced by that, or by the hand clap. But I could be wrong. More info please.

To produce a boom you have to be making a noise of your own. The sound waves from that noise 'bunch up' because the noise-producing object is travelling as fast as the sound it is producing.

The boom of a whip or towel is presumably produced by the whoosh noise of the object travelling through the air, so Superman would have the same problem. Upright he would be less streamlined and therefore make more of a whoosh.

It still surprises me that the makers of Concorde failed to realise that it could never fly over inhabited land because of the sonic boom and that therefore the Atlantic was its only viable route. All that guff we were given by politicians that it would cut down the flight time to Australia made me laugh out loud even before they started on the development.