I'm working on a comics script with a "superhero" protagonist. "Supes" puts on his spandex, and takes off across state, say. :)
OK, as he speeds up, can he tell when he approaches and passes Mach one? I mean, do you think such a character would feel a vibration as he nears the speed of sound, and can slow so he doesn't boom people below? I read where a condensation cloud appears around jets as they pass Mach 1.

If he passes the sound barrier, could he notice it by everything going quiet, despite being buffeted by the wind?

I think as he passes the sound barrier, it would go quiet, cause his ear drums just burst.

This is really a question for Andy Green, the driver of thrust SSC and the fastest person on the planet ;)

ThrustSSC - Wikipedia, the free encyclopedia

Hello c:

What kind of a superhero would he be if he had to watch his speed? If you can make up a guy that flies, you can make up that he crashes through the sound barrier WITHOUT booming anybody..

excon

If he is a super hero, why can this not be one of his powers,
You have a man who flys ( not possible) and you want a natual answer to speed measurement. Let him see his speed in his mind

Chasrob,

I, for one, am glad you're considering real physics when describing your superhero. Of course Supes, himself, may be exempt from certain laws of physics, but the crux of a superhero is that he exists within a non-super world. The air through which he flies is not "super", and therefore it should behave like any other air would when an object flew past at Mach 1, whether the object be a superhero or a fighter jet. He would indeed create a sonic boom, along with a condensation cloud. I don't think he'd experience silence, though. He'd be outrunning his own sound waves, but he'd still hear the wind hitting him in the face and rushing past his ears. Also, even in a fighter jet most of the engine sound heard by the pilot travels through the solid structure of the plane, not through the air outside the plane. The pilot is stationary relative to that medium, so it's not possible to outrun that portion of the sound. I'm pretty sure a pilot going Mach 3 will still hear the engines roaring quite loudly.

I didn't check out the link Curlyben posted, but it sounds like a really good resource to learn about all this sort of stuff.

Captain Joe Kittenger, Broke the Sound Barrier in the 60's without a Jet:
YouTube - ‪Free Fall From Space - Captain Joe Kittinger‬‏

It doesn't bother SUPERMAN!
That's all I have to say about ,LOL