What kind of damage do sonic booms cause?

>> BTW, are there any other ways of going boomlessly supersonic?

> Out of my league here, but how 'bout a perfectly quiet engine?
> (Not that it's possible, just wondering about the theoretical.)
>
> Chris.

A perfectly quiet engine (or just a *rather* quiet engine) would be
wonderful, but wouldn't do anything about sonic boom, because sonic
boom isn't caused by the engine.

I've wondered if it might be possible to "tune" the two engines of,
say, a Boeing 777 so that the noise from each cancels the noise from
the other. Or even a suped-up loudspeaker. Even a 10% noise
reduction would be significant, and a 25% noise reduction would have
those living near airports singing the praises of the first airline
to use it. I'd like to see noice cancellation used in everthing
from jet engines to leaf-blowers.

A loudspeaker to cancel sonic booms? Sorry, those things are too
much to cancel in such a way. A shockwave that can, at close range,
crack brick walls, isn't very likely to be canceled by any suped-up
(anti)boom box that can be carried by an airplane. Then again...

Double booms. Is it possible that the airframe could be modified in
such a way that the two booms are 180 out of phase? Again, even
less-than-perfect cancellation would be wonderful.

Xenophile (cranking up his antiboom box)