[scottlocklin]

"In particular ultrasound can be beamed just like light, making the "perfectly spherical transmission" not even a close approximation"

You do realize that energy from a point source of light also falls off like 1/r^2, right?

[jerf]

OK, since conversation has moved on, let me be blunt: You don't know what you're talking about. Your physics 101 education is not the end-all, be-all of physics, and what "point" transmission does doesn't matter because we aren't talking about points. You are in no position to be lecturing people about physics; you are in a position to be lectured to about physics.