Nor do you need line of site.

This method "exploits "resonance", a phenomenon that causes an object to vibrate when energy of a certain frequency is applied."

Whole article is worth a read.

Darn it. I know I saw a movie recently in which the Tesla character was doing something similar. It was a chic flic my better half had me watch, so I obviously cannot recall the title.

Interesting article.

It was a chic flic my better half had me watch, so I obviously cannot recall the title.

The curse of our other halves, chick flicks.