"Turbulence," Bart repeated. "Think of it like testing a slipstream in an air tunnel. You try to interrupt it, you're going to get all kinds of vortexes depending on the shape. So where those happen, you get erosion or transference or whatever you want to call it."

He left that statement hanging as he took a few bites of steak, thinking.

"Maybe it's got something to do with vibrational harmonics."