Absolutely, but where is the boundary between shock and sound for these kids' cars? At first, I thought the refractive aberrations were just schlieren lines from the heat. Now, with even more powerful systems, I suspect they are shock waves.
BTW, you get a similar effect from the leading edge of high-speed jet aircraft, which allows one to actually see a little past the leading edge under the flight path.
Technically the boundry between shock and sound waves is clearly defined at 191dBA.
However, can probably see sound at lower pressure levels than shockwaves as any pressure change will alter the refractive index of air. I wonder if there's a way to amplify this effect so we can see lower level sounds at low frequencies. I haven't given this much thought.
@Hero999
I bought a sound "laser" kit (makes coherent sound) from the Pennsylvania State University acoustics department. Produces low frequency sound/pressure waves that can blow out a candle at several inches. Intent is to experiment with a directed counter measure. But, no time yet to play with it. John
That is the object: breaking glass.
To cruise thru the hood and pop the windows.
Our gov is just class selective enough to make it effectively not illegal.