@matt_mcmhn: Actually, seems like they don't. This is NOT only a matter of using gears. Think about it. If you are at the same speed of the wind, you can't get energy from it because, from your point of view, there is no wind. And if the wind is "reverse", it's even worse: the energy you get from it actually comes…

Well, according to wikipedia, it seems that it is a thermoacoustic engine, so it works with resonance. My guess? The piston does not move at the speed of sound, so the restriction is responsible for "speeding up" wave generated by the moving piston, so it can be in phase with a sound wave.

1000km/s. That's about... 1/300 of the speed of light. That's FAST.

@Dr. Evil Genius: When Skeletons Live: well, I'm ok with people saying that it "only melts at the tips".

@docb: "At sea level the average body is about 97% effective at loading your red blood cells with Oxygen. "

This thing needs RTS games. Imagine warcraft 3 in it. It could be implemented with very few interface changes.