The theory has been given in detail elsewhere and references therein, so here we discuss only an experiment. We show how to obtain thrust using a heavy reaction mass at one end of our capacitor stack and a lighter end cap on the other. Then we show how this thrust can be eliminated by having two heavy masses at either end of the stack with a central mounting bracket. We show the same capacitor stack being used as a thruster and then eliminate the thrust by arranging equal brass masses on either end, so that essentially the capacitor stack is trying to push in both directions at once. This arrangement in theory would only allow for a small oscillation but no net thrust. We find the thrust does indeed disappear in the experiment, as predicted. The device (in thruster mode) could in principle be used for propulsion. Experimental apparatus based on a very sensitive thrust balance is briefly described. The experimental protocol employed to search for expected Mach effects is laid out, and the results of this experimental investigation are described.
Read the rest here: http://nextbigfuture.com/2013/02/experimental-null-test-of-mach-effect.html
This is one of those things, like cold fusion and high temperature superconductivity, that has supporting physical evidence (and theory, too), and I hope like hell turns out to be true. The universe is stranger than we know.