  The Mach Effect Thruster (MET) is a device which utilizes fluctuations in the
rest masses of accelerating objects (capacitor stacks, in which internal energy
changes take place) to produce a steady linear thrust. The theory has been
given in detail elsewhere [1, 2] 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 [1, 2]. 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.
