Why not read the paper I linked instead of just making stuff up? Alternatively, show your math.
> When relativistic effects are taken into account, it is shown that the photon rocket can only reach energy breakeven as the accelerated mass asymptotically approaches the speed of light. Thus, any device with a thrust-to-power ratio greater than the photon rocket would be able to operate as a perpetual motion machine.
A photon rocket is 3.3 μN/kW, thus the EM drive is too efficient.
