Comment Re:This is not a photon drive (Score 1) 480
They didn't actually put in that much energy compared to the thrust they measured.
The fine article says otherwise:
[...] assuming a 500 to 1,000 Newton/kW efficiency EM Drive system.
While the current maximum reported efficiency is close to only 1 Newton/kW (Prof. Yang's experiments in China), Mr. March noted that such an increase in efficiency is most likely achievable within the next 50 years provided that current EM Drive propulsion conjectures are close to accurate.
Best case scenario here is that 1,000 Newton/kW is 100% efficiency in which case their current efficiency is 0.1% or worse. If 1,000 N/kW is not 100% then their current efficiency is even worse than 0.1% in all experiments.
Also, note that Newtons measure force while kilowatts measure power so it makes no sense to express efficiency as a ratio of Newtons to kilowatts. For example, a c-clamp rated at 10,000 pounds-force will produce 44,000 Newtons for an indefinite period of time without consuming any energy/power after the initial tightening.
BTW, a 108 gram apple feels a force of roughly one Newton on the surface of the earth. Using 1 kilowatt to keep an apple suspended does seem extremely inefficient to me. Also note that I can keep an apple suspended indefinitely with a table and no ongoing energy expenditure.
Finally note that the one experiment that got close to one Newton/kW was not done in a vacuum. It would not surprise me if that one Newton of force could be explained by the light-mill effect.