Physicists are frequently wrong, every new discovery in Physics that's worth anything is correcting something or closing off alternative lines of thought that were previously considered plausible. That's the defining strength of science - it's constantly re-examining itself on the basic assumption that every proposition or theory is wrong in at least some way unless demonstrated or proven otherwise. The same goes for experimental results too though.
That's why when CERN physicists measured Neutrinos beamed between CERN and a lab in Italy as travelling faster than light, they operated on the working assumption that they were wrong. They assumed experimental error, engaged the help and advice of engineers from around the world and eventually tracked down the source of the error. Every result is exposed to just as much scrutiny as any theory. Both ends of the system, theory and practice, need to be examined with rigour.
The initially reported EM drive tests were hardly rigorous and now are pretty comprehensively discredited. The only vacuum test by the Dresden team has produced a null result - no thrust was detected within their sensitivity range. The latest Chinese test measured 0 +/-0.7mN, so nothing there either. They did detect thrust when the device was run on external power just as they did last time, but when they switched to internal battery power the thrust disappeared. As many observers had previously suggested, the 'thrust' turned out to be due to magnetic fields generated by the external power lines. The Chinese team have subsequently withdrawn their original paper on this basis, but of course it still gets raised as 'proof' the drive works on internet forums the world over. All this is on the Wikipedia page.
Honestly, whoever is launching the microsat is wasting their money and time, but I welcome the effort. The sooner this fiasco is put to bed the better and only thorough investigation is going to reach a definitive close. Except of course it won't. I still occasionally come across Cold Fusion true believers who think it was either covered up by the government or was 'never tested properly' to prove it worked. Presumably we'll get conspiracy theories about the Chinese faking a null result to conceal their secret military EM Drive program.
Simon Hibbs
