Article on reactionless drive in a reputable journal

The journal is Dec. edition of American Institute of Aeronautics and Astronautics (AIAA)’s Journal of Propulsion and Power. Here is link to the article. Prudence would indicate refraining from buying a ticket to Mars today, but this seems less likely to be bogus than Rossi’s E-Cat thingamajig.

Can you fit a 20 kWh battery in 100 kg? Back of my envelope says thrusting this mass for a day would get you half a meter per second, so obvious to the naked eye.

Pointer from Tyler Cowen at and here is the article he linked.

It looks a lot like the EM Drive. Short answer, it’s been studied a lot, and an effect has been measured. Almost everyone involved believes that the effect is just due to some systematic error in the experiment, but nobody has yet figured out what that error is. But whatever the source of the effect, it’s small enough that you need really precise tests to study it, and there are a lot of potential error sources that you need to rule out.

May I refer the OP to Irving Langmuir’s [Characteristics of Pathological Science.](Langmuir Talk - Middle Part Symptoms)

Symptoms of Pathological Science:
[ol][li]The maximum effect that is observed is produced by a causative agent of barely detectable intensity, and the magnitude of the effect is substantially independent of the intensity of the cause.[]The effect is of a magnitude that remains close to the limit of detectability; or, many measurements are necessary because of the very low statistical significance of the results.[]Claims of great accuracy.[]Fantastic theories contrary to experience.[]Criticisms are met by ad hoc excuses thought up on the spur of the moment.[*]Ratio of supporters to critics rises up to somewhere near 50% and then falls gradually to oblivion.[/ol][/li][/quote]
This “reactionless drive” seems to meet most of this criteria. That doesn’t mean the claims are wrong, but it raises a huge red flag.

For anyone interested and who can watch a video, here is Scott Manley talking about it on YouTube. There have also been several threads on this topic in the last few years if anyone wants to look them up.

Short answer for those who don’t want to watch the video or slog back through old threads are that there SEEMS to be an effect, but that most physicists think it’s either errors in the experiments or possibly something else that’s causing the effect that they just haven’t pinpointed yet. The amount of thrust per watt is pretty low, regardless…so, in terms of an actual device you get more thrust using something like an ion drive than this thing, at least for the first few years, assuming it’s even a real effect and really works. Since it breaks a lot of stuff we all learned in physics though, the good money is on errors in the experiment or some other force acting on it. Would be cool, though, if there were a reactionless drive, though the implications of that to physics are a bit disturbing.

The short version of the above is that extraordinary claims require extraordinary evidence. Extraordinary claims with very weak evidence and the likelihood of simple non-fantastical explanations should quite properly be treated with great skepticism. Sometimes such claims are advanced for self-serving purposes, and on rare occasions they emerge from legitimate science, like the supposed faster-than-light neutrinos said to be detected at CERN. So staggering would have been the implications if this were true that no one was surprised when it turned out to be experimental error.