[Spaceships] Real Life Non-Super Science Reactionless Engines

[Ulzgoroth]

Originally Posted by Anthony

Without more information, it's hard to say, but it makes me inclined to think they've got an instrument error. In any case, the 'negative control' failing most certainly means it's not something that should be published as anything resembling a success.

They also had a more-negative control which is described as an 'RF load'. While not specified, the implication is that they didn't detect thrust there. And mounting the drive in the reverse direction.

It's possible they messed up the whole thing, and not doing vacuum tests for something intended as a vacuum drive is a serious omission, but I don't see any reason to call this a failure.

[Anthony]

Originally Posted by Ulzgoroth

It's possible they messed up the whole thing, and not doing vacuum tests for something intended as a vacuum drive is a serious omission, but I don't see any reason to call this a failure.

"We had a theory, we tested it, and the theory failed to predict the results" is failure. Separately, the test is worthless junk.

[Ulzgoroth]

Originally Posted by Anthony

"We had a theory, we tested it, and the theory failed to predict the results" is failure.

Whether the device works is a vastly more interesting question than whether one particular theory about why the device works is correct.

Originally Posted by Anthony

Separately, the test is worthless junk.

Explanation needed.

[Anthony]

Originally Posted by Ulzgoroth

Whether the device works is a vastly more interesting question than whether one particular theory about why the device works is correct.

Actually, no, it isn't. It means you need to figure out what went wrong.

Originally Posted by Ulzgoroth

Explanation needed.

See bad experiment setup. Seriously, the most common explanations for 'reactionless' devices are atmospheric interactions and problems with the measurement devices being used, and they don't seem to have corrected for either one, so that's just rank incompetence.

[malloyd]

Originally Posted by Agemegos

Still amazing, though. 30 Newtons per Watt is astounding.

30 Newtons per watt is outright ridiculous - that ought to be pushing your test pendulum into the wall of your test chamber. 30 micronewtons per watt, which is closer to what's been claimed in the prior press releases for this stuff (note that it's not new, and it's always been press releases and not actual peer reviewed papers, which pretty well ought to tell you there is nothing here) is much more in keeping with some sort of ion wind effect.

[Agemegos]

Originally Posted by malloyd

30 Newtons per watt is outright ridiculous - that ought to be pushing your test pendulum into the wall of your test chamber. 30 micronewtons per watt, which is closer to what's been claimed in the prior press releases for this stuff (note that it's not new, and it's always been press releases and not actual peer reviewed papers, which pretty well ought to tell you there is nothing here) is much more in keeping with some sort of ion wind effect.

Exactly so.

Separately, a thruster that ceases to produce thrust as its thrust produces acceleration is nonsense.

[malloyd]

Originally Posted by Agemegos

Exactly so.

Separately, a thruster that ceases to produce thrust as its thrust produces acceleration is nonsense.

Just to clarify that a little, at 30 N/W, space drives are not your market, you need to talk to outboard motor manufacturers instead. This beats the performance of the marine engines by a factor of about 100.

[Anthony]

Incidentally, the 'theory' behind the EmDrive is actually reliant on inability to do basic geometry, as it's a container where somehow internal radiation pressure produces unbalanced effects...

[Agemegos]

The people you need to talk to are the aviation industry. The device described in the FAQ replaces wings, including rotors.

[Ulzgoroth]

Originally Posted by Anthony

Actually, no, it isn't. It means you need to figure out what went wrong.

I really think 'we have a reactionless drive and it turns out we don't understand its mechanism' would be enormously exciting. The incremental excitement of 'also, we know how to make it not work' seems rather minor.

I don't even know what the second sentence means.

Originally Posted by Anthony

See bad experiment setup. Seriously, the most common explanations for 'reactionless' devices are atmospheric interactions and problems with the measurement devices being used, and they don't seem to have corrected for either one, so that's just rank incompetence.

Obviously, they have not properly addressed the possibility that it is interacting with the air in the chamber, and that's bad. I don't know whether or not they corrected for problems with the measuring devices, but I'd like to know how you do.