[Spaceships] Real Life Non-Super Science Reactionless Engines

[Anders]

May be an interesting phenomenon anyway. Maybe this will lead the way to something bigger?

[Varyon]

Originally Posted by vicky_molokh

Having that from NASA seems weird. Genuinely bad experiment control by NASA, or just a badly-written article?

Hard to say, as we can't access the full article (which appears to have actually been a presentation). The two bits Anthony referenced do sound like maybe they could be problematic - microwaves might heat up the sealed container (so we're just looking at a fancy hot-air balloon)*, and the fact they apparently designed a device that wouldn't work, and yet it did implies something screwy is going on in the experiment.

*I assume this is the problem you were referring to, Anthony. I don't really have the physics background to think up any other issue with it being closed and at standard atmospheric pressure (aside from being at atmospheric pressure doesn't lend itself well to figuring out how the device would function in the vacuum of space).

[Anthony]

Originally Posted by vicky_molokh

Having that from NASA seems weird. Genuinely bad experiment control by NASA, or just a badly-written article?

NASA has actually produced a fair amount of crap, it's not really that shocking (sadly).

Originally Posted by Varyon

*I assume this is the problem you were referring to, Anthony.

There are multiple mechanisms that can result in pushing air around (heating or ionization, mostly, but I'm not going to exclude other options without more data), which is why you should test in a vacuum.

[0B1-KN0B]

This does look a bit like another form of the ion wind effect. I've just glanced at a couple of articles about this, but if it's been tested in an atmosphere I'd guess someone's just reinvented the ionocraft. Again.

I stated out a realistic reactionless drive for GURPS once - 'Realistic' meaning it had the same performance as a pure photon drive. I got something like .0001 or .00001 g (Can't remember exactly offhand) for 6 Power Points, assuming 1 PP represents 50 kw output per ton of spaceship. By that standard 30 Newtons per watt is spectacular.

(Note: Take my estimate for a photon drive with several grains of salt. Math is not my strong point.)

[Dwarf99]

Originally Posted by vicky_molokh

Having that from NASA seems weird. Genuinely bad experiment control by NASA, or just a badly-written article?

Considering the OP quotes WIRED, and I've only seen another article about it on IFLScience, I'd0 say it's mostly a bad article.

[Ulzgoroth]

Originally Posted by Anthony

Both of those things are fatal errors. They're getting the appearance of thrust from bad setup, not any real effect.

From elsewhere, I've seen it claimed that the 'negative control' there had a change that should have prevented it from working based on a particular theory about how it works, making that not so fatal on an experimental level.

Not having tested in vacuum is a pretty serious flaw though.

[Anthony]

Originally Posted by Ulzgoroth

From elsewhere, I've seen it claimed that the 'negative control' there had a change that should have prevented it from working based on a particular theory about how it works, making that not so fatal on an experimental level.

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.

[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.