[Shade]

Now that's interesting. Never heard of it before, but it's way cool. There's even instructions for building your own... almost makes me wish I was back in college so I could nag my physics teacher about spending some lessons building one

The really interesting thing is though, that as far as I could read noone really knows why it works, they just know that it does. And mysteries like that are what makes science worthwhile to keep up on.

[Nuke]

if theese things are so common, wtf arent we using them already?

[Shade]

I'm thinking the fact that they require 30-40kV to work, and clearly need a lot of capacitors drawing that to lift just 60g. Kinda not very handy, having to lug around a nuclear powerplant just to make your car hover.

[Turnsky]

remember folks, Feasable from a scientific perspective is one thing, Feasable from an Engineering perspective is another.

[Nuke]

after some research on those other devices i can understand why were not using them, we have motors that can do the job many times better, and they dont work in space because theres no atmosphere. still the emdrive, as its called, has some potential.

[Bobboau]

sort of like an atmosphereic ion drive.

[Descenterace]

A repulsive force between two plates is not quite the same thing as a force applied to the whole system. The emdrive is not in the same league as the capacitor-based lifter for this reason.

Also, simple magnetism is a more powerful lifter than capacitance. The difference is that an electromagnet requires current, while that capacitor just requires charge. if you can stop it leaking, it requires almost no actual power.

[Herra Tohtori]

after some research on those other devices i can understand why were not using them, we have motors that can do the job many times better, and they dont work in space because theres no atmosphere.

Um...

They do.

At least that's what is claimed on this page: This apparatus has been tested in June 2001 by Transdimensional Technologies in the vacuum chamber of the NASA Marshall Space Flight Center ( MSFC ) in Huntsville.

I suppose they really have tested it.

The thrust doesn't seem to be generated by throwing anything "backwards" in this case, despite the utter wierdness of that as concept. Like I said, these things are the true von Munchausens, lifting themselves in air by pulling themselves from hair.

[Nuke]

damn them things are cool. hook a bunch of those up to a nuke reactor and call it a space ship.

[Colonol Dekker]

Does that gizmo need a gravity field to repel against, If so do we need to tie a moon to the arse of the gadget?

[Fragrag]

arr, this thread was already complicated and now in pirate talk

[Ashrak]

this is now well funny thread

[Flipside]

Picture 3 Pirates sittin' round a table in a bar....
 

If we discount th' fact wot this 'ere 'ere is in blatant violation o' all physics (mainly th' conservation o' momentum, which in many way is th' physics, this 'ere 'ere kind o' technique would have several major advantages in space travelin', compared t' rocket engines or ion engines or anythin' wot uses propellant t' create equal an' opposite force.  This 'ere 'ere law says wot th' momentum o' a closed system is constant, period...

[Herra Tohtori]

after some research on those other devices i can understand why were not using them, we have motors that can do the job many times better, and they dont work in space because theres no atmosphere.

Um...

They do.

Disregard my last...

I have gotten information that suggest that these things indeed do not work in vacuum - unless you pour ionized gas into vacuum chamber, which kinda negates the whole idea of a vacuum.

Regardless of that qualm, it would be interesting to actually build a functional lifter... Hmm, I've got an old Sony Trinitron TV sitting right there...

[Shade]

Space isn't a perfect vacuum though, especially near the earth. I wouldn't be surprised if they could still be useful for stationkeeping and minor maneouvering for satellites, since those things can be done quite well with just miniscule amounts of constant thrust over several weeks or  months.

[Herra Tohtori]

Not a chance. It's bloody well enough vacuum to have so little density that it wouldn't really generate any thrust.

So, effectively, these things are nothing more than a primitive ion engine - which was already utilized magnificently in Deep Space 1 probe, for example.

In atmosphere they just use the ionized air molecules as propellant - not unlike jet bypass engines (and traditional propellers of course) use mainly air as propellant, while rocket engines use only exhaust gases, and similarly ion engines have their own propellant ion source with them.

[Shade]

It wouldn't need to generate any significant thrust to still be useful for stationkeeping. Consider that the ISS for example has a low enough orbit that it is constantly subjected to atmospheric drag, so there's definitely something there. Now, the ISS in particular doesn't need it since anytime a spacecraft docks, they spend their reserve fuel boosting it. But for satellites in a similar or lower orbit it might be workable, as they'd only need a couple of grams worth of thrust to counteract the drag if said thrust could be maintained for months on end.

It could definitely never be used for anything sudden, such as docking operations between the shuttle and the ISS, but stationkeeping is a different ballgame.

[Herra Tohtori]

I don't think they could be used in tat purpose even.

Even negating the effect of air drag with these lifters in mentioned air pressures would most likely need so much power that the ISS's panels wouldn't be able to produce that much energy.

If they really did work in vacuum with same lift capacity as they do in atmosphere, then it would be a different matter altogether. But, as things seem to be, you would need to give them ion supply (propellant) to use in the thrust-generating process, and ion engines would do the same thing more efficiently.

Anyway, it is actually easy to test whether or not these things are based on conservation of momentum or some currently unknown principle producing lift from electric potential.

1. build a functional lifter.

2. build a thin-walled box (ie. from light wire and plastic foil). Make sure that the lifter can actually lift the weigh of the box - just set the box on top of your lifter and if it can keep both of them aloft, it's time to do the actual experiment.

3. Place the lifter inside the box.

4. Turn on power. The lifter should rise to the roof of the box; what happens after that defines the quality of the thrust produced.

4a. If the lifter stops to the roof of the box and doesn't lift the box (remember that the capacity of the lifter would lift the box), then it's because of the fact that the box is sufficiently closed system that even though the lifter lifts itself inside the box, the box-lifter system doesn't propel anything downwards and thus doesn't rise.

4b. If the closed box rises with the lifter, then it is indeed some unclear principle causing thrust that makes it possible for the lifter to lift the combination.

Simple and easy experiment. Also applies to this new kind of thrust producing device mentioned in pening message of this thread.

It's simpler to arrange than a high quality vacuum chamber, too. And cheaper...

[Nuke]

after some research on those other devices i can understand why were not using them, we have motors that can do the job many times better, and they dont work in space because theres no atmosphere.

Um...

They do.

Disregard my last...

I have gotten information that suggest that these things indeed do not work in vacuum - unless you pour ionized gas into vacuum chamber, which kinda negates the whole idea of a vacuum.

Regardless of that qualm, it would be interesting to actually build a functional lifter... Hmm, I've got an old Sony Trinitron TV sitting right there...

got a link? ive been curious about theese things sence you posted them and my research indicated they did work in a vaccume.  am i missing something?

[Herra Tohtori]

Well.

I've actually gotten controversial information about these things.

Obviously, the web pages say they should work in vacuum as well as in atmospheric conditions. Otherwise, there's no clear experiment results seen that I could easily found.

However, Jean-Louis Naudin has apparently been behind multiple other... interesting... things that have turned up more or less fraudulous. Things like cold fusion, water fuel, the usual free-energy stuff that does not exactly invoke my trust. Thus, I have my doubts of whether it works or not.

So, some claim it works, some claim it doesn't work.

The only SURE way of knowing would be to conduct an experiment myself, and I might actually do just that some day.

It's simple really. The experiment I described earlier would define without a hitch whether the device uses conservation of momentum to produce thrust or takes advantage of som unknonw phenomenon.

Put the lifter into a closed box and measure the weight of the box when lifter is on, and when it's off. When the lifter is turned on, it should rise to the roof of the box.

However, if the device works along conservation of momentum, the box will still weigh the exact same as when the device is off.

This experiment would pretty well tell whether or not it would work in vacuum as well, because if it "lifts" the box (ie. reduces the weight of the closed box), then it seemingly breaks the conservation of momentum, and then it would also work in vacuum in this case - though I doubt this scenario.

This experiment would be relatively easy to do with a sensitive scale to measure weight. Only difficulty would be to aquire high-voltage supply. I'm not actually comfortable with meddling with CRT monitor/television PSU's... But on the other hand, it seems that net pages really cannot be trusted in this kind of matter. I would have to do the experiment myself to be sure of the results in one direction or another.

And perhaps, perhaps I will, too.

It's getting into me... Perhaps I will build the device and perform the experiment in physics student laboratory in Otaniemi. I bet I could find a high voltage supply there - different thing is, would I be allowed to use it.

Be assured that this forum will be one of the first places I'll post my experiment's results. I know how to make the experiment; the only thing I'm lacking is high-voltage PSU - that is, if I don't disassemble that television sitting on my desk one metre on my left.