Propellantless propulsion, apparently.

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Send out a positively charged stream of nuclei for thrust and use electron guns to correct the imbalance.
 
Billy T said:
You do not understand how ion dirves (at least those with any significant thrust) work. Despite the name, they do not throw out ions (at least not ions of one charge only). If they did the space craft would be come oppositley charged and after traveling some distance from it they would stop and accelerate back to the ship producing no net thrust.

I do not know the details, but in some way what is ejected must be electrically neutral. Perhaps if positive ions (hydrogen nuclei or protons would be best) are thrown out you could also eject an equal nuber of electrons, but most of the electrons would soon combine with the protons to make hydrogen so effectively you are throwing out, as exhaust, fully ionized hydrogen plasma, which cools and becomes hydrogen gas, certaily a "chemical." - the most abundant one in the universe.

I have read of some systems where even before the ion beam leaves the space craft, it is neutralized to make higher than any chemical fuel specific impulse thruster, but again you are throwing out a "chemical" as your exhaust.
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Oh fuck off.
 
I am having difficulty pronouncing the title of this thread. It is pretty interesting though. :cool:
 
Billy T said:
This is nonsense. Every thing you said about photons banging into the "properly shaped" chamber is also true it it is filled with helium gas atoms - each time they hit the wall they too apply a force to it. Do you really think some shape exists that if you fill a sealed chamber of this shape, with either photons or a gas, it will try to move due to the "internal force imbalance"? As I said, non-sense.
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the idea that the shape of the cavity, results in inbalances of the forces involved is not my idea...

its the fundamental basis of the devices supposive operation.

the waves speed up when they enter the wide side.. and slow down when they enter the smaller side.. thus the force displacement.

its not MY idea... im just commenting on it.

and who said anything about helium?

-MT
 
Mosheh Thezion said:
all the starwars technology of floating vehicles could be ours.
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Those vechiles already exist and have been for decades, what we're seeing in these kinds of reports is the public sector finally catching onto the technology.
 
Mosheh Thezion said:
and who said anything about helium?

-MT
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I think the point is if this device work by momentum transfer from photons, so what about momentum xfer from a pressurised gas such as helium? Well, we know that no matter shape we make a container for a pressurised gas, it isn't going to move in one direction due to the impacts of the atoms against the walls.

So why should photons act any differently?

Conservation and Asymmetry are the biggest questions in physics. Like, why did matter not annihilate with anti-matter, why do we see more matter?

If an asymmetry can be found here, it would be deeply profound. Somehow, I think the experiment is flawed, however.
 
I've been following this story for a few days. I'm about 98% skeptical and 1% curious (yes... then another 1% skeptical). The only thing that actually caught my eye was that I've yet to hear an argument (other than Newton's third) on why it doesn't work. On the other hand I have no seen their proof (of their claim) that under special relativity this effect can occur.

Let me see if I can get their claims right. Please correct me if anyone else has a different understanding:

1. This is not throwing photons out the back to impart momentum on the device. They claim that NOTHING (matter or energy) will leave the device to perform the propulsion.

2. They claim that this effect would NOT work with matter because it depends on the group velocity of the microwaves in the resonating chamber (as opposed to the signal velocity).

3. Their claim is NOT that this is an empirical device with no known theoretical backing, but that this effect is predicted by special relativity (though again I have yet to see the proof).

Did I miss anything? Is anything in their NOT what others have gotten from the articles and reports?

-AntonK
 
The relativity thing, if I get this right, means that they are trying to create a gradient in local space-time in the resonant cavity. The problem is that if the object moves relative to the local frame, the gradient changes from what they are trying to induce. They would have to retune and feed it more power to accelerate the vehicle.

In other words, they are trying to push against space-time itself. That's not so far-fetched. The entire mass of the universe is the backstop. You don't actually get away with this without emitting something. Hopefully the function coming out of the ass end is a lot smoother than the input, but there is a disturbance in space-time something like a radio wave.
 
No. I have re-read the original posts. He was incorrect. He got called on it. He had no response, except his traditional one of pretending disinterest. He is to be complimented for taking my ironic put down with good humour. That still fails to make him correct.
 
Ah. I see what you meant to mean. Yes, I had not thought about that aspect of ion engines till BillyT brought it up.

Returning more precisely to the topic, I found the New Scientist article interesting. The inventors credentials are impressive. He may just be onto something. If there is a flaw there must be one in the theory and in practice. He has, after all, measured the thrust produced by his prototype.
 
superluminal said:
Well, if this is indeed predicted by special relativity, it could potentially skirt the newtonian limitation of classical action-reaction. I don't think it does (but what the hell do I know?) but wouldn't it be a kicker if there was a relativistic group velocity loophole that could be exploited?
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Indeed, this is the reason for my 1% interest. Everyone keeps calling "Newton's Third!" "Newton's Third!" and normally I would agree except they have now pulled the one trump card... relativity. Relativity has a record of giving exceptions to Newton's laws. Yet again I repeat this is still my 1% curiousity, the remaining 99% is still skeptical.

-AntonK
 
I understand the basic concept that microwaves moving at a group velocity at, or near, 'c' will impart more momentum to the cavity surface at the 'big end' than microwaves moving at a group velocity of 1/10 'c' wrt the cavity surface at the smaller end. Newton's second law defines force as the rate of change of momentum, thus more force is imparted to the big end due to the imbalance of the forces.
What I don't understand is how the geometry of the waveguide (cavity) can change the group velocity of the microwaves as they bounce back and forth. Possibly one end could be 'in phase' and the other end 'out of phase' when the microwaves are initially injected, but how does changing the diameter of the cavity cause the group velocity of the microwaves to, presumably, all travel faster at the big end than the smaller end as they bounce back and forth? I suspect that mechanism may be above all of our levels of understanding in this forum! :p
 
2inquisitive said:
I understand the basic concept that microwaves moving at a group velocity at, or near, 'c' will impart more momentum to the cavity surface at the 'big end' than microwaves moving at a group velocity of 1/10 'c' wrt the cavity surface at the smaller end. Newton's second law defines force as the rate of change of momentum, thus more force is imparted to the big end due to the imbalance of the forces.
What I don't understand is how the geometry of the waveguide (cavity) can change the group velocity of the microwaves as they bounce back and forth. Possibly one end could be 'in phase' and the other end 'out of phase' when the microwaves are initially injected, but how does changing the diameter of the cavity cause the group velocity of the microwaves to, presumably, all travel faster at the big end than the smaller end as they bounce back and forth? I suspect that mechanism may be above all of our levels of understanding in this forum! :p
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I dont see how it would be above the forums understanding, basically the photons have to be in some way directed to a greater extent at one end of the chamber compared to the other, simple? I dont see how inteference would sway things either.
If the whole thing alludes to be beyond us, maybe it's because it's just another bit of pie in the sky like the usual free energy claims that waft by. What's the precedence for stone dropping articles in the newscientist?
 
From what I understand, the thrust is produced in a resonant cavity. The q-value is the number of times a wave will bounce back and forth without losing significant energy. The waves are preported to generate more momentum to the large end as the waves continually bounce back and forth, always increasing velocity as they 'bounce' from the small end towards the large end. These same waves are preported to slow as they bounce from the large end toward the smaller end, back and forth, over and over again. Always losing group velocity as they travel toward the small end, bounce, then increasing group velocity as they travel to the large end. That's what I don't understand, how do the waves increase group velocity after bouncing from the small end?? I assume it has something to do with some sort of interference pattern set up because of the geometery of the cavity, but this is more a guess than anything.

By constructing the cavities out of niobium instead of copper, then cooling to superconductor temps, the q-value is supposed to dramatically increase as it does in supercollider cavities constructed of niobium. Think of a 'perfect' mirror. Research by supercollider facilities indicate niobium-coated copper cavities are equivalent to solid niobium cavities, dramatically increasing the q-value. As a consequence, as more and more microwave radiation is fed into the cavaties over time, the force exerted on the large end is supposed to increase over time, eliminating the necessity of increasing the energy (microwave radiation) output of the waveguide.Supposedly one of the problems to be solved is to keep the cavity from distorting, or 'bending', because of the force placed upon the cavity ends. The large end would distort first, of course.
 
RESONANCE... the signal is fed in, at the resonate frequency of the wave motion within the cavity.
thus, with each swing of the wave energy, the input adds alittle more in perfect timing... and again and again.. always adding more than is lost in the cavity.
this is a resonate rise.

what i am curious about is the gas inside? its makeup, and whether they use any surrounding field coils in their aparatus, for that would suggest they might be utilising the gas within the chamber to applify this field energy, being ions.

this would then suggest a further means, and perhaps the secret means by which they produce the actual force on the walls.
usng the microwave field, to displace the natural pressure force in the chamber.

hummm..

-MT
 
MT, why do you assume there is a gas inside the enclosure? I'm not sure of course, but my impression from reading the 'popular press' releases was that there was a near vacuum inside the device, no gas, just resonating electromagnetic waves. Is some sort of gas necessary for the difference in group velocities of the microwaves wrt large and small ends?? Wouldn't a gas significantly lower the q-value in the cavities?
By the way, did you see the picture (presumably) of the prototype 'engine'? It is at the bottom of this page:
http://www.shelleys.demon.co.uk/fdec02em.htm
 
imaplanck. said:
What's the precedence for stone dropping articles in the newscientist?
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I can only guess at what the phrase 'stone dropping' means. I have done so.

New Scientist is very careful in this article to neither endorse, nor condemn the idea. (On some other topics they are very happy to do one or the other.) They discuss the inventors credentials, which are rock solid, and note the opinions of others experts, which range from "pure nonsense" to "potentially exciting". All in all, it is a very balanced piece of reporting.
 
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