Author Topic: EM Drive Developments Thread 1  (Read 796076 times)

Offline JPLeRouzic

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Re: EM Drive Developments
« Reply #340 on: 08/17/2014 01:39 PM »
@Frobnicat: First I apologize, English is not my native language. Second: I understand your concern about this topic and how an explanation based on energy conservation could have been misinterpreted as validating the propellantless thruster. The difficulty indeed is that energy is poured in this device and something must happen. However given the very low level of thrust, I find it perfectly possible that this energy is dissipated as heat and therefore, given the assymetry of the device, it warms air more on one side than the other, hence the net thrust.

On contrary it seems to me, that it is impossible to use the conservation of energy as an explanation of the EM drive (or other propellantless thruster) as it would in this case produce much more thrust that people claim it does. A simple RC plane or a RC car use less power for a similar mass and gives visible results, no need for ad hoc extra sensible torsion pendulum  :).
 
@ChrisWilson68: I think that you may have not read my whole post and stop after the first phrase.

My point isn't that a magnet produces some energy, it does not indeed. It is that the given explanation is circular, and I provided another explanation based on energy conservation.
By the way I am sure a modern definition of energy is not "energy is force by distance". What is important and much more modern is that energy is conserved. It was on this premise that I gave my explanation.
« Last Edit: 08/17/2014 01:44 PM by JPLeRouzic »

Offline IslandPlaya

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Re: EM Drive Developments
« Reply #341 on: 08/17/2014 02:05 PM »
The CMB frame of reference is a physical entity.
I'll make no bones about it.
My assertion is wrong.
Thanks guys.

Offline Robotbeat

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Re: EM Drive Developments
« Reply #342 on: 08/17/2014 02:53 PM »
Props for that, Island!
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #343 on: 08/18/2014 01:41 PM »
Says me, yes.
Think about it carefully.
When you have, get back to me.

Just read the oracle.  Sheesh.

http://en.wikipedia.org/wiki/Cosmic_microwave_background

Still, a frame of reference is a different sort of physical entity than say, an apple, subject to gravity.

I keep thinking that there is an ether.  I'm just a nineteenth century guy, I guess.
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #344 on: 08/18/2014 01:41 PM »

How can magnets attract or repel each other indefinitely without expending energy?

Nobody completely understands magnetism either.
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #345 on: 08/18/2014 01:42 PM »

No movement - no impulse. I mean, it is IMHO comparable to a book standing on a table. No-one would imply that the book were to 'violate' impulse conservation in any way ;) . So, what's going on here?

The area that Woodward is looking into regards having a better understanding of inertia.  Sciama holds a theory, based on Mach's work, that the entire universe immediately pushes back on the book, so that, in principle, one can discard the table entirely.  Basically, Woodward is attempting to convert electricity into momentum.  Electricity goes into his device, and then the device moves forward, if not otherwise bound by gravity.
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #346 on: 08/18/2014 01:42 PM »
I think one has to be careful when calling found physical principles 'laws'. They are not laws in the absolute sense, as in given by 'God', or being the final answer. The only thing we can say about the principles that we found and verified by peer-reviewed experiments up to any given point in time is: To the best of our current knowledge, this is what happens. A very important point to make.

Just want to add the observations of C.S. Peirce, who has suggested quite some time ago, that the "laws" of physics might be "habits", and that they change over time.

The gravitational constant, it turns out, is not exactly constant, but appears to vary.

I also want to point out that inanimate interpretations of the beginnings of the universe and evolution are as faith based as any other interpretations.

[Edit: Inadvertently forgot to include the important word "beginnings" of the universe, as was pointed out below.]
« Last Edit: 08/21/2014 12:40 PM by JohnFornaro »
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #347 on: 08/18/2014 01:42 PM »
"But physics can't be bypassed," you say - well who can claim omniscient knowledge of physics? There may be small exploit opportunities which can be exposed here and there.

Then find them and exploit them.  At least Mr. Wooward is making an attempt.  By my reading, few physicists claim omniscient knowledge of physics.
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #348 on: 08/18/2014 01:42 PM »
i have seen people here pan fusion propulsion.; a likely possible near term advancement.

Fixed that for ya.

It is more likely that fission drive (Boom-boom Orion) is near term than fusion drive.  My objection continues to be the careless, unsubstantiated  use of the word "likely".

As to VaSIMIR, I'm a mite confused by all of your negatives:  It isn't that unlikely?  This drive is real, but it has not been scaled to the extent necessary to propel, say, MCT.  It is more "likely" to be a "near term advancement" than boom-boom Orion, the way I see it.
« Last Edit: 08/18/2014 01:43 PM by JohnFornaro »
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Offline Robotbeat

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Re: EM Drive Developments
« Reply #349 on: 08/18/2014 01:54 PM »

How can magnets attract or repel each other indefinitely without expending energy?

Nobody completely understands magnetism either.
(warning, language)


And for the record, we understand magnetism quite well, thank you very much. A direct consequence of classical electrostatics and special relativity.
« Last Edit: 08/18/2014 04:17 PM by Robotbeat »
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Online Stormbringer

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Re: EM Drive Developments
« Reply #350 on: 08/18/2014 02:40 PM »
i have seen people here pan fusion propulsion.; a likely possible near term advancement.

Fixed that for ya.

It is more likely that fission drive (Boom-boom Orion) is near term than fusion drive.  My objection continues to be the careless, unsubstantiated  use of the word "likely".

As to VASIMR, I'm a mite confused by all of your negatives:  It isn't that unlikely?  This drive is real, but it has not been scaled to the extent necessary to propel, say, MCT.  It is more "likely" to be a "near term advancement" than boom-boom Orion, the way I see it.
let me fix it back then: Some fusion propulsion is likely near term both because there are a couple of fusion projects that lend themselves to propulsion and because politically you will see fusion in space well before Dr Chang Diaz gets enough to put more than a satellite booster sized test article on ISS if he ever gets the chance to do even that with slipping schedules, carriers and so forth.

EDIT I need to fix it again XD.

There is one fusion project blatantly stating they are working with NASA on a fusion engine. There are other fusion projects swinging at beating ITER. one of those has mentioned using it as a power source for electric propulsion. that onion layered reactor thing with the fancy spark plug (DPF.) it's not direct fusion drive but the power source for electrical or plasma propulsion. maybe even powering VASIMR.
« Last Edit: 08/18/2014 03:52 PM by Stormbringer »
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Offline Star One

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Re: EM Drive Developments
« Reply #351 on: 08/18/2014 03:08 PM »
I think one has to be careful when calling found physical principles 'laws'. They are not laws in the absolute sense, as in given by 'God', or being the final answer. The only thing we can say about the principles that we found and verified by peer-reviewed experiments up to any given point in time is: To the best of our current knowledge, this is what happens. A very important point to make.

Just want to add the observations of C.S. Peirce, who has suggested quite some time ago, that the "laws" of physics might be "habits", and that they change over time.

The gravitational constant, it turns out, is not exactly constant, but appears to vary.

I also want to point out that inanimate interpretations of the universe and evolution are as faith based as any other interpretations.

To expand on your comment above I see there are some theorists suggesting that gravity at the massive scale, for want of a better term may not be the same as gravity at a local level and that the search for dark matter & energy could be futile. The argument goes that these latter two were invented purely as a kludge in the theory to fit the observations.

Do we even if subconsciously seem somehow to risk slipping back into almost Ptolemaic terms sometimes when discussing the laws of physics?
« Last Edit: 08/18/2014 03:16 PM by Star One »

Offline Mulletron

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Re: EM Drive Developments
« Reply #352 on: 08/18/2014 04:01 PM »
A frame of reference is relative. Just a comparison to another system. It is not a physical thing. It is a physical system, be it thermodynamic, relativistic, quantum, non/inertial, whatever. A lot of folks just assume that when frames of reference are talked about, that it must be inertial. Moreover, a frame of reference is not a container of things, just a way of comparing what is happening here verses there. An interaction with another frame of reference is an interaction with the "things" in that other frame of reference. Of course you can't push against a number 3. Numbers are more epistemological than real. Lets not be obtuse here. That did bring back memories of comparisons I read about how information/energy/matter are equivalent though, and how an AND logic gate will convert that lost bit of information to heat energy, but I digress. I'm not writing about the philosophy of science.

So back to the thruster and how frames of reference are key.

I previously talked about two other qv interactions with matter, the Lamb Shift and Casimir. Here's another possible one. So I read into the controversial Unruh effect that says roughly, in an accelerating frame of reference, virtual particles observed outside your frame of reference (be it stationary or slower) may appear to become real particles. The vacuum of the stationary frame of reference as seen from the accelerating observer appears to contain some real particles. Now in your local yet accelerating frame of reference, virtual particles are there happening around you but aren't observed as "real." Meaning they don't stick around long enough to become real. Meaning you can't do jack with them. But there's hope. Thankfully because acceleration is relative, an observer outside of your frame of reference will see your virtual particles become real. That doesn't help us either, but the methodology is key. As you know, frames of reference are relative.

So I flipped it. How about this: We live in an accelerating universe. Our universe is accelerating at rates which we cannot ever hope to achieve. Furthermore, the rate of expansion is a curve, meaning galaxies further away are flying apart faster than the ones flying apart closer to us. Neat. So from the point of view of the universe, which is the accelerating frame of reference, our emdrive is accelerating slowly, compared to say the CMB frame of reference.

So lets imagine ourselves on a spaceship in Earth orbit and you are equipped with our brand new emdrive technology. From your frame of reference you are barely moving compared to the accelerating speed of universal expansion happening around you. So imagine yourself inside your space ship and you're looking intently at your prototype emdrive looking for real particles to appear out of the qv fluctuations, you don't see them. Now imagine the universe is the observer. The universe observing your emdrive would see some virtual particles from the qv becoming real. This only works if the universe is expanding. So with this mechanism, you get some arbitrary flux of real particles from the qv frame of reference (I'm assuming the qv and its randomly produced particle pairs are not inertially related to our inertial frame of reference) popping into your local frame of reference (as observed from the point of view of the universe). So I'm picturing the pair production happening randomly, becoming real, and immediately flying away at a rate matching the speed and direction of the expansion of the universe minus the influence of gravity, isotropically. My head hurts.

This next part I'm iffy on too: So since the universe has no center from where to measure expansion or acceleration against (correct assumption?), does it make any difference what the acceleration of the space ship is? Would accelerating the ship result in a gain in particle pair longevity? I don't think it becomes an issue until you get near relativistic speeds. Is it possible to accelerate, or are we already accelerating at a rate faster than the LOCAL expansion rate of the universe as seen within the bounds of the emdrive? Is gravity keeping the expansion of the universe in check at small scales? Would accelerating the ship increase the real particle longevity flux? I don't know. Maybe doesn't help anyway. All of this depends on whether the Unruh effect is real or not.

I personally don't have much confidence that this is what is happening, I'm just brainstorming this approach. I think the logic above would have us all awash in real particles all the time. Maybe that's where matter comes from, lol. Maybe that's what boggs us down when approaching the speed of light. The thoughts above concerning the Unruh Effect are just concerned with creating real particles to interact with and I believe the effect is probably small solely because it is controversial. I think it could be small part of what's happening. I read somewhere that a very large charge field within a highly polarized dielectric medium stimulates pair production, which could in turn become real. I think that most of the effect stems from directing the poynting vector of a very strong rf field down the axis of desired acceleration through a dielectric is causing a transfer of momentum in a way I don't fully understand. I disagree with the shape of the bell/pill box on the two drives tested as I think they are unnecessary. I think they should take design cues from coaxial cables, only terminating the end in a way to scavenge the rf for reuse back into the top of the thruster. I think a resonant standing wave doesn't do much for the thruster and that max rf energy flow is key. I'm picturing a bundle of cylinders arranged into a honeycomb shape, with rf distributed into the top and the other ends capped off with a door knob type of rf probe as a pick up. The energy density of the cmb peaks at around 160ghz. I'm not sure if a frequency matching it would be helpful or not. It would make for a very small wavelength, and all the design implications that go along with it.
« Last Edit: 08/18/2014 04:13 PM by Mulletron »
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Online Stormbringer

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Re: EM Drive Developments
« Reply #353 on: 08/18/2014 05:24 PM »
i didn't think Unruh was all that controversial anymore? i think I have seen it outside the usual speculative propulsion related stuff. i thought it was scientifically established?
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #354 on: 08/18/2014 05:46 PM »
Just wanna add that we understand quantum mechanics "quite well" too.  Nobody claims complete knowledge of QM or magnetism.
« Last Edit: 08/20/2014 02:41 PM by JohnFornaro »
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Offline Robotbeat

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Re: EM Drive Developments
« Reply #355 on: 08/18/2014 06:02 PM »
Just wanna add that we understand quantum mechanics "quite well" too.  Nobocy claims complete knowledge of QM or magnetism.
No, we understand exactly what's going on in magnetism. We also under QM fully, too, it's just very counter-intuitive. Just because you don't understand it and just because it takes a lot of effort to understand it doesn't mean it isn't understood.
« Last Edit: 08/18/2014 06:08 PM by Robotbeat »
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Offline IslandPlaya

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Re: EM Drive Developments
« Reply #356 on: 08/18/2014 08:12 PM »
Just wanna add that we understand quantum mechanics "quite well" too.  Nobocy claims complete knowledge of QM or magnetism.
No, we understand exactly what's going on in magnetism. We also under QM fully, too, it's just very counter-intuitive. Just because you don't understand it and just because it takes a lot of effort to understand it doesn't mean it isn't understood.
Nit picking.
We *don't* understand QM fully. It is obviously incomplete.
Gravity etc.

Offline frobnicat

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Re: EM Drive Developments
« Reply #357 on: 08/18/2014 11:45 PM »
What we do know from innumerable experiments is that in a broad range of contexts QM is phenomenally accurate. This broad range includes all mundane particles, real or virtual, with energies up to a few 10s of Gev in any locally linearisable space-time. The fact that GR is a separate formalism doesn't prevent both theories taken together to be effective and precisely verified at predicting measurable outcomes in all but the most distant or artificially unattainable circumstances. The remaining phenomenological mysteries below extreme energies and/or gravitational curvatures might come from neutrinos or weakly interacting particles like dark matter, but they are precisely very weakly coupled to EM fields, otherwise their absence or uncertainties in theories would seriously limit the predicting power of SM which appear is not the case even with higher and higher precision measurements. There's still room for surprises, proton radius appear different when orbited by muon rather than electron. But overall the formalism looks solid and can accommodate extensions, as was and still is classical mechanics in its own range of validity. It's still insufficient by itself to mechanically tell all that can/will be done/discovered with arrangements of lot of particles (ie condensed matter properties...) at "emergent" scales but it certainly has some credit to tell that an arrangement of particles can't globally break a law that is experimentally shown to be respected at every single interaction point. There is a reason why some laws are called fundamental, and it's not a matter of scientists acting as prosecutors to enforce them, it's deeply embedded regularities of reality as it is observed.

So while we don't understand all QM at the frontiers of its validity and beyond, we do know quite well experimentally where the frontiers are, and while the interpretation of QM (the why or the what) is still hotly debated, the empirical predictive power speaks for itself and naturally entails much scepticism from mainstream physicists when a device consisting only of low density microwave photons bouncing around in ordinary matter claims either momentum conservation breaking or transferring momentum to vacuum (which in the later case is taping energy from the vacuum since vacuum is so far so very well experimentally confirmed to be inertial frame invariant).

Clearly if such thrust effects are worth investigating, then they are worth more than a week of a small team (speaking of the latest NASA experiment), and while I would say that they did a terrific experimental job given such a short time and limited resources, indulging themselves in "what if" scenarios of missions at the end of the paper does not serve them in terms of credibility : you can't write such a result and pretend to ignore how it is flying in the face of established physics before it flies to Mars, this is not serious and maintains the idea that such research is fringe science and not worth considerations. I wish despite this clumsiness they are granted more time and resources to either get a decent 0 net thrust measurement result, or a Nobel prize.

Offline Raj2014

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Re: EM Drive Developments
« Reply #358 on: 08/19/2014 12:31 AM »
Has there been any new news on the EM/Cannae drive?

Offline Robotbeat

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Re: EM Drive Developments
« Reply #359 on: 08/19/2014 01:01 AM »
Just wanna add that we understand quantum mechanics "quite well" too.  Nobocy claims complete knowledge of QM or magnetism.
No, we understand exactly what's going on in magnetism. We also under QM fully, too, it's just very counter-intuitive. Just because you don't understand it and just because it takes a lot of effort to understand it doesn't mean it isn't understood.
Nit picking.
We *don't* understand QM fully. It is obviously incomplete.
Gravity etc.
We don't have a theory of quantum gravity, but that'd be an extension of QM. QM itself we understand quite well and is complete. It doesn't have to be the theory of everything to be complete.

Anyway, I'm quitting this thread. In the words of Antares, I'm through arguing with amateurs. People want to skip learning regular physics that we already have a 100% understanding of and instead argue about fringe theories and physics beyond the standard model. It's ridiculous. You can't prove physics is wrong and incomplete until you actually understand physics! It's not like it's secret knowledge or something. The only reason people skip it is because they're lazy.

In a parting shot, I've seen this proposed as the Fourth Law of Thermodynamics:
« Last Edit: 08/19/2014 01:07 AM by Robotbeat »
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