Author Topic: EM Drive Developments Thread 1  (Read 795066 times)

Offline frobnicat

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Re: EM Drive Developments
« Reply #1560 on: 10/06/2014 08:37 AM »
Also (too lazy to search) it was made mention to AC...

I thought it was all AC.  Where's the DC coming from?


From this post :
4)  Of course not.  Sonny would never agree to test one of Woodward's designs.​  All of the ZPFers believe they are in competition with M-E physics.  Despite Sonny has had MLT's on the balance at Eagle, he would NEVER run them with AC the way they were designed.  The QVF model states these ought to produce thrust when driven with DC, and that is all he checked.  IIUC, he got a null result except for the switching transients which ought to produce thrust according to M-E theory.
So "White DC vs Woodward AC" if I get it. This DC wasn't clear, indeed, and I wanted to ask before... my assumption is that "DC" is stationary RF signal (not DC strictly speaking, more like RF AC at constant amplitude) and "AC" would be some kind of modulation (amplitude ?) or transient of the RF signal. What are the modulation characteristic from this Woodward's camp AC, amplitude, frequency, shape ? Anyone ?

Offline Mulletron

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Re: EM Drive Developments
« Reply #1561 on: 10/06/2014 08:47 AM »
Also (too lazy to search) it was made mention to AC...

I thought it was all AC.  Where's the DC coming from?


From this post :
4)  Of course not.  Sonny would never agree to test one of Woodward's designs.​  All of the ZPFers believe they are in competition with M-E physics.  Despite Sonny has had MLT's on the balance at Eagle, he would NEVER run them with AC the way they were designed.  The QVF model states these ought to produce thrust when driven with DC, and that is all he checked.  IIUC, he got a null result except for the switching transients which ought to produce thrust according to M-E theory.
So "White DC vs Woodward AC" if I get it. This DC wasn't clear, indeed, and I wanted to ask before... my assumption is that "DC" is stationary RF signal (not DC strictly speaking, more like RF AC at constant amplitude) and "AC" would be some kind of modulation (amplitude ?) or transient of the RF signal. What are the modulation characteristic from this Woodward's camp AC, amplitude, frequency, shape ? Anyone ?
My long post above puts M-E'ers and ZPF'ers on equal footing.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Mulletron

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Re: EM Drive Developments
« Reply #1562 on: 10/06/2014 08:51 AM »
3 words. RC time constant. DC works too.

You charge the cap then discharge the cap. Do it fast and you have an oscillator and it becomes RLC.
« Last Edit: 10/06/2014 09:00 AM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline frobnicat

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Re: EM Drive Developments
« Reply #1563 on: 10/06/2014 09:16 AM »
Now with a very very scarce medium, the amount of mass/s that can be swallowed by the thruster is so weak that it takes very high ejection speeds to get a thrust level of any significance. When the scarcity of the medium implies relativistic ejection velocities to get interesting thrust, then the fact need [my edit?] to use a medium mass at all becomes irrelevant because you put more energy as kinetic energy than the energy equivalence of harvested mass : if you have that much onboard energy to spend on kinetic energy of the jet, then just creating the rest mass (from energy) of what you are ejecting becomes a negligible term. You are almost as good with a photon rocket and ignoring the medium.

Having had a propeller beanie as a kid, I hang on to that concept concept.  Thanking you again, I continue:.

If it is to be a ramjet, then the intake has to be physically very large.  You can't make it out of matter, you'd have to somehow project a field to harvest the DM as you move thru it, and maybe condense it.  You'd have to start the ramjet going somehow (boom boom Orion?), and discard that stage when the ramjet starts working.

Anyhow, it would not be pushing on the quantum field, and it would have a tailpipe.  I'm thinking you can't suck it up, you have to move thru it.

I'm trying to visualize what a useful spacecraft might look like. Which may be uncomfortably close to speculating about benign wormholes, but hey.

Nearest concept is Bussard ramjet. Since DM appears near impossible to harvest at least at parts per 10^15 within a device, net fishing DM on large spans with fields only is very speculative. You don't necessarily have to move through it as most likely it's already moving through you. Depending on what centre of mass the DM is orbiting, it's speed can't be higher than equivalent escape velocity (40 km/s for yet to be proven solar system bound DM, 500 km/s for "proven" galaxy bound DM, that is at below 1GeV/cm^3) and it is likely in the same ballpark. That is, galactic DM would be in a few 10s or 100s km/s relative to sun, but this is unknown for sure.
The faster you get above this characteristic speed, the more dark mass flow you can swallow, but also the more energy it takes to push back even faster. So the limit of speed is given by some efficiency term, basically how much incoming/harvested mass can be converted to energy. I would say, assuming it's possible at all to "burn" DM mass into energy, a few % of c, but with unlimited delta V (since feeding on the way).

But the problem is the density that is so little that indeed you have to get to a few % of c before mass flow is significant enough to get decent thrust. In this sense this is like a usual ramjet, needs some initial velocity. Compared to Bussard ramjet, mm, interstellar medium would be like between 10^-4 (hot diffuse regions) and 10^6 er... er, let's say proton per cm^3. A proton is circa 1GeV, so you compare  10^-4 < 1 < 10^6

To travel through hot diffuse regions, a 100% (or even 1%) harvesting DM ramjet could be better than a Bussard ramjet. Assuming we know how to field capture DM on large spans, that we know how to burn DM. With Bussard ramjet at least we have a slight idea this can be done and how. For DM we have no idea this can be done, and how is left to SF.

Quote
All the rectifiers I'm familiar with use diodes. You can do it old school with tubes.

Riffing on the spacecraft scale for a sec:  Those tubes would be kilometers in diameter? no?

To be clear : this rectifier effect hypothesis had nothing to do with DM, was about RF AC -> DC conversion that could classically explain the results as some DC induced current loops pushing on the damping magnets.

Offline Mulletron

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Re: EM Drive Developments
« Reply #1564 on: 10/06/2014 09:31 AM »
Just want to add that the emdrive and the METS function on the same principle. METS get it wrong by not enclosing the oscillator within the cone shape. The dielectric in the emdrive acts as the oscillator, excited by the microwaves fired into it.
Challenge your preconceptions, or they will challenge you. - Velik

Offline Mulletron

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Re: EM Drive Developments
« Reply #1565 on: 10/06/2014 09:40 AM »
Quote
Riffing on the spacecraft scale for a sec:  Those tubes would be kilometers in diameter? no?

You're missing the point of the axion approach. The experiments are looking for photons appearing within an oscillating magnetic field by adding energy to theoretical dm axions. These axions were weakly interacting. Until they became photons! Do this within a metal cone and (?if the theories about cosmological derived inertial mass are true) then profit!
« Last Edit: 10/06/2014 09:46 AM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Mulletron

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Re: EM Drive Developments
« Reply #1566 on: 10/06/2014 09:49 AM »
Quote from: frobnicat

To be clear : this rectifier effect hypothesis had nothing to do with DM, was about RF AC -> DC conversion that could classically explain the results as some DC induced current loops pushing on the damping magnets.

Yeah those current loops could influence the damper by virtue of charge opposition, if the thing wasn't grounded properly, and if there wasn't a feedback loop built into the damper. I don't know if either of those things is true. There really isn't enough information to make any further assumptions about this kind of stuff available from the 21 page paper. We're speculating.
Challenge your preconceptions, or they will challenge you. - Velik

Offline frobnicat

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Re: EM Drive Developments
« Reply #1567 on: 10/06/2014 09:51 AM »
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!


So anyway, what that all means is: if the cloud of dark matter is composed of axions AND if they have formed (as was in some axion paper back there) a Bose-Einstein condensate, one does not need enough energy to create axions, just enough to raise the state of some.  If you do this the exitation propagates like a "phonon" in the condensate, which is a momentum transfer against the entire condensate (ie the "ocean to push against)

Highly speculative, who wants to try a calculation ?

mm, to "raise the state of some" naturally occurring DM is still limited by the very low density overall. A condensate could be useful, compared to a non self interacting medium, as there is some "aerodynamics", pressure waves... What would be the "speed of sound" in such a condensate, if such concept has any meaning for a Bose-Einstein condensate ? If it is much higher than the average speed of the medium then yes it could be like er, you know, air augmented double flow in jet engine, better thrust than what is accelerated primarily. Maybe a factor of 10 or 100 ? I don't see much above that, unless a condensate is like a "rigid plate" and push at one place is spread over a much large volume ?

Personally, from my little calculations above, and given the likely <<1 coupling factors with DM I would still discard any explanation involving naturally occurring DM in a classical framework : not enough to account for even the weakest results at Eagle (and way off the compact drives mN better results from elsewhere).

Offline Mulletron

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Re: EM Drive Developments
« Reply #1568 on: 10/06/2014 10:12 AM »
Yes, long wavelength interaction w/ a condensate of bosons acts like a phonon generation.

It's in here: http://cua.mit.edu/8.422_S07/BECinDiluteGases205-214.pdf

My head hertz.

Somebody call NDT!


So anyway, what that all means is: if the cloud of dark matter is composed of axions AND if they have formed (as was in some axion paper back there) a Bose-Einstein condensate, one does not need enough energy to create axions, just enough to raise the state of some.  If you do this the exitation propagates like a "phonon" in the condensate, which is a momentum transfer against the entire condensate (ie the "ocean to push against)

Highly speculative, who wants to try a calculation ?

mm, to "raise the state of some" naturally occurring DM is still limited by the very low density overall. A condensate could be useful, compared to a non self interacting medium, as there is some "aerodynamics", pressure waves... What would be the "speed of sound" in such a condensate, if such concept has any meaning for a Bose-Einstein condensate ? If it is much higher than the average speed of the medium then yes it could be like er, you know, air augmented double flow in jet engine, better thrust than what is accelerated primarily. Maybe a factor of 10 or 100 ? I don't see much above that, unless a condensate is like a "rigid plate" and push at one place is spread over a much large volume ?

Personally, from my little calculations above, and given the likely <<1 coupling factors with DM I would still discard any explanation involving naturally occurring DM in a classical framework : not enough to account for even the weakest results at Eagle (and way off the compact drives mN better results from elsewhere).

Yes I agree. So by cooling the cavity to near absolute zero, I believe the efficiency can be improved drastically. Give me a few and I can back that assertion up. I already found proof of this somewhere and it is right on the tip of my tongue.

Edit:

Seems to me lowering the ground state of energy in the cavity by whatever means, be it lowering the temperature is advantageous. This is getting way too complex to make any clear predictions based of very little due to the complex interaction of temperature and geometry on casimir effects.

Here's some info I found:
http://arxiv.org/pdf/hep-th/0503100v2.pdf
http://www.nature.com/nphys/journal/v7/n3/full/nphys1909.html
http://arxiv.org/pdf/quant-ph/0511037v2.pdf
http://dspace.mit.edu/handle/1721.1/58477
« Last Edit: 10/06/2014 10:42 AM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline frobnicat

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Re: EM Drive Developments
« Reply #1569 on: 10/06/2014 10:21 AM »
Quote from: frobnicat

To be clear : this rectifier effect hypothesis had nothing to do with DM, was about RF AC -> DC conversion that could classically explain the results as some DC induced current loops pushing on the damping magnets.

Yeah those current loops could influence the damper by virtue of charge opposition, if the thing wasn't grounded properly, and if there wasn't a feedback loop built into the damper. I don't know if either of those things is true. There really isn't enough information to make any further assumptions about this kind of stuff available from the 21 page paper. We're speculating.
Charge opposition ?
Trying to clarify : see attached picture (?)

Yes we are speculating. Just dropping another strong magnet in the chamber, seeing the difference in measured result (when subtracting the new different DC power stray force) would be enough to tell if the permanent B field plays a role at all in what is reported as the real thrust...

edit :
the assumption here is that the strong E fields (because high Q) can make some kind of tunnel diode effect somewhere around the dielectric (it was even considered electric breaking so...) The drawing is simplified, there could be a lot of loops, or a lot of small rectifier effects here and there in a bigger loop, there could be a (not perfectly conducting) path parallel to such diode(s) lowering the magnitude but not shunting it to 0...
This hypothesis needs around 1 or 10 mA DC component on a significant span (macroscopic, not microscopic) to work at the needed magnitude  (from F = deltaB I length, deltaB is given by the gradient of permanent B at the loop's span, forward/backward parts of current). Don't know if it holds water at all, was just an idea.
What would be the AC intensities bouncing the waves off the cavity walls, at skin depth ? If this is >>1mA because high Q pumps up the magnitudes, then a small rectifier effect could make enough of DC from this AC.

@Mulletron : I understand a dielectric is an isolator (perfect ?) and can't accommodate a DC current going through its bulk volume, but what about its boundary ? What if its boundary is near (encased) in conducting cavity ? Sorry, this is very vague intuitions...
« Last Edit: 10/06/2014 11:39 AM by frobnicat »

Offline Mulletron

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Re: EM Drive Developments
« Reply #1570 on: 10/06/2014 10:21 AM »
With the aide of Mach and his seminal generalized interpretation of the origin of inertial mass, which informed Einstein and was elaborated on by many in parallel; I am hopeful we have graduated into a new and better world. The problem of EMdrive appears to me as no longer a question of a theoretical problem and has become an engineering problem.


I am confident in that there is such a wide body of knowledge from many great thinkers supporting an extrinsically derived value for inertial mass. It doesn't even matter who is right, as long as one of them is.

HOPEFULLY the EMdrive passes further tests of replication.

The attached pic is my rendering of how I picture the most optimal shape of the apparatus informed by the (difficult for me to grasp so I might have got it wrong) casimir interactions inside/outside 3d shapes, combined with the light cone. So the cone is 45 degrees, the dimensions are wrt dominant TE/TM modes discussed back in the thread, the end is a half sphere instead of flat for a reason; as two casimir spheres attract; the other sphere being the Rindler Horizon. The cone I interpreted as being less attractive with the Hubble sphere than the sphere shape, but internally repulsive to itself. The net effect outside is an inertial bias toward the half sphere end of the device. The net effect inside is the opposite. ..More inertia on left sphere side, gives rise to an energy bias inside the system. Particles moving from skinny to fat end gain energy, unbalance occurs, the system moves toward the pointy end. I hope I got all that right. This is all informed by many other people's work. This is my interpretation.
« Last Edit: 10/06/2014 02:34 PM by Mulletron »
Challenge your preconceptions, or they will challenge you. - Velik

Offline Rodal

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Re: EM Drive Developments
« Reply #1571 on: 10/06/2014 12:04 PM »
With the aide of Mach and his seminal generalized interpretation of the origin of inertial mass, which informed Einstein ...

<<With the aide of Mach >> (Ernst)

perhaps

"With the aide of March" (Paul)

we can get the damping value (N s/m) for the NASA Eagleworks inverted torsional pendulum experiments. 
« Last Edit: 10/06/2014 12:06 PM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1572 on: 10/06/2014 12:11 PM »
With the aide of Mach and his seminal generalized interpretation of the origin of inertial mass, which informed Einstein ...

<<With the aide of Mach >> (Ernst)

perhaps

"With the aide of March" (Paul)

we can get the damping value (N s/m) for the NASA Eagleworks inverted torsional pendulum experiments.

As long as we're getting picky about individual letters, are we talking about someone who helps another, or are we talking about "tribute paid by a vassal to his lord"? (Per definition 4, Webster's seventh, New Collegiate)
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1573 on: 10/06/2014 12:14 PM »
I estimate that an experiment could be put together for less than $2000 of parts.

Looks like you're batting a thousand on the "likes", but $2K is hopelessly optimistic.  Last time I looked, I needed $4K for a decent workstation.  Still, thanks for posting.
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Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1574 on: 10/06/2014 12:17 PM »
... i was like message boy ...

You still don't get it, do ya?  Take a weekend trip to AZ, and get a sense of Yuma.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1575 on: 10/06/2014 12:18 PM »
John Fornaro had mentioned something about black hole drives

It's true that I drive a '92 black 240 wagon.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1576 on: 10/06/2014 12:20 PM »
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1577 on: 10/06/2014 12:24 PM »
I find it hard to believe he has confused mass energy [equivalent rest mass energy, I believe is what he meant]  within the atom with energies of covalent bonds.

They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.

From a grammatical standpoint, it's [note spelling] all material.

However, while it may indeed be factual that equivalent rest mass energy and equivalent covalent bond energy may be indifferentiable in numerical principle, that the magnitudes of the energies involved are so divergent; they are most definitely not "immaterial".
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1578 on: 10/06/2014 12:31 PM »
...Remember that mass is constrained over space and energy is constrained over time! ...

The particles inside have a momentum on a gradient.

Another way to think of the inside of the emdrive cavity is to picture it as its own little universe with a slightly modified space manifold, such that there is an asymmetry in parity.

And they really want to equalize, so the thing moves to compensate. Just like McCulloch said.

Boom!

Now I'm going to obsess over the charge component of CP symmetry.

Phew.

It's own little universe?  Are you sure?  How can that be?
Sometimes I just flat out don't get it.

Offline Mulletron

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Re: EM Drive Developments
« Reply #1579 on: 10/06/2014 12:34 PM »
I find it hard to believe he has confused mass energy [equivalent rest mass energy, I believe is what he meant]  within the atom with energies of covalent bonds.

They're the same thing.  They both gravitate and have inertia.  The scale is wildly different, but that's immaterial.

From a grammatical standpoint, it's [note spelling] all material.

However, while it may indeed be factual that equivalent rest mass energy and equivalent covalent bond energy may be indifferentiable in numerical principle, that the magnitudes of the energies involved are so divergent; they are most definitely not "immaterial".

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

They are not the same thing in our universe. They are symmetric. This is why electrons instantaneously jump from between energy levels. They tunnel and this is KEY.


Edit:
An interesting implication of this is that there is only one electron in the universe. More on that later. My brain is overheating.
« Last Edit: 10/06/2014 12:44 PM by Mulletron »
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