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#980 by cuddihy on 26 Sep, 2014 02:09
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Woodward's theory (in his book) on the "propellantless" propulsion claims it needs both simultaneuously the EM flux (delta E) and the changing acceleration of the mass (delta a). In Brito's experiment I see where the Delta E is coming from but what is providing the delta a?
Or was this an unjustified modification to his theory Woodward proposed after Brito's nullification experiment?
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#981 by Rodal on 26 Sep, 2014 02:37
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Woodward's theory (in his book) on the "propellantless" propulsion claims it needs both simultaneuously the EM flux (delta E) and the changing acceleration of the mass (delta a). In Brito's experiment I see where the Delta E is coming from but what is providing the delta a?
Or was this an unjustified modification to his theory Woodward proposed after Brito's nullification experiment?
Fearn and Woodward make that statement in their recent paper (2013) "Experimental Null Test of a Mach Effect Thruster. Heidi Fearn and James F. Woodward" http://arxiv.org/ftp/arxiv/papers/1301/1301.6178.pdf.
They state, prominently in Italics, the following:
<<Note that the mass fluctuation predicted here only occurs in an object that is being accelerated as the power fluctuates. If no “bulk” acceleration of the object takes place, there is no mass fluctuation.>>
<<Note too that simply charging and discharging capacitors will not produce mass fluctuations. They must at the same time be subjected to large “bulk” accelerations>>
* When did such statements first appear in Woodward's publications?
* What magnitude acceleration is a large “bulk” acceleration according to Woodward? -
#982 by cuddihy on 26 Sep, 2014 02:41
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I've been loosely following Woodward posts here in since 2009, but the first time I saw that claim was 2011 on the talk-polywell forum.
To add--I'm not clear on the theoretical basis for it, only a claimed experimental one.
Second add--I can't find the thread but 2011-ish here or on Talk-polywell either Paul March or GIThruster said March's "MLT" experiments didn't have bulk acceleration either, so would have been invalid. Perhaps that's why they weren't tested on the Eagleworks balance.
I also have to add that whatever inertial force basis Woodward claims, it can't be gravity as we experience it every day and experimentally. You actually have to posit a new gravity-like attractive condition intrinsic to the structure of spacetime that is not "gravity", because of the specific time-travelling (or Wheeler-Feynman radiation reaction that Woodward prefers but is actually inaccurate) inertial reactions. Whatever it would be, it aint gravity. -
#983 by RotoSequence on 26 Sep, 2014 08:42
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<<The observed negative results for [Brito's EM drive] activation in non-modulated power mode, imply that the following theoretical approaches are wholly or partially falsified: Transient mass fluctuation, Thrust predicted according to Woodward’s formulation is around 3.4 mN, thus according to the results reported here no Mach induced mass fluctuation is taking place up to the sensitivity of the experimental apparatus.>>
This is the kind of disappointing outcome that I was expecting.
Does Stardrive, or anyone else working with these devices have a rebuttal, or does the "thrust" only manifest on overly complicated, magnetically dampened, inverted torsion pendulums? -
#984 by cuddihy on 26 Sep, 2014 11:34
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Rotosequence, see the above. Woodward's claim is that the Brito experiment (and some others) don't disprove the effect because they're missing the "changing acceleration of the bulk mass".
I.e. The claim is that the Brito experiment only tests half the necessary conditions for the effect to be observed. -
#985 by Rodal on 26 Sep, 2014 12:26
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*****EDIT
Some people have found the wording here to be offensive. My apologies. My intention was never to accuse anybody, I was only trying to understand this issue. An explanation has been given concerning the "MLT" type of thruster and I have since then, further understood that the "MLT" experiments in slide 40 of Dr. White were not performed at NASA.
I very much appreciate everyone else's opinion on EM Drive Developments.
October 1, 2014
****
Do people get a sense of a moving goal post ? .
When experiments do not show the predicted effect, multiplicative fudge factors ranging from 0 to 1, such that for a value of zero there is no Woodward effect, are proposed by Buldrini. No estimation is presented of what the value of the fudge factors should be.
Now a new condition is added that the effect won't manifest itself unless the drive is simultaneously accelerated by external power. When did this condition first appear in Woodward's publications?
What magnitude of “bulk” acceleration is large enough according to Woodward?
It is elucidating that we get now a recognition by Woodward that:
<<simply charging and discharging capacitors will not produce mass fluctuations. >>
This effectively recognizes that solely replacing fluctuations in the rest energy by the fluctuations in the electric power input to a capacitor is not just "overly optimistic" but invalid. See: http://forum.nasaspaceflight.com/index.php?topic=29276.msg1260795#msg1260795 He now adds the extra condition that the device needs to be simultaneously accelerated to an unspecified large enough “bulk” acceleration. The new experimental setup used by Woodward involves the linear (in voltage) piezoelectric effect and the quadratic (in voltage) electrostrictive effect in a stack of PZT disc capacitors.
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#986 by JohnFornaro on 26 Sep, 2014 13:17
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http://arxiv.org/ftp/arxiv/papers/1301/1301.6178.pdf.
This paper describes a PZT mechanism which has nothing whatsoever to do with the experimental apparatus described above.Quote from: Fearn, Woodward 2013The theory of the Mach effect thruster (MET) has been written in great detail elsewhere...
I've written a lot about the USG HSF policies and funding priorities elsewhere. While I'm certain that I make a correct assessment of these issues, having written about these issues elsewhere doesn't validate my assessment.
So too, that the ever changing M-E theory has been written about elsewhere proves nothing about its validity. There are flaws in the assumptions about the earlier theories which have been previously posted on this thread. The flaws are mathematical and procedural, particularly in the experimental apparatus.Quote from: Fearn, Woodward 2013[1] H. Fearn & J. F. Woodward, “Recent Results of an Investigation of Mach Effects Thrusters”, Joint Propulsion Conference 2012 to be published in American Institute of Aeronautics and Astronautics.
[2] J. F. Woodward “Making Starships and Stargates” Springer 2013.
They quote their own work, which is not a substitute for peer review.Quote from: Fearn, Woodward 2013Evidently, the simplest Mach effect depends on the square of the acceleration of the body in which it is produced.
Evidently, equations model reality and do not cause reality.Quote from: Fearn, Woodward 2013To start with, we wish to show that the stack (called N4) is capable of producing a linear thrust. The production of thrust depends on combining a periodic force on an object undergoing periodic mass fluctuations at the frequency of the fluctuations. You also require the appropriate phase so that the force on the object in one part of each cycle is different from that in another part of the cycle.
Ok.Quote from: Fearn, Woodward 2013(We should really multiply by a factor of 4 pi to allow for SI units but as you will see this will still lead to an underestimate.)
We should? I thought they were using SI units!Quote from: Fearn, Woodward 2013Steiner-Martins give 3.2 x10-10 mV-1 for the “d33” piezoelectric constant for the SM-111 material. That is the value of Kp. They list no value for the electrostrictive constant. But electrostrictive effects are generally smaller than piezoelectric effects [3-5]. Using the value for Kp we find
|F|= 191.4 K sub e (12)
(I used the pipe character because of HTML character conflict)
From the power spectrum we can estimate that the electrostrictive constant must be somewhere between 1/6th and 1/10th of the piezoelectric constant. If we take the electrostrictive constant to be 1/8th of the piezoelectric constant, or approximately 4 x 10-11 mV-2, we find that a thrust on the order of 8 nN is predicted. We should in fact multiply by 4π to allow for the SI units, but the observed thrust for these parameters is a couple of microNewtons.
IOW, they don't know what the electrostrictive constant is, so they assume a value, which they then don't convert to SI units, and lo, a predicted thrust is suggested.Quote from: Fearn, Woodward 2013... the condition that the capacitor restmass vary in time is met as the ions in the lattice are accelerated by the changing external electric field.
The rest mass fluctutions that may occur cannot be measured with the power levels applied to the equipment illustrated. Period.Quote from: Fearn, Woodward 2013Some of this energy is likely stored in the gravitational field...
And the rest is "likely" stored in a compressed hummoingbird wing composite? It is not a "reasonable" place to start. It appears to me that there is an alchemical faith in pentagrams being expressed here. That is, here is an equation that we have made. Let us then build a transformative mechanism which will produce the effect that the equation predicts.Quote from: Fearn, Woodward 2013The power amplifier employed was a Carvin DCM 1000 operating in bridged mode.
If I operate my Mac 275 in bridged mode, I can use it to operate a shaker table. Which fluctuates mass. In bulk. There's not enough power in their experimental setup to detect rest mass fluctuations. -
#987 by JohnFornaro on 26 Sep, 2014 13:26
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#988 by JasonAW3 on 26 Sep, 2014 14:09
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Take a look at my subsequent comment:
<<But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air? Is the air also ionized by the electric field? How could that generate propulsion, unless we have a leaky microwave cavity ?>>
These are my malformed , incomplete, thoughts in "poking around" looking for different explanations of the measurements.
If the propulsion is the result of ionized air leaking from the cavity, I see this as much less effective than present ion rockets. Also take into account that they tested thrust pulses for only ~30 sec duration and that would not get us anywhere. A cracked dielectric resonator emitting electrons and/or ionization of air won't work long enough or effectively enough...
Also as far as specific force, the results from the Cannae and Frustum testing were not too encouraging. The Boeing/DARPA specific force tests show an impulse instead of a rectangular pulse. The trips to the moons of Saturn and Jupiter are predicated on very optimistic extrapolations...
Problem is, I thought that they'd also tested it in a vacume chamber as well and still got positive results.
I may be a bit confused on this one as it seems that I've heard both that they WERE going to test it in a Vacume Chamber and that they HAD tested it in a vacume chamber.
If they haven't yet tested it in a vacume, then your "Ion Wind" theory is possible, but if they have, again, some other mechanism must be at work.
Could someone clear this one up for me, have they or haven't they tested in a vacume chamber and if not, why? It shouldn't be too hard to set up and experiment like this in a vacume chamber. (I do remember some discussion about vacume resistant capacitors, but that should have been corrected by now). -
#989 by Rodal on 26 Sep, 2014 14:23
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Take a look at my subsequent comment:
<<But, if electrons are emitted by field emission from a dielectric-resonator experiencing breakdown under the electric field, what happens to the electrons in the air? Is the air also ionized by the electric field? How could that generate propulsion, unless we have a leaky microwave cavity ?>>
These are my malformed , incomplete, thoughts in "poking around" looking for different explanations of the measurements.
If the propulsion is the result of ionized air leaking from the cavity, I see this as much less effective than present ion rockets. Also take into account that they tested thrust pulses for only ~30 sec duration and that would not get us anywhere. A cracked dielectric resonator emitting electrons and/or ionization of air won't work long enough or effectively enough...
Also as far as specific force, the results from the Cannae and Frustum testing were not too encouraging. The Boeing/DARPA specific force tests show an impulse instead of a rectangular pulse. The trips to the moons of Saturn and Jupiter are predicated on very optimistic extrapolations...
Problem is, I thought that they'd also tested it in a vacume chamber as well and still got positive results.
I may be a bit confused on this one as it seems that I've heard both that they WERE going to test it in a Vacume Chamber and that they HAD tested it in a vacume chamber.
If they haven't yet tested it in a vacume, then your "Ion Wind" theory is possible, but if they have, again, some other mechanism must be at work.
Could someone clear this one up for me, have they or haven't they tested in a vacume chamber and if not, why? It shouldn't be too hard to set up and experiment like this in a vacume chamber. (I do remember some discussion about vacume resistant capacitors, but that should have been corrected by now).
The (Cannae and Frustum microwave) devices tested in the last NASA Eagleworks report "Anomalous thrust ..." were not tested in a vacuum chamber, because they realized, late in the latest round of Eagleworks testing, that their electrolytic capacitors were not rated for vacuum conditions. See the last page of the report:
<<Vacuum compatible RF amplifiers with power ranges of up to 125 watts will allow testing at vacuum conditions which was not possible using our current RF amplifiers due to the presence of electrolytic capacitors. >>
The Boeing/DARPA device (of which practically nothing has been disclosed concerning its internal workings) was reportedly tested in a vacuum chamber. However, the Boeing/DARPA thrust was an impulse, not a rectangular pulse, hence it is questionable as to how and whether the Boeing/DARPA device could be used for sustained thrusting, under the assumption that the Boeing/DARPA device results are not an artifact of the inverted pendulum with magnetic dampening testing at NASA Eagleworks. The shape (and unreproducible behavior of one the impulses) of the response could very well be a testing artifact (see below).
Based on everything up to this point, my opinion is that all the inverted pendulum results, including those at NASA Eagleworks, are to be suspected as artifacts due to A) the instability of the inverted pendulum resulting in chaotic motion and B) the magnetic dampening which results in limit cycles. I will explain this further as I get the time to do so.
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#990 by Rodal on 26 Sep, 2014 14:34
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The problem with a lot of this testing (except for the classical Cavendish type of hanging pendulum -which is known from the classical gravitation and Casimir force measurements- also used by Brito, Marini and Galian to nullify previous results) is that an inadequate analysis of the testing device (i.e. inverted pendulum) testing is presented.
No analysis of mode coupling, no analysis of self-excitation, no analysis of parasitic modes, no analysis of nonlinear dampening is presented. Both mechanical and electromagnetic coupling and self-excitation are not analyzed.
It is evident from the NASA Eagleworks results that the magnetic dampening plays a very important role in their results (admittedly affecting the baseline), yet there is no closed-form or numerical analysis of its interaction, or an attempt to assess it experimentally by trying other forms of dampening. Also recall that at the MIT Aero and Astro department the inverted pendulum devices designed by Prof. Martinez-Sanchez for testing ion thrusters, has been designed such that the tested thruster remains horizontal at all times. This is needed in order to eliminate coupling between swinging and torsional modes and self-excitation.
NASA Eagleworks stated that
<<The Johns Hopkins University Applied Physics Laboratory has also expressed an interest in performing a Cavendish Balance style test>>
This would be the most effective way to proceed.
Even if (as I suspect) there is no big enough vacuum chamber available/affordable to perform a Cavendish type of test in a vacuum, it is is much more important (in my opinion) at this point to perform a Cavendish type of test -even at room conditions- than testing in a vacuum again with an inverted pendulum using magnetic dampening. -
#991 by aceshigh on 26 Sep, 2014 16:38
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reply from GiThruster regarding Brito's experiments posted by Dr RodalQuote
Yes well, you'll have to forgive me that I can't read all what Dr. Rodal is posting. It's pretty obvious he is not familiar with the work. Neither was Brito when he decided to do an M-E experiment using a discarded design a year or two after it had been abandoned.
Quote from: Rodal* When did such statements first appear in Woodward's publications?
* What magnitude acceleration is a large “bulk” acceleration according to Woodward?
This is almost asking the right question. It is not the magnitude of the bulk that qualifies it as "bulk" but rather, it is accelerating both ends of the electromechanical spring found in bulk matter. The MLT design used by Brito in the above only accelerated the mobile ion inside the BaTiO3 dielectric cage or lattice. What needs to happen is one accelerates the entire lattice because this includes then, both ends of these EM springs. Accelerating only the mobile ion does not accelerate the entire spring.
Nembo Buldrini's "bulk acceleration conjecture" that corrected the efforts in M-E research was back in early 2008 I believe. It was certainly before Brito's experiments. And again, this is why it is so foolish to do replications or validations of anyone's work without availing oneself to the current state of the art. (And really one hopes people wanting to criticize such work ought to be cognizant of the facts as well.)
I was actually the first to argue that as far as I understood the theory, not just the mobile ion needed to be accelerated, but the entire lattice. Nembo Buldrini then showed this is true from the math and all of the M-E work immediately changed. I was the first to abandon the Mach Lorentz Thruster (the design Brito used) and focus on the previous design, what is now known as the Mach Effect Thruster or MET.
There are two very important aspects to the Bulk Acceleration Conjecture. First is, since the entire active mass material lattice needs to move, it can't be sintered with compounds intended to repress electromechanical responses the way the MLT caps used were, and I presume the caps used by Brito. The lattice needs to accelerate and the magnitude of this acceleration determines both the magnitude of the Mach Effect generated (by the 1w acceleration) and the mass fluctuation rectification into force (by the 2w acceleration). So what it turns out is, the thrust generated from these 1/4 wave oscillator/resonators is quadratic with mechanical Q, and Brito's design had no Q to speak of. It was not a 1/4 wave resonator. If you don't use a reaction mass or acoustic mirror in your design, even given the shabby acceleration generated by ceramics sintered to repress piezo-action and electrostriction, you get 1/2 wave mechanical action which means acceleration in two opposite directions which then cancel each other as regards force generated.
So long story short is, the design used by Brito had been abandoned a year or two before he did his experiment for good reasons and ought not have worked according to theory. This has all been explained by me in several forums over the years, and if Dr. Rodal thinks he is qualified to remark about "moving the goalposts" or whatever, I would just suggest to him he do his homework first. He could for example read Jim's book. -
#992 by Rodal on 26 Sep, 2014 16:49
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reply from GiThruster regarding Brito's experiments posted by Dr Rodal
...He could for example read Jim's book.
GiThruster writes <<When did such statements first appear in Woodward's publications?...This is almost asking the right question...He could for example read Jim's book>>
Sorry, I need some translation
So I continue to ask these questions (@cuddihy gave his answer << the first time I saw that claim was 2011 on the talk-polywell forum.>>, perhaps others can also shed some light):
Is the answer by GiThruster to the question
<<When did such statements
[
<<Note that the mass fluctuation predicted here only occurs in an object that is being accelerated as the power fluctuates. If no “bulk” acceleration of the object takes place, there is no mass fluctuation.>>
<<Note too that simply charging and discharging capacitors will not produce mass fluctuations. They must at the same time be subjected to large “bulk” accelerations>>
]
first appear in Woodward's publications?>>
that the first time that GiThruster sees this appear in Woodward's publication is in Woodward's book published in December 14, 2012? Or is he saying that I should read his book to find out the answer to that question?
Why is it that I have to read a book published much later, in Dec 2012, to find out whether he wrote about this prior to Brito's August 2009 report?:
Publisher: Springer; 2013 edition (December 14, 2012)
ISBN-13: 978-1461456223
years after Brito, Milani Galiani's 2009 presentation ?:
2009, Hector H. Brito, Ricardo Marini and Eugenio S. Galian, "Null Findings on Electromagnetic Inertia Thruster Experiments using a Torsion Pendulum" 45th AIAA/ASME/SAE/ASEE Joint Propulsion Conference & Exhibit 2 - 5 August 2009, Denver, Colorado
http://enu.kz/repository/2009/AIAA-2009-5070.pdf
When GiThruster writes <<I was actually the first to argue that as far as I understood the theory, not just the mobile ion needed to be accelerated, but the entire lattice.>> ?
Is GiThruster claiming that he argued this before Prof. Woodward ? Or is GiThruster claiming to be the first to argue this in the forum?
When GiThruster writes <<the design used by Brito had been abandoned a year or two before he did his experiment for good reasons and ought not have worked according to theory. This has all been explained by me in several forums over the years>> is GiThruster saying that it had been abandoned by Brito or by Woodward "a year or two before Brito's experiment" ?
If the answer is the later, then it appears that GiThruster is saying that Woodward abandoned his initial (theoretical and experimental) notion that simply charging and discharging capacitors will produce mass fluctuations around 2008 ?
____________________________________
Again, it is some progress that they now recognize that:
<<simply charging and discharging capacitors will not produce mass fluctuations.>>
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#993 by JohnFornaro on 26 Sep, 2014 17:59
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reply from GiThruster regarding Brito's experiments posted by Dr Rodal
Quote... (0) It's pretty obvious [Rodal] is not familiar with the work.
Quote from: Rodal* When did such statements first appear in Woodward's publications?
* What magnitude acceleration is a large “bulk” acceleration according to Woodward?
This is almost asking the right question. It is (1) not the magnitude of the bulk that qualifies it as "bulk" but rather, it is accelerating both ends of the electromechanical spring found in bulk matter. ...
There are two very important aspects to the (2) Bulk Acceleration Conjecture. ...
(3) So long story short is, ... [Rodal] could for example read Jim's book.
0. Seems to me that Rodal has at least a passing familiarity with the work.
1. I call el poopo del toro.
Either mass is moving or else it is not. There is no scientific definition of the term "bulk" which can be invoked.
2. I'll weigh myself before and after yoga this afternoon, and report on my bulk.
3. I too, have suggested that Rodal purchase and read the book.
AcesHigh is to be thanked for his relay services, but unfortunately, there is no substantive answer to Rodal's questions. -
#994 by Rodal on 26 Sep, 2014 18:02
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I plead guilty as charged, concerning reading the "Making Starships and Stargates: The Science of Interstellar Transport and Absurdly Benign Wormholes " December 14, 2012 book. I even had a very generous offer from one of the people in this forum to send me his/her book by mail. I prefer to consider published papers, particularly those in peer-reviewed publications, rather than books, as books are not peer-reviewed and contain more errors. Book editors edit for style and grammar and not for scientific content.
However, I have read, and quoted, several of Woodwards's papers prior to and after publication of his book.
Therefore, what I wrote cannot be taken as a criticism of Woodward's "Starships and Stargates" book, only of the specific papers that I quoted. The paper I have quoted most often is "FLUX CAPACITORS AND THE ORIGIN OF INERTIA", Foundations of Physics, October 2004, Volume 34, Issue 10, pp 1475-1514. The latest paper I have quoted is "Experimental Null Test of a Mach Effect Thruster" by Heidi Fearn and James F. Woodward, arXiv:1301.6178 [physics.ins-det]
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#995 by Rodal on 26 Sep, 2014 21:57
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GiThruster wrote <<I was actually the first to argue that as far as I understood the theory, not just the mobile ion needed to be accelerated, but the entire lattice. Nembo Buldrini then showed this is true from the math and all of the M-E work immediately changed. I was the first to abandon the Mach Lorentz Thruster (the design Brito used) and focus on the previous design, what is now known as the Mach Effect Thruster or MET.>>
If my understanding is correct, GiThruster is referring to the experiments performed by Paul March, reported in this paper: Paul March and Andrew Palfreyman. "The Woodward Effect: Math Modeling and Continued Experimental Verifications at 2 to 4 MHz" http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=31119.0;attach=496011, since Paul March refers to his experiments as Mach Lorentz Thruster:
<<This type of electromagnetic field thruster, or Mach-Lorentz Thruster (MLT), purports to create a transient mass differential that is expressed in a working medium to produce a net thrust in the dielectric material contained in several capacitors.>>
So, if I understand GiThruster correctly, the experiments by Paul March quoted by Dr. White in his slide 40 (in August 2013) of http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf :
______________________________
Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2004:
SPECIFIC FORCE= 0.4 N/kW (up to 90 000 times larger than the photon rocket)
______________________________
Paul March Woodward-Effect device tested with a load-cell-in-vertical-motion in 2005:
SPECIFIC FORCE= 0.3 N/kW (up to 67 000 times larger than the photon rocket)
______________________________
have been deemed to be an experimental artifact? as GiThruster states that "they" [meaning Woodward ?] have abandoned this kind of thruster as not being able to produce thrust because the "bulk" is not accelerated?
because <<simply charging and discharging capacitors will not produce mass fluctuations.>>
My interpretation of all this is that GiThruster and Woodward think that the kind of MLT drive that Paul March tested in 2004/5 cannot generate sizeable thrust according to the latest interpretation (post 2008? and certainly post-Brito-2009-null experiment) of Woodward. But since Dr. White presented these results of Paul March in his slide 40 (in August 2013) as a Q-thruster, Dr. White thinks that Paul March's MLT thruster can theoretically deliver thrust according to White's Quantum Vacuum theory. -
#996 by JohnFornaro on 27 Sep, 2014 01:40
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This semantic web is too tangled for me to unravel.
Summary for the proletariat: The first theory didn't get experimental verification. Neither did the second, nor the third. Is the experimental apparatus and associated theory of the OP the fourth? -
#997 by Rodal on 27 Sep, 2014 01:58
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Furthermore, it appears that the initials SFE in "SFE Test Article at JSC" of Dr. White's slide 40 (August 2013) presentation http://ntrs.nasa.gov/archive/nasa/casi.ntrs.nasa.gov/20140000851.pdf may stand for "Serrano Field Effect" (using Google to search for this).
This website http://jnaudin.free.fr/lifters/act/html/sfptv1.htm by by Jean-Louis Naudin at http://jnaudin.free.fr/ has further information on what (this "free," French, website) claims is this "SFE" effect, as well as this one: http://www.mednat.org/new_scienza/antigravita'%201.pdf.
Also see this March 2003 article "Force on an Asymmetric Capacitor", by Thomas B. Bahder and Chris Fazi", Army Research Laboratory, Adelphi, MD http://arxiv.org/ftp/physics/papers/0211/0211001.pdf
<<During the 1920s, Thomas Townsend Brown was experimenting with an x-ray tube known as a "Coolidge tube," which was invented in 1913 by the American physical chemist William D. Coolidge. Brown found that the Coolidge tube exhibited a net force (a thrust) when it was turned on. He believed that he had discovered a new principle of electromagnetism and gravity. Brown applied for a British patent on April 15, 1927, which was issued on November 15, 1928 as Patent No. 300,311, entitled, “Method of Producing Force or Motion.”>> http://www.sunrisepage.com/ufo/files/Brown,%20Thomas%20Townsend.%20British%20Patent%20300,311.pdf
<<We have presented a brief history of the Biefeld-Brown effect: a net force is observed on an asymmetric capacitor when a high voltage bias is applied. The physical mechanism responsible for this effect is unknown. In section 4, we have presented estimates of the force on the capacitor due to the effect of an ionic wind and due to charge drift between capacitor electrodes. The force due to ionic wind is at least three orders of magnitude too small. The force due to charge drift is plausible, however, the estimates are only scaling estimates, not a microscopic model.
In section 5, we have presented a detailed thermodynamic theory of the net force on a capacitor that is immersed in a nonlinear dielectric fluid, such as air in a high electric field. The main result for the net force on the capacitor is given in equation (33). The thermodynamic theory requires knowledge of the dielectric properties of the fluid surrounding the capacitor plates. It is not possible to estimate the various contributions to the force until we have detailed knowledge about the high-field dielectric properties of the fluid. More experimental and theoretical work is needed to gain an understanding of the Biefeld-Brown effect. As discussed, the most pressing question is whether the Biefeld-Brown effect occurs in vacuum. It seems that Brown may have tested the effect in vacuum, but not reported it (Appendix B). More recently, there is some preliminary work that tested the effect in vacuum, and claimed that there is some small effect—smaller than the force observed in air; see the second report cited in reference [2]. Further work must be done to understand the effect in detail. A set of experiments must be performed in vacuum, and at various gas pressures, to determine the force versus voltage and current. A careful study must be made of the force as a function of gas species and gas pressure. In order to test the thermodynamic theory presented here, the dielectric properties of the gas must be carefully measured. Obtaining such data will be a big step toward developing a theoretical explanation of the effect. On the theoretical side, a microscopic model of the capacitor (for a given geometry) must be constructed, taking into account the complex physics of ionization of air (or other gas) in the presence of high electric fields. Only by understanding the Biefeld-Brown effect in detail can its potential for applications be evaluated. >>
This is a 2008 Purdue report on the ionic wind: http://docs.lib.purdue.edu/cgi/viewcontent.cgi?article=1226&context=nanopub
The "SFE Test Article at JSC" is the EM Drive tested at NASA Eagleworks in 2013 which we have been referring to as the "Boeing/DARPA drive".
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#998 by cuddihy on 27 Sep, 2014 02:45
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Ok, John you've made way too many comments on the related threads here not to have at least followed the claimed story unless it's deliberate. The story is that the 'bulk acceleration' conjecture doesn't impact Woodward's 'source of inertia' theories at all because it's a question of correct method for engineering a 'unidirectional force generator' from the theory, not demonstrating a yeah/nay experiment that 'suggests itself' directly from the maths. Woodward's theory and maths suppose a 'particle' or 'mass' as the object being pushed/pulled on. Translating that to an observable mass pushed or pulled on at observable scale is not simple.
1. Early experiments by Woodward and Mahood did not consider the "bulk" acceleration criterion and saw mixed results that were not clear enough either way to prove or disprove anything, with different devices showing different responses and lots of concerns about standard effects, and straight up disagreement with the original calculated scaling, but enough to sniff that there could be something there. This was of the first suggested "MET" device, not because they knew they would need that construction but because from what I understand PZT stacks were easiest for Woodward to construct and the most obvious approach for a cheap setup.
2. Palfreyman, Buldrini, Woodward, March, and even I believe at one point John Kramer attempted various types of replications using different schemes, including other METs, a 'mach guitar', March's MLTs, and a 'rotator'. Again, mixed results that caused some folks to be satisfied the theory had been invalidated and others to be satisfied there was something consistent there but something unknown in the application that made even the 'successful' tests not match expected scaling with power & frequency.
3. At some point (and I thought it was much later, but GIThruster says 2008), a conjecture was made public that non-bulk 'ion' acceleration schemes like the MLT were poor analogues for the 'particle' or 'mass' in the derivations because as an 'inertial' effect, not a significant enough portion of the matter in a 'non-bulk' mass would be changing acceleration in synch enough to overcome the stationary portion's inertia. Whereas of the whole mass is moving, there's no doubt it's an analogue to the Woodward theory 'particle' or 'mass'.
Then, going back, woodward's early experiments of the MET type would happen to correctly meet this criteria.
Not saying any of that makes this smell legit. But that's the story as I understand it. -
#999 by Rodal on 27 Sep, 2014 02:49
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Thanks @cuddihy for the information.
