Author Topic: EM Drive Developments Thread 1  (Read 765758 times)

Offline birchoff

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Re: EM Drive Developments
« Reply #1220 on: 10/01/2014 08:54 PM »
Dr. Rodal, I agree with your opinion of the guys posting in this forum.  Can I presume you agree that you, amongst others here, have posted now quite a few opinions about work you're not familiar with, and thus validate my observation that these forums do indeed do what I'm saying they do?

And it is funny.  :-)  And you can find the same at Talk Polywell, and Next Big Future and Physics.org and Phys.org, etc.
You are incorrect.   I have only commented about the specific papers I have read and I have made that clear in my posts, including links and explicit quotations.

In my limited time here Rodal you are honestly the first most consistent I have come across, that said most of my time has been spent on this thread in particular. Outside of this thread and forum you would be considered an anomaly.
« Last Edit: 10/01/2014 08:56 PM by birchoff »

Offline 93143

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Re: EM Drive Developments
« Reply #1221 on: 10/01/2014 09:03 PM »
I have only commented about the specific papers I have read and I have made that clear in my posts, including links and explicit quotations.

Yes, but your comments are not always in strict logical progression from the contents of those papers, which I myself have found very frustrating in the past.

I'd spend more time here, but I don't have it; if I were to engage in detail it could easily suck up weeks of work.  I tend to put a lot of effort into such posts...

Also, check your PMs (been a while, but late is better than never)...
« Last Edit: 10/01/2014 09:06 PM by 93143 »

Online Rodal

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Re: EM Drive Developments
« Reply #1222 on: 10/01/2014 09:05 PM »
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.
This above, Dr. Rodel; was brought to my attention in another forum, because you are here slandering a good man and accusing him of moving the goal posts, saying the predicted effect didn't show up, using fudge factors when in fact no thrust magnitude prediction had been made for good reason, and of creating "new conditions" when in fact these conditions are in the peer reviewed literature going back almost 20 years now.  If I'm wrong and you've been unusually restrained you have my apology but it looks like you're acting very typically for this sort of venue.

Mr. Stahl,  you have now raised this to another, serious level.  You have now stated  << you are here slandering a good man >>.  Slander is "the action or crime of making a false spoken statement damaging to a person's reputation"
I asked a question, whether goal posts where being moved, regarding the appearance of "bulk acceleration," which I had not seen previously.  The explanation was given by a number of people in this forum, regarding what you call the MLT type of thruster that motivated my question.  I have not questioned those answers and I have moved over to other issues as I always made clear that I had no other interest than the NASA experiments.  At that time I thought that Dr. White's slide 40 (on the "MLT") was an experiment run at NASA.

You should know all this by now, so you are the one making a completely unfounded charge. 

You should retract your unfounded charge that I slandered anybody.
« Last Edit: 10/01/2014 09:07 PM by Rodal »

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #1223 on: 10/01/2014 09:23 PM »
Quote
Hold tha damn phone.

Am I correct in my interpretation that you or some group of people you know is actively attempting to Sheppard Woodward's work all the way through to commercialization??
Yes.

And where can a space geek go to keep abreast of such developments?
I'll splash news onto a couple forums when we make some headway, but as I stated the other day, I am still looking for a pair of Principle Investigators to run the UFG MET project and to run the Rad Hardening project.  Both grants need PhD's to run them who demonstrate aptitude for the task.  The first (the thruster) is very complex.  We don't need nor even want a "believer" in the commons sense and are better suited with a skeptic, but in any case we need folks who are able to understand the complex details of the setup, as well as construction and a handful of other things.  A physicist could do it but I'd rather have an able engineer.

The second project probably needs a plasma physicist who can model a spacecraft flying through the Van Allen Belt on COMSOL, and most physicists don't use engineering programs so that position is hard to fill as well.

Offline Ron Stahl

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Re: EM Drive Developments
« Reply #1224 on: 10/01/2014 09:30 PM »
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.
This above, Dr. Rodel; was brought to my attention in another forum, because you are here slandering a good man and accusing him of moving the goal posts, saying the predicted effect didn't show up, using fudge factors when in fact no thrust magnitude prediction had been made for good reason, and of creating "new conditions" when in fact these conditions are in the peer reviewed literature going back almost 20 years now.  If I'm wrong and you've been unusually restrained you have my apology but it looks like you're acting very typically for this sort of venue.

Mr. Stahl,  you have now raised this to another, serious level.  You have now stated  << you are here slandering a good man >>.  Slander is "the action or crime of making a false spoken statement damaging to a person's reputation"
I asked a question, whether goal posts where being moved, regarding the appearance of "bulk acceleration," which I had not seen previously.  The explanation was given by a number of people in this forum, regarding what you call the MLT type of thruster that motivated my question.  I have not questioned those answers and I have moved over to other issues as I always made clear that I had no other interest than the NASA experiments.  At that time I thought that Dr. White's slide 40 (on the "MLT") was an experiment run at NASA.

You should know all this by now, so you are the one making a completely unfounded charge. 

You should retract your unfounded charge that I slandered anybody.
You're entirely right.  Slander was a very unfortunate choice of words.  Slander is always intentional IIUC, and my point was certainly, that you mischaracterized this issue out of ignorance rather than malice.  I do not think you intended any malice, but rather; that you are demonstrating a very common and understandable skepticism.  Lets be candid shall we?  Not one in 100 schemes like what we're here talking about is worth the time to look at.  And nothing against engineers! but almost always they are the result of an engineer pretending to be a physicist.  There used to be an entire site dedicated to this kind of chicanery--"American Antigravity".  So anyone who is interested in the field of advanced propulsion, necessarily needs to develop some skepticism over time.  Almost all this stuff is crackpot!  IMHO, the QVF stuff is crackpot and that's coming from NASA!

So there are no hard feelings here and I really should not have written "slander" as that was just plain wrong and you have my apology.  Please do try to sympathize, I've known Jim for many years now, and he is an excellent man of honor and integrity, due proper respect and a fair shake, which he does not usually get.
« Last Edit: 10/01/2014 09:33 PM by Ron Stahl »

Offline Lar

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Re: EM Drive Developments
« Reply #1225 on: 10/01/2014 09:37 PM »
There is a very serious lack of being excellent to each other in the last several pages. I'm pressed for time so my temptation is to just up and delete all of it. That might throw some good info out.

I would strongly suggest that people try being a lot softer in their word choices, or some mod WILL do just that.

Protip: If you find yourself typing "peanut gallery" you probably ought to rethink your whole approach.

Edit: Note that if you're using the web interface, you have the ability to go in and revise any prior post to improve it. There are a number of posts that would benefit from such editing.
« Last Edit: 10/01/2014 09:54 PM by Lar »
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Offline Ron Stahl

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Re: EM Drive Developments
« Reply #1226 on: 10/01/2014 09:48 PM »
Fair enough.  Everyone has my apology.

Online Rodal

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Re: EM Drive Developments
« Reply #1227 on: 10/01/2014 09:52 PM »
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.
This above, Dr. Rodel; was brought to my attention in another forum, because you are here slandering a good man and accusing him of moving the goal posts, saying the predicted effect didn't show up, using fudge factors when in fact no thrust magnitude prediction had been made for good reason, and of creating "new conditions" when in fact these conditions are in the peer reviewed literature going back almost 20 years now.  If I'm wrong and you've been unusually restrained you have my apology but it looks like you're acting very typically for this sort of venue.

Mr. Stahl,  you have now raised this to another, serious level.  You have now stated  << you are here slandering a good man >>.  Slander is "the action or crime of making a false spoken statement damaging to a person's reputation"
I asked a question, whether goal posts where being moved, regarding the appearance of "bulk acceleration," which I had not seen previously.  The explanation was given by a number of people in this forum, regarding what you call the MLT type of thruster that motivated my question.  I have not questioned those answers and I have moved over to other issues as I always made clear that I had no other interest than the NASA experiments.  At that time I thought that Dr. White's slide 40 (on the "MLT") was an experiment run at NASA.

You should know all this by now, so you are the one making a completely unfounded charge. 

You should retract your unfounded charge that I slandered anybody.
You're entirely right.  Slander was a very unfortunate choice of words.  Slander is always intentional IIUC, and my point was certainly, that you mischaracterized this issue out of ignorance rather than malice.  I do not think you intended any malice, but rather; that you are demonstrating a very common and understandable skepticism.  Lets be candid shall we?  Not one in 100 schemes like what we're here talking about is worth the time to look at.  And nothing against engineers! but almost always they are the result of an engineer pretending to be a physicist.  There used to be an entire site dedicated to this kind of chicanery--"American Antigravity".  So anyone who is interested in the field of advanced propulsion, necessarily needs to develop some skepticism over time.  Almost all this stuff is crackpot!  IMHO, the QVF stuff is crackpot and that's coming from NASA!

So there are no hard feelings here and I really should not have written "slander" as that was just plain wrong and you have my apology.  Please do try to sympathize, I've known Jim for many years now, and he is an excellent man of honor and integrity, due proper respect and a fair shake, which he does not usually get.

Thank you for your very gracious reply.  My only interest in this thread is to understand the NASA results.  I have enjoyed very much the technical discussion, including the latest one concerning axionic Dark Matter. :)

Online aero

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Re: EM Drive Developments
« Reply #1228 on: 10/01/2014 11:06 PM »
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...

I could very easily be making an error in my calculations - BUT - Fig. 14 is for the Cannae Cavities while my calculations address the tapered frustum. The paper doesn't give a Q-factor for the Cannae Cavities so I can't do a calculation to check myself with that example. On the other hand, I can do a calculation to estimate what the Q-factor would be if the stored RF wave energy results in an electric field of 4.7189E+04 volts per meter. It is very, very small. Small to the point of being nonsense at ~0.0007.

Correct me where I'm wrong, but the E field energy of the RF wave is given from w = epsilon_sub_o* E^2 where w is energy per unit volume, epsilon_sub_o = 8.85418782 × 10-12 m-3 kg-1 s4 A2 and the Quality factor is energy stored / energy lost per cycle. So I'm taking w = 28 watts with the unit volume of one and calculating much larger values than Fig. 14 shows.
 
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Offline frobnicat

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Re: EM Drive Developments
« Reply #1229 on: 10/01/2014 11:07 PM »
. . .my feeling (as an average mainstream science educated person somehow following the topic) is that the various teams involved in experiments are choosing the wrong methodology and should follow some guidelines for fundamental research experimentalists
I'm sorry but that's not true at all.  Obviously, you have not read the book.

Obviously I have not. This was just a feeling of an anonymous forum contributor, interested but not directly involved and having other focus preventing me to read the 100s pages of scientific literature linked to daily here by good dr Rodal and other contributors. So this could be not true at all. My feeling is true, as a feeling, why I expressed it. I am less aware of Woodward's works, so what I said was possibly totally unfair relative to his (and team's) work and way of doing it. Don't take the volume of words used by me to answer in 100 lines a 1 line remark as an implied pretention of authority.

Right now, in spite of knowing my knowledge of the subject is very limited, I still have the same view about  shortcomings with this line of research : strange methodological priorities. And this is a feeling shared by a number of friends and colleagues somehow "average mainstream science educated person" when informally discussing the topic. While they would be ready to accept a solid experimental result, right now they wouldn't give a kopeck on the whole line of research to yield anything of substance, theoretically or practically, or even give it enough interest to buy a book or even subscribe to the appropriate mailing list. Maybe this is unfair, but it is how mainstream science and tech works, sociologically, when subjects dealing with apparent breaking of momentum/energy conservation are investigated, because so much positive or "almost certainly positive" results claimed for decades and still not a single rock solid self contained experiment confirming there is something at all. That and no need for the theories backing such possibilities when dealing with day to day usual reality (from action/reaction in mechanical engineering to hadron jets reconstruction in colliders, all in perfect agreement with standard theories so far. Alright, muonic hydrogen anomalies, dark sector etc, we still have plenty ongoing mysteries...).

Also I should note, as a French citizen, that we (French) are always criticizing everything, it seems we are never happy with any given situation and we should always have an opinion on a way things should be better. This "lesson giver" bias is also a very common trait on online forums, but we French people have raised that to a standard of living. When I say "dr White et al have a poor methodology" you should not hear "they are incompetent crooks" but rather "I would appreciate a shift in their focus toward a more definite answer as to whether there is an effect at all" as all French techies would interpret the statement from its brutal formulation. You might say, they are already striving all they can to get to this definite answer, but this is not my impression, my impression is that they so hardly believe in a positive answer that it gets in the way of getting an answer, that could be negative. This would not be the first time that very bright people follow a line of research that, cruelly, proves to be a dead end. Some of the finest minds of earth have dedicated decades on string theory, and some other of the finest minds of earth think this is leading nowhere because it is not predicting anything more and not falsifiable, and while this was interesting to investigate we should shift focus on other approaches.

Anyway, I am not expecting expressing this view here on this forum to change the mind of really involved persons, free to work as they wish (within their limited budgets and other constraints of reality) and that's good. May be the people they have to answer for ask for different kind of indication of credibility. But this very sceptical perception by a general scientific population (at least French, and caprine, that I can testify) might become a handicap in the long run, no ?

They hope and work to have a solid confirmation. But what if it doesn't come in 10 years, in 20 years ? The bet is that it comes soon ?

Quote
Quote
please produce a complete detailed description of one single self contained airtight device, thermally isolated, energetically isolated, electromagnetically shielded, that is reproducible and will guarantee anyone caring to follow the instructions to observe a thrust/power effect better than 1/c for a few seconds
While I understand and appreciate what you're trying to do, all i can say in few words is, you are putting out criteria that are unreasonable and unnecessary.

I do also appreciate your contributions in this thread. Don't know if this is the place to do real serious science but great to exchange different views.

All I can say in a few word is I strongly disagree ahem. I have a different view.
This should be the top priority.
It is not unreasonable : Brito, Marini and Galian did a pretty good job at isolating thermally and energetically a device in an airtight configuration and on a well behaved balance. Sure this must be a pain to "vent" the thermal energy between the sessions, but this gives a very credible result. Should their result have been positive it would have had a rather serious impact not only for my little person but for the scientific community at large, even if not in vacuum. Note also that their self contained design would be "easily" amenable to a check in a vacuum chamber, had their result been positive and worth of it.
It is necessary : because a rock solid positive, or at least a signal that couldn't be handwaved away by sceptics as "must be thermal or something" is the only way to convince some labs beyond the aerospace to investigate. And if such effect is possible it would be so much beyond "down to space" considerations, this needs to be investigated as fundamental science.

Quote
  In the words of Dr. Dennis Bushnell, NASA's Chief Scientist and point man for all propulsion and power exploration like these, the reason NASA is not biting is that they don't have anyone able to judge the theory.
And people able to judge the theory wont be interested to even read the book before there are clear enough signals in clean enough experimental setups (see above -> necessary).

Quote
The experimental setup is not the trouble.  Since they cannot do a real evaluation of theory, what they've asked for is more thrust, which is what Jim is working on.

That makes no sensible sense to me. In this context this would be an application driven research ? So the trouble is the experimental setup. Why should they care about theories ? If the effect is hinting at being anything like it says it is, then pour the money and hire the third party experimentalists to do an all or nothing confirmation of any real effect at all. Even if all it takes is a mW thruster mounted on an atomic force microscope cantilever to get a few pN of thrust, just to see it's real. Then make phenomenological model. Then build better/bigger devices and see if it fits such or such ground breaking theory.
Even if the fact to pursue a higher thrust might contribute to show this is not a real effect and therefore allow for a progress, my point is that putting the focus on that is not the best way to assert the reality of any effect at all.
Again, the "this is impossible" hypothesis appears not well accommodated by the strategy. The way to conduct the experiments should be neutral as to the reality of the effect. Not in a spirit of "in all likelyhood this is possible, let's see how" but "is it possible or not". I'm speaking from a point of view of fundamental research, which this line of research should be considered part of, because of its principal consequences, which are not better probes to Saturn, but complete rewriting of physics.

Sorry, NASA is great, probes are great, I'm a space enthusiast (wouldn't care to be here otherwise), but this may not be the ideal context to assert the reality of such effect. It's all right, reality is not always as we want.

I read and appreciate the rest of your post, that answer some of the above remarks.
Will answer also, time permitting (yeah yeah, I use too much words...)
Sorry to flood with my rants.

will try to be constructive and bring some numbers to this axion craze (might be 6 order of magnitude off target...)
« Last Edit: 10/01/2014 11:13 PM by frobnicat »

Online Rodal

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Re: EM Drive Developments
« Reply #1230 on: 10/01/2014 11:48 PM »
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...

I could very easily be making an error in my calculations - BUT - Fig. 14 is for the Cannae Cavities while my calculations address the tapered frustum. The paper doesn't give a Q-factor for the Cannae Cavities so I can't do a calculation to check myself with that example. On the other hand, I can do a calculation to estimate what the Q-factor would be if the stored RF wave energy results in an electric field of 4.7189E+04 volts per meter. It is very, very small. Small to the point of being nonsense at ~0.0007.

Correct me where I'm wrong, but the E field energy of the RF wave is given from w = epsilon_sub_o* E^2 where w is energy per unit volume, epsilon_sub_o = 8.85418782 × 10-12 m-3 kg-1 s4 A2 and the Quality factor is energy stored / energy lost per cycle. So I'm taking w = 28 watts with the unit volume of one and calculating much larger values than Fig. 14 shows.
Thank you for pointing out that the Q factor for the Cannae drive is not given. I had forgotten that.
This is my understanding:

Cannae drive: E field data is provided.  No Q factor provided.
Tapered Cavity: E field numerical data range not provided.  Q factor provided.

________________

These are my calculations for the Maximum power  density in ("Teflon") PTFE dielectric resonator for Cannae device (notice the frequency  "f" in the calculation):

MaximumPower = 2 Pi f (E^2) (permittivity of free space) (epsilon')

Taking the

maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m , and the given

frequency of 935 MHz, it follows (for the Teflon PTFE dielectric resonator) that:


MaximumPower per unit volume [W/m^3] = 2 Pi (935*10^6 1/s) (( 4.7189*10^4)^2) (8.85418782*10^(-12)) (2.1)

MaximumPower per unit volume (in the dielectric resonator)~  243 W/cm^3
« Last Edit: 10/01/2014 11:52 PM by Rodal »

Offline raketa

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Re: EM Drive Developments
« Reply #1231 on: 10/02/2014 12:14 AM »
What you're describing is one of 5 plans in progress for the DARPA grant process.

DARPA grants are very odd compared to other grants because they require the whole TRL process.  They generally cover TRL6 and 7 in 2 phases, but they require the TRL-1-5 history, the phase 1 TRL6 plan in detail, the follow on TRL7 plan in detail (though they expect changes after phase 1), the plan for the jump to TRL8 commercialization including whom will build the product and a market analysis of who would pay for it.  What you're taking about is part of the TRL9 analysis, which is to provide Dragon with an M-E trunk that can take it to the Moon and Mars.  This is one of 5 early "low thrust" applications, but the trunk needs to be completely refitted so this is not a cheap nor simple issue.

What is cheap is to catch a free ride to orbit for a nanosat, but this still requires miniaturization.  And really you don't want to send stuff to orbit without paying for that step because that is the step where radiation hardening takes place, and where the actual FOM's for future spacecraft with all their working systems come from.  You want the grant to pay for the miniaturization so you have it ready to go to market.  In our case, miniaturization does not happen until phase 2/TRL7, but this is quite normal and the electrical engineering for this can be shopped out to literally dozens of places so there is little challenge there save how it affects delivery times of other portions of the project.
Got it, thank you for explaining process.

Online Rodal

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Re: EM Drive Developments
« Reply #1232 on: 10/02/2014 12:16 AM »
will ... bring some numbers to this axion craze ..

Here is some Axion music craze, in the interim  (AXION ESTI ODYSSEAS ELITIS ):

« Last Edit: 10/02/2014 12:18 AM by Rodal »

Offline raketa

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Re: EM Drive Developments
« Reply #1233 on: 10/02/2014 01:03 AM »
Making Starships and Stargates: The Science of Interstellar Transport and Absurdly Benign Wormholes (Springer... by James F. Woodward (Dec 14, 2012)
This is the book you suggest to read.

Online Rodal

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Re: EM Drive Developments
« Reply #1234 on: 10/02/2014 01:07 AM »
I was wondering how much energy was stored within the cavity (truncated frustum) so have been (off and on) looking at math for which I have absolutely no background beyond undergraduate course work. Using the input power and Q-factors given, I calculate that the RF wave B field and E field has energy like:

B field range from 0.27 to 0.62 tesla, and
E field range from 80.4 to 184.8 Mv per metre.

Are these reasonable values?

I also calculated that the energy mass of the RF wave ranges from 0.00064 to 0.0034 micrograms.

At this point I don't know what to do with these numbers but maybe someone will find them interesting.

We know from the "Anomalous Thrust ..." report that the COMSOL finite element calculations display a maximum Electric field of 47189 Volts per meter (p. 10, Fig. 14).  I couldn't find any numerical information given for the Electric Field results from COMSOL for the Tapered Cavity.

Also, you may find something useful for comparison in FIg. 16 of the report, for the predicted and actual gain (S21), as attached here (vertical scale: Amplitude (dB); horizontal scale: frequency):

(The numbering convention for S-parameters is that the first number following the “S” is the port where the signal emerges, and the second number is the port where the signal is applied. S21 is a measure of the signal coming out port 2 relative to the RF stimulus entering port 1: the ratio of transmitted to incident voltage signals.  S21 is the forward complex transmission coefficient)

It is apparent that the comparison from this COMSOL analysis to the actual results is not that great...

I could very easily be making an error in my calculations - BUT - Fig. 14 is for the Cannae Cavities while my calculations address the tapered frustum. The paper doesn't give a Q-factor for the Cannae Cavities so I can't do a calculation to check myself with that example. On the other hand, I can do a calculation to estimate what the Q-factor would be if the stored RF wave energy results in an electric field of 4.7189E+04 volts per meter. It is very, very small. Small to the point of being nonsense at ~0.0007.

Correct me where I'm wrong, but the E field energy of the RF wave is given from w = epsilon_sub_o* E^2 where w is energy per unit volume, epsilon_sub_o = 8.85418782 × 10-12 m-3 kg-1 s4 A2 and the Quality factor is energy stored / energy lost per cycle. So I'm taking w = 28 watts with the unit volume of one and calculating much larger values than Fig. 14 shows.
Thank you for pointing out that the Q factor for the Cannae drive is not given. I had forgotten that.
This is my understanding:

Cannae drive: E field data is provided.  No Q factor provided.
Tapered Cavity: E field numerical data range not provided.  Q factor provided.

________________

These are my calculations for the Maximum power  density in ("Teflon") PTFE dielectric resonator for Cannae device (notice the frequency  "f" in the calculation):

MaximumPower = 2 Pi f (E^2) (permittivity of free space) (epsilon')

Taking the

maximum value of the Electric Field shown in Fig. 14, p.10, as 4.7189*10^4 V/m , and the given

frequency of 935 MHz, it follows (for the Teflon PTFE dielectric resonator) that:


MaximumPower per unit volume [W/m^3] = 2 Pi (935*10^6 1/s) (( 4.7189*10^4)^2) (8.85418782*10^(-12)) (2.1)

MaximumPower per unit volume (in the dielectric resonator)~  243 W/cm^3

If you divide your

<<E field range from 80.4 to 184.8 Mv per metre>>

by the square root of the angular frequency for the Cannae drive:

 Sqrt[ 2 Pi (935*10^6 1/s) ] = 76647.1

one gets:

E field range from 1049 to 2411 Volts per meter.

which is not too far from the COMSOL calculations (there is also an uncertainty due to the Volume)


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
While for the tapered cavity

If you divide your

<<E field range from 80.4 to 184.8 Mv per metre>> by the actual square root of the angular frequency

 Sqrt[ 2 Pi (1932.6*10^6 1/s) ] = 110195

one gets

E field range from 730 to 1677 Volts per meter (there is also an uncertainty due to the Volume)
« Last Edit: 10/02/2014 01:43 AM by Rodal »

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1235 on: 10/02/2014 01:32 AM »
In the words of Dr. Dennis Bushnell, NASA's Chief Scientist and point man for all propulsion and power exploration like these, the reason NASA is not biting is that they don't have anyone able to judge the theory.  The experimental setup is not the trouble.

It has been asserted and supported that the spurious signals associated with the experimental apparatus are a flaw in the experimental procedure which should be accomodated.  Attempts to calculate the magnitude of some kinds of the spurious forces depend upon dimensional data of the apparatus, data which has been deliberately kept under wraps.

Analysis of the theory itself has suggested substantial flaws, with several attempts to propose more and more esoteric phenomena instead of the mass fluctuations which are the foundation of Woodward's theory.  In fact, some posters have suggested that the experiment will be sufficient proof of the anomalous thrusts, regardless of the correctness of the theory.

Many posters here have provided the caveat of how they don't have the time to understand and critique the theory, but go on to assert, without support, the soundness of the theory, or to propose yet another far fetched special effect of physics in support of the theory.

Bottom line: If NASA doesn't understand the theory, it should not pretend to support reseach into it. Should your credibility be an important asset to you, please link Dennis Bushnell's comment about their scientific ignorance in this arcane but necessary field.
« Last Edit: 10/02/2014 01:43 AM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1236 on: 10/02/2014 01:32 AM »


Ron, I'm new to this site, but it is my impression is that it would help if you would also include the author of the quotes...

And I'm partly new, but mostly older.  Pretty sure Ron Stahl didn't say "     ". do what I do, and include a portion of his remarks in the HTML quote, so we can have a better handle on what part of his comment you are referring to.

Oh. E dal dipartimento di "Solo Dicendo", che lo scorso Martini tuo mancava di sostanza, diciamo.
« Last Edit: 10/02/2014 01:44 AM by JohnFornaro »
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1237 on: 10/02/2014 01:33 AM »
Yes, that was my opinion he quoted.  And I'm sorry if that truth seems to annoy but it is the truth.

Sorry bud.  Your opinion does not become truth in one unsubstantiated sentence. [Waves hand.]  I'm an American. [Waves hand.]  Your cognitively infiltrative remarks don't work on me.

Quote from: Ron Stahl
...anyone who has been around a few years on one or more of these boards knows how opinionated and predictable these forums are.

You knew they were going to start talking about axions, and you you didn't warn us?  This is borderline nonsense.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1238 on: 10/02/2014 01:33 AM »

quite funny indeed. ...

Here however we have a clear demonstration of how rational choice theory often fails. It is always complicate to justify rationally the behaviour of individuals wasting their time to say "there is nothing to say here because you are all wrong and uninteresting".

Due punti per Gryfindor.
Sometimes I just flat out don't get it.

Offline JohnFornaro

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Re: EM Drive Developments
« Reply #1239 on: 10/02/2014 01:33 AM »
Outside of this thread and forum you would be considered an anomaly.

Well, his martinis are an anomaly.  Dunno about the man, but hey.  I'm being as "excellent" to him as I can!
Sometimes I just flat out don't get it.

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