Author Topic: EM Drive Developments - related to space flight applications - Thread 3  (Read 1803871 times)

Offline vulture4

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If you discover fire (i.e. you come zipping overhead in a reactionless vehicle, or that electrons cannot be ejected from a cathode by photons below a specific energy) then yes, I grant that theory will have to follow. But in this case the detected results have all been well withing the range that can easily be produced by spurious gas-thermal or electromagnetic force induction effects, since the principal mode of attenuation in a resonator is the induction of eddy currents in the conductive shell. Occam's Razor applies; the simplest explanation is generally the most likely.

And this is not an accidental discovery of a dramatic but unexpected phenomenon. It is an attempt to observe a postulated phenomenon that has never been observed and is contrary to current theory. This requires a new theory, otherwise it is impossible to design an effective test.
« Last Edit: 06/25/2015 11:30 PM by vulture4 »

Offline rfmwguy

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If you discover fire (i.e. you come zipping overhead in a reactionless vehicle, or that electrons cannot be ejected from a cathode by photons below a specific energy) then yes, I grant that theory will have to follow. But in this case the detected results have all been well withing the range that can easily be produced by spurious gas-thermal or electromagnetic force induction effects, since the principal mode of attenuation in a resonator is the induction of eddy currents in the conductive shell. Occam's Razor applies; the simplest explanation is generally the most likely.

And this is not an accidental discovery of a dramatic but unexpected phenomenon. It is an attempt to observe a postulated phenomenon that has never been observed and is contrary to current theory. This requires a new theory, otherwise it is impossible to design an effective test.

What you say is true about resolution or dynamic range in test equipment/platforms. Results have to be "out of the noise" and monitored for natural causes. Where many differ from your academic/classic approach is that discoveries are not always predicted on paper first.

Speaking solely for myself, where science has stumbled lately is a too heavy reliance on theory first. Its conservative and followed by most business entities to satisfy accountants and egos (fear of failure). If you look at breakthrough discovery trends, we have very little in the way of game-changing technologies...miniaturization of existing design, more computing power? Yes...Propulsion? No way, Jose (sorry Doc).

This field has been stuck in the goddard days, scaled up, yes, but name a breakthrough...ion engines aside. There have been none. Everything in propulsion is simple retooling of past discoveries. So my advice is to go to grass-roots, independent experimentation and serendipity*. Discouragement of that is not helpful IMO. We have enough accepted theories without solid experimental evidence, lets get some proof and let the theories catch up.../end ramble

* https://en.wikipedia.org/wiki/Role_of_chance_in_scientific_discoveries

Offline zero123

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Frankly, between the proposal that the EM Drive somehow "knows" its velocity so that it cannot become a free-energy machine and this proposal that the EM Drive has to have an unspecified level of vibration amplitude and frequency to exert a force... well I better stop here. :)

What Free Energy?
The Work done by the EMDrive generated Force moving a Mass, is powered by Energy from the power supply.

Electrical energy to

Microwave energy to

Mechanical energy to

Acceleration to

Kinetic energy

An EMDrive powered ship obeys A = F/M.
Accumulated ships Velocity or Kinetic Energy is not part of A = F/M.

As for getting an EMDrive to generate an external Force, there 1st needs to be an external Force that moves the EMDrive and causes an internal Doppler shift of the resonant standing waves.

With no external Force, there is no internal Doppler shift and no EMDrive generated Force.

I already showed you here how Shawyer's own proposed interstellar probe gains much more kinetic energy than the energy its power source can produce and yet you still claim that it just converts electrical energy to kinetic energy and that all is good. Why is that? Where does all of that extra kinetic energy come from?
« Last Edit: 06/26/2015 12:13 AM by zero123 »

Offline Tetrakis

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This field has been stuck in the goddard days, scaled up, yes, but name a breakthrough...ion engines aside. There have been none. Everything in propulsion is simple retooling of past discoveries. So my advice is to go to grass-roots, independent experimentation and serendipity*. Discouragement of that is not helpful IMO. We have enough accepted theories without solid experimental evidence, lets get some proof and let the theories catch up.../end ramble

* https://en.wikipedia.org/wiki/Role_of_chance_in_scientific_discoveries

I completely agree with your sentiment. In my own scientific work, keeping my eyes open for unexpected, serendipitous results has given me many insights. This is why I think that a more rational approach is to focus on theories that rely on effects that have an experimental basis (not things like QV, below-ZPE energies, etc.). Its fine to keep an eye out for fire, but I think that focusing on theories that are known to be senseless narrows "search by chance" too much.

I don't think its too much to ask that if you want to do something that would require new physics, the rational place to start is with making new physics. Be a physicist, come up with a sound model that has a testable hypothesis, and test it in a rigorous way. What we have here are unsound models being tested without due rigor (in most cases).

« Last Edit: 06/26/2015 12:21 AM by Tetrakis »

Online aero

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Am I reading right?

Everything there is to know is already known?
Don't bother with education.
Everything there is to discover has already been discovered?
So quit looking.
Every word there is to speak has already been spoken?
So why doesn't everyone just close their mouths?
Retired, working interesting problems

Offline DrBagelBites

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rfmwguy,


First time posting, so take it easy on me. :) I have been reviewing your build, and I am building a very similar one as well. The problem I have been finding when doing some preliminary calculations is measuring the very small differences due to the thrust.

You described your setup as a balanced fulcrum with a laser pointer on one end to measure the deflection. While, I am not sure what you will be using to measure the distance traveled by the laser, it is still a very small amount.

I was thinking of the same setup, but decided to go a difference route after doing some calculations.

I have attached an explanation of my thinking. Could definitely be wrong and not at all what you are doing, but I thought I would share.

-I

Offline Rodal

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Welcome to our forum !

Have you seen rfmwguy's video ?

Thank you for the welcome!

I have not seen the video, no.

Here it is:


Offline rfmwguy

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rfmwguy,


First time posting, so take it easy on me. :) I have been reviewing your build, and I am building a very similar one as well. The problem I have been finding when doing some preliminary calculations is measuring the very small differences due to the thrust.

You described your setup as a balanced fulcrum with a laser pointer on one end to measure the deflection. While, I am not sure what you will be using to measure the distance traveled by the laser, it is still a very small amount.

I was thinking of the same setup, but decided to go a difference route after doing some calculations.

I have attached an explanation of my thinking. Could definitely be wrong and not at all what you are doing, but I thought I would share.

-I

I remember helping you with the 8W amp selection...cool. After you watch my 1st fulcrum video here, I'll give you some updates below that:

EDIT - Ooops, Doc already posted video

Based on NSF inputs (thanks) I will enhance the simple fulcrum in a few ways; add oil dampening system to minimize oscillations and settling time; stiffen the beam with a wire and mast configuration. Increase the laser path length. I hope to play around with it this weekend and take another video. I want it settled before I start on the frustum assembly.

There is no laser distance measurement, only deflection of the laser terminus (spot). The video shows about a 2.5 inch deflection of 200 mg. I plan on trying to get this deflection distance down to about 40 mg, well above what I think the "noise" will be. Regardless, I'll only be convinced of "thrust" if the results are repeatable and at least twice the displacement of "noise" or random oscillations of the assembly. No digital scales until it passes the basic mechanical-only testing.
« Last Edit: 06/26/2015 12:46 AM by rfmwguy »

Offline Prunesquallor

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It seems that a consensus has emerged, even among EMdrive proponents, that Shawyer's math is wrong and his experiments suspect. Yang's results are suspect because of the poor testing environment and the generally atrocious quality of scientific institutions in China. NASA's results, under the highest quality testing environment of the three significant experimental efforts, also show the smallest measured force (probably within their experimental error, as shown by the test with different device orientation). DIY EMDrivers' results are, so far, all suspect and lack rigor; they will not exceed the standards set by NASA.

So the inventor of this device has little credibility, the positive results from other labs are suspect, null, or insignificant with respect to error, and yet there is still enormous enthusiasm in its development. Herculean efforts are put forth to provide a theoretical basis for data that is too weak to publish in a reputable journal. Why?

Because the implications, if true are complete game-changers comparable to the invention of the internal combustion engine.

That's why.
Retired, yet... not

Offline DrBagelBites

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I remember helping you with the 8W amp selection...cool. After you watch my 1st fulcrum video here, I'll give you some updates below that:



Based on NSF inputs (thanks) I will enhance the simple fulcrum in a few ways; add oil dampening system to minimize oscillations and settling time; stiffen the beam with a wire and mast configuration. Increase the laser path length. I hope to play around with it this weekend and take another video. I want it settled before I start on the frustum assembly.

There is no laser distance measurement, only deflection of the laser terminus (spot). The video shows about a 2.5 inch deflection of 200 mg. I plan on trying to get this deflection distance down to about 40 mg, well above what I think the "noise" will be. Regardless, I'll only be convinced of "thrust" if the results are repeatable and at least twice the displacement of "noise" or random oscillations of the assembly. No digital scales until it passes the basic mechanical-only testing.

Alright, I have watched the video and your setup looks great!

I must have typed it incorrectly, but I was referring to the laser terminus, not actual laser measurement. So, my fault on that.

Have you checked for linearity of distance to weight?

The NASA test around our power input of 8W is 0.05 mN which is roughly 0.005 mg. So, assuming you have a linear relationship  of 2.5 in/40 mg, the hypothetical thrust will cause a rise of about 0.000318 inches.

Is that correct?

-I

edit: changed 200mg to 40 mg
« Last Edit: 06/26/2015 01:01 AM by DrBagelBites »

Offline rfmwguy

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(...)

Alright, I have watched the video and your setup looks great!

I must have typed it incorrectly, but I was referring to the laser terminus, not actual laser measurement. So, my fault on that.

Have you checked for linearity of distance to weight?

The NASA test around our power input of 8W is 0.05 mN which is roughly 0.005 mg. So, assuming you have a linear relationship  of 2.5 in/200 mg, the hypothetical thrust will cause a rise of about 0.0000625 inches.

Is that correct?

-I

I saw that in your information. I used traveller's spreadsheet, which is the only working spreadsheet publicly released, (many thanks Mr T.) and it came up with 185 mg of gram-force with a Q of 50K. Not expecting to see that type of Q, I scaled it back to 10K. Plug some numbers into the spreadsheet and see where gram force comes out. Your numbers would be far too small for EMDIYers to validate. Let me know.

Offline Prunesquallor

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Quote
All we have now is theoretical naysayers claiming such, but not one, to my knowledge has completed nor commissioned a build, so sure of their own belief system.
I am all for testing and trying out this idea. But I think it is unfair to say doubt is based only on a belief system. I've carefully reviewed the available papers, with or without peer review, and discussed the ideas with physicists who would dearly love to have a reactionless drive. The difficulty is that there are errors in the theoretical rationale and in the experimental procedures. I am trying to get the money together for a simple test of the thermal recoil effect, i.e. the apparent thrust produced by unequal heating, using resistance heating only (no RF) at various pressures between atmospheric and vaccuum. Test results are useless unless errors are carefully measured.

Really though, theory must come first. An experiment is only useful in physics when a solid theoretical foundation is developed first. That doesn't mean the exact results of the experiment can be predicted, i.e. no one knew exactly what mass the Higgs boson would have. But the theory underlying it was so solid there was almost no doubt the particle existed. Similarly, the first demonstration of the Casimir effect was considered almost routine, since its existence was so well based in physical theory.

Disagree.  See Rutherford, Curie, Penzias, et. al.
« Last Edit: 06/26/2015 03:04 AM by Prunesquallor »
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Offline Rodal

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(...)

Alright, I have watched the video and your setup looks great!

I must have typed it incorrectly, but I was referring to the laser terminus, not actual laser measurement. So, my fault on that.

Have you checked for linearity of distance to weight?

The NASA test around our power input of 8W is 0.05 mN which is roughly 0.005 mg. So, assuming you have a linear relationship  of 2.5 in/200 mg, the hypothetical thrust will cause a rise of about 0.0000625 inches.

Is that correct?

-I

I saw that in your information. I used traveller's spreadsheet, which is the only working spreadsheet publicly released, (many thanks Mr T.) and it came up with 185 mg of gram-force with a Q of 50K. Not expecting to see that type of Q, I scaled it back to 10K. Plug some numbers into the spreadsheet and see where gram force comes out. Your numbers would be far too small for EMDIYers to validate. Let me know.
Hey Dave,

take a gander at this table:  http://emdrive.wiki/Experimental_Results

in the rightmost columns labeled Force/PowerInput

the numbers from TheTraveller are based on Shawyer's formula: they are (rounding off) 100 to 1,000 times greater than NASA' findings with mode TM212.

So, if your Q is 5,000 instead of 50,000 and your force/PowerInput agrees with NASA (as Iulian Berca's did) then your force could be 10,000 (ten thousand times) smaller than what TheTraveller calculated.

Such is the disparity between what NASA and Shawyer have reported.  That's why many people in this forum have stated that NASA effectively nullified Shawyer's measurements (actually NASA got zero force without a dielectric).
« Last Edit: 06/26/2015 01:20 AM by Rodal »

Offline DrBagelBites

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I saw that in your information. I used traveller's spreadsheet, which is the only working spreadsheet publicly released, (many thanks Mr T.) and it came up with 185 mg of gram-force with a Q of 50K. Not expecting to see that type of Q, I scaled it back to 10K. Plug some numbers into the spreadsheet and see where gram force comes out. Your numbers would be far too small for EMDIYers to validate. Let me know.

That is the problem I have been having. My calculated values, by using experimental data found on the emdrive wiki, are far to small to be measured by the EMDIYer. So, I am a bit stuck on what to expect.

I don't have that kind of space to create what you have, so I have to figure out a smaller way of testing this thing.


Offline frobnicat

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...
If you have to play a guitar string, where should you strike the string ?  at a maxima of the string vibration? or at a node of the string vibration, where nothing will move?
...

Not so fast doc, exciting a resonance with a single hit (strike a string) and then the resonating body is free from interaction with the excitation agent (thumb away from string after strike) may not have the same constraints as increasing and maintaining a resonance in a constant way, period after period, with excitation agent always interacting with resonating body. For instance when I want to make a street post wiggle in resonance at ever increasing amplitude, I will give a periodic nudge near the base (close to the node) and not at top of post as it would be hard not to dampen oscillation at wide amplitudes (rather than add energy). This is just ... arm waving, maybe I'm wrong on this one and the mechanical analogy doesn't hold for RF resonant cavity (not my domain). Trying to be more precise : when coupling a periodic active action (drive) with a passive (driven) resonant system, impedance must match otherwise power bounces back from driven system to the drive, no ? Exciting at a node is clearly sterile, but when manually wiggling a (solidly grounded elastic) post, the anti-node at top is not the best place, at least for an arm waver...

Offline Rodal

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...
If you have to play a guitar string, where should you strike the string ?  at a maxima of the string vibration? or at a node of the string vibration, where nothing will move?
...

Not so fast doc, exciting a resonance with a single hit (strike a string) and then the resonating body is free from interaction with the excitation agent (thumb away from string after strike) may not have the same constraints as increasing and maintaining a resonance in a constant way, period after period, with excitation agent always interacting with resonating body. For instance when I want to make a street post wiggle in resonance at ever increasing amplitude, I will give a periodic nudge near the base (close to the node) and not at top of post as it would be hard not to dampen oscillation at wide amplitudes (rather than add energy). This is just ... arm waving, maybe I'm wrong on this one and the mechanical analogy doesn't hold for RF resonant cavity (not my domain). Trying to be more precise : when coupling a periodic active action (drive) with a passive (driven) resonant system, impedance must match otherwise power bounces back from driven system to the drive, no ? Exciting at a node is clearly sterile, but when manually wiggling a (solidly grounded elastic) post, the anti-node at top is not the best place, at least for an arm waver...
Yeap, the guitar string is a bad example of a resonating cavity.  Thanks,  I'm editing my post.
« Last Edit: 06/26/2015 01:49 AM by Rodal »

Offline SeeShells

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rfmwguy,


First time posting, so take it easy on me. :) I have been reviewing your build, and I am building a very similar one as well. The problem I have been finding when doing some preliminary calculations is measuring the very small differences due to the thrust.

You described your setup as a balanced fulcrum with a laser pointer on one end to measure the deflection. While, I am not sure what you will be using to measure the distance traveled by the laser, it is still a very small amount.

I was thinking of the same setup, but decided to go a difference route after doing some calculations.

I have attached an explanation of my thinking. Could definitely be wrong and not at all what you are doing, but I thought I would share.

-I

I remember helping you with the 8W amp selection...cool. After you watch my 1st fulcrum video here, I'll give you some updates below that:

EDIT - Ooops, Doc already posted video

Based on NSF inputs (thanks) I will enhance the simple fulcrum in a few ways; add oil dampening system to minimize oscillations and settling time; stiffen the beam with a wire and mast configuration. Increase the laser path length. I hope to play around with it this weekend and take another video. I want it settled before I start on the frustum assembly.

There is no laser distance measurement, only deflection of the laser terminus (spot). The video shows about a 2.5 inch deflection of 200 mg. I plan on trying to get this deflection distance down to about 40 mg, well above what I think the "noise" will be. Regardless, I'll only be convinced of "thrust" if the results are repeatable and at least twice the displacement of "noise" or random oscillations of the assembly. No digital scales until it passes the basic mechanical-only testing.
Good information and some sweet basic engineering. I also am going with the fulcrum. I've  started to laminate the beam I'm going to use.

Took a 100 mile RT today only to find that the very nice piece of copper with perforations sold this morning, they we supposed to hold it for me. grrrr. So I will be finding another supplier.

Shell

Offline DrBagelBites

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Good information and some sweet basic engineering. I also am going with the fulcrum. I've  started to laminate the beam I'm going to use.

Took a 100 mile RT today only to find that the very nice piece of copper with perforations sold this morning, they we supposed to hold it for me. grrrr. So I will be finding another supplier.

Shell

Wow! What a build! :D

How long of a beam are you using?

-I


Offline Rodal

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...
Good information and some sweet basic engineering. I also am going with the fulcrum. I've  started to laminate the beam I'm going to use.

Took a 100 mile RT today only to find that the very nice piece of copper with perforations sold this morning, they we supposed to hold it for me. grrrr. So I will be finding another supplier.

Shell
To those that see this for the first time: notice that Shell's EM Drive would be subject to buoyancy problems if it would be made with homogeneous  copper sheet (like all other EM Drive testers up to now).  Shell's will be made with a perforated sheet so she will eliminate buoyancy and other gas effects.
« Last Edit: 06/26/2015 02:01 AM by Rodal »

Offline rfmwguy

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I saw that in your information. I used traveller's spreadsheet, which is the only working spreadsheet publicly released, (many thanks Mr T.) and it came up with 185 mg of gram-force with a Q of 50K. Not expecting to see that type of Q, I scaled it back to 10K. Plug some numbers into the spreadsheet and see where gram force comes out. Your numbers would be far too small for EMDIYers to validate. Let me know.

That is the problem I have been having. My calculated values, by using experimental data found on the emdrive wiki, are far to small to be measured by the EMDIYer. So, I am a bit stuck on what to expect.

I don't have that kind of space to create what you have, so I have to figure out a smaller way of testing this thing.

If I achieve null results using the shawer inspired spreadsheet, then I would conclude his position is irrelevant. Reason I chose to follow it was its the only public tool I am aware of and its within a diyers measurement capability. Should nasa cough up a designers tool, which I highly doubt, I would consider it provided it doesn't require NIST to test the results.


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