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#520
by
edzieba
on 05 Nov, 2021 12:49
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Not sure where you place the bar for "independently verifiable evidence"
1) An independently built device*.
2) Tested on an independently designed and built rig by an independent team
3) With a measured signal above the noise floor of that rig
4) With all the known false-positives (e.g. thermal expansion, air currents, supply lead Lorentz force, magnetic field interaction, etc) identified and eliminated as possible signal sources
* At this point, with Shawyer's abject failure to successfully document "these are the cavity dimensions, made of these materials, driven with a signal of X current and Y voltage with waveform Z" in a single specsheet, I'd even accept a Shawyer-built cavity tested completely independently (i.e. Shawyer doesn't get to touch it after handing it over).
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#521
by
D_Dom
on 07 Nov, 2021 22:36
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I agree on the importance (1 and 2) of independent verification which is why I included the reference from his 2014 IAC paper.
The details of construction for his flight thruster are included in his 2019 paper titled "flighthrusterreportissue2.pdf"
Test setup details and results in the paper titled "IAC2019Paper.pdf"
Available on his emdrive.com website.
I have been increasing my knowledge of design for experiments (3 and 4) as I follow this effort over the years. My expectation is that increasing signal to noise and a better understanding of potential false positive results will continue to enlighten.
Low chance I will overcome a lifetime of procrastinating complex mathematics, gaining a full understanding, but it continues to hold my attention (ooh look, SHINY!)
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#522
by
JohnFornaro
on 09 Nov, 2021 13:36
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Low chance I will overcome a lifetime of procrastinating complex mathematics, gaining a full understanding, but it continues to hold my attention (ooh look, SHINY!)
I feel your pain, brother. BTW, I just had some copper roofettes built on my house and I've got a shiny roll of copper left over. Want some? But sriously, the "documentation" offered to date is insufficient for one to build a device such as theirs from scratch.
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#523
by
D_Dom
on 14 Nov, 2021 16:30
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I've got a shiny roll of copper left over. Want some? But sriously, the "documentation" offered to date is insufficient for one to build a device such as theirs from scratch.
You had me at shiny! Let me layout a cone to cubesat flight thruster dimensions and I will send it to you. Have been practicing my welding so if your material doesn't fit the template at least I could work on thin gauge copper LOL.
Building the hardware to provided specifications is no guarantee of developing thrust. Once I gather enough flight quality parts I can get some expert guidance on qual testing the components.
12U is bigger than I was hoping but launch capability at this scale is competitive in the market and increasingly so.
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#524
by
sghill
on 16 Nov, 2021 11:31
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I've got a shiny roll of copper left over. Want some? But sriously, the "documentation" offered to date is insufficient for one to build a device such as theirs from scratch.
You had me at shiny! Let me layout a cone to cubesat flight thruster dimensions and I will send it to you. Have been practicing my welding so if your material doesn't fit the template at least I could work on thin gauge copper LOL.
Building the hardware to provided specifications is no guarantee of developing thrust. Once I gather enough flight quality parts I can get some expert guidance on qual testing the components.
12U is bigger than I was hoping but launch capability at this scale is competitive in the market and increasingly so.
Well, if you are going to try a new cavity build, may I humbly suggest getting away from the multi-mode resonant cavity used in previous devices. I believe it is a huge waste of energy as I elaborated many moons ago in an earlier thread. If you are going to build a resonant cavity. Build one that actually resonates. We've had good equations on how to do this for hundreds of years.
https://forum.nasaspaceflight.com/index.php?topic=45824.msg1857383#msg1857383Quote from: oyzw on 09/16/2018 08:14 am
Maybe EW will loan Jamie their cavity, so he can apply my alterations and start to see significant thrust?
Quote
Professor Yang and I have endorsed the theoretical explanations of Dr. Chen Yue and Cannae's patents that emdirve uses an asymmetric structure to induce the electromagnetic field distribution to form a gradient difference, which produces a radiation pressure difference. In order to achieve this goal, the cone cavity is not the best choice. It uses a more special induction structure to asymmetrically pull the electromagnetic field, such as a very asymmetrical shape, filling with a polymer, adding a metal diaphragm, and etching trenches. They are all common goals. My cavity is just a visual copy, and there is no strict theoretical calculation, so even in the TE013 mode, there is probably no obvious electromagnetic gradient distribution. I will next copy the cavity of Dr. Chen Yue and use the high K substance to further change the trapezoidal cavity.
Since we are on the subject of efficient cavity shapes (and I don't want to read yet another fight between TheTraveller and others). May I take us back to this dicussion:
https://forum.nasaspaceflight.com/index.php?topic=42978.msg1735418#msg1735418
and
https://forum.nasaspaceflight.com/index.php?topic=42978.msg1736210#msg1736210
A trapezoidal cavity is a terrible resonant device.
IMHO, Webster's Horn Equation is the direction to look for improved resonant cavity design, even if the analogies between EM and acoustic propagation don't completely overlap.
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#525
by
TheTraveller
on 26 Nov, 2021 12:51
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#526
by
TheTraveller
on 26 Nov, 2021 13:12
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#527
by
TheTraveller
on 27 Nov, 2021 14:28
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#528
by
Alex_O
on 27 Nov, 2021 16:12
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To consider
No TT, this information does not explain well how emdrive works. And it seems to me that Roger Shawyer himself does not understand well how emdrive works. I think that he has positive results of thrust measurements in secret stands, but he sees and knows that there are measurement artifacts. But if you carefully read the reports of Shawyer, then it seems to me that his reports contain very important information that the thrust of the emdrive will appear only with the correct tuning of not only the cavity, but the entire microwave system.
I tried to study this better, and drew attention to the term
traveling wave.
I found an article discussing traveling wave resonator. And I want to ask experienced members of this forum to look at this article, and suggest thinking about how the information from the article can be useful for emdrive.
SUPERCONDUCTING TRAVELING WAVE CAVITY TUNING STUDIES
https://inspirehep.net/files/18da8e4882c21e36a994033d6695fa37Abstract
Superconducting traveling wave cavity (SCTW) can provide 1.2-1.4 times larger accelerating gradient than conventional standing wave SRF cavities [1]. Firstly, traveling wave opens the way to use other than Pi-mode phase advance per cell which increase transit time factor. Secondly, traveling wave is not so sensitive to cavity length as standing wave, which length is limited to 1 meter because of field flatness degradation. 3 cell SCTW cavity was proposed [2] and built for high gradient traveling wave demonstration and tuning studies. This paper describes analytical model that was used for cavity development. Tuning properties and requirements are also discussed.
Look at Figure 1. We see an example of a microwave cavity with a
feedback waveguide.A superconducting traveling wave cavity (SCTW) was proposed to increase the accelerating gradient [1]. However, it requires a feedback waveguide to transfer RF power from the output of the cavity back to its input section.
Two cavities were built. Traveling wave was successfully adjusted in one of them at room temperature [6].
Analytical model was created to investigate traveling wave adjustment in resonator with feedback waveguide and at the same time include effects of mechanical deformations, such as microphonics, Lorentz force and tuner.
The 3-Cell SCTW cavity analytical model contains four main elements: particle acceleration part (I), tuner (II), waveguide bend (III) and a power coupler (IV). Straight waveguide inserts (Li) can be added mathematically between those elements. As well known, cavity with feedback waveguide resonant frequency corresponds to its electrical length which should be multiple of 2 pi
Thus, cavity can be adjusted mathematically by changing electrical length of the inserts without any additional calculations in FEM software. Also, main elements position along the cavity can be changed by the inserts which is very helpful and does not require any calculation. It is only required to solve a matrix equation of the model to get information about circulating waves in the cavity
TRAVELING WAVE AT ROOM TEMPERATURE
The analytical model was used to predict the required parameters for traveling wave excitation in the 3-Cell SCTW cavity for room temperature test, which was successfully done [6]. It was found that amplitude and phase variation of input signals was enough to highly damp a backward wave which is shown on Figure 3. Input signal parameters found from the model was used in HFSS simulation and a TW regime was obtained, see Figure 5.
It is clear from Figure 5 that there are two EM wave flows in the resonator - forward and backward. And to obtain the traveling wave mode in the microwave path, a simple technique is used.
It was found that amplitude and phase variation of input signals was enough to highly damp a backward wave which is shown on Figure 3.
The rest of this article discusses FEEDING SCHEME.
One of the tuning features of a superconducting traveling wave cavity with feedback waveguide with at least two power couplers is a redistribution of amplitude and phase in the couplers.
It consists of a main power amplifier, two hybrids, two trombone phase shifters, two isolators (circulator with RF load) in a feeding part of the scheme. The first hybrid equally divides the input signal between two channels but adds 90/180 degree phase advance to one of them.
CONCLUSION
A special analytical model, based on S-matrix formalism was created to analyze traveling wave excitation in 3-Cell superconducting traveling wave cavity at different conditions. The model includes such effects as microphonics, Lorentz force detuning and influence of a 2D tuner.
The tuner was calculated by coupled electromagnetic and structural analysis which simulates effect of waveguide wall deformation on propagating H10 mode Sparameters. The model was used to find traveling wave parameters at room temperature and HFSS simulation showed the TW regime at the predicted frequency with the predicted amplitude and phase input signals.
A special feeding scheme with power redistribution capability was proposed and discussed in the paper. This scheme was successfully used for traveling wave excitation in 3-Cell niobium traveling wave cavity at room temperature [6].
So, I have highlighted the important details in this article and I want to ask (everyone !!) - what can you say about
traveling waves? Do you see reliable algorithms for the excitation of traveling waves in the emdrive cavity in the well-known stands? Do you remember how
NASA EW simulated flying bubbles in a virtual vacuum and thought that a simple cavity would easily create a kind of
material flow in a vacuum, which would easily carry an impulse from the internal frame of reference emdrive into the external environment? But in that model, standing waves were created in the RF cavity , and this is like a pendulum, pendulums cannot fly, traveling waves must be used for flight in outer space.
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#529
by
Redclaws
on 27 Nov, 2021 16:26
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To consider
No TT, this information does not explain well how emdrive works. And it seems to me that Roger Shawyer himself does not understand well how emdrive works. I think that he has positive results of thrust measurements in secret stands, but he sees and knows that there are measurement artifacts. But if you carefully read the reports of Shawyer, then it seems to me that his reports contain very important information that the thrust of the emdrive will appear only with the correct tuning of not only the cavity, but the entire microwave system.
I tried to study this better, and drew attention to the term traveling wave.
I found an article discussing traveling wave resonator. And I want to ask experienced members of this forum to look at this article, and suggest thinking about how the information from the article can be useful for emdrive.
SUPERCONDUCTING TRAVELING WAVE CAVITY TUNING STUDIES
https://inspirehep.net/files/18da8e4882c21e36a994033d6695fa37
Abstract
Superconducting traveling wave cavity (SCTW) can provide 1.2-1.4 times larger accelerating gradient than conventional standing wave SRF cavities [1]. Firstly, traveling wave opens the way to use other than Pi-mode phase advance per cell which increase transit time factor. Secondly, traveling wave is not so sensitive to cavity length as standing wave, which length is limited to 1 meter because of field flatness degradation. 3 cell SCTW cavity was proposed [2] and built for high gradient traveling wave demonstration and tuning studies. This paper describes analytical model that was used for cavity development. Tuning properties and requirements are also discussed.
Look at Figure 1. We see an example of a microwave cavity with a feedback waveguide.
A superconducting traveling wave cavity (SCTW) was proposed to increase the accelerating gradient [1]. However, it requires a feedback waveguide to transfer RF power from the output of the cavity back to its input section.
Two cavities were built. Traveling wave was successfully adjusted in one of them at room temperature [6].
Analytical model was created to investigate traveling wave adjustment in resonator with feedback waveguide and at the same time include effects of mechanical deformations, such as microphonics, Lorentz force and tuner.
The 3-Cell SCTW cavity analytical model contains four main elements: particle acceleration part (I), tuner (II), waveguide bend (III) and a power coupler (IV). Straight waveguide inserts (Li) can be added mathematically between those elements. As well known, cavity with feedback waveguide resonant frequency corresponds to its electrical length which should be multiple of 2 pi
Thus, cavity can be adjusted mathematically by changing electrical length of the inserts without any additional calculations in FEM software. Also, main elements position along the cavity can be changed by the inserts which is very helpful and does not require any calculation. It is only required to solve a matrix equation of the model to get information about circulating waves in the cavity
TRAVELING WAVE AT ROOM TEMPERATURE
The analytical model was used to predict the required parameters for traveling wave excitation in the 3-Cell SCTW cavity for room temperature test, which was successfully done [6]. It was found that amplitude and phase variation of input signals was enough to highly damp a backward wave which is shown on Figure 3. Input signal parameters found from the model was used in HFSS simulation and a TW regime was obtained, see Figure 5.
It is clear from Figure 5 that there are two EM wave flows in the resonator - forward and backward. And to obtain the traveling wave mode in the microwave path, a simple technique is used.
It was found that amplitude and phase variation of input signals was enough to highly damp a backward wave which is shown on Figure 3.
The rest of this article discusses FEEDING SCHEME.
One of the tuning features of a superconducting traveling wave cavity with feedback waveguide with at least two power couplers is a redistribution of amplitude and phase in the couplers.
It consists of a main power amplifier, two hybrids, two trombone phase shifters, two isolators (circulator with RF load) in a feeding part of the scheme. The first hybrid equally divides the input signal between two channels but adds 90/180 degree phase advance to one of them.
CONCLUSION
A special analytical model, based on S-matrix formalism was created to analyze traveling wave excitation in 3-Cell superconducting traveling wave cavity at different conditions. The model includes such effects as microphonics, Lorentz force detuning and influence of a 2D tuner.
The tuner was calculated by coupled electromagnetic and structural analysis which simulates effect of waveguide wall deformation on propagating H10 mode Sparameters. The model was used to find traveling wave parameters at room temperature and HFSS simulation showed the TW regime at the predicted frequency with the predicted amplitude and phase input signals.
A special feeding scheme with power redistribution capability was proposed and discussed in the paper. This scheme was successfully used for traveling wave excitation in 3-Cell niobium traveling wave cavity at room temperature [6].
So, I have highlighted the important details in this article and I want to ask (everyone !!) - what can you say about traveling waves? Do you see reliable algorithms for the excitation of traveling waves in the emdrive cavity in the well-known stands? Do you remember how NASA EW simulated flying bubbles in a virtual vacuum and thought that a simple cavity would easily create a kind of material flow in a vacuum, which would easily carry an impulse from the internal frame of reference emdrive into the external environment? But in that model, standing waves were created in the RF cavity , and this is like a pendulum, pendulums cannot fly, traveling waves must be used for flight in outer space.
Or *maybe*, just maybe, Shawyer is measuring only artifacts. The entire post here starts with the ironclad assumption that EmDrive (whatever that actually is) *works*.
Traveling wave excitation is unimportant, since there's no medium for them to push against.
It is so odd to read this thread - it is so obvious with a moments observation that the various proponents of EmDrive are running along the edges of nothing, hiding the truth either from themselves or from others. They operate with a conviction that it must work but periodically shrink the scale of purported thrust or entirely change the mechanism by which it is supposed to work (and therefore the detailed requirements of the design). This combination of things *should* be considered to invalidate all previous results (since the scale of the thrust was incorrect and/or the supposed mechanism was wrong), but it never is.
It's so obviously a continual process based on conviction that something has been found and it must work. When the actual something that has been supposedly found vanishes, the response is to move on to a different something, but still call it EmDrive.
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#530
by
Alex_O
on 27 Nov, 2021 19:44
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Traveling wave excitation is unimportant, since there's no medium for them to push against.
Everything is correct. This means that you must learn new physics, which will allow a closed microwave cavity to create a physical process of radiation of a pulse from the cavity to the outside. Traveling waves can be useful, and it is possible that people just haven't figured it out yet.
upd
Maybe you should try to see how EM waves move in the EM cavity? When I thought about traveling waves, I mentally saw how in a cavity, at the speed of light, a portion of matter rotates (EM field is a type of matter, this matter has density, it has mass, right?) And mentally I compared it all with a gear oil pump. In the well-known experiments of Emdrive there is only one part from this pump - only one gear (and two gears are needed). And it cannot even rotate, as there are standing waves. Therefore, there is no rocket thrust.
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#531
by
Alex_O
on 29 Nov, 2021 06:37
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Hi Bob Woods and SpacedX!
Guys, I don’t understand why you put likes for a post where people don’t believe in emdrive?
It seems to me that I have shown very well how to properly tune the design of a microwave system, isn't it?
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#532
by
Crispy
on 29 Nov, 2021 08:34
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It is so odd to read this thread - it is so obvious with a moments observation that the various proponents of EmDrive are running along the edges of nothing, hiding the truth either from themselves or from others. They operate with a conviction that it must work but periodically shrink the scale of purported thrust or entirely change the mechanism by which it is supposed to work (and therefore the detailed requirements of the design). This combination of things *should* be considered to invalidate all previous results (since the scale of the thrust was incorrect and/or the supposed mechanism was wrong), but it never is.
It's so obviously a continual process based on conviction that something has been found and it must work. When the actual something that has been supposedly found vanishes, the response is to move on to a different something, but still call it EmDrive.
It is exactly the same behaviour you see with "end times" cults. When the predicted rapture does not materialise, the followers will happily convince themselves that this is still all part of the plan and that *next time* they will be ushered into paradise. Cult is a strong word so to be clear I'm not calling the EM Drive a cult. But human behaviour is universal and the same patterns can be found everywhere
When other reactionless drive threads get shut down without mercy, I'm astonished that this one is still here tbh.
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#533
by
sghill
on 29 Nov, 2021 15:29
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When other reactionless drive threads get shut down without mercy, I'm astonished that this one is still here tbh.
Because this thread provides a respectful place to share thoughts on a technology that has not been falsified. We could have an equally controversial thread on whether or not the Big Bang occurred as described in the Standard Model.
For my own part, I am of the opinion that this topic has generated enormous interest (some generated by posters in this thread), and the possibility of a reactionless thruster would open the stars to humanity, so I'm willing to put up with some level of handwaving in pursuit of the topic.
IMHO, a dedicated thread where hand-waving is discouraged and sober mathematics are pursued has almost no downside other than somehow offending people such as yourself. This topic has remained remarkably self-constrained over a number of years, and we are now on thread 12. Please contribute to either the falsification or proof of the topic or move on.
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#534
by
Alex_O
on 29 Nov, 2021 15:34
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Okay, let's talk a little.
1. Why emdrive?
Because a space engine based on an EM resonator is the ideal engine.
1. The engine consumes energy in a convenient form - in the form of electricity.
2. Energy is used in a convenient, practical form - in microwaves, there is no radiation and high temperatures (in comparison with a nuclear or photon engine for annihilation reactions).
3. A high energy density can be created in the RF resonator. For example, 10 orders of magnitude more than in a photon (microwave) rocket.
4. This is a cold engine. If the resonator is made of superconductors, such a motor can be cooled by space cold, and in general such a motor can operate at ambient temperature.
5. Theorem (postulate) - an ideal space engine is a cold engine that operates at the cryogenic temperature of space, there are no heat losses in it.
5.1 If the photonic rocket is the best (in terms of specific impulse and possible 100% conversion of the internal energy stored in the fuel) - then this is the worst rocket, since all the energy of the photonic rocket flies out of the rocket into the "exhaust pipe". A photonic rocket is a heating pad, the photonic rocket spends all its energy on heating the universe. Its working body (mirror) in practical design can be under radiation pressure at the level of 1 atmosphere and the temperature of the mirror will be at the level of 150,000 K. This main working body must be cooled, which is practically impossible .. And there is also a high level of radiation that will hit the rocket crew ..
6. Methods for increasing the efficiency of motors through energy recovery are known in the art. Any resonator is an example of an energy recovery engineering system. In emdrive, the recuperation coefficient can be at the quality level
quality factor, 10 orders of magnitude higher than that of a photonic rocket. Consequently, the thrust of an emdrive can be 10 orders of magnitude greater than that of a photonic rocket.
7. An ideal engine should use simple, cheap and widely available resources (such as water, air, sand ..).
In space, there is the cheapest and most common resource of the system - outer space. Cosmic emptiness, vacuum. An ideal space engine would use this cheap resource - the space vacuum. And even in the most general case - outer space.
There are physicists and there are engineers. Engineers build machines, make inventions, find new ideas for using machines. And physics is just a provider, a provider of physical effects. An engineer, when designing machines, uses fundamental knowledge from the history of development (evolution, improvement of machines) and the fundamental laws of the development of technical systems.
With that said, we make a very short summary.
Emdrive is the perfect motor. Its main function is to create movement in space. Emdrive must use a cheap resource - space (vacuum). And physicists must offer the EMDrive engineer useful physical effects - for the direct use of the resources of the vacuum.
In Dresden, the task of building a laboratory experiment of the highest possible purity was solved. It worked.
Now we need to learn how to create a rocket thrust through the use of physical effects, which will create thrust through the use of the cheapest resource in nature - space void/emptiness.
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#535
by
Phil Stooke
on 29 Nov, 2021 15:42
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OK. Let us know when you get it working.
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#536
by
daedalus1
on 29 Nov, 2021 15:49
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Seems like he's just plucking numbers out of thin air, or is it space?
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#537
by
HoratioNelson
on 29 Nov, 2021 15:59
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In Dresden, the task of building a laboratory experiment of the highest possible purity was solved. It worked.
Could you explain what you mean by "In Dresden"? Because Tajmar et al. at the Dresden University of Technology state:
Our measurements refute all EmDrive claims by at least 3 orders of magnitude.
Are you talking about a different research group? Or something else? Or are you trying to claim that their preliminary conference paper (with the known, and now corrected, experimental error) prove something?
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#538
by
Alex_O
on 29 Nov, 2021 16:01
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OK. Let us know when you get it working.
https://forum.nasaspaceflight.com/index.php?topic=49270.msg2097195#msg2097195The approximate setting of the problem is described in this post.
Question to Dr. Harold "Sonny" White (trial, please evaluate, can this be a good question?)
Vacuum. There are virtual particles in a vacuum. A high-energy photon can create (from vacuum?) A pair of electron-positron particles, (for example). But you need a photon with a lot of energy, and this is somehow bad.
What if you try to use low-energy photons (as in Emdrive) to create (I use my own, special term) certain pseudoparticles, quasiparticles (https://en.wikipedia.org/wiki/Quasiparticle). These are (figuratively) not electrons and not positrons. This is something else. This is something that can be completely virtual, with a short life span. Perhaps the term phonon, soliton - is somehow suitable for describing this idea.
In short, here is a vacuum, and we in his virtual world want to create something like that, a little bit less virtual. I will call it a vacuum chip. This chip is something that should be useful for space flights - since this chip will have useful physical properties.
For example, this chip may have electrical, magnetic properties. And this chip can somehow be pushed. Using, for example, electromagnetic forces.
We discussed
traveling waves above, and we understand that standing waves are not suitable at all.
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#539
by
Alex_O
on 29 Nov, 2021 16:15
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In Dresden, the task of building a laboratory experiment of the highest possible purity was solved. It worked.
Could you explain what you mean by "In Dresden"? Because Tajmar et al. at the Dresden University of Technology state:
Our measurements refute all EmDrive claims by at least 3 orders of magnitude.
Are you talking about a different research group? Or something else? Or are you trying to claim that their preliminary conference paper (with the known, and now corrected, experimental error) prove something?
I have of course discussed the results of Tajmar et al. at the Dresden University of Technology state.
But I asked why there is no thrust? Earlier on this forum, I asked if emdrive can work - then where, in what place, with the help of what physics it will create, will it create, should it create thrust?
--
Various hypotheses have been proposed, but there is no proposal for a physical interface. On the physical protocol for the transmission of a pulse from a closed-type microwave resonator to the outside. That in order to use this protocol, the design of the RF cavity must have a special element, device, or simply an adapter. And it is obvious that this physics (adapter) must work at some subtle, microscopic level, at some frequency, according to a special algorithm.
