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#1520 by OnlyMe on 12 Sep, 2017 17:45
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I don't understand why people can simultaneously say that gravity isn't a force (it isn't) and at the same time gravitation is a member of the fundamental force club. Probably why it hasn't been quantized yet.
Maybe it isn't quantized.Quotepeople can simultaneously say that gravity isn't a force (it isn't)
MIT Professor Bertschinger disagrees that gravity is not a force, also the whole https://en.wikipedia.org/wiki/Hierarchy_problem has to do with the weakness of the gravitational force compared to the other forces (electromagnetic, weak and strong). It is agreed that there are "4 forces: gravity, weak, strong and electromagnetic" look deeper:
The discussions about gravity "not being a force" are pedagogical, trying people to get to understand the geometrical nature of gravity in general relativity as arising from spacetime curvature.
Dr. Rodal,
To some extent I believe this post of yours supports my interpretation of our earlier posts re: whether GR and spacetime might be interpreted as descriptive of gravitation, rather than a causative model.
As a descriptive model of gravitation, GR and spacetime could accommodate gravity as either a force or "not a force". Quantum gravity models would no longer have to mirror the field equations of GR, as long as the force carries, whether particles or fields, provide an energy/momentum structure that can be described as a field consistent with the field equations of GR.
It is easy to describe the propagation and distribution of sound waves, even EM radiation, as geometric fields and still associate both with a transfer of momentum, of one sort or another. In both of those cases we have a far better understanding of the fundamental underlying classical and quantum mechanical mechanisms.
Interpreting GR and spacetime as descriptive, permits the potential for the existence of more fundamental mechanisms, without excluding the possibility of the causative interpretation. While fixation on spacetime as the causative basis of gravitation, does tend to preclude the inclusion and/or incorporation of other potential fundamental mechanisms, which could be described by the same geometric dynamics. -
#1521 by LowerAtmosphere on 12 Sep, 2017 18:01
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Physicists at Princeton develop quantitative prediction for alpha radiation resulting from Alfven waves in confined plasma, thereby discovering that the key to plasma stability may be elongation and r at qmin.
https://www.eurekalert.org/pub_releases/2017-09/dppl-ppn091217.php
https://phys.org/news/2017-09-physicists-stabilize-next-generation-fusion-plasmas.html
http://dx.doi.org/10.1088/1741-4326/aa6456
To little surprise they determined that the number (and instability) of Alfven waves is directly responsible for 40% particle loss during operation and this allowed them to predict conditions under which there would be less alpha particle loss (radiation of walls). Practical applications can be found in confined plasmas and even regular confined particle fields as the suppression of Alfven eigenmodes and reduction of turbulence can increase even EM Drive coherency and peak energy density. The most interesting result is regarding r. Might be useful in circularized EM Drive designs and would imply that kinks and elongation in the design are required IF the walls are proven to have sufficient current to contain the particles and improved absorption (controlled emissions/controlled shearing and therefore momentum pulses) by the internal particle soup is desired.
Key take-away snippets from the paper*:
There are two methods for suppressing AEs in fusion plasmas: the eigenmodes can be pushed out of their gaps and into the Alfvén continuum by manipulating the equilibrium profiles, the fast-ion drive can be changed by moving the fast-ion drive away from the mode location[...] A better way to increase α (normalized pressure gradient within the plasma mean free path) is by raising q0 and elevating the q profile in the plasma center. Note that α is proportional to q2, so raising q0 is an effective way to increase α while αcrit depends on the shear and is independent of q0[...] To suppress reverse shearing however it is best to locate Qmin as far as possible from the fast-ion reconnection area. This new insight, includes moving Qmin as far out as possible (increasing the radius). This makes sense going from the previous understanding that the Alfven continuum damping increases with r and from a more general view it also would decrease the energy density given the same input.
*All Q and values from the context of the plasma stream not the containment field
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Hopefully this may distract from some of the bickering
Edit: added some slides which may help 'guide' you into the topic
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#1522 by Rodal on 12 Sep, 2017 18:35
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I attach a picture of the present MEGA drive (bottom picture) to compare with the early version from years ago shown in the book (top picture).From what I was thinking about above, the same thing is happening in a MET (just talking about the device, not Mach effects theory). A changing energy density (capacitor being charged and discharged) is being jerked around (back and forth in the case of a MET) by a PZT. The return journey doesn't look like a good design feature to have, although if you think about it, it's inevitable in a resonant system. I'm thinking really hard about why the addition of the rubber pad (from the book Making Starships) greatly increased the thrust. That's a good way to absorb energy and reduce the return energy by reducing r. That rubber pad is dissipative. That's the asymmetry. This is an electromechanical version of the EMdrive. They're analogous.
Pics included for research purposes.
May I suggest that the rubber pad allowed room for the copper block to move back and forth, thus allowed more intense vibration? If so, it can be replaced with a compressed spring.
It looks to me like the rubber pad is the dissipative element, serving the same function as the dielectric disc in an EMdrive. They're both lowering the amount of reflected energy by turning it into heat. They both serve to facilitate a partial standing wave.
If you really think about it, it's immediately obvious why a fully superconducting EMdrive is a BAD idea. You better have a load on it.
Do you predict the "thrust" to change direction, if the rubber washer is installed on the other side (on the nut side, not on the bolt side)? From my understanding of how it worked, the "thrust" will likely change direction.
Notice how much smaller is the rubber gasket compared to the rubber pad used for the device of many years ago shown in the book. The present rubber gasket is confined to distribute stresses resulting from the fasteners, to reduce stress concentrations (see https://forum.nasaspaceflight.com/index.php?topic=42978.msg1721787#msg1721787 for explanation), rather than a large rubber pad as shown in the book. Moreover, when thicker rubber pads were tested, the measured force decreased, as one would expect from dissipation effect decreasing the quality of resonance Q, so experiment confirms theory.
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#1523 by TheTraveller on 12 Sep, 2017 18:36
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Something to think about:
Cavity Q is defined as stored energy / energy loss per cycle. Which means after Q cycles, all the photon's energy is gone, mainly converted into thermal heating of the cavity via wall eddy currents.
Photons in a cavity eventually die, losing some energy each cycle to ohmic wall heating.
The source of the eddy currents induced in the cavity walls are the time varing H fields of the photons. Energy flows from the photons into the thermal heating of the eddy current rings around the end plates and around the side walls.
In both accelerator cavities and in EmDrives additional photon energy loss per cycle is due to some cavity energy being used to accelerate mass. Either very small particles, very rapidly to near c velocity as in particle accelerators or EmDrive and ship mass as in the EmDrive.
Spend some time and research accelerator cavity Q and learn there are 3 ways trapped photons lose energy per cycle and as photon energy drops, so too does photon momentum drop ie p = E/c.
The 3 ways are:
1) photon energy loss per cycle to cavity wall heating via eddy currents. Referred to as Qu or Q unloaded.
2) photon energy loss per cycle back through the coupler, which should be the same energy loss per cycle as in 1. Referred to as Ql or Q loaded.
3) photon energy and momentum used or loss per cycle for the acceleration of mass where both CofM and CofE are conserved. Referred to as Qext or Q external.
I understand some here may be learning new stuff here, so before thinking it is fluff, do some research on how accelerator cavities convert electrical energy into Rf energy, then into photon energy and finally increased particle KE external to the cavity and thermal energy in the cavity walls.
Then you will start to understand the energy conversion processes occuring inside accelerator and EmDrive cavities as mass is accelerated and it's KE is increased.
Different dog, same leg action.
Back to sleep. -
#1524 by PotomacNeuron on 12 Sep, 2017 19:17
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I attach a picture of the present MEGA drive (bottom picture) to compare with the early version from years ago shown in the book (top picture).
Notice how much smaller is the rubber gasket compared to the rubber pad used for the device of many years ago shown in the book. The present rubber gasket is confined to distribute stresses resulting from the fasteners, to reduce stress concentrations (see https://forum.nasaspaceflight.com/index.php?topic=42978.msg1721787#msg1721787 for explanation), rather than a large rubber pad as shown in the book. Moreover, when thicker rubber pads were tested, the measured force decreased, as one would expect from dissipation effect decreasing the quality of resonance Q, so experiment confirms theory.
Do you know whether he is willing to sell/loan his devices to non-believers like me? Has him done that before? I am interested in testing one of his devices. My purpose is to find out why it seems to work. Much like to find out why the Dean drive seems to work. Of course if I can not find the reason I would just say so. -
#1525 by Rodal on 12 Sep, 2017 19:25
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...Do you know whether he is willing to sell/loan his devices to non-believers like me? Has him done that before? I am interested in testing one of his devices. My purpose is to find out why it seems to work. Much like to find out why the Dean drive seems to work. Of course if I can not find the reason I would just say so.
Please contact the person you are interested in, directly, with any such questions. -
#1526 by Josave on 12 Sep, 2017 21:26
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The Wayv Adventurer portable microwave heater is ready for preorder, priced 244 USD:
https://world.taobao.com/item/542830022465.htm?fromSite=main&spm=a21m2.8232368.0.0.14e472776kwOSV
Advantages of using this device for an EmDrive rapid prototyping:
-Battery operated.
-Included antenna and no coax required.
-300w 2450 MHz solid state RF source, high efficiency and power control.
Some reverse engineering is needed to see if the VCO is tunable in small steps and also has phase control, something very desirable for active resonators setups:
http://ael.snu.ac.kr/paper_file/MTT_S%202004_6%20YoungTaek%20Lee.pdf
Probably the VCO is the Kinetics MKW40Z used in this module that seems was never released to the market:
https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems
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#1527 by TheTraveller on 12 Sep, 2017 21:54
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Here is a design for a much smaller TE011 500MHz thruster
Bd:1.169 m
Sd: 0.731 m
Len: 0.615 m
Df: 0.7730
Qu: 310k with Cu at room temp
Specific Force: 1.6N/KW at above Qu
YBCO data predicts 360N/kW at 77K -
#1528 by Mulletron on 12 Sep, 2017 21:54
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I attach a picture of the present MEGA drive (bottom picture) to compare with the early version from years ago shown in the book (top picture).From what I was thinking about above, the same thing is happening in a MET (just talking about the device, not Mach effects theory). A changing energy density (capacitor being charged and discharged) is being jerked around (back and forth in the case of a MET) by a PZT. The return journey doesn't look like a good design feature to have, although if you think about it, it's inevitable in a resonant system. I'm thinking really hard about why the addition of the rubber pad (from the book Making Starships) greatly increased the thrust. That's a good way to absorb energy and reduce the return energy by reducing r. That rubber pad is dissipative. That's the asymmetry. This is an electromechanical version of the EMdrive. They're analogous.
Pics included for research purposes.
May I suggest that the rubber pad allowed room for the copper block to move back and forth, thus allowed more intense vibration? If so, it can be replaced with a compressed spring.
It looks to me like the rubber pad is the dissipative element, serving the same function as the dielectric disc in an EMdrive. They're both lowering the amount of reflected energy by turning it into heat. They both serve to facilitate a partial standing wave.
If you really think about it, it's immediately obvious why a fully superconducting EMdrive is a BAD idea. You better have a load on it.
Do you predict the "thrust" to change direction, if the rubber washer is installed on the other side (on the nut side, not on the bolt side)? From my understanding of how it worked, the "thrust" will likely change direction.
Notice how much smaller is the rubber gasket compared to the rubber pad used for the device of many years ago shown in the book. The present rubber gasket is confined to distribute stresses resulting from the fasteners, to reduce stress concentrations (see https://forum.nasaspaceflight.com/index.php?topic=42978.msg1721787#msg1721787 for explanation), rather than a large rubber pad as shown in the book. Moreover, when thicker rubber pads were tested, the measured force decreased, as one would expect from dissipation effect decreasing the quality of resonance Q, so experiment confirms theory.
Great, so we have preliminary indications that we want to design for an optimal "informed" Q (instead of max Q, or you can still design for max Q but you have to deliberately and intelligently add a damping mechanism which will end up lowering your system's Q anyway), in such a way to tailor the amplitude of the reflected wave coming from one end because we want an optimum partial standing wave (or you can actually damp each end independently by some predictable and controllable means, so that you have another way to control or reverse thrust). There lots of creative ways to do this. For electromechanical systems there's simple things like taking advantage of how rubber is stiffer when it's cold. That's just one of a multitude of creative ways to get the job done. For electrical conductivity in a cavity, the sky is the limit too for options *. You can just vent energy, or lose it forever as heat, or you can scavenge it to make electricity or heat water. No matter how you go about doing it, you have to have an exhaust.
*Thought this was pretty neat:
http://news.mit.edu/2011/switch-conductivity-0429
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#1529 by TheTraveller on 12 Sep, 2017 21:56
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The Wayv Adventurer portable microwave heater is ready for preorder, priced 244 USD:
https://world.taobao.com/item/542830022465.htm?fromSite=main&spm=a21m2.8232368.0.0.14e472776kwOSV
Advantages of using this device for an EmDrive rapid prototyping:
-Battery operated.
-Included antenna and no coax required.
-300w 2450 MHz solid state RF source, high efficiency and power control.
Some reverse engineering is needed to see if the VCO is tunable in small steps and also has phase control, something very desirable for active resonators setups:
http://ael.snu.ac.kr/paper_file/MTT_S%202004_6%20YoungTaek%20Lee.pdf
Probably the VCO is the Kinetics MKW40Z used in this module that seems was never released to the market:
https://www.everythingrf.com/News/details/2552-plug-and-play-rf-cooking-module-reduces-time-to-market-for-appliance-oems
Excellent news. Thanks.
Will be buying a few to play with. -
#1530 by Mulletron on 12 Sep, 2017 22:07
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TT do you have a conflict of interest which would influence your behavior in a public forum?
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#1531 by Josave on 12 Sep, 2017 22:15
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As for if we engineers agree,
You are not an engineer. Engineers can perform a basic force balance, and know the difference between an open and closed system. Referring to yourself as an engineer when you can't do this is an insult to engineers.
What in the world kind of data are you imagining?
Go back to the last CoM conversation and try answering even the most basic question that you were asked.
You are wrong, sorry meberbs to say that things are not so simple, and is not fair using the very old and naïve CoM law to discredit TT arguments. You can use any scientific authority arguments, but all of them are approximations of the Laws of Nature, that have nothing to do with the Law of Physics, that are just our approximations... our theories... but not more than models done by our limited knowlegde.
The generalization of the 2-particles mechanics to the n-particles is the Hamiltonian mechanics. Roughly said, in this mechanics the invariant is no longer Conservation of Momentum, but the quantity conserved is the observable G, a function not only of the mass of the n-particles, but also of the inter-distances of all the particles of the system.
And yes, I am an Engineer and Doctor of Engineering, and I don´t know the difference between and open and a closed system. I propose you to write a PhD dissertation about that differences and I will be proud to be a member of your evaluation board. A mathematician will be also needed probably. Start by defining what is a system... think about it... then continue defining what is an observable... if you can define what is the mass probably you will be lost by the time... don´t forget a full chapter about the role of the observer and relativity issues, and conclude with references to information theory and Landauer principle...
I assure you that none of your arguments are valid to say that EmDrive cannot work and discredit believers (or discredit non-believers). No one. Healthy skepticism is ok, but don't be radical against TT. In these four years following this enlightening forum, I have discovered so many interesting theories, and is very hard to say which are testable and which are not, but is totally impossible to say which are true or which are false. -
#1532 by wicoe on 12 Sep, 2017 22:49
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As for if we engineers agree,
You are not an engineer. Engineers can perform a basic force balance, and know the difference between an open and closed system. Referring to yourself as an engineer when you can't do this is an insult to engineers.
What in the world kind of data are you imagining?
Go back to the last CoM conversation and try answering even the most basic question that you were asked.
You are wrong, sorry meberbs to say that things are not so simple, and is not fair using the very old and naïve CoM law to discredit TT arguments. You can use any scientific authority arguments, but all of them are approximations of the Laws of Nature, that have nothing to do with the Law of Physics, that are just our approximations... our theories... but not more than models done by our limited knowlegde.
The generalization of the 2-particles mechanics to the n-particles is the Hamiltonian mechanics. Roughly said, in this mechanics the invariant is no longer Conservation of Momentum, but the quantity conserved is the observable G, a function not only of the mass of the n-particles, but also of the inter-distances of all the particles of the system.
And yes, I am an Engineer and Doctor of Engineering, and I don´t know the difference between and open and a closed system. I propose you to write a PhD dissertation about that differences and I will be proud to be a member of your evaluation board. A mathematician will be also needed probably. Start by defining what is a system... think about it... then continue defining what is an observable... if you can define what is the mass probably you will be lost by the time... don´t forget a full chapter about the role of the observer and relativity issues, and conclude with references to information theory and Landauer principle...
I assure you that none of your arguments are valid to say that EmDrive cannot work and discredit believers (or discredit non-believers). No one. Healthy skepticism is ok, but don't be radical against TT. In these four years following this enlightening forum, I have discovered so many interesting theories, and is very hard to say which are testable and which are not, but is totally impossible to say which are true or which are false.
Could you please confirm (or comment otherwise) that you are satisfied with this explanation, taken from the Shawyer's web site (and repeated several times by TT):
Q. Why does the EmDrive not contravene the conservation of momentum when it operates in free space?
A. The EmDrive cannot violate the conservation of momentum. The electromagnetic wave momentum is built up in the resonating cavity, and is transferred to the end walls upon reflection. The momentum gained by the EmDrive plus the momentum lost by the electromagnetic wave equals zero. The direction and acceleration that is measured, when the EmDrive is tested on a dynamic test rig, comply with Newtons laws and confirm that the law of conservation of momentum is satisfied.
Doesn't this raise any red flags at all? Such as, where does the wave get its initial momentum from? Doesn't it push back on the source when it is generated/reflected? Etc etc. I'm really curious if this "explanation" makes sense to anybody here... or perhaps I'm the only one who fails to see how it can make any sense at all? -
#1533 by meberbs on 12 Sep, 2017 23:02
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You are wrong, sorry meberbs to say that things are not so simple, and is not fair using the very old and naïve CoM law to discredit TT arguments.
TT says that the emDrive obeys conservation of momentum, and that no new physics is required to explain the emDrive. How in the world is it then unfair to check whether those claims are consistent with the rest of his statements?And yes, I am an Engineer and Doctor of Engineering, and I don´t know the difference between and open and a closed system.
You seem to have not read far enough back to see the context of the discussion. This is not discussion of defining conservation laws in highly curved spacetime, or complications related to quantum non-locality and particle indistinguishability. This is the context of applying basic mechanics. A rigorous formal definition is not what was needed, but an understanding of the most basic conceptual definition.is totally impossible to say which are true or which are false.
When a theory includes the following statements:
-Existing physics including conservation of momentum is obeyed.
-A device can start with no net linear momentum and end up moving at a constant velocity with net linear momentum equal to m*v.
-That device does not expel any of its mass as exhaust, emit significant EM radiation, or apply forces to (equivalently: have forces applied on it by) anything else.
It is simply inconsistent with itself and therefore wrong. -
#1534 by mrmittens on 12 Sep, 2017 23:08
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Long time reader, first time poster.
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This current derailment was enough for me to finally post about it. Can we please all stop paying any attention to him until he provides some evidence of actual use beyond 'Take my word for it!'?
I likewise have been lurking here for a few months now to keep track of the progress as this forum seems to generally have the most up-to-date information on all EmDrive related activities including activities like Monomorphic and SeaShell's builds which aren't reported by mainstream media (and wouldn't be until MAYBE after actual results/papers are published). The last few pages have been utter nonsense. It's disappointing to see what is normally an interesting thread spiral into a flame war where the attackers feel justified in their childish behavior.
Certainly things seem to typically go south when TT posts; however, I can't say that I've ever actually seen him post any personal attacks like what he has been repeatedly subjected to. His comments are controversial to the extent that they are not "valid physics" as meberbs and others have presented. The downward spiral seems to generally be the result of others' responses to him and not from TT himself, in my opinion. I've been reading here since at least thread 7 and I can't say I've ever seen him post anything remotely resembling the personal attacks that have been consistently directed towards him (often from meberbs).
meberbs, whether you agree with TT's viewpoints or not, the posts from him that I have seen have always been objective and non-confrontational, while you consistently prepend your responses to him with personal attacks:Do you even know the definition of the phrase "open system"?
It is apparently difficult for you to understand.
Or if that is too hard for you try these:
You are not an engineer. ... Referring to yourself as an engineer when you can't do this is an insult to engineers.
...
I am fairly certain you can't even describe the experimental setups for these measurements, let alone have actually done them. Especially the part about wavelength, which you have previously demonstrated an inability to even properly define.
These are direct, personal attacks towards TT. I am going to report your posts to moderators going forward if this continues. Claiming someone can't possibly understand high school physics and/or deriding them as "not an engineer" when you have no direct personal knowledge of their vocation is in no way factual, objective, nor productive.
Furthermore, you (meberbs) argue continuously in postulates and conjectures about things which cannot be proven as if they are fact, and use these conjectures to support your other deriding comments:you "being under NDA" doesn't make sense. If anything it is the company buying from you that should be under NDA, with maybe restrictions on you identifying them, although even that wouldn't be typical.
There have been many comments about whether or not TT or Shawyer are actually under NDAs or not, or whether or not Shawyer is working with the UK MOD. It is all pointless conjecture. TT claims he is under an NDA. Given his posts are the only source of "truth" for these claims, arguing about whether he is actually under NDA is pointless. The real question is why do you care so much? There is no personal injury to you or anyone else on this forum by TT coming in and claiming that he is under an NDA.
If these statements are true and EMDrive does work, then it will certainly make for an interesting future when EMDrives become a reality. If it's not true, then by responding the way you have is just feeding a forum troll by giving them what they want: a rise out of other people.
Finally, you (meberbs) continuously get bogged down arguing back and forth with TT about CoM from a current physics point of view:The EmDrive works.
Therefore momentum is not conserved.
Nothing leaves the cavity.
This argument has been beat to death over and over and over again. Can we please move on until we have a working EMDrive to test against, or until sufficient negative tests have been performed to provide a reliable set of data that most likely the effect does not exist? In the absence of a working EMDrive, you are simply postulating that IF the EMDrive works, THEN momentum is either a) not conserved or b) is conserved through an unknown mechanism but have no way to test either of the two theories. Option (c) is that simply, EMDrive does not work in which case everyone should simply stop posting to or following this thread.
TT claims CoM is obeyed, but since they don't seem to be supported by current physics would likely fall under (b). We can simply accept this and move on, there have been many theories proposed on this thread, none of which have drawn the criticism that has been directed at TT and none of which can be verified without a working drive.
It is fine that you disagree with TT's statement of how the EMDrive might work, but you don't need to resort to personal attacks to make your point. If you disbelieve him entirely, you should just ignore him. As you and others have stated here, there is no reliable test data that is not affected by experimental or other errors which can either prove or disprove any conjectures about the EMDrive other than how to make a better experiment to test it.
Until there is reliable, publicly available data unequivocally demonstrating the EMDrive does or does not work, then all arguments about the physics underlying the EMDrive remain in the realm of conjecture. Maybe it works, maybe it doesn't. Eventually if no working drive is produced by Shawyer/TT or any other experimenter, then the obvious conclusion will be that it does not work. Presently there is no way to demonstrate that any given theory is correct when we do not have a sufficient body of reliable experimental data on which to draw conclusions from.
As a participant in this thread you must allow for the possibility that maybe it does work by some mechanism; otherwise participating in this thread makes you the troll, not TT, by consistently berating people’s intelligence for proposing theories about how it might work. If you are simply here to argue that EMDrive does not and cannot possibly work because it is not supported by current physics, and you are unwilling to accept that TT or Shawyer might have a working drive then you should take your arguments elsewhere, as that viewpoint does not allow for open debate and is in fact in favor of option (c), EMDrive does not work and you should simply spend your time more fruitfully elsewhere on theories and technologies that hold more promise.
TT himself recently stated:As I have said before, I have no 100% proof the SPR theory is correct but it sure fits how to design an EmDrive and dynamic tests do suggest that CofE is conserved as force is not constant and reduces as KE increases.
So, he admits SPR theory may not be correct, and he states that tests "suggest" momentum is conserved. You disagree with him about CoE/CoM from an existing physics standpoint and again, that's fine to disagree on, but I must restate that we do not have access to his experimental data and no other sufficient experimental data exists for us to have a reasonable debate over. Only two people blowing hot air into the wind, one person claiming it works in some way based on their own supposed private set of data to which we have no access, and a separate person arguing that the first person's claims are invalid because we don't have access to said data. If we had an experiment demonstrating a working EMDrive, then we could begin to propose hypothesis of HOW it works and additional experiments could be performed to exercise these hypothesis and ignore TT/Shawyer’s lack of transparency entirely.
You could simply accept that TT and your viewpoints don't line up and move on. Most people seem to agree that what TT has presented is not correct from an existing physics point of view. However, if TT/Shawyer have built working EMDrives and if they have their own theories which they use to successfully produce working EMDrives, then whether or not their theory is completely correct or not or lines up with known physics doesn't really matter. What matters at present is whether or not EMDrive is a real effect at all.
It's like if someone were to claim "I can make light in a glass tube from lightning," and you claimed that they are wrong because you have never seen that effect before and anyone who knows anything knows that lightning comes from the sky and is too volatile to ever possibly be contained.
If/when a working EMDrive is publicly demonstrated, then surely many experiments and theories will take off at that point to determine the exact nature of the drive and how/why it works. All EMDrive experimentation to date is based on the possibility that the EMDrive effect may or may not be real. The body of publicly available work to date is very small. It should follow that Shawyer's theories, though perhaps an inaccurate description of the microscopic level of the underlying physics of any real effect might possibly be a workable theory at the macro level which can be used to produce working EMDrives. Assuming the theory is incorrect at the microscopic level, then it again follows that if EMDrive effect is real, future refinements of the theory which more accurately reflect the actual inner workings of the drive would result in higher yields as the direct result of better understanding of the underlying physics, and better modeling and predictions to produce more effective drive designs. This is basically the history of all science as we know it. A rough but working theory produces increasingly more fine grained theories/models as new information becomes available to which existing theories do or do not fit. You wouldn't throw out general relativity just because it doesn't work at the quantum level. So, it doesn't really matter if his theory is correct or not, it only matters if working EMDrives can be produced from it.
The most effective theory is the one that produces a working drive with the most thrust/kW.
TT is entitled to his own opinion, especially IF he has in fact built a working EMDrive. If he has, then he obviously has more experience/data than anyone else commenting in this thread to draw from. Arguing with him serves in no way to advance the EMDrive. Your arguments here that he has not built a working EMDrive is again conjecture based on the lack of hard evidence supporting his claims, not any actual evidence demonstrating that he has unequivocally NOT built such a device. This is no different than the debate a few pages back about whether or not the Chinese had built a working EMDrive and/or tested one in space, where media announcements by them either for or against it must be some sort of misinformation campaign, and where all possible media announcements could be postulated as being either in support of or against them having a working EMDrive.
You assume TT has some vested interest in making his data available to improve public opinion in the effect, when in fact no such vested interest exists. TT is exactly right that lack of interest in EMDrive is a significant advantage to any company who can produce a working drive and is looking to be first to market. It would be entirely within his interest to not share specific information which could provide a significant launchpad for competition which may have large resources than his own and/or information that may violate his NDA, whether or not such NDA exists.
TT claims, and Shawyer claims, to have developed working EMDrives based on this theory. Could it be a big hoax? Maybe. But in that case Shawyer would ultimately end up in jail for misleading investors. I very much doubt anyone would invest millions of dollars in non-demonstrable vaporware, but there have been bigger hoaxes and pyramid schemes in the past. Are the "physics" they present wrong about how the EMDrive works, IF it works? Very possibly. But that's what makes public projects like Monomorphic's, SeaShells and others important to prove if and how the EMDrive works.
Over and over and over again this same argument keeps coming up and every time it death spirals into a storm of posts back and forth on a topic where it has become obvious that a) you, others, and TT are not going to agree and b) has already been beaten to death many times. Can we please stop and instead focus on friendly, objective debate and the status of ongoing experiments by Jamie and others?
TT's claims, whether factual or non-factual, inflict no personal injury on yourself or others, other than the costs of time and money it may incur trying to prove/disprove these claims by experimentation. However, were it not for these claims, then this thread and these experiments would not exist at all. -
#1535 by flux_capacitor on 12 Sep, 2017 23:34
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Here is a design for a much smaller TE011 500MHz thruster
Bd:1.169 m
Sd: 0.731 m
Len: 0.615 m
Df: 0.7730
Qu: 310k with Cu at room temp
Specific Force: 1.6N/KW at above Qu
YBCO data predicts 360N/kW at 77K
To give an idea of the size of this TE011 L-band (500MHz) thruster:
At least this is a much rational dimension to experiment with as a demonstrator than the previous TE013 proposed one at the same frequency:Roger is a clever engineer, damn me for not doing a reverse engineering on the Interstellar Probe's EmDrives as he gave all the needed bread crumbs.
Bd: 2.193m
Sd: 0.938m
Len: 1.060m
Df: 0.7725
Mode: TE013
Freq: 500MHz
Cu room temp Qu: 560k <<<< amazing Qu!!!!!
YBCO 77K Qu: 1.25x10^8 (125,000,000)
Specific Force: 645N/kW
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#1536 by Tcarey on 12 Sep, 2017 23:49
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If I had a guy working for me and I had him sign a nondisclosure agreement, I certainly wouldn't allow him to post ANYTHING about the subject on a public forum that would help anyone else. None of this makes sense what's going on here.
All depends on what the NDA prohibits. Each NDA is different. It could have be a poorly drawn up NDA. I have signed NDA's that were very carefully drawn up and very restrictive, other ones no so much.
Personally I would like to see TT build and demonstrate his 500 Mhz EM drive.
My appreciation to all of the folks here that are building and testing for the benefit of us all.
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#1537 by Mulletron on 13 Sep, 2017 00:21
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I'm pretty sure it's a good idea to do the opposite of what TT says. I think he's even wrong about aiming for as high a Q factor as possible. It's not that simple. You have to ask yourself, why is that important? Or I'm building a very high Q cavity for this particular frequency, so what? That's a good feature to have for a resonator, but is it a good feature to have for a resonant cavity thruster? If he's really wrong about this, and that's what people are building to achieve, they won't be getting the thrust they had hoped for. There's a very simple reason for why we don't see EMdrives flying around. It's because the theory of operation isn't nailed down, so there's no way to make predictions which would lead to the development of improvements in performance, besides trial and error. The performance is so bad now (from the data I/we have access to) that it's not even possible to make a compelling thrust measurement good enough to shut up the believers or the critics. I built an EMdrive once and suspended it on a balance from a single thread of Berkeley Nanofil, and it did absolutely nothing (probably because I'm a bad experimentalist, or that galinstan slip ring I made, or I only gave it 8 watts, or all of the above) but I also realized that I was testing the same non (or barely) working thing everyone else had, so I put it in a box and decided to think about it for a few years.
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#1538 by meberbs on 13 Sep, 2017 00:30
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meberbs, whether you agree with TT's viewpoints or not, the posts from him that I have seen have always been objective and non-confrontational,
How is repeatedly making proclamations that have been repeatedly disproven not confrontational?
What about repeatedly ignoring direct, simple questions?while you consistently prepend your responses to him with personal attacks:
Context matters.Do you even know the definition of the phrase "open system"?
This was after repeated statements from him that indicated he does not know the definition.It is apparently difficult for you to understand.
This was in response to him posting literal nonsense followed by "This is not difficult to understand."Or if that is too hard for you try these:
After he had ignored the preceding question twice. His eventual response was a quote from Wikipedia that included irrelevant context. He never did reply to the questions that followed.You are not an engineer. ... Referring to yourself as an engineer when you can't do this is an insult to engineers.
You said you have been here for a few months, so you probably didn't read far enough back in old threads to see all the times he was asked to define "guide wavelength" in the context of a resonator and failed to do so. Or the conversations where he insisted on the equivalent of saying that pushing an object to the left makes it move to the right.
...
I am fairly certain you can't even describe the experimental setups for these measurements, let alone have actually done them. Especially the part about wavelength, which you have previously demonstrated an inability to even properly define.Finally, you (meberbs) continuously get bogged down arguing back and forth with TT about CoM from a current physics point of view:
Depends, can you get TT to stop proclaiming contradictory statements?The EmDrive works.
Therefore momentum is not conserved.
Nothing leaves the cavity.
This argument has been beat to death over and over and over again. Can we please move on until we have a working EMDrive to test against, or until sufficient negative tests have been performed to provide a reliable set of data that most likely the effect does not exist?In the absence of a working EMDrive, you are simply postulating that IF the EMDrive works, THEN momentum is either a) not conserved or b) is conserved through an unknown mechanism but have no way to test either of the two theories. Option (c) is that simply, EMDrive does not work in which case everyone should simply stop posting to or following this thread.
Exactly this is all that the momentum argument amounts to. The problem is that TT keeps proposing that momentum is conserved, but unlike in option b there is no unknown mechanism. Him repeatedly insisting on this is counterproductive to serious investigation of the emDrive.If you disbelieve him entirely, you should just ignore him.
Why should false and contradictory statements be allowed to stand in an open forum without someone pointing out that they are false and contradictory?As a participant in this thread you must allow for the possibility that maybe it does work by some mechanism; otherwise participating in this thread makes you the troll, not TT, by consistently berating people’s intelligence for proposing theories about how it might work.
I have no problem with people proposing theories. If I see a flaw, I will point it out so the theory can be improved or discarded and the next one looked for. TT refuses to move on and ignores the flaws, claiming they don't exist. It is not berating someone's intelligence to point out a flaw in a theory, coming up with a theory at all is hard. I decline to comment on what it says about someone when their response to criticism is "I'm right, you're wrong. The emDrive works."TT himself recently stated:
Yet he continues to insist on design rules following a theory that is inconsistent with itself, which of course leads to inconsistent rules.As I have said before, I have no 100% proof the SPR theory is correct but it sure fits how to design an EmDrive and dynamic tests do suggest that CofE is conserved as force is not constant and reduces as KE increases.
So, he admits SPR theory may not be correct, and he states that tests "suggest" momentum is conserved.TT is entitled to his own opinion, especially IF he has in fact built a working EMDrive. If he has, then he obviously has more experience/data than anyone else commenting in this thread to draw from. Arguing with him serves in no way to advance the EMDrive. Your arguments here that he has not built a working EMDrive is again conjecture based on the lack of hard evidence supporting his claims, not any actual evidence demonstrating that he has unequivocally NOT built such a device.
Go look through the posts again. While I have my doubts about what experiments he has done, I generally have been leaving that as an unknown and addressing his understanding of the definition of a force and similar issues. Others have been more directly vocal about his unreliability as a witness, which is based on years of empty promises from him.TT's claims, whether factual or non-factual, inflict no personal injury on yourself or others, other than the costs of time and money it may incur trying to prove/disprove these claims by experimentation. However, were it not for these claims, then this thread and these experiments would not exist at all.
If his nonsensical claims are left to stand as if correct, it harms the quality of this site, which is the best resource for information on the space industry I have found. Also, some of what he says about how to run an experiment is based on nonsense contradictory to how forces work. If anyone listens to the problematic and contradictory bits of advice, it will interfere with them running a good experiment that can settle the issue. -
#1539 by TheTraveller on 13 Sep, 2017 01:11
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Here is what I can share of the known operational characterists of an EmDrive. Would suggest alternative theories would need to explain ALL these characterists.
1) force scales linear with Rf power
2) force scales linear with Q. Bit trickey that but it seems to be so.
3) force scales linear with Df. Interesting that as the Df relates to the ratio difference between guide wavelength at each end plate.
4) force drops during constant acceleration. Seems to correlate with accelerated mass KE increase.
5) cavity Q drops during acceleration. Know this as my cavities are pulsed, which allows measurement of the forward power rise time. This enables Q measurement on every Rf pulse.
6) non accelerating cavity does not generate force. Know this from testing on torsion test rigs that stop forward motion when the stored torque in the wire balances EmDrive torque. When that happens the EmDrive stops generating force and the stored torque in the torsion wire forces the EmDrive back to it's starting position. Jamie's tests have shown this effect.
7) non accelerating cavity needs a small one time external force applied to cause small end forward acceleration.
8) during acceleration small end experiences Red Doppler shift, while big end experiences Blue Doppler shift.
9) doing end plate radiation calcs pressure shows less pressure on the small end plate vs the big end plate.
10) point 9 suggest the cavity should accelerate big end forward but it accelerates small end forward.
11) I don't understand why 10 happens.
