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#4100 by meberbs on 02 Aug, 2016 07:24
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In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense, it can't stop moving, because it is on the earth, which is spinning, and travelling around the sun, which is travelling around the galaxy... etc. There is nothing fundamental for it to be moving or stopped relative to. And anyway, if it did stop producing force, the torsion pendulum would cause it to swing back, and this effect could be characterized.Please read and try to understand Roger's advise:
You have posted that before, and I responded to it before. Everything is wrong with that document from the first force diagram with extra magical arrows on it. I am not going to repeat the details, go look up my old post if you want them.
http://www.emdrive.com/EmDriveForceMeasurement.pdfThat Jamie has been able to show a thrust bandwidth, that aligns with VNA bandwidth is the biggest take away of his efforts to date. While I and one other have done this before, it is good to see Jamie likewise map his frustum's thrust bandwidth. Had he been able to use single freq excitation, he would have found the thrust bandwidth is actually narrower than the RL bandwidth.
Where heat is dissipated also correlates with resonance, so until the sources of the other effects in the data are clearly determined, this might not be accurate. You love to post quotes about how experiments trump theory, but then in a face of an experiment that doesn't match your pre-conceptions, you make up a theory for why you are still right and the experiment is wrong. The thrust bandwidth, (if that is a real signal clearly) is wider than resonance bandwidth. Even if this is due to magnetron noise, and a more pure tone would be more efficient, it doesn't matter as long as the effect is measurable, and the wider effective bandwidth makes detecting it easier. This is too many ifs though, first it needs to be shown that there is any useful effect to begin with. -
#4101 by frobnicat on 02 Aug, 2016 08:54
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Monomorphic, I join the others and congratulate you on the progress (and impressive DIY work overall).
May I add my grain of salt to some other's advice or requests : please each time you get to the point of having a stable setup (for instance this is the case now with your surrounding box) and do a recording, do at least 3 recordings separated by the time it takes the system to cool down (30mn ? 1hr ?). I understand this would take a little more time, and maybe this will shorten the life of the magnetron since it is operated in stressful conditions, but really each time we have a single recording for a unique combination of parameters there is no way to tell the significant from the random.
For instance your latest recording (before box around) triggers an avalanche of excitation and interpretations on the forum because of the coincident max displacement with peak resonance. But we have really no idea if it is statistically significant at all, maybe a next run with exactly same parameters could have turn out the max disp. before the max resonance (weakening the case for a causality...) or a flatter max, or more bumps or less bumps... Now if you run again with the box around and get a plot significantly different (which is likely) we don't know the part of chance and the part of causality in the changes.
In short, a single plot can't tell us how typical was the run or how significant are the distinctive features. It's not like Ligo claiming confirmation of colliding black holes on a single event, where there is a complete reconstruction of the expected signal from well understood model (and no other choice than to wait for natural event). Here we don't have a complete model of thermal heating, convection forces, temperature induced changes in wires stiffness and magnetron's permanent magnets, Lorentz forces... and all that can play at a few 100s of µN levels.
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#4102 by TheTraveller on 02 Aug, 2016 09:00
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In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
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#4103 by Monomorphic on 02 Aug, 2016 13:11
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please each time you get to the point of having a stable setup (for instance this is the case now with your surrounding box) and do a recording, do at least 3 recordings separated by the time it takes the system to cool down (30mn ? 1hr ?).
In short, a single plot can't tell us how typical was the run or how significant are the distinctive features.
I actually did two runs with the exact same settings. There was a run before test01, that was going to be called 01, but there was a problem with the spectrum analyser span setting. After going back to the spec data, it is still usable. I missed RF on frequency and the first 15 seconds of RF frequency data, but I know the magnetron starts at 2.475.
Maximum beam displacement is equivalent to 31.9mg = 0.3128mN
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#4104 by X_RaY on 02 Aug, 2016 13:38
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That is even more nonsense.In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
There is no prefered reference frame like you adopt with this statement. -
#4105 by Gilbertdrive on 02 Aug, 2016 14:41
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That is even more nonsense.In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
There is no prefered reference frame like you adopt with this statement.
I have no opinion on the idea that acceleration is needed for the Emdrive to work, and your statement is true about speed. There is no prefered reference frame about non zero speed. Speed is relative to other bodies.
At the opposite, if a spaceship uses a thruster for acceleration (not because of gravity) it is something absolute.
If I am inside a train that has a constant speed, and without no Windows, I can not know the speed of the train. Without taking the landscape as a referential, I have no correct definition of my speed. I can not have a speedometer in my pocket that give me the speed of the train. That is a big issue about the Shawyer use of Kinetic Energy, and it was explicited earlier in these threads.
At the opposite, if the train is accelerating, I can mesure this acceleration with an accelerometer in my pocket. I do not need to look at the Windows to experimentate it.
The frustrum reference frame if the referential in which the frustrum has zero speed. This reference frame would not help to give us a speed (by definition, the speed will always be zero in this referential)
But we can use this referential to define an absolute acceleration. We can mesure the acceleration of the frustrum relatively to the laboratory, and we can put an accelerometer on the frustrum, it will gives us around the same result.
So, it makes sense. The acceleration does not need an external referential to be defined, even if it is a simple way to mesure it
Anyway, the meberbs statement about the fact that an item on the earth is moving is also true about acceleration. I do not speak about the gravity. The acceleration due to the gravity fields can not be mesured in the referential of the item. But there is an acceleration due to the earth rotation. The coriolis acceleration. That means that an item fixed on the earth, not free to move, is experimenting a very small absolute acceleration. If I had a very precise accelerometer, I could mesure it.
So, if even a small absolute acceleration is enough, the emdrive should work even if it is not moving in the earth referential.
The Traveller, please, can you give a precise rule ? how much absolute acceleration is needed ? does it means that if a big ship it propelled by a small frustrum, the small acceleration of the system makes the frustrum less efficient ?
Also, the Shawyer incorrect modelisation of the drive does not need absolute acceleration to make it work.
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#4106 by X_RaY on 02 Aug, 2016 19:19
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FYI mode mixing
https://arxiv.org/ftp/arxiv/papers/1603/1603.02325.pdf
There are additional modes that exists in a truncated conical cavity, but not in a cylindrical one. Frank Davies called the index TE1(1.5)3 for example because the mode seems to consists of two different modes shapes. Is it possible that this kind of non-Hermitian solution (paper above)could be a source of (possible) thrust generation while the mode and the energy density changes in such an unusual way?*
If yes it would be recommend to focus into this special field patterns and/or geometrical mode-mixing cavity designs.
*Some kind of mode conversion between both sides of the resonator.
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#4107 by Mezzenile on 02 Aug, 2016 20:20
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From what I have understood of the explanations of Mc Culloch for the EMdrive phenomena, it is neccessary that Unruh waves exist in a somewhat asymetric configuration to provide variable inertia to the photons of the oscillating field inside the cavity. These Unruh waves are produced with the right wavelength, by the huge acceleration of the photons inside the cavity which are bouncing very fast between the two end plates of the frustum. Apparently according this interpretation, there is no need of a first mechanical acceleration of the device to initiate the EM drive phenomena, the electromagnetic field setting in the cavity take care of all. It is only my understanding ....In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
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#4108 by Gilbertdrive on 02 Aug, 2016 20:36
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From what I have understood of the explanations of Mc Culloch for the EMdrive phenomena, it is neccessary that Unruh waves exist in a somewhat asymetric configuration to provide variable inertia to the photons of the oscillating field inside the cavity. These Unruh waves are produced with the right wavelength, by the huge acceleration of the photons inside the cavity which are bouncing very fast between the two end plates of the frustum. Apparently according this interpretation, there is no need of a first mechanical acceleration of the device to initiate the EM drive phenomena, the electromagnetic field setting in the cavity take care of all. It is only my understanding ....In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
You are totally right, in the MiHsC theory, there is no need for the cavity to accelerate. The Traveller has another theory about how it works, with the need of an initial acceleration to go into a "motor mode"
But I do not remember any theoretical explanation for this.
Also, in the experiments where there are vibrations, the ask for initial acceleration is fulfilled (a vibration means an acceleration in a direction during a short time, followed by an acceleration in the other direction)
But it would not work for solid state Emdrive with no vibrations.
I do not have an opinion about this ask of an initial acceleration, but I notice that this hypothesis would explain null results for solid state Emdrive if no initial acceleration and no vibrations. If the future experiments were giving null results for such devices, it would give a good reason to take into account this hypothesis. -
#4109 by Tellmeagain on 02 Aug, 2016 20:55
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You are totally right, in the MiHsC theory, there is no need for the cavity to accelerate. The Traveller has another theory about how it works, with the need of an initial acceleration to go into a "motor mode"
But I do not remember any theoretical explanation for this.
Also, in the experiments where there are vibrations, the ask for initial acceleration is fulfilled (a vibration means an acceleration in a direction during a short time, followed by an acceleration in the other direction)
But it would not work for solid state Emdrive with no vibrations.
I do not have an opinion about this ask of an initial acceleration, but I notice that this hypothesis would explain null results for solid state Emdrive if no initial acceleration and no vibrations. If the future experiments were giving null results for such devices, it would give a good reason to take into account this hypothesis.
If my memory served me right, this assertion came from Mr. Shawyer's observation that his rotary test needed the initial acceleration to move. It was discussed here a while ago. By then I suggested it might have been caused by the need to overcome some kind of static friction. -
#4110 by TheTraveller on 02 Aug, 2016 23:53
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That is even more nonsense.In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
There is no prefered reference frame like you adopt with this statement.
Roger's advise on what happens if external forces are eliminated is based on experimentally gathered data:
http://www.emdrive.com/EmDriveForceMeasurement.pdf
If you and others choose to ignore what the gathered data is revealing about the operational characterists of the EmDrive, so be it.
To restate, the frustum must experience some amount of external accelerative force, big to small to enter motor mode or small to big to enter generator mode. Instead of fighting that EmDrive experimentally determined reality, maybe try to stretch your mind and ask yourself what would be happening to the 2 opposite direction travelling waves inside the frustum as the frustum experienced initial acceleration in either direction. Roger has explained it in past papers. The information is there. -
#4111 by meberbs on 03 Aug, 2016 00:38
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Roger's advise on what happens if external forces are eliminated is based on experimentally gathered data:
http://www.emdrive.com/EmDriveForceMeasurement.pdf
If you and others choose to ignore what the gathered data is revealing about the operational characterists of the EmDrive, so be it.
To restate, the frustum must experience some amount of external accelerative force, big to small to enter motor mode or small to big to enter generator mode. Instead of fighting that EmDrive experimentally determined reality, maybe try to stretch your mind and ask yourself what would be happening to the 2 opposite direction travelling waves inside the frustum as the frustum experienced initial acceleration in either direction. Roger has explained it in past papers. The information is there.
There is no experimental data used in that paper. It is a description of a (completely nonsensical) theory of how to measure a force. It completely abuses and misuses terminology. This should be obvious to anyone who has taken high school physics and attempts to read that paper.
My original description of some of the issues with that paper is here.
Your attacks on other posters (claiming that they are ignoring experimental data when you are not presenting any experimental data, and they are pointing out that you are presenting a theory that doesn't make sense) are inappropriate. -
#4112 by masterharper1082 on 03 Aug, 2016 00:56
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Agree - there is always at least a little acceleration going on, due to the rotation of the earth and the earth's orbit around the sun. So how much acceleration do you need? Does it have to be an impulse? Why do you need work input? How will it work in open space after you turn it off, unless you have a chemical rocket to "kick" it?
That is even more nonsense.In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
There is no prefered reference frame like you adopt with this statement. -
#4113 by RotoSequence on 03 Aug, 2016 01:57
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Agree - there is always at least a little acceleration going on, due to the rotation of the earth and the earth's orbit around the sun. So how much acceleration do you need? Does it have to be an impulse? Why do you need work input? How will it work in open space after you turn it off, unless you have a chemical rocket to "kick" it?
That is even more nonsense.In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
There is no prefered reference frame like you adopt with this statement.
When are we going to stop going around in circles in text and start going around in circles on a battery powered rotary test bed? It's the one test design where the broad consensus is that it will be able to resolve the "thrust or no thrust" question, yet none of the replication builders have published an investment towards performing such a test.
Sorry for kvetching, and it's great to see more replications and solid, nay, excellent data from Monomorphic's own tests, but I'm starving for a new angle that helps resolve the ambiguities that have plagued EM drive experiments from the beginning. -
#4114 by mikegem on 03 Aug, 2016 03:06
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In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
I really don't get what you're saying.
The frustum is in an accelerated frame due to Earth's gravity, Earth's rotation, Earth's solar orbit, Sun's galactic orbit. Milky Way's orbit in the Local Group, etc. I don't see how the frustum can exist in a frame without acceleration.
Would you clarify? Thank you.
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#4115 by rfmwguy on 03 Aug, 2016 03:36
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New PCM in mag core permits 5 minutes at 100% power without thermal runaway.
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#4116 by zen-in on 03 Aug, 2016 06:58
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That is even more nonsense.In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
There is no prefered reference frame like you adopt with this statement.
Roger's advise on what happens if external forces are eliminated is based on experimentally gathered data:
http://www.emdrive.com/EmDriveForceMeasurement.pdf
If you and others choose to ignore what the gathered data is revealing about the operational characterists of the EmDrive, so be it.
To restate, the frustum must experience some amount of external accelerative force, big to small to enter motor mode or small to big to enter generator mode. Instead of fighting that EmDrive experimentally determined reality, maybe try to stretch your mind and ask yourself what would be happening to the 2 opposite direction travelling waves inside the frustum as the frustum experienced initial acceleration in either direction. Roger has explained it in past papers. The information is there.
I can see how that applies to automobile propulsion. If the car is not moving the engine can't do any work accelerating the car. And if the car is stopped the brakes don't convert kinetic energy into heat. Am I getting this right? -
#4117 by Gilbertdrive on 03 Aug, 2016 11:33
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In this setup, when the frustum stops moving, it might stop producing force.
That is nonsense
It is not nonsense but I should have said "stops accelerating". EmDrive force is only produced when the frustum reference frame experiences acceleration. Initial accelerative force on the frustum needs to be external.
I really don't get what you're saying.
The frustum is in an accelerated frame due to Earth's gravity, Earth's rotation, Earth's solar orbit, Sun's galactic orbit. Milky Way's orbit in the Local Group, etc. I don't see how the frustum can exist in a frame without acceleration.
Would you clarify? Thank you.
There are several types of accelerations. It is not the same to be accelerated by the gravity, and to be accelerated by another body pushing agains us, or by a rocket motor. If I am in free fall (for example in earth orbit) an accelerometer in my pocket will indicate zero acceleration, even if I am accelerating at around 1 G because of the earth gravity.
At the opposite, if I have even a small thruster that gives me far less than one G, my accelerometer will measure it.
I did not see an unified way of naming the part of the acceleration that can be locally measured. I would like to call it subjective acceleration, because it is felt from the viewpoint of the accelerating subject.
If the Emdrive device were needing acceleration to work (I have no opinion on this idea) only subjective acceleration makes sense.
Our Orbits around the sun or the galaxy gives us no subjective acceleration, because we are in free fall around the sun and around the galaxy. In fact it needs that we are ponctual items to be totally true, but it is still a good approximation for small objects.
At the opposite, we are not free falling in the earth gravity field. We get a reaction force from the floor, and a resulting acceleration of 1G.
That is this acceleration from the floor that we detect, not the gravity itself.
That means that we have a subjective acceleration of 1G directed toward the sky. An accelerometer in our pocket will measure it, and, the weighting machines also. GR assumes that we would feel the same in a ship accelerating at one G. Even if we are now immobile on the earth
If the frustrum is set vertical, or at least inclined, this 1 G acceleration should fullfill the Traveller requirement.
If the frustrum is perfectly horizontal, this acceleration is not in the good direction
The force induced by the earth rotation itself is already taken into account in the detection of the vertical.
But there are still other very small forces, for example due to the deformation of the earth by the moon, because the earth is not ponctual.
The Traveller (and Shawyer) claims about initial acceleration needed to go into motor mode would need at least a number. Do you need 0.000001 G ? 0.00000000004 G ? Is there a relation between the acceleration, and the force provided by the frustrum ? (the more acceleration, the more the frustrum is efficient) or is it all or nothing ?
Also, since 1 G is enormous relatively to the acceleration provided by the frustrum, a very very small incline should be enough to provide a small subjective acceleration to the frustrum in the right direction. That is why, the idea of Tellmeagain that this rule might have been caused by the need to overcome some kind of static friction, makes much sense. -
#4118 by Mezzenile on 03 Aug, 2016 11:49
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... I did not see an unified way of naming the part of the acceleration that can be locally measured. I would like to call it subjective acceleration, because it is felt from the viewpoint of the accelerating subject.
The General Relativity is the best point of view to adress this subject.
...
Only a body which follows a geodesic of the space-time will experience no acceleration. This is the so-called "free-fall" situation. Geodesics of the space time are geometric trajectories imposed by the energy/momentum content of the universe. For a body following a geodesic the gravity does not exist anymore.
Anybody on earth by opposition will experience acceleration (mainly our weight imposed on us by the earth gravitation) as he is prevented to follow the local geodesic by the reaction force of the ground on which he stands.
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#4119 by meberbs on 03 Aug, 2016 13:39
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If you stop the car on an incline, the brakes still are applying a force. The brakes can't do work when the car is not moving though, which is only because the car has a special rest frame (the road). There is no special frame that could apply to the EMDrive.
...
To restate, the frustum must experience some amount of external accelerative force, big to small to enter motor mode or small to big to enter generator mode. Instead of fighting that EmDrive experimentally determined reality, maybe try to stretch your mind and ask yourself what would be happening to the 2 opposite direction travelling waves inside the frustum as the frustum experienced initial acceleration in either direction. Roger has explained it in past papers. The information is there.
I can see how that applies to automobile propulsion. If the car is not moving the engine can't do any work accelerating the car. And if the car is stopped the brakes don't convert kinetic energy into heat. Am I getting this right?
The engine can do work when the car is in a stopped position, otherwise you couldn't start moving. It can also apply a force while doing no work if the car is pointed uphill and you balance the engine output to match gravity when the car is stopped. Alternatively the same engine setting would be doing work if the car had an initial velocity uphill. (It would climb with constant velocity, gaining gravitational potential energy)
This shows why TheTraveller's claims are not consistent with reality. A device such as a motor can produce a force, but external factors determine whether or not that force does any work. TheTraveller is proposing that the EMDrive magically knows the difference between these situations and suddenly stops applying a force in one of them. This probably stems from Shawyer's strange abuses and misuses of terminology in that paper he keeps linking.
Edit: fixed broken quote
