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#1440 by WarpTech on 12 Oct, 2016 05:09
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Here's a thought experiment:
Consider a horizontal cylinder of length L, in free space, zero-g.
At each end of the cylinder is a mass M, which is large compared to the mass of the cylinder.
The mass on the left is firmly fixed to the end of the cylinder.
The mass on the right starts at the far right, but is free to float around in the cylinder.
If no external forces act on the system, the only force will be the gravitational attraction between the two masses. After a time, the two masses will accelerate toward each other, and eventually both will be in contact at the left end of the cylinder. Assuming the CM did not move... From the outside, it appears that the cylinder has accelerated and moved a distance L/2 to the right. Then stops, when the two masses meet and their momentum cancels out.
Consider the possibility that after some time, the movable mass M is dissipated as heat, into a heatsink on the left. Imagine a battery that feeds in a new mass M on the right side that is free to move in the cylinder. This is possible when using electromagnetic mass and it's momentum when injected is irrelevant. It just adds to the total mass.
http://www.feynmanlectures.caltech.edu/II_28.html
REPEAT ad nausea...
Momentum is conserved. Energy is conserved, and there is no propellant coming out the back except heat. It uses gravity to move itself. No fancy stuff, just gravitational attraction of one mass toward another, and a loss of mass though random heat exchange. Who disagrees with this and why?
Todd
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#1441 by TheTraveller on 12 Oct, 2016 05:33
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A EmDrive is NOT A ROCKET MOTOR. It does not act like a rocket motor. If it can't accelerate, there is no force generated.
So we can forget about hover cars, and those tests that show "anomalous" force when the EmDrive is standing on a scale or attached to a torsional pendulum are invalid (since there's no acceleration)?
Scales and torsion pendulums have a spring constant that allows some initial acceleration.
A hover car is accelerating upward at 1g.
An EmDrive operates in 1 of 3 modes.
Idle, no internal doppler shift of the dual travelling waves.
Motor mode supporting acceleration via initial force big to small.
Generator mode resisting acceleration, via initial force small to big. -
#1442 by ThinkerX on 12 Oct, 2016 05:46
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Todd, I note you keep using a cylinder in your mathematical models. Yet, one of the very few things that is known about this device is that a symmetrical shape (cylinder) results in zero thrust. So why persist in using a shape that will not work?
Another thought that keeps crossing my mind these days: evanescent waves. Clear back to the first versions of these threads, electrical engineers with extensive experience kept saying over and over again that this device, according to what they knew, should generate massive amounts of evanescent waves. Yet, as I recollect, this line of inquiry kept getting dropped or put off. Rodal's summary of the one theory at the recent Colorado conference is the first mention of evanescent waves I recollect seeing here in a long, long while.
Another thing I have started wondering about in recent weeks are the 'surges' - difficult or impossible to repeat episodes of very high thrust. Shell mentioned one such, as did Traveler. Possibly rfmwguy and Yang as well. These episodes turn up in multiple efforts, yet remain a puzzle.
There is also the puzzle with the model work - the ones that over a period of a thousandth of a second, if that - show exponential asymmetrical forces building within the cavity. I have yet to see one of these simulations extended to several seconds, to gauge just how great these internal forces may become. There is a tendency here to dismiss these simulations as 'noise,' yet they also predict the various modes with fair accuracy.
Then there are the 'nulls' - the builds that either produced no 'thrust,' or 'thrust' indistinguishable from the noise level.
And finally, there are the vacuum tests, which seem to produce 'thrust' far smaller than that in an atmosphere.
To my mind, a successful theory for how this device works needs to account in some way for all of these elements.
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#1443 by SeeShells on 12 Oct, 2016 05:57
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Todd, I note you keep using a cylinder in your mathematical models. Yet, one of the very few things that is known about this device is that a symmetrical shape (cylinder) results in zero thrust. So why persist in using a shape that will not work?
What can I say ThinkerX? That this is the reason I'm doing my new Lab? One of the quests I'm on is very close to what you describe.
Another thought that keeps crossing my mind these days: evanescent waves. Clear back to the first versions of these threads, electrical engineers with extensive experience kept saying over and over again that this device, according to what they knew, should generate massive amounts of evanescent waves. Yet, as I recollect, this line of inquiry kept getting dropped or put off. Rodal's summary of the one theory at the recent Colorado conference is the first mention of evanescent waves I recollect seeing here in a long, long while.
Another thing I have started wondering about in recent weeks are the 'surges' - difficult or impossible to repeat episodes of very high thrust. Shell mentioned one such, as did Traveler. Possibly rfmwguy and Yang as well. These episodes turn up in multiple efforts, yet remain a puzzle.
There is also the puzzle with the model work - the ones that over a period of a thousandth of a second, if that - show exponential asymmetrical forces building within the cavity. I have yet to see one of these simulations extended to several seconds, to gauge just how great these internal forces may become. There is a tendency here to dismiss these simulations as 'noise,' yet they also predict the various modes with fair accuracy.
Then there are the 'nulls' - the builds that either produced no 'thrust,' or 'thrust' indistinguishable from the noise level.
And finally, there are the vacuum tests, which seem to produce 'thrust' far smaller than that in an atmosphere.
To my mind, a successful theory for how this device works needs to account in some way for all of these elements.
Shell -
#1444 by TheTraveller on 12 Oct, 2016 05:58
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Bottom line is:
There is no clear evidence that that statement is true. I will continue waiting for you to provide any of the promised demonstrations.
1) EmDrive does work2) No CofM violation as the ships gained momentum is sources from the Em Wave's momentum as yes it is red shifted as a result.
The momentum that the em wave has originally came from the ship, so this is like saying you can move a car by sitting inside and pushing on the steering wheel.
And even if there was em momentum stored inside the cavity, this is limited by the momentum/energy ratio of a photon which is 1/c, and in less than 1 nanosecond, those photons will have reflected, reversed direction and caused the cavity to start moving in the other direction.3) No CofE violation in regard to the local frame as the drive obeys A = F/M.
You keep ignoring that the ship frame is noninertial. CoE is broken in ALL frames by propellantless thrusters, but you have to include "fictitious" forces to realize it in noninertial frames. (If photons were leaving the device, that would not be propellantless, and it would be no better than a laser for force generation.)Oh BTW you can't hook of a EmDrive to a generator as the generator runs at a fixed RPM, IE no increase in angular velocity = no angular acceleration = no angular acceleration = no EmDrive Force generated. To generate Force the EmDrive must accelerate. A EmDrive is NOT A ROCKET MOTOR. It does not act like a rocket motor. If it can't accelerate, there is no force generated.
The claim of not producing force if it can't accelerate does not make any sense. Put an EMDrive up against a brick wall. The wall will have no effect on the drive unless the drive first applies a force to the wall. What you are proposing is then that the emDrive magically knows there is a wall in the way and won't generate force to begin with.
Besides, as was stated by GilbertDrive above, it is easy to turn just let it accelerate while hooked to a generator, or to let it run up to speed then hook up the generator to slow it down and take the kinetic energy. If you think constant rotational velocity is needed by generators, then you don't know how electric generation works. Wind turbines can feed the grid, and with inverters, and similar devices, who cares whether the free energy you are getting is AC or DC?
Again you refuse to accept the experimental data.
Inside a waveguide, EmWave momentum varies as the guide wavelength varies as Cullen proved in 1950. As diameter reduces, guide wavelength increases and momentum decreases. In a resonant cavity end plate radiation pressure increases as Q and power increase. In a frustum a momentum gradient is established being highest at the big end and smallest at the small end. This gradient generates an internal force toward the big end. The frustum moves toward the small end as a balancing reaction force.
The cavity in effect transfers momentum from the dual travelling waves (the apparent standing wave is just an illusion created by the dual travelling waves) EmWave to the frustum. Cavity stored energy drops as does cavity Q. -
#1445 by meberbs on 12 Oct, 2016 06:11
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Here's a thought experiment:
Consider a horizontal cylinder of length L, in free space, zero-g.
At each end of the cylinder is a mass M, which is large compared to the mass of the cylinder.
The mass on the left is firmly fixed to the end of the cylinder.
The mass on the right starts at the far right, but is free to float around in the cylinder.
If no external forces act on the system, the only force will be the gravitational attraction between the two masses. After a time, the two masses will accelerate toward each other, and eventually both will be in contact at the left end of the cylinder. Assuming the CM did not move... From the outside, it appears that the cylinder has accelerated and moved a distance L/2 to the right. Then stops, when the two masses meet and their momentum cancels out.
Consider the possibility that after some time, the movable mass M is dissipated as heat, into a heatsink on the left. Imagine a battery that feeds in a new mass M on the right side that is free to move in the cylinder. This is possible when using electromagnetic mass and it's momentum when injected is irrelevant. It just adds to the total mass.
http://www.feynmanlectures.caltech.edu/II_28.html
REPEAT ad nausea...
Momentum is conserved. Energy is conserved, and there is no propellant coming out the back except heat. It uses gravity to move itself. No fancy stuff, just gravitational attraction of one mass toward another, and a loss of mass though random heat exchange. Who disagrees with this and why?
Todd
What do you mean "no propellant coming out the back except heat"? Heat is a property of matter, not a substance. Do you mean thermal radiation? To dissipate the entire mass as radiation, you would need half of it to be antimatter, and if you directed that energy straight out the back you would get a lot of momentum out of it, enough to be moving at a fraction of light speed I believe.
The step where a battery feeds in a new mass sounds like magic to me. Where does this new mass come from? If it is coming from the battery, then the battery must start with mass greater than M and it loses mass M in creating that mass. And assuming the battery is attached to the cylinder to begin with you then have to go back and redo the original calculations accounting for that, and don't forget to add in the effect of moving that mass around as well.
I am not sure why you posted that link, but it talks about several subtle concepts, and has some intermediate conclusions that it later explains the issues with. Anything short of reading the whole thing will give you an incorrect impression. My attempt to summarize the conclusion of it is that mass of fundamental particles that are charged is in part due to the electromagnetic potential energy, but not entirely, and we don't know if there is a way to tell the difference or if it matters. (The specifics are more subtle than this, but you have to read the whole thing to get it.) Nothing in it changes what I said above about the mass having to already be in the mass of the battery, if the battery creates the mass. -
#1446 by TheTraveller on 12 Oct, 2016 06:22
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Look we have no idea how entanglement works, yet it does. The EmDrive works and produces constant force, which produces constant acceleration, well if properly designed to handle internal doppler shift.
Do you at least agree that, in Shawyer theory, this Doppler shift correspond to an energy proportional to the speed ? (I.E. if the ship goes 2 times faster in it's departure reference frame, each photon loose 2 times more energy by doppler shift) ?
As the frustum accelerates, the internal EmWave loses energy and is red shifted. In a high Q cryo cavity that red shift may be enough to cause the longer wavelength to be outside the cavities narrow bandwidth. Roget compensates for this by progressively increasing the cavity length during each short input pulse of Rf energy.
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#1447 by meberbs on 12 Oct, 2016 06:28
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Again you refuse to accept the experimental data.
What experimental data am I ignoring? There have been no conclusive results shared.Inside a waveguide, EmWave momentum varies as the guide wavelength varies as Cullen proved in 1950. As diameter reduces, guide wavelength increases and momentum decreases. In a resonant cavity end plate radiation pressure increases as Q and power increase. In a frustum a momentum gradient is established being highest at the big end and smallest at the small end. This gradient generates an internal force toward the big end. The frustum moves toward the small end as a balancing reaction force.
First, Cullen did not work with waveguides that vary diameter, and it is not trivial to extend that work, especially since the emDrive is a tapered cavity, not a cylindrical waveguide. You have repeatedly failed to even provide a physical definition of guide wavelength for this case when asked.
Second, assuming that the momentum in the fields does change along the length, this would have to happen due to interactions with the side walls. These forces on the sidewalls balance the difference in forces on the end plates. There obviously are forces on the sidewalls, because otherwise, you wouldn't need them to contain the radiation between the plates. Ignoring the sidewall forces and saying the momentum in the fields magically changes with no interactions breaks conservation of momentum by definition.
Third, even ignoring the balancing force on the sidewalls, you then said that there would be a force towards the big end. This is the force the EM fields exert on the end plate, and is the "correct" result if you blindly apply Cullen's equations and ignore the sidewall forces. This means that the drive should move towards the big end because that is the direction of the force applied to it. The "reaction" statement you made makes no sense. Based on that statement, then if I push an object to the left, then I would expect it to react by moving to the right, and that is not how things work. All I am doing here is applying F=M*a, but you seem to want F = - M*a. -
#1448 by francesco nicoli on 12 Oct, 2016 06:33
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Again you refuse to accept the experimental data.
What experimental data am I ignoring? There have been no conclusive results shared.
the data only himself has seen because it's "proprietary". But hey, he tells you that conclusive data exist, so why should you have the sligthest disbelief they might not? -
#1449 by Gilbertdrive on 12 Oct, 2016 07:21
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Even if resonnance is maintained, the force is inversely proportional to the speed. (In the old Shawyer Theory)
Do you at least agree that, in Shawyer theory, this Doppler shift correspond to an energy proportional to the speed ? (I.E. if the ship goes 2 times faster in it's departure reference frame, each photon loose 2 times more energy by doppler shift) ?
The EmDrive cannot know its "speed", because speed is not an absolute value, it is always relative to something else. Also, "speed" implies a movement at a constant pace. Alternatively, are we talking about Δv? Shall the correct phenomenon when such a "doppler shift" may occur within the cavity rather be when the drive is accelerating (and more exactly, when it is undergoing a proper acceleration).
Very pertinent argument. Also note that the context is clearly in Shawyer Theory
In Shawyer Theory paper 9.4, it woks as if the Emdrive was knowing it's speed in it's departure reference frame, and the Force is inversely proportional to the speed in this referential. I a just trying to convince that it is like that in the old Shawyer theory, not that it is true.
It is important to understand a theory before to discuss it's validity. Of course, I can understand the problem that there is in the emdrive knowing where it comes from. 2 drives coming from different places coud be very close, and have different performances since they come from different initial places. But this theory satisfy CoE. That is not worse.
I am the one who had the idea earlier in these threads that the acceleration needed mentionned by Shawyer was in fact proper acceleration
Also if proper acceleration is needed for the emdrive to work, all static test should be null results. In that case, all experiments showing thrust are bias, except Shawyer Rotary test rig. And the cannae cubesat will be in generator mode because of the drag and will fell even faster than without the drive.
I already asked how much proper acceleration is needed for the drive to work. 0,0001G ? 0,00000000001G ? never got an answer.
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#1450 by Gilbertdrive on 12 Oct, 2016 07:51
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Here's a thought experiment:
Consider a horizontal cylinder of length L, in free space, zero-g.
At each end of the cylinder is a mass M, which is large compared to the mass of the cylinder.
The mass on the left is firmly fixed to the end of the cylinder.
The mass on the right starts at the far right, but is free to float around in the cylinder.
If no external forces act on the system, the only force will be the gravitational attraction between the two masses. After a time, the two masses will accelerate toward each other, and eventually both will be in contact at the left end of the cylinder. Assuming the CM did not move... From the outside, it appears that the cylinder has accelerated and moved a distance L/2 to the right. Then stops, when the two masses meet and their momentum cancels out.
Consider the possibility that after some time, the movable mass M is dissipated as heat, into a heatsink on the left. Imagine a battery that feeds in a new mass M on the right side that is free to move in the cylinder. This is possible when using electromagnetic mass and it's momentum when injected is irrelevant. It just adds to the total mass.
http://www.feynmanlectures.caltech.edu/II_28.html
REPEAT ad nausea...
Momentum is conserved. Energy is conserved, and there is no propellant coming out the back except heat. It uses gravity to move itself. No fancy stuff, just gravitational attraction of one mass toward another, and a loss of mass though random heat exchange. Who disagrees with this and why?
Todd
That is why we can not discuss of CoE about the drive without any hypothesis isolated, or non isolated
The two masses are not isolated from each other. Because of the gravity. So I shall revisit the formulation of Wicoe
Actually, less: the final kinetic energy of the rocket equals the chemical energy delivered by the fuel burnt less the total kinetic energy gained by the propellant, and less the energy lost as waste heat.
it becomes : the final kinetic energy of the rocket equals the chemical energy delivered by the fuel burnt less the total kinetic energy gained by the propellant, less the energy lost as waste heat, and less the potential gravity energy gained by the system ship-propellant (the presence of the propellant in space slow down a very very little the ship by gravity, and vice versa)
Generally we forget these "propellant gravity losses" because they are so smalls...
Of course, there is no need for a violation of CoE if the emdrive exploits any potential energy. Gravity, fields, ZPF, etc.
That is why when debating about CoE, we have to postulate if the emdrive works as an isolated system, or not.
Also, your example make me ask a fundamental question about relativist effect. With your thought experiment, from an external viewpoint, does the mass keep constant ?
A charged battery is more heavier than a discharged one. The potential chemical energy translates into mass with E=MC^2
Is it different for potential gravity energy ?
To calculate the total energy of a system, do we need to directly take into account the potentials energies, or is it enough to take temperature, masses and relative speeds ?
I am sure a GR specialist can tell us ! -
#1451 by TheTraveller on 12 Oct, 2016 07:59
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Again you refuse to accept the experimental data.
What experimental data am I ignoring? There have been no conclusive results shared.Inside a waveguide, EmWave momentum varies as the guide wavelength varies as Cullen proved in 1950. As diameter reduces, guide wavelength increases and momentum decreases. In a resonant cavity end plate radiation pressure increases as Q and power increase. In a frustum a momentum gradient is established being highest at the big end and smallest at the small end. This gradient generates an internal force toward the big end. The frustum moves toward the small end as a balancing reaction force.
First, Cullen did not work with waveguides that vary diameter, and it is not trivial to extend that work, especially since the emDrive is a tapered cavity, not a cylindrical waveguide. You have repeatedly failed to even provide a physical definition of guide wavelength for this case when asked.
Second, assuming that the momentum in the fields does change along the length, this would have to happen due to interactions with the side walls. These forces on the sidewalls balance the difference in forces on the end plates. There obviously are forces on the sidewalls, because otherwise, you wouldn't need them to contain the radiation between the plates. Ignoring the sidewall forces and saying the momentum in the fields magically changes with no interactions breaks conservation of momentum by definition.
Third, even ignoring the balancing force on the sidewalls, you then said that there would be a force towards the big end. This is the force the EM fields exert on the end plate, and is the "correct" result if you blindly apply Cullen's equations and ignore the sidewall forces. This means that the drive should move towards the big end because that is the direction of the force applied to it. The "reaction" statement you made makes no sense. Based on that statement, then if I push an object to the left, then I would expect it to react by moving to the right, and that is not how things work. All I am doing here is applying F=M*a, but you seem to want F = - M*a.
FEKO can compute the resonant freq of a frustum in say TE013 mode.
Excel modeling the frystum as a large number of small length connected cylinder sections yields the guide wavelength for each section per the excited mode & freq. Integrating them yields the average guide wavelength for the frustum. Then for say TE013 mode, calculating the resonance agrees very closely to the FEKO value thus showing using conventional microwave waveguide theory can be used to calculate guide wavelength at any point of the frustum.
The drop in EmWave momentum from the big to small end is not linear, so you can't just add up the axial side wall forces plus small end plate force and assume it equals big end plate force.
BTW with a constant diameter waveguide, such as used by Cullen, how can there be axial side wall forces that caused the reduction in end plate radiation pressure? What Cullen discovered was the end plate radiation pressure drops as per (external wavelength / guide wavelength) * conventional radiation pressure equation.
Here is a thought experiment for you. Take a resonant frustum, extend each end with a 1/4 wave length extension that matches the frustum end diameter, has constant diameter and has an end plate. Would you agree that the radiation pressure at end end plate should agree with Cullen's equations?
Would you agree that Cullen's equation will not show a linear decrease in end plate radiation as the diameter is altered?
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#1452 by flux_capacitor on 12 Oct, 2016 09:53
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Generator mode resisting acceleration, via initial force small to big.
TT, do you know or think that this "generator mode" provides some electric power while braking, or at least that the RF power fed to the cavity is less in this case than while creating the same force in a positive acceleration aka motor mode? -
#1453 by Gilbertdrive on 12 Oct, 2016 10:04
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The recent debate however concerned whether a constant force at a constant power is even possible in classical mechanics which is independent of EmDrives or MET devices.
My assumption is that it's not possible, and I would be very interested to see a working example of such as system (where the mechanism is well known). The problem is that constant force means constant acceleration, which breaks CoE in faster moving reference frames (since the power spent per time unit is the same). Since you can accelerate only by pushing against something (object, or perhaps some unknown or known field?), your speed relative to that "something" will increase, and it will be harder and harder to push (since you provide a larger increase of kinetic energy to that "something").
I agree.
There is a possible working example for a limited time. We can tune an electric train for exemple, so that it drains a power from the line proportional to the speed, and run it in a vacuum tunnel.
It would for example drain 1kw at 1km/h (it is arbitrary) 2kw at 2km/h 100kw at 100 km/h
We can do this until the maximum instantaneous power that the motor can deliver is reached. We can probably do it easily from 1km/h to 500km/h, and have constant accceleration.
but once it is achieved, we can not continue any longer constant acceleration with the train.
The problem is that having constant acceleration drains an increasing quantity of power. so, we are limited by our energies.
To maintain constant force at constant power without braking CoE, an Emship just does not have to steal energy, it has to steal more energy when it goes faster.
We are used to exploit energies. In the history, exploitation of new energies is unseparable from technical progress. We started with human muscle power. Then animal Power, then water power (watermills in medieval period) then wind power, then steam power, then petrol power, then nuclear power.
Each new energy gave new possibilities, and some a very strong increase in awailable total power, but each one was limited in production. Each animal, windmill, watermill, steam machine, nuclear power plant is capable of a given power. No one can give a power linearily increasing during time. If the emdrive was working a constant acceleration for constant power by stealing energy, it would be the biggest revolution that energy production has ever seen.
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#1454 by Gilbertdrive on 12 Oct, 2016 10:14
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A EmDrive is NOT A ROCKET MOTOR. It does not act like a rocket motor. If it can't accelerate, there is no force generated.
So we can forget about hover cars, and those tests that show "anomalous" force when the EmDrive is standing on a scale or attached to a torsional pendulum are invalid (since there's no acceleration)?
Scales and torsion pendulums have a spring constant that allows some initial acceleration.
A hover car is accelerating upward at 1g.
An EmDrive operates in 1 of 3 modes.
Idle, no internal doppler shift of the dual travelling waves.
Motor mode supporting acceleration via initial force big to small.
Generator mode resisting acceleration, via initial force small to big.
True for the Hover car.
about Scales and torsion pendulums
Just before the emdrive is turned on, even if it is linked to a spring, there is no proper acceleration due to the spring. It should not give force.
But this debate is futile if you do not give an order of the minimal proper acceleration needed. If my frustrum receives 1 more photon on one side, Does the radiative pressure of this photon give enough proper acceleration to go in motor mode ? do you need 0.00001 G ?0.000000000000001 G? 10^-50 G ? -
#1455 by TheTraveller on 12 Oct, 2016 12:08
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Roger's new patent application. GB2537119.
My oh my.
IBTimes has already done a report on the new patent:
http://www.ibtimes.co.uk/emdrive-roger-shawyer-patenting-new-design-next-gen-superconducting-thruster-1585982
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#1456 by Flyby on 12 Oct, 2016 12:59
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from the patent :Quote
"a single crystal sapphire substrate is glued to the major end plate..."
Euh.. why the sapphire?
What special property does it have, that it is needed for the inside of the big plate? -
#1457 by SeeShells on 12 Oct, 2016 13:08
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from the patent :
He got the Helical antenna right on. (one a NSFer did for me by 3D printing July 2015)Quote"a single crystal sapphire substrate is glued to the major end plate..."
Euh.. why the sapphire?
What special property does it have, that it is needed for the inside of the big plate?
Saphire is a great thermal conductor and has a High dielectric constant (9.39 from 1.0 MHz to 8.5 GHz) a nice pick.
Shell
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#1458 by rq3 on 12 Oct, 2016 13:28
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from the patent :
He got the Helical antenna right on. (one a NSFer did for me by 3D printing July 2015)Quote"a single crystal sapphire substrate is glued to the major end plate..."
Euh.. why the sapphire?
What special property does it have, that it is needed for the inside of the big plate?
Saphire is a great thermal conductor and has a High dielectric constant (9.39 from 1.0 MHz to 8.5 GHz) a nice pick.
Shell
But according to the patent application, the sapphire is strictly a substrate for the superconductor. It never sees the EM field due to the YBCO film. If the idea was to have a thermally stable substrate, quartz would have been a better (and certainly less expensive) choice. Additionally, the lattice mismatch between single crystal sapphire (Al2O3) and YBCO is pretty severe. Not a good choice. -
#1459 by TheTraveller on 12 Oct, 2016 13:29
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The curved small end plate is clever as it correct for the phase distortion introduced by using the flat big end plate.
As the small end plate is not superconducting, it also generates a smaller radiation pressure on reflection than if superconducting so the result of Big force - Small force is a much larger action force toward the big end plate and thus a much larger reaction force toward the small end plate that makes the thruster accelerate big end to small end.
All as predicted by Roger's theory.
Beautiful patent of a real world partial cryo EmDrive. Well done Roger and team SPR.
