Author Topic: EM Drive Developments - related to space flight applications - Thread 2  (Read 2103647 times)

Offline ArthurEKing

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     Okay, well I'm a first time poster, I'm not a physics major, or mathematician, and I'm expecting people to shoot down what I'm going to say anyways, but hopefully someone will pay it a little mind.  That said, I think I may have an idea about this that may just answer many of the problems that most people have with the still-experimental results that Dr. White is posting here.

     I will start by saying that I really don't know what math exactly would be involved, and if anyone DOES know, and is willing to either do it, or help me do it, then feel free!  Also I'm going to start my theory making only 3 assumptions.  They are as follows.

Assumption 1) That the results Dr. White is posting are correct, and unbiased, that he has followed scientific protocols within the limits of his abilities, and that he has drawn conclusions from empirical evidence as is the scientific method.

Assumption 2) That the suspected warp-bubble like effects are NOT a malfunction of scientific instrumentation, and are not being either misrepresented, or misinterpreted.

Assumption 3)  The laws of physics are in fact NOT being broken.

     Now  assumption 3 is of course the big one that everyone has a problem with, but if you hear me out I believe you may be able to come to an understanding about it.

     You see the law of conservation of momentum, easily stated, is that every action has an equal and opposite reaction.  Of course, being a law, it is inviolable, and anything that does not conform to it cannot exist, and has to be immediately discarded as junk science, right?  And of course the EMDrive DOES seem to break this law, and therefore it has to be fake, or some kind of misunderstanding.

     But what if it ISN'T breaking that law?  What if instead we include ANOTHER law of physics.

     The law of conservation of energy.

     You see, energy cannot be created, or destroyed, it can only change forms.  So if we are not seeing an equal and opposite reaction in kinetic energy, than perhaps the energy has been converted to some other form, and THIS is in fact the reason why the EMDrive actually works, as it is effectively converting kinetic energy from one direction into some other form of energy, and ergo there is a net thrust differential.

     But what form would this energy take?  Waste heat is always a good culprit, as entropy states.  But that doesn't seem to be the whole store, so perhaps could there be a different answer?

     Dr. White has theorized that the EMDrive is in some way interacting with the quantuum vacuum (and other scientists have theorized the same).  IF it is in fact interacting with the quantuum vacuum in some manner, than perhaps this may give us the solution to the warp-field being detected. 

     The quantuum vacuum is often stated as being the lowest possible energy-state of the universe, or in another way of looking at it, a state of 0 energy, which is of course why you can't extract thrust from it, or interact with it, because there's no energy to be extracted.

     However, if you DID in fact do so, you would in essence be creating a negative energy sum.  which when added to the thrust of the EMDrive, would equate to a 0-sum, and thus an equal, and opposite, reaction.  Just that the reaction would not be in a form that we would recognize as momentum, ergo, it appears to us as net thrust.

     If that is the case, this would satisfy some of the requirements of Alcubierre's theorem, allowing for the production of warp-bubbles, which in turn would explain the interference pattern that has been detected.

     Again, this is all just conjecture, and perhaps my understanding of physics is horribly flawed, or someone will do the math involved, and just disprove what I postulated.  However, if it's accurate, it would in essence explain all of the results we have experienced, and effectively wrap everything up in a neat little package that actually makes sense, and does NOT defy the laws of physics.

     Now as for HOW it is converting that energy, THAT I have no idea, but again, this is just something I came up with today.  Feel free to poke holes in it.


Offline Rodal

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I know Shawyer and EW have tried a dielectric in the frustum. Are there any specifications for that dielectric? Material properties? Absorption properties at microwave frequencies?
I was looking at Pyramid Absorbers for microwaves, they can attenuate up to -55dB. A high power microwave source, pumped through a diode into such an absorber, seems to me should have a higher probability of thrust than the EM Drive and relatively simple to construct.


Todd D.

NASA Eagleworks has used a High Density Polyethylene dielectric insert for most of their experiments.  It was obtained from McMaster Carr.  It came from a supplier of extruded HDPE rods.

http://www.mcmaster.com/#standard-plastic-rods/=w0bzy0

under Rigid HDPE Polyethylene, apparently they no longer supply the 6.25" dimension.  Biggest diameter they list is 6.00 inches:  Rigid HDPE Polyethylene Rod, 6" Diameter

Tan delta or the dielectric constant of the HDPE were not measured at NASA Eagleworks.  I understand from prior communications in this thread that NASA Eagleworks does not have a dielectrometer at their lab.  So they used commonly known values for HDPE in their calculations.



Bigger image (click here to download):
http://forum.nasaspaceflight.com/index.php?action=dlattach;topic=36313.0;attach=634621
............................................

DIELECTRIC STRENGTH

Under Performance of Plastics it directs you to a .pdf  that lists

450-1,800  Dielectric Strength, volts/0.001inch

that is 17.72 million V/m (on the low end) that's a little lower than the lowest value listed here: 

http://hypertextbook.com/facts/2009/CherryXu.shtml

but the same minimum listed here:

http://www.rfcafe.com/references/electrical/dielectric-constants-strengths.htm

************
The only attenuation parameter that was discussed was the attenuation dielectric loss tangent, but in other contexts:

DIELECTRIC LOSS TANGENT

Paul March, during some discussions quoted

Quote
RF loss tangent from that of HDPE  (~0.0004)



Interestingly (for this thread's discussion due to the significance that the NASA experimenters have placed on the dielectric being responsible for providing the measured thrust) is what happens in the High Density PolyEthylene (HDPE) dielectric polymer insert.  Because the dimensions of the dielectric are not negligible compared to the EM Drive's dimension, and the dielectric is not modeled as just a boundary condition.

The loss tangent of HDPE is reported to be

tan delta = 0.0004

Therefore the intrinsic impedance angle is

intrinsic impedance angle =(ArcTan[0.0004])/2

Therefore, inside the HDPE dielectric the electric and magnetic fields, instead of being out of phase by 90 degrees (as they are in the air or vacuum medium), will be out of phase by:

90 - (180/Pi) (ArcTan[0.0004])/2 = 89.98854084470854 degrees

EDIT: Thanks to @ace for pointing out the originally missing conversion factor from radians to degrees

This phase angle (89.9885 degrees)  will show practically no visual difference with 90 degrees at the resolution of the following image :



TRAVELLING WAVE POYNTING VECTOR                                           STANDING WAVE POYNTING VECTOR
OPEN WAVEGUIDE                                                                          CLOSED CAVITY

The Poynting vector inside the HDPE dielectric, instead of having a zero time average, will have the following factor multiplying ExB/mu :

Cos[(Pi/180) (90 - (180/Pi) (ArcTan[0.0004])/2)]/2= 0.00009999999400006368

So, inside the HDPE polymer dielectric the Poynting vector has this small magnitude over a period (or multiples thereof).

So, the extent of this approximation, for the HDPE dielectric is about 0.01 % (which is negligible in comparison to several other approximations).


Now, let's examine what this (very small intensity Poynting vector time average) means, concerning the discussion in this EM Drive.

If one were to posit that the EM Drive's thrust is due to the very small magnitude of the time average of the Poynting vector due to these thermal losses (in the HDPE dielectric or in the copper):

1) It would mean that there should be more thrust with lower Q.  This is the complete opposite of what the experimenters like Shawyer claims (Shawyer claims that the higher the Q, the greater the thrust).  Notice that

Tan [loss angle] = Tan[ 2 impedance angle ]= 1/Q

2) All the equations proposed so far (by Shawyer, McCulloch and @Notsosureofit) have predicted thrust proportional to Q.  This is the complete opposite of what such a Poynting vector would predict (it would predict thrust proportional to 1/Q instead), because

Tan delta= 1/Q

measured Q        effective tan delta

7320                  1.366* 10 ^(-4)
22000                4.545* 10 ^(-5)
10^6                  10^(-7)

3) It would mean that experimenters like Shawyer and Fetta are in the completely wrong track pursuing superconducting EM Drives, as superconducting EM Drives would lead to practically no thrust (the opposite of what they claim) because superconducting EM Drives would display practically no heat losses and hence zero time average Poynting vector.

4) Considering the HDPE dielectric acting as a sink (energy flowing from the EM Drive towards the HDPE where the energy is dissipated internally in the dielectric polymer due to its tandelta and hence irretrievably lost instead of being reflected), the Poynting vector would be directed towards the HDPE dielectric, that is towards the small base, and hence the EM Drive should experience a recoil force and acceleration towards the big base.  This is the opposite direction force found in NASA's experiments with the dielectric.  (Recall that NASA Eagleworks found no thrust force with mode TE012 without a HDPE dielectric and that with the HDPE dielectric inserted at the small base they found a force and acceleration directed towards the small base.)

« Last Edit: 05/08/2015 11:09 AM by Rodal »

Offline PaulF

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     Okay, well I'm a first time poster, I'm not a physics major, or mathematician, and I'm expecting people to shoot down what I'm going to say anyways, but hopefully someone will pay it a little mind.  That said, I think I may have an idea about this that may just answer many of the problems that most people have with the still-experimental results that Dr. White is posting here.

     I will start by saying that I really don't know what math exactly would be involved, and if anyone DOES know, and is willing to either do it, or help me do it, then feel free!  Also I'm going to start my theory making only 3 assumptions.  They are as follows.

Assumption 1) That the results Dr. White is posting are correct, and unbiased, that he has followed scientific protocols within the limits of his abilities, and that he has drawn conclusions from empirical evidence as is the scientific method.

Assumption 2) That the suspected warp-bubble like effects are NOT a malfunction of scientific instrumentation, and are not being either misrepresented, or misinterpreted.

Assumption 3)  The laws of physics are in fact NOT being broken.

     Now  assumption 3 is of course the big one that everyone has a problem with, but if you hear me out I believe you may be able to come to an understanding about it.

     You see the law of conservation of momentum, easily stated, is that every action has an equal and opposite reaction.  Of course, being a law, it is inviolable, and anything that does not conform to it cannot exist, and has to be immediately discarded as junk science, right?  And of course the EMDrive DOES seem to break this law, and therefore it has to be fake, or some kind of misunderstanding.

     But what if it ISN'T breaking that law?  What if instead we include ANOTHER law of physics.

     The law of conservation of energy.

     You see, energy cannot be created, or destroyed, it can only change forms.  So if we are not seeing an equal and opposite reaction in kinetic energy, than perhaps the energy has been converted to some other form, and THIS is in fact the reason why the EMDrive actually works, as it is effectively converting kinetic energy from one direction into some other form of energy, and ergo there is a net thrust differential.

     But what form would this energy take?  Waste heat is always a good culprit, as entropy states.  But that doesn't seem to be the whole store, so perhaps could there be a different answer?

     Dr. White has theorized that the EMDrive is in some way interacting with the quantuum vacuum (and other scientists have theorized the same).  IF it is in fact interacting with the quantuum vacuum in some manner, than perhaps this may give us the solution to the warp-field being detected. 

     The quantuum vacuum is often stated as being the lowest possible energy-state of the universe, or in another way of looking at it, a state of 0 energy, which is of course why you can't extract thrust from it, or interact with it, because there's no energy to be extracted.

     However, if you DID in fact do so, you would in essence be creating a negative energy sum.  which when added to the thrust of the EMDrive, would equate to a 0-sum, and thus an equal, and opposite, reaction.  Just that the reaction would not be in a form that we would recognize as momentum, ergo, it appears to us as net thrust.

     If that is the case, this would satisfy some of the requirements of Alcubierre's theorem, allowing for the production of warp-bubbles, which in turn would explain the interference pattern that has been detected.

     Again, this is all just conjecture, and perhaps my understanding of physics is horribly flawed, or someone will do the math involved, and just disprove what I postulated.  However, if it's accurate, it would in essence explain all of the results we have experienced, and effectively wrap everything up in a neat little package that actually makes sense, and does NOT defy the laws of physics.

     Now as for HOW it is converting that energy, THAT I have no idea, but again, this is just something I came up with today.  Feel free to poke holes in it.
As far as the QV goes, and also assuming all the thing you just assumed (also my preference) the QV could be considered point-like when you actually tap into it. A singularity. Only difference is this singularity is the same singularity where ever in the universes spacetime you poke a hole. No matter where you are, poke a hole in spacetime and you are tapping into the exact same singularity. Not a singularity like a black hole as we know it, but one that is the result of a higher dimensional Quantum Vacuum. In that higher dimension, the QV could be anything, We cant know that. Some accepted theories use more than our 3+1 spacetime dimensions. Having no dimensions to us means that it also has no preferred reference frame, solving that part of GR. What it manifests itself as could be in fact like the earth is for our electricity grid. It doesn't matter where on earth you are you can use it as a return for your power line.
At this moment, it just costs a whole load of power to punch through to our "QV-earth".

Continuing on that matter, it could be possible that the energy that black holes suck in is energy that in fact is just being returned to the QV, where it presumably came from. Big bang anyone?

Could it be that by opening a "hole" to the QV , that the effect of negative energy is leaking through to our dimensions causing the, by some asumed, gradient? I say negative energy because on our side we have only positive energy. It sounds reasonable if one posits that the big bang burped all it's energy into two realities; positive in one, and negative in the other (the QV), hell for all that matters the QV could be nothing else than the negative-energy mirror of our universe. By the way that could also explain dark energy. I know I don't sound scientific by bantering all this, they are just thoughts to ponder. Maybe one day someone will get an inception for something truely wonderful from this.
« Last Edit: 05/08/2015 12:58 AM by PaulF »

Offline LasJayhawk

Does anyone know on the EW tests, what the total forward and reflected power was ( not the net )?

iOS auto correct strikes again...
« Last Edit: 05/08/2015 01:21 AM by LasJayhawk »

Offline TheTraveller

Using low temps and low power is definitely the way to go during this "how does it work?" phase.  Much safer.  But keep your eyes away from it and have a microwave leak detector at hand.

The high-power engineering can be done after the basic principles involved are understood.
2.45GHz is home microwave oven frequency. Most run around 600W. I'm sure forum menber have seen what 600W of microwave can do in regard to plasma creation and other pryotechinque tricks in a microwave oven.

Using a 1kW magnetron could do serious damage to people & equipment around a EM Drive if any microwave energy escaped. So please use microwave leak detectors and limit time close to the cavity.

Shawyer has experienced this. He made this comment about leaking microwaves interfering with his video camera when filming the rotary test rig.

Is why I'll build a Faraday Cage around my test unit so to stop microwave leaks interfering with my test and control system.
« Last Edit: 05/08/2015 01:09 AM by TheTraveller »
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline deltaMass

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@TheTraveller
A small, slow-speed generator with magnetic bearings is I think what you need. I have looked but so far had no luck. One can find them in profusion, however, for direct drive power generation from a wind power machine. These are of course massive and expensive.
http://www.alibaba.com/product-detail/2014-promotional-bldc-motor-magnetic-bearing_1803241008.html
might fit the bill, using good quality gearing so the gennie runs fast

Offline PaulF

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I've been looking at surplus 20kw radar magnetrons on ebay, and the availability of 3D printed silicons carbide base on which to plate my Magnesium diboride superconductor, and also at cryocoolers. It's all very complex and expensive, and with the cryo, somewhat dangerous. I am most definitely in the realm of a 'hacker' in this endeavor (and have been so in other fields for a number of years), so I know what to expect (or at least I think I do).

Radar magnetrons operate in pulsed mode.    The output power during the pulse may be 20 kW but the duration is very short and so the average power output is very low.   Any high power CW magnetron is very dangerous to play with when it is removed from the equipment it was designed for.    The RF discharges can cause serious injury and temporary blindness.
But..if those pulses have enough duration to make measurements..one could potentially see what happens at those powers without scaling the dangers with it so much.

Offline WarpTech

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Thanks a lot! Indeed my idea was to justify White's results that appear already striking from a physicist's standpoint. I am working on the frustum case and I hope to update the paper soon.

Nice work Marco! I just finished reading through it a few times. Thank you for sharing.

Todd



Offline maciejzi

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Has anyone compared the thrust of a closed setup with one side open or two sides open setup?

As in this amateur video:
« Last Edit: 05/08/2015 02:07 AM by maciejzi »

Offline TheTraveller

@TheTraveller
A small, slow-speed generator with magnetic bearings is I think what you need. I have looked but so far had no luck. One can find them in profusion, however, for direct drive power generation from a wind power machine. These are of course massive and expensive.
http://www.alibaba.com/product-detail/2014-promotional-bldc-motor-magnetic-bearing_1803241008.html
might fit the bill, using good quality gearing so the gennie runs fast
Looks interesting.
Will check it out for sure.
Thanks.
"As for me, I am tormented with an everlasting itch for things remote. I love to sail forbidden seas.”
Herman Melville, Moby Dick

Offline Bubs

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Can someone explain why the EMdrive experiment isn't run inside Helmholtz Coils (to cancel Earth magnetic field)?

The propulsion could be easily explained by the interaction between the large DC currents used to operate the magnetron/RF power amplifier with Earth’s magnetic field by way of the Lorentz force. In other words, a homopolar motor. This is an experiment that any child can do with a battery and a piece of wire:

http://en.wikipedia.org/wiki/Homopolar_motor

To do a proper measurement, the Earth's magnetic field should be canceled around the experiment using this setup:

http://en.wikipedia.org/wiki/Helmholtz_coil

Offline deltaMass

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Can someone explain why the EMdrive experiment isn't run inside Helmholtz Coils (to cancel Earth magnetic field)?

The propulsion could be easily explained by the interaction between the large DC currents used to operate the magnetron/RF power amplifier with Earth’s magnetic field by way of the Lorentz force. In other words, a homopolar motor. This is an experiment that any child can do with a battery and a piece of wire:

http://en.wikipedia.org/wiki/Homopolar_motor

To do a proper measurement, the Earth's magnetic field should be canceled around the experiment using this setup:

http://en.wikipedia.org/wiki/Helmholtz_coil
It's all AC past the tie-off points, so there's no net current for this effect.

Offline Bubs

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There is still a shared ground connection between the source and the device-under-test, so it's not fully balanced AC. You can never be sure about residual ground currents, ground loops etc. It can easily cause this residual force, and explain the large variation between various experimental setups.

It would be a wise precaution to run this experiment inside Helmholtz coils to cancel possible interactions with Earth's magnetic field.

Offline Rodal

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Can someone explain why the EMdrive experiment isn't run inside Helmholtz Coils (to cancel Earth magnetic field)?

The propulsion could be easily explained by the interaction between the large DC currents used to operate the magnetron/RF power amplifier with Earth’s magnetic field by way of the Lorentz force. In other words, a homopolar motor. This is an experiment that any child can do with a battery and a piece of wire:

http://en.wikipedia.org/wiki/Homopolar_motor

To do a proper measurement, the Earth's magnetic field should be canceled around the experiment using this setup:

http://en.wikipedia.org/wiki/Helmholtz_coil

Assuming one believes Shawyer's experimental reports, wouldn't that interaction with the Earth's negative field be negated by the fact that Shawyer claims to have measured similar thrust/PowerInput for the EM Drive pointing small base UP (vertical), small base DOWN (vertical), small base to the RIGHT (horizontal)  ?

(since the Lorentz force vector due to the Earth's magnetic field would have a definite direction, and therefore the measured force should vary upon direction)
« Last Edit: 05/08/2015 02:40 AM by Rodal »

Offline Bubs

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Can someone explain why the EMdrive experiment isn't run inside Helmholtz Coils (to cancel Earth magnetic field)?

The propulsion could be easily explained by the interaction between the large DC currents used to operate the magnetron/RF power amplifier with Earth’s magnetic field by way of the Lorentz force. In other words, a homopolar motor. This is an experiment that any child can do with a battery and a piece of wire:

http://en.wikipedia.org/wiki/Homopolar_motor

To do a proper measurement, the Earth's magnetic field should be canceled around the experiment using this setup:

http://en.wikipedia.org/wiki/Helmholtz_coil

Assuming one believes Shawyer's experimental reports, wouldn't that interaction with the Earth's negative field be negated by the fact that Shawyer claims to have measured similar thrust/PowerInput for the EM Drive pointing small base UP (vertical), small base DOWN (vertical), small base to the RIGHT (horizontal)  ?

I referring to NASA's experimental setup, not Shawyer's. (I consider Shawyer's setup to be too sloppy - rotating platform, with laptop? with fans? and rotating hard-disk? Extremely unprofessional).

In NASA's setup, there is still a shared ground connection between the source and the device-under-test, so it's not fully balanced AC. You can never be sure about residual ground currents, ground loops etc. It can easily cause this residual force, and explain the large variation between various experimental setups.

It would be a wise precaution to run this experiment inside Helmholtz coils to cancel possible interactions with Earth's magnetic field.

Offline zen-in

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There is still a shared ground connection between the source and the device-under-test, so it's not fully balanced AC. You can never be sure about residual ground currents, ground loops etc. It can easily cause this residual force, and explain the large variation between various experimental setups.

It would be a wise precaution to run this experiment inside Helmholtz coils to cancel possible interactions with Earth's magnetic field.

The EW apparatus has one or two large NIB magnets attached to the torque pendulum; part of an eddy current brake.    This has been one source of error discussed in their Aug. 2014 paper.

Offline Rodal

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...
I referring to NASA's experimental setup, not Shawyer's. (I consider Shawyer's setup to be too sloppy - rotating platform, with laptop? with fans? and rotating hard-disk? Extremely unprofessional).

In NASA's setup, there is still a shared ground connection between the source and the device-under-test, so it's not fully balanced AC. You can never be sure about residual ground currents, ground loops etc. It can easily cause this residual force, and explain the large variation between various experimental setups.

It would be a wise precaution to run this experiment inside Helmholtz coils to cancel possible interactions with Earth's magnetic field.

Shawyer also had this non-rotating setup (if I recall correctly he had the EM Drive vertically in the UP and DOWN positions):



Shawyer's website SPR states:

Quote
The maximum thrust, measured using a precision balance was 16mN for an input power of 850W, which is very close to the thrust of 16.6mN predicted from equation 1.

The thrust could be varied from zero to maximum by varying the input power, or by varying the resonant frequency of the thruster. Considerable efforts were made to test for possible thermal and electromagnetic spurious effects. The primary method was to carry out all tests in both nominal and inverted orientations, and to take the mean of the results. The thruster was also sealed into a hermetic enclosure to eliminate buoyancy effects of the cooling air. Three different types of test rig were used, two using 1 mg resolution balances in a counterbalance test rig and one using a 100 mg resolution balance in a direct measurement of thruster weight.

Comparison of the rates of increase of thrust for the different spring constants, using pulsed input power, gave a clear proof that the thrust was produced by momentum transfer and was not due to any “undefined” spurious effect.

The total test programme encompassed 450 test runs of periods up to 50 seconds, using 5 different magnetrons.



 If you are aware of Shawyer's non-rotating force measurements, did you find it to be similarly

Quote from: Bubs
Extremely unprofessional
?
« Last Edit: 05/08/2015 03:00 AM by Rodal »

Offline LasJayhawk

Dr. Rodel. What would happen if the signal with the phase shifted E&H fields ran into a non-shifted signal with the same amplitude and the E field 180 degrees out? There is a lot of RF bouncing in there after all. Seems all that would be left is a bit of the H field.

Would that leave me with a magnetic monopole? ( now wouldn't that be funny...)

Offline deltaMass

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There is still a shared ground connection between the source and the device-under-test, so it's not fully balanced AC. You can never be sure about residual ground currents, ground loops etc. It can easily cause this residual force, and explain the large variation between various experimental setups.

It would be a wise precaution to run this experiment inside Helmholtz coils to cancel possible interactions with Earth's magnetic field.
I ran the numbers and was surprised how little current it takes. I assumed it ran in the shield of the RF feed coax and took length to be 0.5m. That yields 4 Amps of ground loop current necessary to produce 100 uN in the Earth's field.

So yeah - except that reversing the test article pretty much reverses the thrust and does NOT reverse your Lorentz force. So I think it's unnecessary.

Offline WarpTech

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4) Considering the HDPE dielectric acting as a sink (energy flowing from the EM Drive towards the HDPE where the energy is dissipated internally in the dielectric polymer due to its tandelta and hence irretrievably lost instead of being reflected), the Poynting vector would be directed towards the HDPE dielectric, that is towards the small base, and hence the EM Drive should experience a recoil force and acceleration towards the big base.  This is the opposite direction force found in NASA's experiments with the dielectric.  (Recall that NASA Eagleworks found no thrust force with mode TE012 without a HDPE dielectric and that with the HDPE dielectric inserted at the small base they found a force and acceleration directed towards the small base.)

Thank you Dr. Rodal for a very informative post!

This last statement is what I was looking for. The drive works precisely because there is no internal polarizable medium pushing the other way. I was thinking about a straight cylinder with an absorber at one end and a reflector at the other end, but it's still no better than a photon rocket even with a high Q.

Todd





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