Author Topic: EM Drive Developments - related to space flight applications - Thread 6  (Read 1083111 times)

Offline zen-in

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That's correct, electroplating is detrimental to conductivity when compared to pure copper, to the point that rather than increasing the Q, electroplating silver may actually decrease Q drastically, by up to 50% according to this peer-reviewed article:

"It is often found that silver-plating a copper conductor increases the radio-frequency losses (reduces Q) instead of reducing them as expected"

(Radio-frequency) investigations have shown that the conductivity of much of the commercial silver-plating is about half of that of pure copper

So that silver-plating, rather than increasing the Q by 40%, according to this classic paper, apparently will reduce Q to half of the Q with pure copper

Radio Frequency Performance of Electro Plated Finishes

A.M. Fowler

Proceedings IREE Australia May 1970

http://k6mhe.com/n7ws/Plating.pdf

I think a lot depends on how the Silver electroplate is done.  The hobbyist brush method likely puts a porus coat of Silver down so it's conductivity would be reduced.   I have only done Silver plating with a Silver Cyanide solution which may be unobtanium now.   When the Silver plate sets it is a flat white color and I suspect that surface is also porus to a degree.   Microwave cavities all seem to be made from brass and then are Silver plated.   The companies that make these filters must be doing something to improve the surface conductivity of the Silver plate.   I don't know if the home hobbiest can improve Silver plate to where its conductivity is better than Copper.
« Last Edit: 12/11/2015 08:25 pm by zen-in »

Offline SteveD

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Stupid question: how does a spacecraft propelled by an EMDrive (if it works) slow down?  The basic answer is by creating a force in the opposite direction.  What happens to the energy that the drive has been loading into the spaceship?  It can't simply be destroyed, it has to go somewhere.  Where?
1. Yes turn the ship or the device by 180° what is generating the thrust to slow down.
2. The device have to generate thrust... Some work has to be done to slow the ship done, this will generate some heat/ thermal radiation. All of this will increase the entropy of the universe... such as in the acceleration case. There isn't a difference between the acceleration and the deceleration phase. Acceleration and the deceleration are equal in the light of Relativity.
https://en.wikipedia.org/wiki/Work_%28physics%29
https://en.wikipedia.org/wiki/Entropy
3. Conservation of energy is one of the fundamental statements of modern physics, energy don't will destroyed.

Seems like that's only rephrasing the question in formalized terms.

Quote
In thermodynamics, entropy (usual symbol S) is a measure of the number of specific realizations or microstates which may realize a thermodynamic system in a defined state specified by macroscopic observables. Entropy is commonly understood as a measure of disorder. According to the second law of thermodynamics the entropy of an isolated system never decreases; such a system will spontaneously proceed towards thermodynamic equilibrium, the configuration with maximum entropy. Systems that are not isolated may decrease in entropy, provided they increase the entropy of their environment by at least that same amount. Since entropy is a state function, the change in the entropy of a system is the same for any process that goes from a given initial state to a given final state, whether the process is reversible or irreversible. However, irreversible processes increase the combined entropy of the system and its environment.

A sealed box on a spaceship would seem like an isolated system.  How is it increasing universal entropy as a way to shed energy and slow down?

Offline R.W. Keyes

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How important are computational resources in emdrive development? How much can be gained by more MEEP installations? What if we had some sort of web-based job management system for a distributed, volunteer computation system? I'd want to start simply, and not spread one job on multiple systems, but rather, have some sort of gatekeeper and dispatcher between emdrive developers and others who would donate computational time.

A few months ago, there was conversation about doing simulations on GPUs, which MEEP doesn't currently support, but there is a similar program for CUDA called B-CALM. Did anything ever come of this? Do we have some port of the MEEP simulation codes to B-CALM?

I don't want to go to the cloud for this, I want to take advantage of currently underutilized resources, specifically for emdrive development purposes.

Offline SeeShells

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That's correct, electroplating is detrimental to conductivity when compared to pure copper, to the point that rather than increasing the Q, electroplating silver may actually decrease Q drastically, by up to 50% according to this peer-reviewed article:

"It is often found that silver-plating a copper conductor increases the radio-frequency losses (reduces Q) instead of reducing them as expected"

(Radio-frequency) investigations have shown that the conductivity of much of the commercial silver-plating is about half of that of pure copper

So that silver-plating, rather than increasing the Q by 40%, according to this classic paper, apparently will reduce Q to half of the Q with pure copper

Radio Frequency Performance of Electro Plated Finishes

A.M. Fowler

Proceedings IREE Australia May 1970

http://k6mhe.com/n7ws/Plating.pdf

I think a lot epends on how the Silver electroplate is done.  The hobbyist brush method likely puts a porus coat of Silver down so it's conductivity would be reduced.   I have only done Silver plating with a Silver Cyanide solution which may be unobtanium now.   When the Silver plate sets it is a flat white color and I suspect that surface is also porus to a degree.   Microwave cavities all seem to be made from brass and then are Silver plated.   The companies that make these filters must be doing something to improve the surface conductivity of the Silver plate.   However for home hobbiest it is moot.

Ok you presented something that should be worried about if anyone is going to silver plate at home or even as a prototype in a lab.

This is how I addressed those concerns in the paper.

CasWell electroplating soultion lays down a 99.9% pure silver layer, no brighteners or any other additives.

Using the little wand they give you is very slow and very tedious and will only do a couple of microns per minute. The bottom of the frustum is sealed so I filled it with ~3-4 inches of plating fluid and used a Stainless Steel 316 rod that was ~ 3/8" or  10mm and inserted it into the captured bath. Slowly moved it around about 30-40mm from the bottom for a hour.

This gave a very thick 40-50 um electroplated silver coating.

Offline OnlyMe

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Stupid question: how does a spacecraft propelled by an EMDrive (if it works) slow down?  The basic answer is by creating a force in the opposite direction.  What happens to the energy that the drive has been loading into the spaceship?  It can't simply be destroyed, it has to go somewhere.  Where?
1. Yes turn the ship or the device by 180° what is generating the thrust to slow down.
2. The device have to generate thrust... Some work has to be done to slow the ship done, this will generate some heat/ thermal radiation. All of this will increase the entropy of the universe... such as in the acceleration case. There isn't a difference between the acceleration and the deceleration phase. Acceleration and the deceleration are equal in the light of Relativity.
https://en.wikipedia.org/wiki/Work_%28physics%29
https://en.wikipedia.org/wiki/Entropy
3. Conservation of energy is one of the fundamental statements of modern physics, energy don't will destroyed.

Seems like that's only rephrasing the question in formalized terms.

Quote
In thermodynamics, entropy (usual symbol S) is a measure of the number of specific realizations or microstates which may realize a thermodynamic system in a defined state specified by macroscopic observables. Entropy is commonly understood as a measure of disorder. According to the second law of thermodynamics the entropy of an isolated system never decreases; such a system will spontaneously proceed towards thermodynamic equilibrium, the configuration with maximum entropy. Systems that are not isolated may decrease in entropy, provided they increase the entropy of their environment by at least that same amount. Since entropy is a state function, the change in the entropy of a system is the same for any process that goes from a given initial state to a given final state, whether the process is reversible or irreversible. However, irreversible processes increase the combined entropy of the system and its environment.

A sealed box on a spaceship would seem like an isolated system.  How is it increasing universal entropy as a way to shed energy and slow down?

The box is not entirely sealed relative to the exterior environment. Microwaves are being pumped in.

The problem is that everything we know about microwaves says the net forces on the inside walls should be zero. If the box does produce thrust unrelated to heat dissipation etc..., and we set aside any quantum vacuum speculations, there would have to be something new in the way the resonance of the microwaves inside the box interact with the walls that results in an asymmetric transfer of momentum.

Strictly speaking if what is happening is just a transfer of momentum from the microwaves to the frustum, while it would be something we have not seen before and thus new physics, it should not involve a violation of conservation of momentum until and unless the thrust produced out paces the energy pumped in...

First thing is reproduce the claims of thrust and then as many here have been saying all along meticulously account for all heat and magnetic/electromagnetic related affects... In the DIY builders domain, that really means a need for probably double or triple digit mN of force.., and repeatability. Preferably with an independent copy of the build.

EDIT - Something else that has been bothering me, is that if this is a direct transfer of momentum from microwaves to the frustum.., it seems to me that the frustum being grounded might be required. There has to be some kind of loop that may not be reproducible in space... Unless just grounding back to power supply is sufficient.
« Last Edit: 12/11/2015 08:06 pm by OnlyMe »

Offline X_RaY

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Stupid question: how does a spacecraft propelled by an EMDrive (if it works) slow down?  The basic answer is by creating a force in the opposite direction.  What happens to the energy that the drive has been loading into the spaceship?  It can't simply be destroyed, it has to go somewhere.  Where?
1. Yes turn the ship or the device by 180° what is generating the thrust to slow down.
2. The device have to generate thrust... Some work has to be done to slow the ship done, this will generate some heat/ thermal radiation. All of this will increase the entropy of the universe... such as in the acceleration case. There isn't a difference between the acceleration and the deceleration phase. Acceleration and the deceleration are equal in the light of Relativity.
https://en.wikipedia.org/wiki/Work_%28physics%29
https://en.wikipedia.org/wiki/Entropy
3. Conservation of energy is one of the fundamental statements of modern physics, energy don't will destroyed.

Seems like that's only rephrasing the question in formalized terms.

Quote
In thermodynamics, entropy (usual symbol S) is a measure of the number of specific realizations or microstates which may realize a thermodynamic system in a defined state specified by macroscopic observables. Entropy is commonly understood as a measure of disorder. According to the second law of thermodynamics the entropy of an isolated system never decreases; such a system will spontaneously proceed towards thermodynamic equilibrium, the configuration with maximum entropy. Systems that are not isolated may decrease in entropy, provided they increase the entropy of their environment by at least that same amount. Since entropy is a state function, the change in the entropy of a system is the same for any process that goes from a given initial state to a given final state, whether the process is reversible or irreversible. However, irreversible processes increase the combined entropy of the system and its environment.

A sealed box on a spaceship would seem like an isolated system.  How is it increasing universal entropy as a way to shed energy and slow down?
In fact it is part of a closed system namely the universe. The device interats with the space around.(Complete isolated systems are not present at all since the total range of EM fields as well as G fields is unlimeted per definition)
Microwave energie will heat the resonant cavity caused by the ohmic losses. The cavity will radiate in the IR spectrum also at its outer side.. Even if it is installed on a ship, the radiation will heating the ship. The ship radiates the thermal energy into the free space around it.
This process is irreversible. You can use a part of the heat to generate electrical energy but never all of it. I think its impossible to create a "perpetuum mobile" or any kind of "free energy harvesting machine".  ;)
If the EM Drive works one need to put energy into it. Till now there is no closed and accepted theory that explains the observed thrust. As far as we know the HF to kinetic energy conversion is really bad, the biggest part of the energy will converted into heat.

And again,  acceleration and deceleration (negative acceleration, sign is used per human agreement/convention in relation to the total speed of a second object like a planet) are equal.
« Last Edit: 12/11/2015 08:47 pm by X_RaY »

Offline glennfish

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How important are computational resources in emdrive development? How much can be gained by more MEEP installations? What if we had some sort of web-based job management system for a distributed, volunteer computation system? I'd want to start simply, and not spread one job on multiple systems, but rather, have some sort of gatekeeper and dispatcher between emdrive developers and others who would donate computational time.

A few months ago, there was conversation about doing simulations on GPUs, which MEEP doesn't currently support, but there is a similar program for CUDA called B-CALM. Did anything ever come of this? Do we have some port of the MEEP simulation codes to B-CALM?

I don't want to go to the cloud for this, I want to take advantage of currently underutilized resources, specifically for emdrive development purposes.

IMHO either not very or not much.

My thinking is that the only computational model that's being worked with at present is MEEP on the assumption that high Q is key to whatever is going on.  To that end, those who need MEEP have it either in a linux box or a vmware linux emulator.  It's slow slow slow, but it works.

However, if at some point there's a positive  signal that won't go away, and the physics community agrees that it's real, then there would be a strong desire to characterize why it's there, and a need to build a simulator that matched real world results.  If MEEP is still relevant at that point, then there would be a need for speed, and perhaps serious parallel processing efforts.

On the other hand, a positive signal that doesn't go away might have no design relationship to MEEP, since it probably wouldn't be something you could calculate with EM codes like MEEP.  The new code EMEEP would evolve either through experiments that tie down the parameters, or a yet to be agreed upon theory as to what it should be simulating.  How those calculations would be done is in the TBD domain.  If things get there, let's collaborate on building an EMEEP engine.  :)

Offline zen-in

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...

Ok you presented something that should be worried about if anyone is going to silver plate at home or even as a prototype in a lab.

This is how I addressed those concerns in the paper.

CasWell electroplating soultion lays down a 99.9% pure silver layer, no brighteners or any other additives.

Using the little wand they give you is very slow and very tedious and will only do a couple of microns per minute. The bottom of the frustum is sealed so I filled it with ~3-4 inches of plating fluid and used a Stainless Steel 316 rod that was ~ 3/8" or  10mm and inserted it into the captured bath. Slowly moved it around about 30-40mm from the bottom for a hour.

This gave a very thick 40-50 um electroplated silver coating.

The one alternative for those who want the absolute best Q possible is to use Silver fill Copper.   This is Copper with a thin (1 mil or less) layer of Fine Silver that is bonded to the Copper using a hot roll process.   I haven't seen it available in large sheets though.   The plating solution you are using is probably safe to use.   I doubt it contains any cyanide.

Offline Notsosureofit

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Stupid question: how does a spacecraft propelled by an EMDrive (if it works) slow down?  The basic answer is by creating a force in the opposite direction.  What happens to the energy that the drive has been loading into the spaceship?  It can't simply be destroyed, it has to go somewhere.  Where?
1. Yes turn the ship or the device by 180° what is generating the thrust to slow down.
2. The device have to generate thrust... Some work has to be done to slow the ship done, this will generate some heat/ thermal radiation. All of this will increase the entropy of the universe... such as in the acceleration case. There isn't a difference between the acceleration and the deceleration phase. Acceleration and the deceleration are equal in the light of Relativity.
https://en.wikipedia.org/wiki/Work_%28physics%29
https://en.wikipedia.org/wiki/Entropy
3. Conservation of energy is one of the fundamental statements of modern physics, energy don't will destroyed.

Seems like that's only rephrasing the question in formalized terms.

Quote
In thermodynamics, entropy (usual symbol S) is a measure of the number of specific realizations or microstates which may realize a thermodynamic system in a defined state specified by macroscopic observables. Entropy is commonly understood as a measure of disorder. According to the second law of thermodynamics the entropy of an isolated system never decreases; such a system will spontaneously proceed towards thermodynamic equilibrium, the configuration with maximum entropy. Systems that are not isolated may decrease in entropy, provided they increase the entropy of their environment by at least that same amount. Since entropy is a state function, the change in the entropy of a system is the same for any process that goes from a given initial state to a given final state, whether the process is reversible or irreversible. However, irreversible processes increase the combined entropy of the system and its environment.

A sealed box on a spaceship would seem like an isolated system.  How is it increasing universal entropy as a way to shed energy and slow down?
In fact it is part of a closed system namely the universe. The device interats with the space around.(Complete isolated systems are not present at all since the total range of EM fields as well as G fields is unlimeted per definition)
Microwave energie will heat the resonant cavity caused by the ohmic losses. The cavity will radiate in the IR spectrum also at its outer side.. Even if it is installed on a ship, the radiation will heating the ship. The ship radiates the thermal energy into the free space around it.
This process is irreversible. You can use a part of the heat to generate electrical energy but never all of it. I think its impossible to create a "perpetuum mobile" or any kind of "free energy harvesting machine".  ;)
If the EM Drive works one need to put energy into it. Till now there is no closed and accepted theory that explains the observed thrust. As far as we know the HF to kinetic energy conversion is really bad, the biggest part of the energy will converted into heat.

And again,  acceleration and deceleration (negative acceleration, sign is used per human agreement/convention in relation to the total speed of a second object like a planet) are equal.

...or if you like the Sachs/Schwebel GR versions...into gravitational currents.

Offline R.W. Keyes

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How important are computational resources in emdrive development? How much can be gained by more MEEP installations? What if we had some sort of web-based job management system for a distributed, volunteer computation system? I'd want to start simply, and not spread one job on multiple systems, but rather, have some sort of gatekeeper and dispatcher between emdrive developers and others who would donate computational time.

A few months ago, there was conversation about doing simulations on GPUs, which MEEP doesn't currently support, but there is a similar program for CUDA called B-CALM. Did anything ever come of this? Do we have some port of the MEEP simulation codes to B-CALM?

I don't want to go to the cloud for this, I want to take advantage of currently underutilized resources, specifically for emdrive development purposes.

IMHO either not very or not much.

My thinking is that the only computational model that's being worked with at present is MEEP on the assumption that high Q is key to whatever is going on.  To that end, those who need MEEP have it either in a linux box or a vmware linux emulator.  It's slow slow slow, but it works.
OK. I've got a core i5 3470 3.2 ghz w/ 32gb of ram, running Debian. I don't know what's common in this community but I think of it as a decently fast machine, and want to do useful things with it while I am asleep.
However, if at some point there's a positive  signal that won't go away, and the physics community agrees that it's real, then there would be a strong desire to characterize why it's there, and a need to build a simulator that matched real world results.  If MEEP is still relevant at that point, then there would be a need for speed, and perhaps serious parallel processing efforts.

On the other hand, a positive signal that doesn't go away might have no design relationship to MEEP, since it probably wouldn't be something you could calculate with EM codes like MEEP.  The new code EMEEP would evolve either through experiments that tie down the parameters, or a yet to be agreed upon theory as to what it should be simulating.  How those calculations would be done is in the TBD domain.  If things get there, let's collaborate on building an EMEEP engine.  :)
I am looking forward to that. Until I can actually equip a lab (funds are coming...someday), running simulations is about the only useful thing I can do.

Offline SeeShells

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Ok you presented something that should be worried about if anyone is going to silver plate at home or even as a prototype in a lab.

This is how I addressed those concerns in the paper.

CasWell electroplating soultion lays down a 99.9% pure silver layer, no brighteners or any other additives.

Using the little wand they give you is very slow and very tedious and will only do a couple of microns per minute. The bottom of the frustum is sealed so I filled it with ~3-4 inches of plating fluid and used a Stainless Steel 316 rod that was ~ 3/8" or  10mm and inserted it into the captured bath. Slowly moved it around about 30-40mm from the bottom for a hour.

This gave a very thick 40-50 um electroplated silver coating.

The one alternative for those who want the absolute best Q possible is to use Silver fill Copper.   This is Copper with a thin (1 mil or less) layer of Fine Silver that is bonded to the Copper using a hot roll process.   I haven't seen it available in large sheets though.   The plating solution you are using is probably safe to use.   I doubt it contains any cyanide.
Details
Before I did this I wanted to make sure there wasn't any cyanide and I don't even think you can get that stuff anymore.
http://www.caswellplating.com/electroplating-anodizing/silver-plating-kits/silver-brush-plating-solution-1-pint.html
(Caswell Silver is a new type of alkaline cyanide free silver plating solution that will plate over nickel, sterling silver, gold, rhodium, copper, brass and bronze. The system will provide uniform color consistency and even coverage.)
Needed to prevent this...
X X
 ^


Offline ThereIWas3

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Please make a backup copy of your model before you refine it so that we can be sure to reconcile our models.
It is all kept in a github repository that tracks every change and from which every past version can be recalled.  I have been doing software development for 40 years and you quickly learn not to make the mistake of having only one copy.
Quote
The Shells model you are using was much different than mine, but I have made a model of what I think you are running. If the attached looks like what you have, I will run it with your input data to verify our models. I don't recall whether or not it is similar to the model that Dr. Rodal worked with. Maybe he does.
The dimension numbers I was using came directly from SeeShells herself, very recently.  I have not done any image generation runs with it yet.  That will come next.
 
Quote
Edit add: Oh, and I suggest that you change your coordinate system to use the z-coordinate  as the axis of rotation. I used x at the time the NSF-1701 model was uploaded but it did cause confusion among our physicists friends. That's why I changed it to the generally accepted convention that holds z as the direction of propagation of EM waves.

Yes, I saw the comment about that in the code.  I will change that so everyone follows the same convention.
"If you want to build a ship, don’t drum up people to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea" - Antoine de Saint-Exupéry

Offline glennfish

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OK. I've got a core i5 3470 3.2 ghz w/ 32gb of ram, running Debian. I don't know what's common in this community but I think of it as a decently fast machine, and want to do useful things with it while I am asleep.


That's a sweet box.  Uncommon in most home based communities.

ALL.  This person is offering, I believe, MEEP processing services for this community.  With those specs he can probably knock the socks off of any home PC and trim processing times.

Unless some of you folks are "borrowing" your boxes from your employers, this looks like a sweet offer.  I'd recommend you PM him if you want to shave some time.

Gimme data, I'll give you stats.

Give him a problem, he'll give you a simulation.

At least that's how I read it. 

Offline ThereIWas3

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How important are computational resources in emdrive development? How much can be gained by more MEEP installations?
...
However, if at some point there's a positive  signal that won't go away, and the physics community agrees that it's real, then there would be a strong desire to characterize why it's there, and a need to build a simulator that matched real world results.
...

If the effect turns out to be real, I expect universities with supercomputers to fall all over themselves wanting to work on this.  My own school has one.

I see the contribution of simulation being in visualizing what is actually going on inside the frustrum, which leads toward a theory of why the thing works (if it works at all).  The various DIY experimentors are working on does it work.   Existing published results each present their own theory as to how it works, but I do not find any of them convincing.
"If you want to build a ship, don’t drum up people to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea" - Antoine de Saint-Exupéry

Offline AG4D

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Hi everyone

Sorry for this incursion, but do you think to use three magnetrons is better than one.  And perhaps to refresh at -25° your EMdrive before dynamique test is better too ?

For example, dynamique test during ten seconds, to -25° at 100° ?

Offline SeeShells

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How important are computational resources in emdrive development? How much can be gained by more MEEP installations?
...
However, if at some point there's a positive  signal that won't go away, and the physics community agrees that it's real, then there would be a strong desire to characterize why it's there, and a need to build a simulator that matched real world results.
...

If the effect turns out to be real, I expect universities with supercomputers to fall all over themselves wanting to work on this.  My own school has one.

I see the contribution of simulation being in visualizing what is actually going on inside the frustrum, which leads toward a theory of why the thing works (if it works at all).  The various DIY experimentors are working on does it work.   Existing published results each present their own theory as to how it works, but I do not find any of them convincing.

Data, we need data. without data the theories are just theories and subject to hammering from the physics crowd. EagleWorks believes there is a anomalous thrust remaining even after quantifying any errors or other sources that could qualify as thrust. They have a peer paper being reviewed and you can bet it's going to be a very very rigorous review.

I don't have the heavy physics math to do a paper but I will provide data. This process is going to take sometime, but I hope in some small way to add to the growing plus side that there is thrust. Like EagleWorks I'm slowly going over absolutely everything and retesting, rerunning.

Hang in there, good data takes time.

Shell

Offline ThereIWas3

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Hi everyone

Sorry for this incursion, but do you think to use three magnetrons is better than one.

My thought is it would be worse.  There is little chance of keeping multiple magnetrons phase locked with each other in these types of setups.
"If you want to build a ship, don’t drum up people to collect wood and don’t assign them tasks and work, but rather teach them to long for the endless immensity of the sea" - Antoine de Saint-Exupéry

Offline aero

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Hi everyone

Sorry for this incursion, but do you think to use three magnetrons is better than one.

My thought is it would be worse.  There is little chance of keeping multiple magnetrons phase locked with each other in these types of setups.

Yes, I know that Shell's gave you the numbers, I saw the post. I was just remarking that I needed to make that model in order to run comparisons. Which I have done, but the model I imaged and posted does not resonate at all with Hz excitation. What EM component or components did you use to excite your antenna?

Meep will calculate a different Q for each of the 6 EM components.

Oh, and if you insert this -      (at-end output-hfield-y) right before your harminv statement, you can see what the fields look like. Actually you can do as much output there as you like, except that you need to know how many cycles the job will run in order to output time slices.
« Last Edit: 12/11/2015 11:54 pm by aero »
Retired, working interesting problems

Offline SteveD

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Hi all.  Busy, got to run, but got something stuck in my head. 

The entropy of an isolated system cannot decrease.

Isn't Q factor a measure of entropy?  I mean the classic definition is the number of cycles of a pendulum per unit of energy.

An EmDrive would seem like an isolated system.

But some of these simulations are suggesting the modes are unstable.  Don't some of these simulations show instability even with a narrowband feed?  If a mode fell apart -- lower Q -- and then another mode developed -- higher Q -- (or simply two modes of differing Qs fluctuated) that that would seem like a system moving to a higher degree of order.  Which suggests the system is not isolated.  For that matter, if you could redshift photons, couldn't you setup a situation where the photons where just above a resonant frequency and would be redshifted down into it (meaning that order would increase).

Or am I saying something wrong here.  The first two things that come to mind are that 1. the redshift example would simply reflect a situation where the device hasn't reached a stable energy level yet (but isn't that what Shawyer is doing by injecting energy in bursts - completing whatever is going on before a stable energy level is reached).  2.  Could the movement to a higher Q be reflected in heat feeding back into the external rf feed -- making the system not isolated (or perhaps its with heat exchange to the outside).

But I still can't help thinking that there might be some way to use fluctuation in Q or in the modes to show a decrease in entropy proving that a sealed tin can isn't a closed system -- its just exhausting into the QV, gravitational waves, or [insert your favorite theory here].

Offline Prunesquallor

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Stupid question: how does a spacecraft propelled by an EMDrive (if it works) slow down?  The basic answer is by creating a force in the opposite direction.  What happens to the energy that the drive has been loading into the spaceship?  It can't simply be destroyed, it has to go somewhere.  Where?

Weeeelll, assuming a simplified interpretation of EMDrive thrust, you simply thrust in the opposite direction as the spacecraft's velocity vector.

Energy generally isn't "loaded" in this context. The EM Drive (theoretically) converts stored energy (e.g., from fissile material in a nuclear reactor) or external energy (e.g., solar) into kinetic energy.  However, as we have debated ad nauseum, it leads to a paradox if you assume an EM Drive provides constant thrust at constant power with no propellant consumption.
Retired, yet... not

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