Author Topic: EM Drive Developments - related to space flight applications - Thread 11  (Read 646816 times)

Offline scienceguy

  • Regular
  • Full Member
  • ****
  • Posts: 836
  • Lethbridge, Alberta
  • Liked: 155
  • Likes Given: 279
what does it take to reflect a microwave? A metal? Or will another microwave reflect a microwave?
e^(pi*i) = -1

Offline SeeShells

  • Senior Member
  • *****
  • Posts: 2442
  • Every action there's a reaction we try to grasp.
  • United States
  • Liked: 3186
  • Likes Given: 2708
what does it take to reflect a microwave? A metal? Or will another microwave reflect a microwave?
No it will not, although it's not that simple.
Great reading.
https://en.wikipedia.org/wiki/Electromagnetism
Even more thoughts to ponder.
https://en.wikipedia.org/wiki/Electromagnetism#Chaotic_and_emergent_phenomena

Back to stealth mode and being very busy.

My Very Best,
Shell

Offline TheTraveller

what does it take to reflect a microwave? A metal? Or will another microwave reflect a microwave?

Microwave photons do not reflect nor bounce.

Instead the photon impacts an orbital electron, is absorbed and almost immediatley re emitted. If the impact and emit events are elastic, ie there is no momentum nor energy transfer between photon and atom, the emitted photon freq is the same as the impacted photon freq. If the event is nonelastic, ie momentum and energy are exchanged between photon and atom, then the freq of the emitted photon will not match that of the impacted photon.

EmDrive acceleration is the result of assymetric nonelastic impact and emit events where the gained accelerated mass' momentum and KE is sourced from lost photon momentum and energy, which causes the photon emitted freq to decrease. As the photons lose monentum to the gained accelerated mass momentum, CofM is conserved. Likewise gained acceelerated mass KE is sourced from loss photon energy and CofE is conserved.

Question to be experimentally proved is can a tapered resonant cavity generate an assymetric force? If it can be shown to happen, then it follows why and how CofM and CofE are conserved without expelling mass. Ie the wavelength lengthened photons, with lower momentum, are what carries away the required Newton 3 momentum gain of the accelerated mass.

Would be interesting for someone to ray trace an averaged photon pathway, from say big end plate to small end plate and back to big end plate, in a TE013 resonant cavity. Some may be very surprised what that exercise will reveal. Can share that for a round trip there will be 8 side wall & end plate impact and emit events.

Even more interesting to work out the radiation pressure that will be generated at each impact and emit event. Thoughts the radiation pressure will be the same at each impact and emit event site are very wrong. Likewise thoughts that the overall force will be zero are also very wrong.

Such a simple exercise but after so many years, as far as I know, no one here has ever actually done the calculations but instead made statement, without any proof, the overall force would be zero.
« Last Edit: 07/08/2018 07:47 am by TheTraveller »
It Is Time For The EmDrive To Come Out Of The Shadows

Online meberbs

  • Senior Member
  • *****
  • Posts: 3096
  • Liked: 3379
  • Likes Given: 777
what does it take to reflect a microwave? A metal? Or will another microwave reflect a microwave?

Microwave photons do not reflect nor bounce.
Your statements about the waves being absorbed and re-emitted is simply not how quantum mechanics works. You are completely ignoring the wave nature of photons. It is much more complicated than that, and also irrelevant to the energy and momentum balance. It is reflected, and you can go back to one of my first posts on this site to see the amount of Doppler shift that happens.

Question to be experimentally proved is can a tapered resonant cavity generate an assymetric force? If it can be shown to happen, then it follows why and how CofM and CofE are conserved without expelling mass. Ie the wavelength lengthened photons, with lower momentum, are what carries away the required Newton 3 momentum gain of the accelerated mass.
How many times do you have to be told that the photons are part of the system? They never leave the cavity and all momentum they have originally came from the cavity. If the drive were to work as you claim, by the time you turn it off, it will have changed momentum, and there is nothing remaining in the universe that has corresponding opposite momentum. That is the definition of breaking conservation of momentum.

Would be interesting for someone to ray trace an averaged photon pathway, from say big end plate to small end plate and back to big end plate, in a TE013 resonant cavity. Some may be very surprised what that exercise will reveal. Can share that for a round trip there will be 8 side wall & end plate impact and emit events.
Wait so, you are admitting that their is force on the sidewalls? If you have done the calculation you claim, share the details. If you got any result other than no net force, you made a mistake. The whole concept is a mistake anyway, since at every point in the cavity, there are photons travelling in many different directions, and no photon can be localized to a point, they are spread out in space on the order of a wavelength. A hypothetical path more representative of an atom bouncing around in vacuum could still be used to show you why momentum conservation means that there can be no asymmetric force.

Even more interesting to work out the radiation pressure that will be generated at each impact and emit event. Thoughts the radiation pressure will be the same at each impact and emit event site are very wrong. Likewise thoughts that the overall force will be zero are also very wrong.

Such a simple exercise but after so many years, as far as I know, no one here has ever actually done the calculations but instead made statement, without any proof, the overall force would be zero.
You are lying here. You have been shown the calculations many times:
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html
You have never pointed out a single mathematical mistake in that (there is none), and it is derived directly from the same Maxwell's equations that Cullen used. (And you also haven't given a single experimental example where the experiment has resonance results that disagree with the theory, despite being challenged to support your claims many times.)

Offline TheTraveller

.....

When a photon impacts an orbital metallic electron, the photon energy and momentum are gained by the orbital electron. As it is not enough energy to alter the electron orbit, the absorbed energy and momentum are remitted as a newly created photon with either the same freq as impacted or a lower freq if the atom gained energy and momentum from the impact. Well established physics and what happens with a solar sail.

The photons in a resonant cavity have energy and momentum that was created by the Rf energy that flowed in the coupler and resulted in the creation of the photons. So Rf electrial energy is converted into photon momentum and energy. If some of those photons lose some of their energy and momentum via inelastic events, the emitted photons having a longer wavelength. Well estabished physics.

Only question is can a tapered resonant cavity generate an assymetric force?
It Is Time For The EmDrive To Come Out Of The Shadows

Offline RERT

Meberbs -

Noether's theorem regarding energy conservation relates to space(time) which is translationally invariant. It's quite difficult to arrange an experiment containing physical objects which is translationally invariant. One is probably left arguing that translational invariance is the correct approximation when some small test apparatus is much smaller than the translations you care about. The immediate proximity of a tapered copper can is definitely not.

Others -

My guess on the physics discussions: we won't get anywhere with linear theories. Having said that, there are opportunities for interesting non-linear calculations just by letting the skin resistance in the copper depend on temperature ~ current ~ field, though the MEGA concept seems to finger GR as the obvious non-linear starting point.

I'm not wildly concerned about energy or momentum conservation. 120 years ago we thought mass was conserved, until we figured out it wasn't. We will have to follow where the data leads, though at the moment that doesn't look to be very far :(!

Offline LowerAtmosphere

  • Full Member
  • *
  • Posts: 106
  • Liked: 67
  • Likes Given: 91
Meberbs -

Noether's theorem regarding energy conservation relates to space(time) which is translationally invariant. It's quite difficult to arrange an experiment containing physical objects which is translationally invariant. One is probably left arguing that translational invariance is the correct approximation when some small test apparatus is much smaller than the translations you care about. The immediate proximity of a tapered copper can is definitely not.

Others -

My guess on the physics discussions: we won't get anywhere with linear theories. Having said that, there are opportunities for interesting non-linear calculations just by letting the skin resistance in the copper depend on temperature ~ current ~ field, though the MEGA concept seems to finger GR as the obvious non-linear starting point.

I'm not wildly concerned about energy or momentum conservation. 120 years ago we thought mass was conserved, until we figured out it wasn't. We will have to follow where the data leads, though at the moment that doesn't look to be very far :(!
Quote
Having said that, there are opportunities for interesting non-linear calculations just by letting the skin resistance in the copper depend on temperature ~ current ~ field,
So some sort of metal alloy which has variable resisitivity based on temperature? Or a feedback mechanism based on wall temperature?
Piezoelectrics come to mind... maybe we need a wall made of micro copper filaments which share a field when excited but in their nonexcited state it is merely a grid. We know the wavelength is too long to leak out. This would also dissipate heat better.

What about thin copper wire rings are used in the upper cavity for the first half wavelength and a mesh/grid for the lower cavity? The reasoning is the coils will compress the upper field while the lower field has no directional compression in either lateral or vertical components of the internal field?

If done with 3D printing you could even create a design with a gradient from rings to grid. To help visualize, imagine the upper wall being a long thin copper spiral while the lower wall is like a chicken coop fence/sieve.

Additionally, this would help characterize the wall interactions and determine whether the effect is even related to the walls or if we can keep one end open as was suggested earlier. I had a theory that the thrust may be caused due to wall discontinuities (microscopic scratches/null points in the evanescent waves). The roughness and field along the wall must be imaged. If it behaves as expected, electrons should "jump the gap" between wall segments when excited sufficiently. If, however, they merely adapt and follow the lattice and the metallics then we may have a way of experimentally disproving the relativistic nature of electrons as suggested by recent experiments. Thoughts?

Offline OnlyMe

  • Full Member
  • ***
  • Posts: 361
  • So. Calif.
  • Liked: 210
  • Likes Given: 195
...
How many times do you have to be told that the photons are part of the system? They never leave the cavity and all momentum they have originally came from the cavity. If the drive were to work as you claim, by the time you turn it off, it will have changed momentum, and there is nothing remaining in the universe that has corresponding opposite momentum. That is the definition of breaking conservation of momentum.
...

meberbs,

Part of this argument has always bothered me, but first remember that I do not believe that bouncing anything inside a frustum generates any net anomalous force/acceleration.

The part that bothers me is the emphasis on conservation of momentum, where it seems obvious that a significant amount of the electromagnetic energy introduced into the frustum is converted to and dissipated as heat, and for the EmDrive as a whole, Lorentz forces etc., which moves the problem to one of conservation of energy rather than just momentum.

Even in classical everyday mechanical systems like a vehicle moving down a roadway a portion of the initial momentum generated by an engine never makes it to an end stage transfer of momentum. Except in hypothetical situations it is almost always a conservation of energy balancing act and situation, while if all you follow is momentum in and out, conservation of momentum will always appear to be broken.

This is part of what has lead to so much focus on improving experimental design, an account of energy in vs. energy out. And the possibility that some as yet undetermined mechanism might generate some useable force/acceleration... or not.


Online meberbs

  • Senior Member
  • *****
  • Posts: 3096
  • Liked: 3379
  • Likes Given: 777
Meberbs -

Noether's theorem regarding energy conservation relates to space(time) which is translationally invariant. It's quite difficult to arrange an experiment containing physical objects which is translationally invariant. One is probably left arguing that translational invariance is the correct approximation when some small test apparatus is much smaller than the translations you care about. The immediate proximity of a tapered copper can is definitely not.
The asymmetry has to be embedded in the laws of physics themselves. Just arranging objects in an asymmetric way does not allow you to break conservation laws. For theories short of GR there is simply nothing in them that has the necessary type of asymmetry.

GR is a bit more complicated. On a global level conservation of momentum can no longer be easily defined due to asymmetries, but it still holds on a local level. Even with the global definition problem, gravitational waves are the one way to lose break what conservation of momentum intuitively says, and they have the same energy momentum ratio as photons, at least in the realistic limit where such calculations can be done. Local is relative to the curvature of spacetime, and based on the speed of light, at the mass and size scale of an emDrive, it is completely negligible. If you include the whole mass of the Earth, you can measure a slight decrease of momentum from photons travelling vertically up, but even then, this decrease corresponds to the decrease a physical object would have from travelling upwards in a gravitational field. It prevents you from getting around conservation of momentum and energy by sending massless particles straight up out of a gravitational well, showing that for our purposes even GR generally is aligned against propellantless propulsion claims.

Offline OnlyMe

  • Full Member
  • ***
  • Posts: 361
  • So. Calif.
  • Liked: 210
  • Likes Given: 195
.....

When a photon impacts an orbital metallic electron, the photon energy and momentum are gained by the orbital electron. As it is not enough energy to alter the electron orbit, the absorbed energy and momentum are remitted as a newly created photon with either the same freq as impacted or a lower freq if the atom gained energy and momentum from the impact. Well established physics and what happens with a solar sail.

The photons in a resonant cavity have energy and momentum that was created by the Rf energy that flowed in the coupler and resulted in the creation of the photons. So Rf electrial energy is converted into photon momentum and energy. If some of those photons lose some of their energy and momentum via inelastic events, the emitted photons having a longer wavelength. Well estabished physics.

Only question is can a tapered resonant cavity generate an assymetric force?

TT,

I believe this implies a simplistic and inaccurate situation. If the microwaves inside of the frustum interacted as you describe there would be no degradation of the conductive walls.

I am pretty sure that past DIY experimental attempts have shown pitting of the inside copper surface(s). That alone proves that there is enough electromagnetic energy to alter electron orbits even to the point of ionizing atoms resulting surface pitting...

Then again maybe those ionized (charged) copper atoms flying around inside the frustum under the influence of an asymmetric electromagnetic field is the source of an anomalous thrust... but then, if this were the case, wouldn’t the surface pitting degrade the Q, affect the over all efficiency and limit the drives usesful life cycle/span?

Point is contrary to your comment above, ”As it is not enough energy to alter the electron orbit,...” microwaves inside a frustum have been shown to interact destructively with the conductive walls of the frustum.

Online meberbs

  • Senior Member
  • *****
  • Posts: 3096
  • Liked: 3379
  • Likes Given: 777
...
How many times do you have to be told that the photons are part of the system? They never leave the cavity and all momentum they have originally came from the cavity. If the drive were to work as you claim, by the time you turn it off, it will have changed momentum, and there is nothing remaining in the universe that has corresponding opposite momentum. That is the definition of breaking conservation of momentum.
...

meberbs,

Part of this argument has always bothered me, but first remember that I do not believe that bouncing anything inside a frustum generates any net anomalous force/acceleration.

The part that bothers me is the emphasis on conservation of momentum, where it seems obvious that a significant amount of the electromagnetic energy introduced into the frustum is converted to and dissipated as heat, and for the EmDrive as a whole, Lorentz forces etc., which moves the problem to one of conservation of energy rather than just momentum.

Even in classical everyday mechanical systems like a vehicle moving down a roadway a portion of the initial momentum generated by an engine never makes it to an end stage transfer of momentum. Except in hypothetical situations it is almost always a conservation of energy balancing act and situation, while if all you follow is momentum in and out, conservation of momentum will always appear to be broken.

This is part of what has lead to so much focus on improving experimental design, an account of energy in vs. energy out. And the possibility that some as yet undetermined mechanism might generate some useable force/acceleration... or not.
The choice between considering conservation of momentum or energy can go either way for these discussions. Breaking conservation of momentum trivially leads to a situation where conservation of energy is violated. The same may be true in reverse, though possibly dependent on what form a hypothetical device makes the energy appear in, I have never tried working out a general case, which would get confusing since you need to start with an essentially contradictory assumption.

For the example of a vehicle on a roadway, the problem is equally energy or momentum conservation. The main momentum loss is to air resistance, so you have to track either the energy or momentum loss to the air, which are both equally difficult to do from my perspective. For hills, I will agree that tracking energy is easier than tracking changes in the Earth's momentum.

I don't think it is accurate to be described as experiments focusing on "energy in/ energy out" To do that, they would need to determine the heat capacity of the cavity and track its temperature accurately. Given non-uniformities in the heat distribution, this would be almost impossible to get right. Instead efforts have been focused on isolating from external forces, which is more of a momentum balance perspective.

Although honestly this is basically a po-tay-to po-tah-to situation, as far as anything important goes I think we completely agree.

Offline Jim Davis

  • Full Member
  • ****
  • Posts: 560
  • Liked: 124
  • Likes Given: 2
I'm not wildly concerned about energy or momentum conservation. 120 years ago we thought mass was conserved, until we figured out it wasn't.

Just out of curiosity, does that attitude extend to other contexts? For example, would you think there might be something to an engine that runs only on water because, after all, 120 years ago we thought mass was conserved?

Online meberbs

  • Senior Member
  • *****
  • Posts: 3096
  • Liked: 3379
  • Likes Given: 777
.....

When a photon impacts an orbital metallic electron, the photon energy and momentum are gained by the orbital electron. As it is not enough energy to alter the electron orbit, the absorbed energy and momentum are remitted as a newly created photon with either the same freq as impacted or a lower freq if the atom gained energy and momentum from the impact. Well established physics and what happens with a solar sail.

The photons in a resonant cavity have energy and momentum that was created by the Rf energy that flowed in the coupler and resulted in the creation of the photons. So Rf electrial energy is converted into photon momentum and energy. If some of those photons lose some of their energy and momentum via inelastic events, the emitted photons having a longer wavelength. Well estabished physics.

Only question is can a tapered resonant cavity generate an assymetric force?

TT,

I believe this implies a simplistic and inaccurate situation. If the microwaves inside of the frustum interacted as you describe there would be no degradation of the conductive walls.

I am pretty sure that past DIY experimental attempts have shown pitting of the inside copper surface(s). That alone proves that there is enough electromagnetic energy to alter electron orbits even to the point of ionizing atoms resulting surface pitting...

Then again maybe those ionized (charged) copper atoms flying around inside the frustum under the influence of an asymmetric electromagnetic field is the source of an anomalous thrust... but then, if this were the case, wouldn’t the surface pitting degrade the Q, affect the over all efficiency and limit the drives usesful life cycle/span?

Point is contrary to your comment above, ”As it is not enough energy to alter the electron orbit,...” microwaves inside a frustum have been shown to interact destructively with the conductive walls of the frustum.
Thanks, I was trying to figure out how to respond to that post since most of what it says simply ignores my previous post, and my response is to go re-read the part about how the momentum of the photons doesn't spontaneously appear, since that would by definition break conservation of momentum.

To add to what you said, the description of electrons in "orbits" is inherently wrong in itself. The valence band electrons in metals exist in a continuous "sea", they already aren't in a single "orbit" and are capable of absorbing essentially infinitesimal amounts of energy as a result. In this situation the extreme number of overlapping electrons have to be treated together as a wave rather than individual particles, just like the photons can't be correctly treated individually. Every event affects every member of the group, because they are all non-localized and indistinguishable. One of the many oddities of quantum.

Offline RERT

Jim -

It's right to be very sceptical of all claims with no mechanism of action within known physical laws.

It's also wrong to lose sight of the fact that those laws change from time to time, eg conservation of mass.

Perhaps contracting this to being not wildly concerned about conservation of momentum - though implicitly   somewhat concerned - might have left something on the cutting room floor...

Offline RERT

LowerAtmosphere -

I was meaning something quite prosaic really, which may actually be embedded in the mode shape simulations seen here, though I suspect not.

A frustrum in resonance has wall currents. The current densities are not uniform, in a gross sense: by which I mean that the current round the sides of the frustrum might be very different to the current in the end caps. If I'm understanding right, the mutual Lorentz forces from these currents are meant to be in balance, producing zero net force.

But as the current densities differ, ohmic heating differs - that's why mode shapes have been viewed with a thermal camera.

When copper gets hot, it's resistance increases, and you would expect the pattern of current flows to change. If they stayed the same, power dissipation would rise, and that's fixed by the input power to the frustrum. So that's a different current pattern to the one which previously had no net Lorentz force, and one which is slowly changing to boot.

At this point intuition fails me: but I would guess that COMSOL might be able to simulate resistance changing with temperature, and temperature with current.

Offline flux_capacitor

  • Full Member
  • ****
  • Posts: 708
  • France
  • Liked: 860
  • Likes Given: 1076
You are lying here. You have been shown the calculations many times:
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

Please, not this page again

Rodal explained back to the EM Drive Thread #3 (three years ago!) that aero's simulations (as predicted by Notsosureofit BTW) showed how Greg Egan's "demonstration" you quoted, involving standing waves only, was wrong as it didn't reflect the reality of what is going on in a real asymmetric cavity, when considering the flow of time and the presence of an antenna constantly feeding new RF energy:

Quote from: Rodal
So people that proclaim left to right symmetry fail to take into account time.

Greg Egan's analysis assumes a sinusoidal change with time.  Clearly this is not the case. There is TIME-ASYMMETRY left to right.  The origin of the asymmetry is the RF feed, that Greg Egan does not take into account.  There is an interaction between standing waves and the travelling waves from the RF feed.

As Notsosureofit said:  steady state standing waves by themselves never occurs as long as the RF feed is on.
Quote from: Rodal
YES, they contradict Egan. http://gregegan.customer.netspace.net.au/SCIENCE/Cavity/Cavity.html

Egan assumed that the time variation of the fields was symmetric, given by a sinusoid in time.  His weakness is that he failed to consider the effect of the RF feed travelling wave.  Greg Egan's results only apply for the RF feed being OFF.
Quote from: Rodal
NEW INFORMATION: We show here that those (Greg Egan, etc.) that pontificate that the electromagnetic fields inside the EM Drive produce a Poynting vector that sums up to zero over integer periods of time are plain wrong.  The reason is that the Poynting vector sums up to zero over integer periods of time only when the electromagnetic fields are standing waves (waves that do not travel in the longitudinal direction).  The RF feed antenna disturbs what would otherwise be a standing wave frozen in space and results in waves that travel in the longitudinal direction back and forth and a time variation of the amplitude electromagnetic field that is not a simple sinuosoid, as long as the RF feed is on.  This results in a non-zero Poynting vector with a net pointing from the small base to the big base over integer periods of time (probably due to geometric attenuation of the travelling waves due to the conical taper).  During EM Drive experiments, the RF feed is on: it is only with the RF feed on that forces have been measured. 
Notice that the period of this non-sinusoidal variation of the Poynting vector is half the period of the electromagnetic field (as expected from theoretical considerations).

See here, here and there. Of course, as also pointed out obviously by Rodal (miss you a lot José, long time no see…) such an asymmetry does not explain on itself how propellantless propulsion could be achieved, bus since Egan's oversimplistic explanation has been contradicted, we should definitely stop referring to it. More especially when using such a flawed explanation (incomplete and far from reality) to prove someone's quote is flat wrong or that he would even lie.

Offline Jim Davis

  • Full Member
  • ****
  • Posts: 560
  • Liked: 124
  • Likes Given: 2
It's right to be very sceptical of all claims with no mechanism of action within known physical laws.

It's also wrong to lose sight of the fact that those laws change from time to time, eg conservation of mass.

Well, then let me rephrase.

Both an Em drive and a water engine violate conservation laws.

Why does only the latter case raise a red flag with you? Why does only the Em drive rate the "those laws change from time to time" qualification?

Online meberbs

  • Senior Member
  • *****
  • Posts: 3096
  • Liked: 3379
  • Likes Given: 777
You are lying here. You have been shown the calculations many times:
http://www.gregegan.net/SCIENCE/Cavity/Cavity.html

Please, not this page again

Rodal explained back to the EM Drive Thread #3 (three years ago!) that aero's simulations (as predicted by Notsosureofit BTW) showed how Greg Egan's "demonstration" you quoted, involving standing waves only, was wrong as it didn't reflect the reality of what is going on in a real asymmetric cavity, when considering the flow of time and the presence of an antenna constantly feeding new RF energy:

...

See here, here and there. Of course, as also pointed out obviously by Rodal (miss you a lot José, long time no see…) such an asymmetry does not explain on itself how propellantless propulsion could be achieved, bus since Egan's oversimplistic explanation has been contradicted, we should definitely stop referring to it. More especially when using such a flawed explanation (incomplete and far from reality) to prove someone's quote is flat wrong or that he would even lie.
That page obviously doesn't include antenna distortion or turn on transients. It is physically correct version of the "add up the momentum changes as a photon bounces in a closed path," that TT suggested. Saying that that page should never be referenced again ignores that it does correct calculations for an ideal cavity, which makes it useful for multiple things such as predicting resonance modes and disproving nonsense from TT.

If you want to get strict about it, the simulations you reference are wrong too. They only match cavity geometry at discrete points, and only model the field at discrete points as well, plus there is limited precision in the numbers used. On the other hand, what I linked accounts for the exact shape of an ideal cavity, and describes the fields perfectly at every point, within the constraints mentioned above. None of that means the simulations should be banished forever either, it means you need to know what you are working with and its limitations.

So as I originally said, TT was straight up lying with his "no one here has ever actually done the calculations but instead made statement, without any proof, the overall force would be zero." You have been around here enough where you should know that TT wasn't thinking of any of your objections even if they were relevant. Besides, as far as TT's statement goes, the link I provided also has a general proof for an arbitrary cavity shape. The fact of momentum conservation is built straight into Maxwell's equations, and as the quotes you provided from Rodal said, none of the details he mentioned change that fact. The full, general momentum conservation proof in any case ever is in any decent textbook.

Offline flux_capacitor

  • Full Member
  • ****
  • Posts: 708
  • France
  • Liked: 860
  • Likes Given: 1076
Theoretical calculation for ideal cavities that fail to predict several real experimental phenomena, as well as discrete and incomplete simulations involving Maxwell equations only, can't account for any propellantless thrust. This is true.

However as Rodal also pointed out many times on these boards, such calculations and simulations fail to take into account the possibility that the EmDrive is not a closed system. If there is any kind of field propulsion making the EmDrive an open system, propellantless propulsion (not reactionless propulsion!) becomes non-impossible. No current calculation or EM simulation based on Maxwell laws only can predict such an effect.

On the other hand I agree that Shawyer's simple explanation about the radiation pressure imbalance between the two end plates as the cause of thrust does not correctly fall in the true definition of an "open system".

But Mach effects, quantised inertia, scalar–tensor theories -among others- qualify for the possibility of an open system and a field-effect propulsion for the EmDrive.

Online meberbs

  • Senior Member
  • *****
  • Posts: 3096
  • Liked: 3379
  • Likes Given: 777
Theoretical calculation for ideal cavities that fail to predict several real experimental phenomena, as well as discrete and incomplete simulations involving Maxwell equations only, can't account for any propellantless thrust. This is true.

However as Rodal also pointed out many times on these boards, such calculations and simulations fail to take into account the possibility that the EmDrive is not a closed system. If there is any kind of field propulsion making the EmDrive an open system, propellantless propulsion (not reactionless propulsion!) becomes non-impossible. No current calculation or EM simulation based on Maxwell laws only can predict such an effect.

On the other hand I agree that Shawyer's simple explanation about the radiation pressure imbalance between the two end plates as the cause of thrust does not correctly fall in the true definition of an "open system".

But Mach effects, quantised inertia, scalar–tensor theories -among others- qualify for the possibility of an open system and a field-effect propulsion for the EmDrive.
I was responding to TT's post where he incorrectly represents the results of standard electrodynamics. I would appreciate it if you stopped misrepresenting the context of what I was saying, obviously I was not talking about a situation where there is some background that the emDrive pushes off. Your tangent here is a waste of everyone's time, and can only serve to confuse anyone who doesn't know better about whether or not TT has a point. (Based on likes, at least one person was tricked by his non-response that literally ignored what I had already said.)

We clearly are in agreement about the basic physics here, so can we just agree that we are in violent agreement, and move on to something useful?

Tags:
 

Advertisement NovaTech
Advertisement Northrop Grumman
Advertisement
Advertisement Margaritaville Beach Resort South Padre Island
Advertisement Brady Kenniston
Advertisement NextSpaceflight
Advertisement Nathan Barker Photography
0