Quote from: SeeShells on 08/07/2015 03:19 pmTheories. They abound and we're at what? Close to a dozen right now? the way I see it each and every one has its good points and bad and if you're here to discover the truth you can't strap yourself to just one. You might be eating your hat. I have my favorite but that cannot and will not detract or bias me in finding the why. The only real data that is true is mother natures and she trumps and belittles us all, she wrote the book we can barely read.I've been quite surprised by the simulations in meep and even though meep has it's limits it's enough to allow me to setup several testing criteria to test for different data. One is if this was a normal waveguide or resonant chamber you would expect a stable mode generation and a clean traveling wave locked into Q or traveling down the wave guide. This hasn't been the case. Because of the frustum's variable geometry I see in just a short run for a few cycles in meep mode changes and decays up and down the frustum. Can anyone explain to me when I see a mode shift in the meep time slices the time it seems to happen... it's within the meep data sample rate. The modes shift from top to bottom or side to side and if actions within the cavity still obey basic laws how can I see a full mode shift top to bottom in less than 1 ns (from sample rate to sample rate which is 1/10th of a cycle?) Light and most actions travels about ~11 inches in 1 ns. I'm so trying to gork opps grok this. I guess I need someone to give me a primmer.ShellSame thing happens in dynamic structural response, for example in earthquake analysis or the dynamic response of a rocket during lift-off https://en.wikipedia.org/wiki/Structural_dynamics#Modal_participation_factor.Think of the response of a structure to an earhtquake, or the dynamic response of a rocket during the initial lift-off. The whole concept of "modal response" analysis is a simplification to real response that involves a variety of modes. For linear response one can describe a so called mode participation factor.The difference between Meep and a closed-form solution is that Meep is NOT conducting a modal response. Actually there are no explicit things as "evanescent waves", "travelling waves" or "standing waves", "group velocity" or "phase velocity" in Meep's solution method. All there is in Meep are fields vs time. The meaning of the the response has to be analyzed and is not obvious. Meep is solving Maxwell's equations using the finite difference method. To put the solution in terms familiar like "modes" for example requires achieving something approaching steady state that has not been achieved in the very short-time response being analyzed (less than 0.01 microseconds as I recall). The Meep solution so far should be interpreted as a transient response, not as a steady-state response.
Theories. They abound and we're at what? Close to a dozen right now? the way I see it each and every one has its good points and bad and if you're here to discover the truth you can't strap yourself to just one. You might be eating your hat. I have my favorite but that cannot and will not detract or bias me in finding the why. The only real data that is true is mother natures and she trumps and belittles us all, she wrote the book we can barely read.I've been quite surprised by the simulations in meep and even though meep has it's limits it's enough to allow me to setup several testing criteria to test for different data. One is if this was a normal waveguide or resonant chamber you would expect a stable mode generation and a clean traveling wave locked into Q or traveling down the wave guide. This hasn't been the case. Because of the frustum's variable geometry I see in just a short run for a few cycles in meep mode changes and decays up and down the frustum. Can anyone explain to me when I see a mode shift in the meep time slices the time it seems to happen... it's within the meep data sample rate. The modes shift from top to bottom or side to side and if actions within the cavity still obey basic laws how can I see a full mode shift top to bottom in less than 1 ns (from sample rate to sample rate which is 1/10th of a cycle?) Light and most actions travels about ~11 inches in 1 ns. I'm so trying to gork opps grok this. I guess I need someone to give me a primmer.Shell
I'm not here to defend TT, but I find that a regretful attitude.... Whatever experiment TT does, due to his great similarity with what Shawyer did in the past, it will help to assess if Shawyer's experiments hold any value or not.At least, in contrast with Shawyer, TT promised total transparency on his approach. That will make it much easier to follow the experiment and draw conclusions from it.So, in that respect TT's experiment remains valuable, regardless of the huge clash of opinion you both have...I'm looking forward to ALL the experiments, not just a few of them...Even from the baby EMdrive, we could draw some conclusions that can be useful for future experiments.I don't see the point to start bickering over experiments that have not taken place yet...?Good experiments, bad experiments, failures.. you need it all to make progress when you're into uncharted territory...
Backward?That data is based on microwave industry equations and Cullen 15 for the radiation pressure on the end plate bounce Force / momentum transfer per bounce.
Given his announced commercial (licensing) relationship with Shawyer and unwillingness to consider anything that deviates from what is prescribed by Shawyer, it has become apparent that it is a waste of my time to spend any further time discussing anything related to TheTraveller. I have also arrived at the conclusion that I cannot trust any experimental claims that TheTraveller may present.I look forward to the experiments of rfmwguy and SeeShells and hopefully to any further news from NASA Eagleworks and Tajmar.
Quote from: Flyby on 08/07/2015 01:23 pmI'm not here to defend TT, but I find that a regretful attitude.... Whatever experiment TT does, due to his great similarity with what Shawyer did in the past, it will help to assess if Shawyer's experiments hold any value or not.At least, in contrast with Shawyer, TT promised total transparency on his approach. That will make it much easier to follow the experiment and draw conclusions from it.So, in that respect TT's experiment remains valuable, regardless of the huge clash of opinion you both have...I'm looking forward to ALL the experiments, not just a few of them...Even from the baby EMdrive, we could draw some conclusions that can be useful for future experiments.I don't see the point to start bickering over experiments that have not taken place yet...?Good experiments, bad experiments, failures.. you need it all to make progress when you're into uncharted territory...The thing is, if you read TT's posts carefully it appears that he has already concluded what the outcomes of his experiments will be. This is a very dangerous attitude for an experimenter to have and it is not entirely unreasonable for people to doubt any results even before they come out. Yes, in principle, data from a well-designed experiment should speak for itself. But in practice, such extreme biases have ways of getting in the way.
Quote from: Mulletron on 08/07/2015 02:04 pmIt doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector.We have a great opportunity to understand what is going on in the near future because we have two very trustworthy people working on independent objective tests (rfmwguy and SeeShells). It is a very unusual opportunity because (just as we did for a while with Paul March at NASA) both rfmwguy and SeeShells are active in this thread. Their approach to testing is unbiased and objective. Unlike what happened with NASA we are under no threat of the communication being interrupted, and unlike what happened with Iulian they are active in the thread and we are under no threat of rfmwguy or SeeShells suddenly stopping their experiments.PS: coincidentally, I had also been looking to friction as well. To be explicit: related to the boundary conditions between air and the frustum and between the electromagnetic field and the frustum.
It doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector.
Quote from: Mulletron on 08/07/2015 02:04 pmIt doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector*.* http://forum.nasaspaceflight.com/index.php?topic=37642.msg1401370#msg1401370The momentum loss to the internal EM wave is balanced by the momentum gained by the external frustum, so CofM is maintained. Why is that hard to understand? It is a balanced momentum transfer.Inside the frustum there are 4 momentum reactions:1) Small end plate bounce of the longer EM wavelength with smaller momentum and smaller opposite but equal Force on the Frustum toward the big end.2) Large end plate bounce of the shorter EM wavelength with larger momentum and larger opposite but equal Force on the frustum toward the small end.3) Momentum EM wave gain as the EM wave propagates small end to big end with an opposite but equal momentum Force on the frustum toward the small end. (rocket like effect)4) Momentum Em wave loss as the EM wave propagates big end to small end with a Force on the frustum toward the small end. (downwind sail like effect)Shawyer has shown cases 1 and 2 balance out and do not generate any external Force as attached.What cases 1 and 2 do is to set up the conditions for cases 3 and 4 to exist and transfer EM wave momentum to the frustum. The lost internal EM wave momentum is balanced by the external frustum's gained momentum, so CofM is conserved as both Shawyer and Prof Yang claimed.
It doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector*.* http://forum.nasaspaceflight.com/index.php?topic=37642.msg1401370#msg1401370
The difficulty I have is that by setting f=2.45, P=1, Lambda=c/f, Bigend widest dimension=lambda, smallend widest dimension = lambda/2+0.000001m and plugging that into the Cullin equation I get<snip>...The force is bigger on the big end by the Cullin Equation you posted. Try it.
Quote from: TheTraveller on 08/07/2015 02:34 pmQuote from: Mulletron on 08/07/2015 02:04 pmIt doesn't matter anyway what the radiation pressure is at either end. Even if there are unbalanced forces at each end, internal to the frustum, it isn't going to move.This is central to why everyone (mostly celebrity scientists and the media) is saying this thing violates COM.I recommend we get rid of any theory that features unbalanced forces at the large/small end and focus on what we recently learned from @Aero and @Rodal that there is a net (and increasing) Poynting vector*.* http://forum.nasaspaceflight.com/index.php?topic=37642.msg1401370#msg1401370The momentum loss to the internal EM wave is balanced by the momentum gained by the external frustum, so CofM is maintained. Why is that hard to understand? It is a balanced momentum transfer.Inside the frustum there are 4 momentum reactions:1) Small end plate bounce of the longer EM wavelength with smaller momentum and smaller opposite but equal Force on the Frustum toward the big end.2) Large end plate bounce of the shorter EM wavelength with larger momentum and larger opposite but equal Force on the frustum toward the small end.3) Momentum EM wave gain as the EM wave propagates small end to big end with an opposite but equal momentum Force on the frustum toward the small end. (rocket like effect)4) Momentum Em wave loss as the EM wave propagates big end to small end with a Force on the frustum toward the small end. (downwind sail like effect)Shawyer has shown cases 1 and 2 balance out and do not generate any external Force as attached.What cases 1 and 2 do is to set up the conditions for cases 3 and 4 to exist and transfer EM wave momentum to the frustum. The lost internal EM wave momentum is balanced by the external frustum's gained momentum, so CofM is conserved as both Shawyer and Prof Yang claimed.And what about the backward momentum of the magnetron? The frustum and the magnetron are both rigidly attached to the same structure. If this thing were floating in space inside a ship, it would go nowhere."The total momentum of a system remains constant provided that no external forces act on the system."The "system" is the thruster plus ship and power source. How does Shawyer's theory open up the system? Where is the external force acting on the system?
The thing is, if you read TT's posts carefully it appears that he has already concluded what the outcomes of his experiments will be. This is a very dangerous attitude for an experimenter to have and it is not entirely unreasonable for people to doubt any results even before they come out. Yes, in principle, data from a well-designed experiment should speak for itself. But in practice, such extreme biases have ways of getting in the way.
Anyone watching the live stream will see the results.
Quote from: TheTraveller on 08/07/2015 05:15 pmAnyone watching the live stream will see the results.Hi, will you allow spectators to experiment and let them access and inspect the setup?I am not asking for myself, just to know.