Quote from: deltaMass on 07/10/2015 04:32 amQuote from: WarpTech on 07/10/2015 03:16 amIn a way, you are correct. In the Newtonian approximation the break even happens for k=1/c when 2/3 of the initial rest mass has been converted into kinetic energy. That is a significant speed where relativity is no longer negligible.You must have been reading someone else's posts, because I never wrote any of that (and nor do I plan to)! In my simple Newtonian analysis, the value of 'k' is not specified at all. I have no clue where you get this stuff!You said,Quote from: deltaMass on 07/09/2015 07:55 pm...1. Writing 'u' for the phase velocity, you get k = u/c2 Newton/Watt = 1/c when u=c,or in other words a pure photon rocket. But experimental evidence suggests a much higher value for k, and so if your formula is correct, it is predicting a superluminal phase velocity.Is that your intent? Do you think that this observation is important?...I used 1/c as an example to solve for a particular case where break even was < c. But then I had an "AH HA Moment". LOL! Here is the Newtonian version too, in this case, the velocity goes to infinity rather than c, when 100% of the initial rest-energy has been spent. I hope you realize what this is saying. That for whatever energy is available in the battery to use for thrust, there will be a limiting velocity because the battery will go dead. It will not suddenly start to recharge when the speed exceeds some limit. Todd
Quote from: WarpTech on 07/10/2015 03:16 amIn a way, you are correct. In the Newtonian approximation the break even happens for k=1/c when 2/3 of the initial rest mass has been converted into kinetic energy. That is a significant speed where relativity is no longer negligible.You must have been reading someone else's posts, because I never wrote any of that (and nor do I plan to)! In my simple Newtonian analysis, the value of 'k' is not specified at all. I have no clue where you get this stuff!
In a way, you are correct. In the Newtonian approximation the break even happens for k=1/c when 2/3 of the initial rest mass has been converted into kinetic energy. That is a significant speed where relativity is no longer negligible.
...1. Writing 'u' for the phase velocity, you get k = u/c2 Newton/Watt = 1/c when u=c,or in other words a pure photon rocket. But experimental evidence suggests a much higher value for k, and so if your formula is correct, it is predicting a superluminal phase velocity.Is that your intent? Do you think that this observation is important?...
Quote from: TheTraveller on 07/10/2015 09:39 amQuote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.You guys are in my world when you talk Q, and yes, I've used $100K network analyzers and handhelds. Here's the deal...A Q of 10K is theoretically possible but highly unlikely. A 2.45 Ghz bandpass cavity would have to have a 3dB (half power BW) of 245 Khz...I've never seen such a beast. Here's the problem...center frequency drift of both the cavity and the source. You'd be chasing your tail trying to keep it centered.I'm for projecting Qs of this design between 1 and 5K, meaning between about 2 & 5 Mhz 3dB BW. Even at this reduced Q, there will be drift concerns due to heating.Bottom line, Qs are not 5 digits. On paper, yes...real world, no.
Quote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.
The extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.
Quote from: rfcavity on 07/10/2015 02:19 pmQuote from: TheTraveller on 07/10/2015 02:10 pmQuote from: rfmwguy on 07/10/2015 01:45 pmQuote from: TheTraveller on 07/10/2015 09:39 amQuote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.You guys are in my world when you talk Q, and yes, I've used $100K network analyzers and handhelds. Here's the deal...A Q of 10K is theoretically possible but highly unlikely. A 2.45 Ghz bandpass cavity would have to have a 3dB (half power BW) of 245 Khz...I've never seen such a beast. Here's the problem...center frequency drift of both the cavity and the source. You'd be chasing your tail trying to keep it centered.I'm for projecting Qs of this design between 1 and 5K, meaning between about 2 & 5 Mhz 3dB BW. Even at this reduced Q, there will be drift concerns due to heating.Bottom line, Qs are not 5 digits. On paper, yes...real world, no.Maybe you need to actually measure a EMDrive cavity, as Eagleworks did as per attached.With the low power from the NA, there will not be any significant heating of the cavity, so the resonant frequency will not be shifting around. You will need to sweep very slowly as it will take time for the cavity to fully fill with energy.The shape of the emdrive cavity, just due to its nature, will have a lower Q than a cylindrical cavity. Any EM professional (or even just grad student) has done material characterization in a cylindrical cavity of high Q in a strict measurement environment. This is because it's a required course at most places. Large Q is tricky to get, and can vary wildly with tiny temperature variations. The higher the q, the larger the variations. Why you find it prudent to argue against multiple experts with a Chinese journal paper (notoriously low quality) will forever be beyond me.Why you ignore the Eagleworks measured Q, attached, is beyond me? For my build, length changes need to exceed +-0.04m for any significant resonance to change and even then it is small. Both Shawyer and the Chinese have recognised this effect and designed variable Rf generators that automatically adjust their frequency to track cavity resonant changes, as have I.You see when you give an engineer a problem, he/she designs a way to cope with it and makes a more robust system.BWT for the 5 Chinese peer reviewed papers, there are 4 different Journals/Publications involved.
Quote from: TheTraveller on 07/10/2015 02:10 pmQuote from: rfmwguy on 07/10/2015 01:45 pmQuote from: TheTraveller on 07/10/2015 09:39 amQuote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.You guys are in my world when you talk Q, and yes, I've used $100K network analyzers and handhelds. Here's the deal...A Q of 10K is theoretically possible but highly unlikely. A 2.45 Ghz bandpass cavity would have to have a 3dB (half power BW) of 245 Khz...I've never seen such a beast. Here's the problem...center frequency drift of both the cavity and the source. You'd be chasing your tail trying to keep it centered.I'm for projecting Qs of this design between 1 and 5K, meaning between about 2 & 5 Mhz 3dB BW. Even at this reduced Q, there will be drift concerns due to heating.Bottom line, Qs are not 5 digits. On paper, yes...real world, no.Maybe you need to actually measure a EMDrive cavity, as Eagleworks did as per attached.With the low power from the NA, there will not be any significant heating of the cavity, so the resonant frequency will not be shifting around. You will need to sweep very slowly as it will take time for the cavity to fully fill with energy.The shape of the emdrive cavity, just due to its nature, will have a lower Q than a cylindrical cavity. Any EM professional (or even just grad student) has done material characterization in a cylindrical cavity of high Q in a strict measurement environment. This is because it's a required course at most places. Large Q is tricky to get, and can vary wildly with tiny temperature variations. The higher the q, the larger the variations. Why you find it prudent to argue against multiple experts with a Chinese journal paper (notoriously low quality) will forever be beyond me.
Quote from: rfmwguy on 07/10/2015 01:45 pmQuote from: TheTraveller on 07/10/2015 09:39 amQuote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.You guys are in my world when you talk Q, and yes, I've used $100K network analyzers and handhelds. Here's the deal...A Q of 10K is theoretically possible but highly unlikely. A 2.45 Ghz bandpass cavity would have to have a 3dB (half power BW) of 245 Khz...I've never seen such a beast. Here's the problem...center frequency drift of both the cavity and the source. You'd be chasing your tail trying to keep it centered.I'm for projecting Qs of this design between 1 and 5K, meaning between about 2 & 5 Mhz 3dB BW. Even at this reduced Q, there will be drift concerns due to heating.Bottom line, Qs are not 5 digits. On paper, yes...real world, no.Maybe you need to actually measure a EMDrive cavity, as Eagleworks did as per attached.With the low power from the NA, there will not be any significant heating of the cavity, so the resonant frequency will not be shifting around. You will need to sweep very slowly as it will take time for the cavity to fully fill with energy.
Quote from: TheTraveller on 07/10/2015 02:29 pmQuote from: rfcavity on 07/10/2015 02:19 pmQuote from: TheTraveller on 07/10/2015 02:10 pmQuote from: rfmwguy on 07/10/2015 01:45 pmQuote from: TheTraveller on 07/10/2015 09:39 amQuote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.You guys are in my world when you talk Q, and yes, I've used $100K network analyzers and handhelds. Here's the deal...A Q of 10K is theoretically possible but highly unlikely. A 2.45 Ghz bandpass cavity would have to have a 3dB (half power BW) of 245 Khz...I've never seen such a beast. Here's the problem...center frequency drift of both the cavity and the source. You'd be chasing your tail trying to keep it centered.I'm for projecting Qs of this design between 1 and 5K, meaning between about 2 & 5 Mhz 3dB BW. Even at this reduced Q, there will be drift concerns due to heating.Bottom line, Qs are not 5 digits. On paper, yes...real world, no.Maybe you need to actually measure a EMDrive cavity, as Eagleworks did as per attached.With the low power from the NA, there will not be any significant heating of the cavity, so the resonant frequency will not be shifting around. You will need to sweep very slowly as it will take time for the cavity to fully fill with energy.The shape of the emdrive cavity, just due to its nature, will have a lower Q than a cylindrical cavity. Any EM professional (or even just grad student) has done material characterization in a cylindrical cavity of high Q in a strict measurement environment. This is because it's a required course at most places. Large Q is tricky to get, and can vary wildly with tiny temperature variations. The higher the q, the larger the variations. Why you find it prudent to argue against multiple experts with a Chinese journal paper (notoriously low quality) will forever be beyond me.Why you ignore the Eagleworks measured Q, attached, is beyond me? For my build, length changes need to exceed +-0.04m for any significant resonance to change and even then it is small. Both Shawyer and the Chinese have recognised this effect and designed variable Rf generators that automatically adjust their frequency to track cavity resonant changes, as have I.You see when you give an engineer a problem, he/she designs a way to cope with it and makes a more robust system.BWT for the 5 Chinese peer reviewed papers, there are 4 different Journals/Publications involved.But to make rfcavity's point, if we are going to quote NASA, these are the published Q's for their experiments:NASA Brady, White, March, Lawrence, and Davies, a 7320 NASA Brady, White, March, Lawrence, and Davies, b 18100NASA Brady, White, March, Lawrence, and Davies, c 22000NASA March et.al. Partial vacuum 6726 Minimum Q = 6726 (vacuum experiment)Maximum Q = 22 000 (experiment with TE012 that they were NOT able to replicate)Mean Q = 13500
...Please stop with the one sided half truths. You know very well those cavities had a big dielectric inside then and dielectrics inside the cavity increase losses and reduce Q, yet you failed to mention that very important fact.I will attach again the Eagleworks measured Q of their copper cavity WITHOUT A DIELECTRIC. As I assume you can read, if you ignore it again, well that is your loss.You need to understand I have every image and document Paul March attached to his many years of NSF posts.
Quote from: rfcavity on 07/10/2015 02:19 pmQuote from: TheTraveller on 07/10/2015 02:10 pmQuote from: rfmwguy on 07/10/2015 01:45 pmQuote from: TheTraveller on 07/10/2015 09:39 amQuote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.You guys are in my world when you talk Q, and yes, I've used $100K network analyzers and handhelds. Here's the deal...A Q of 10K is theoretically possible but highly unlikely. A 2.45 Ghz bandpass cavity would have to have a 3dB (half power BW) of 245 Khz...I've never seen such a beast. Here's the problem...center frequency drift of both the cavity and the source. You'd be chasing your tail trying to keep it centered.I'm for projecting Qs of this design between 1 and 5K, meaning between about 2 & 5 Mhz 3dB BW. Even at this reduced Q, there will be drift concerns due to heating.Bottom line, Qs are not 5 digits. On paper, yes...real world, no.Maybe you need to actually measure a EMDrive cavity, as Eagleworks did as per attached.With the low power from the NA, there will not be any significant heating of the cavity, so the resonant frequency will not be shifting around. You will need to sweep very slowly as it will take time for the cavity to fully fill with energy.The shape of the emdrive cavity, just due to its nature, will have a lower Q than a cylindrical cavity. Any EM professional (or even just grad student) has done material characterization in a cylindrical cavity of high Q in a strict measurement environment. This is because it's a required course at most places. Large Q is tricky to get, and can vary wildly with tiny temperature variations. The higher the q, the larger the variations. Why you find it prudent to argue against multiple experts with a Chinese journal paper (notoriously low quality) will forever be beyond me.Why you ignore the Eagleworks measured Q, attached, is beyond me? For my build, length changes need to exceed +-0.04m for any significant resonance to change and even then it is small. Both Shawyer and the Chinese have recognised this effect and designed variable Rf generators that automatically adjust their frequency to track cavity resonant changes.You see when you give an engineer a problem, he/she designs a way to cope with it and makes a more robust system.BWT for the 5 Chinese peer reviewed papers, there are 4 different Journals/Publications involved.
Quote from: TheTraveller on 07/10/2015 02:54 pm...Please stop with the one sided half truths. You know very well those cavities had a big dielectric inside then and dielectrics inside the cavity increase losses and reduce Q, yet you failed to mention that very important fact.I will attach again the Eagleworks measured Q of their copper cavity WITHOUT A DIELECTRIC. As I assume you can read, if you ignore it again, well that is your loss.You need to understand I have every image and document Paul March attached to his many years of NSF posts.My post was correct: I listed all of NASA's experimental reports for Q where they reported thrust from an EM Drive.I even took the time to list the authors, the reported Q, and to calculate the Min, Max, and Mean of the measurements.You instead are reporting the Q of an EM Drive sitting on a surface, not involved in any experimental thrust measurement ! , and with an accusation.
..You listed a selected subset of the available data. Plus now and then you failed to mention an important fact:All those measured cavity Qs you listed had an internal dielectric that increases losses and reduced the Q.So you can't compare those dielectric cavity Qs to a cavity that has no dielectric.This is the data you selected to not mention:Shawyer's 1st Experimental EMDrive used a dielectric, reported Q 5,900.Shawyer's 2nd Demonstrator EMDrive did not use a dielectric, reported Q 45,000.Shawyer's 3rd Flight Thruster EMDrive did not use a dielectric, reported Q 50,000.
Quote from: Rodal on 07/10/2015 02:58 pmQuote from: TheTraveller on 07/10/2015 02:54 pm...Please stop with the one sided half truths. You know very well those cavities had a big dielectric inside then and dielectrics inside the cavity increase losses and reduce Q, yet you failed to mention that very important fact.I will attach again the Eagleworks measured Q of their copper cavity WITHOUT A DIELECTRIC. As I assume you can read, if you ignore it again, well that is your loss.You need to understand I have every image and document Paul March attached to his many years of NSF posts.My post was correct: I listed all of NASA's experimental reports for Q where they reported thrust from an EM Drive.I even took the time to list the authors, the reported Q, and to calculate the Min, Max, and Mean of the measurements.You instead are reporting the Q of an EM Drive sitting on a surface, not involved in any experimental thrust measurement ! , and with an accusation.You listed a selected subset of the available data. Plus now and then you failed to mention an important fact:All those measured cavity Qs you listed had an internal dielectric that increases losses and reduced the Q.So you can't compare those dielectric cavity Qs to a cavity that has no dielectric.This is the data you selected to not mention:Shawyer's 1st Experimental EMDrive used a dielectric, reported Q 5,900.Shawyer's 2nd Demonstrator EMDrive did not use a dielectric, reported Q 45,000.Shawyer's 3rd Flight Thruster EMDrive did not use a dielectric, reported Q 50,000.
It is exactly that. The mass at any time after you start the engine is (m - Ein/c^2). It is the mass you started with minus the mass you are using to accelerate. In your derivation, you hand wave this part by saying Ein, when in fact, there is no input to the system. Then you ignore where the energy is coming from by assuming that what comes out of the battery has negligible mass, then claim over unity by counting the energy gained from that expenditure as gravy. Paradox resolved, case closed. My job is not to convince you, but to make sure others don't buy into more of this paradox fantasy.Todd
Paradox resolved, case closed. My job is not to convince you, but to make sure others don't buy into more of this paradox fantasy.
Quote from: TheTraveller on 07/10/2015 02:29 pmQuote from: rfcavity on 07/10/2015 02:19 pmQuote from: TheTraveller on 07/10/2015 02:10 pmQuote from: rfmwguy on 07/10/2015 01:45 pmQuote from: TheTraveller on 07/10/2015 09:39 amQuote from: zen-in on 07/10/2015 08:38 amThe extremely high Q claimed for the Chinese and other em-drive cavities is completely wrong. I have already showed they are not calculating Q correctly. The graph shown is not a photo taken from a network analyzer and so I believe it is just made up data. These cavities are similar in most respects to cavity filters used for VHF and UHF repeaters. A 145 MHz cavity typically has a Q = 350. Scaling this up to 2.5 GHz and the Q may be as high as 1,000 - 2,000. The skin effect and other factors increase the losses at higher frequencies.So easy to claim the Chinese data has been made up, despite having no proof. Along with silly claims that would also say Eagleworks doesn't know how to measure Q either as per attached measured Q of 50,995.I'll not bother to send you my data as you will claim it is also made up.You guys are in my world when you talk Q, and yes, I've used $100K network analyzers and handhelds. Here's the deal...A Q of 10K is theoretically possible but highly unlikely. A 2.45 Ghz bandpass cavity would have to have a 3dB (half power BW) of 245 Khz...I've never seen such a beast. Here's the problem...center frequency drift of both the cavity and the source. You'd be chasing your tail trying to keep it centered.I'm for projecting Qs of this design between 1 and 5K, meaning between about 2 & 5 Mhz 3dB BW. Even at this reduced Q, there will be drift concerns due to heating.Bottom line, Qs are not 5 digits. On paper, yes...real world, no.Maybe you need to actually measure a EMDrive cavity, as Eagleworks did as per attached.With the low power from the NA, there will not be any significant heating of the cavity, so the resonant frequency will not be shifting around. You will need to sweep very slowly as it will take time for the cavity to fully fill with energy.The shape of the emdrive cavity, just due to its nature, will have a lower Q than a cylindrical cavity. Any EM professional (or even just grad student) has done material characterization in a cylindrical cavity of high Q in a strict measurement environment. This is because it's a required course at most places. Large Q is tricky to get, and can vary wildly with tiny temperature variations. The higher the q, the larger the variations. Why you find it prudent to argue against multiple experts with a Chinese journal paper (notoriously low quality) will forever be beyond me.Why you ignore the Eagleworks measured Q, attached, is beyond me? For my build, length changes need to exceed +-0.04m for any significant resonance to change and even then it is small. Both Shawyer and the Chinese have recognised this effect and designed variable Rf generators that automatically adjust their frequency to track cavity resonant changes.You see when you give an engineer a problem, he/she designs a way to cope with it and makes a more robust system.BWT for the 5 Chinese peer reviewed papers, there are 4 different Journals/Publications involved.I have to say Mr. T. if there was anything that singlehandedly caused me to doubt EW's testing, it was their staggering claims of 50K Q and 1.1 VSWR. I've refrained from beeing too disbelieving, but the topic has come up too many times. I was not there and don't feel the right to hammer them, just want to make the point that in 30+ years of working with similar stuff (all symetrical cans and boxes designed for max Q) I have never seen anything like it. Consider this a rare hand-wave.
Quote from: TheTraveller on 07/10/2015 03:12 pmQuote from: Rodal on 07/10/2015 02:58 pmQuote from: TheTraveller on 07/10/2015 02:54 pm...Please stop with the one sided half truths. You know very well those cavities had a big dielectric inside then and dielectrics inside the cavity increase losses and reduce Q, yet you failed to mention that very important fact.I will attach again the Eagleworks measured Q of their copper cavity WITHOUT A DIELECTRIC. As I assume you can read, if you ignore it again, well that is your loss.You need to understand I have every image and document Paul March attached to his many years of NSF posts.My post was correct: I listed all of NASA's experimental reports for Q where they reported thrust from an EM Drive.I even took the time to list the authors, the reported Q, and to calculate the Min, Max, and Mean of the measurements.You instead are reporting the Q of an EM Drive sitting on a surface, not involved in any experimental thrust measurement ! , and with an accusation.You listed a selected subset of the available data. Plus now and then you failed to mention an important fact:All those measured cavity Qs you listed had an internal dielectric that increases losses and reduced the Q.So you can't compare those dielectric cavity Qs to a cavity that has no dielectric.This is the data you selected to not mention:Shawyer's 1st Experimental EMDrive used a dielectric, reported Q 5,900.Shawyer's 2nd Demonstrator EMDrive did not use a dielectric, reported Q 45,000.Shawyer's 3rd Flight Thruster EMDrive did not use a dielectric, reported Q 50,000.Can you demonstrate the calculation method of these q and the calibration method to move the analyzers reference plane to the cavity?
Both the results of the Experimental EMDrive and of the Demonstrator EMDrive were checked by a group of UK aerospace experts, under control of the UK Dept of Defense.
...Initially, when power on energy front just left the antenna and is coasting to destination, we see thrust. The energy front doesn't even know yet that the other end of the cavity is closed, if it were open this initial thrust would be gained "for good". But since it is closed, it is absorbed and opposite thrust compensate the initial kick. We have reached live steady state, a constant flow of energy from places A (battery) to places B (cavity walls, some patches more, some less). During this phase, the process is not thrusting, but it is coasting, at (very small) constant velocity that was given by the (very short lived) initial transient kick. We would like to continue on this acquired velocity at no ongoing energetic flow (constant power) cost, but switching off the process we will see the energy tail leave the antenna a little bit before it reaches the walls : during this transient the kick is opposite to the initial one, and we are back at the same inertial rest frame as initially (albeit a little bit translated). Overall, on the on/off cycle we have gained a delta X but not a delta V....
Quote from: frobnicat on 07/10/2015 01:22 am...Initially, when power on energy front just left the antenna and is coasting to destination, we see thrust. The energy front doesn't even know yet that the other end of the cavity is closed, if it were open this initial thrust would be gained "for good". But since it is closed, it is absorbed and opposite thrust compensate the initial kick. We have reached live steady state, a constant flow of energy from places A (battery) to places B (cavity walls, some patches more, some less). During this phase, the process is not thrusting, but it is coasting, at (very small) constant velocity that was given by the (very short lived) initial transient kick. We would like to continue on this acquired velocity at no ongoing energetic flow (constant power) cost, but switching off the process we will see the energy tail leave the antenna a little bit before it reaches the walls : during this transient the kick is opposite to the initial one, and we are back at the same inertial rest frame as initially (albeit a little bit translated). Overall, on the on/off cycle we have gained a delta X but not a delta V....@frobnicat's excellent analysis of the initial (and final) transient of the on/off cycle got me thinking...It's true that the on/off transitory is too quick (a microsecond or so, somebody calculated) and doesn't affect the experiments much.However, it occurs to me that it should be possible, by modulating Pin with a Low Frequency Oscillation (i.e. very low compared to the resonant frequency, fLFO << fresonance), to induce a corresponding LFO in the frustum's position.The amplitude modulation of the power constitutes a "signal" carried over the "carrier" which is the EM wave at the resonance frequency (hah! My little knowledge of signal theory is finally useful! Well, sort of...).This signal propagates at the group velocity vg, so if the resonant signal "bounces" a lot of times there is a very small but significant delay between the power issued at the RF feed and the power eventually dissipated at some point in the frustum.If the RF feed is positioned so that the radiation emitted by the RF feed hits one plate with less delay than the other, there will be a difference in the power hitting each plate, but not in the power emitted in any direction at the RF feed. So the instantaneous momentum transfer from the RF feed to the body of the device is zero, but the instantaneous momentum transfer to the device from the power modulation hitting the plates is non-zero.Of course, it all integrates to zero on an integer number of LFO periods. I'm not claiming average thrust, only oscillation.Basically, if the power is modulated, the "delayed" version on one plate is always at a phase offset compared to the "delayed" version on the other plate. The "bouncing" only exasperates this effect as the phase offset situation repeats at every "bounce" and at each plate we have a composition of a large number of phase-shifted copies of the modulation. If the power modulation is a sinusoid, the sum of these phase-delayed sinusoids produces, again, a sinusoid (as it is well known). And so the difference of the power hitting each plate is again a sinusoid at fLFO.The net effect is that there will be a swing towards one side, and then a swing towards the other side, following the LFO modulation of Pin, and the total net effect averaged over an integer number of periods will still be zero. Nil.However, fLFO can be made arbitrarily low. The lower it is, the longer the oscillation will be, although at the same time the entity of the oscillation force reduces. Still, the oscillation force is amplified by the "bouncing" (i.e. by the Q?) because of the constructive composition of all the phase-shifted sinusoids and might end up being measurable.Why is this important?If our experiments only bother to measure thrust for a few seconds (e.g. Iulian's), and the power supply to the RF feed has some LFO we don't know about, with a frequency low enough, we could erroneously believe to have measured genuine thrust when we have measured only a portion of a transient oscillation.Any EmDrive experiment should run for a long time, or alternatively carefully check Pin for LFOs.Don't just "wub" the frustum!