Quote from: txdrive on 05/19/2015 02:43 pmQuote from: TheTraveller on 05/19/2015 02:32 pmQuote from: txdrive on 05/19/2015 02:02 pmUltimately what Shawyer's and White's theories amount to, is that there is a radiation pressure imbalance on the inside of the cavity, resulting in a net force, which is a non small fraction of the total radiation pressure on the inside of the cavity (more than 1%). Shawyer says it is in accordance with Maxwell's equations, which is flat out wrong.Where is Shawyer wrong?1) Is the cutoff wavelength different at the small and big ends or not?2) Is the guide wavelength different at the small and big ends or not?3) Is the group velocity different at the small and big ends or not?4) Is the bounce force different at the small and big ends or not?5) Is the bounce force at the big end greater than at the small end or not?6) Is there a bounce force on the side walls or not?Just trying to understand where you believe Shawyer is wrong?Well, firstly, Shawyer has greater radiation pressure upon the wide end, but his drive is pushing narrow end forwards. Secondarily, yes, there is an interaction between the EM field and the walls, which results in a force on the side walls, equal to change in momentum of the EM field travelling down it, per time.Maxwell has a cosine factor to adjust for waves that hit the bounce surface at an angle. Max force at the end plates and min force at the walls as attached.
Quote from: TheTraveller on 05/19/2015 02:32 pmQuote from: txdrive on 05/19/2015 02:02 pmUltimately what Shawyer's and White's theories amount to, is that there is a radiation pressure imbalance on the inside of the cavity, resulting in a net force, which is a non small fraction of the total radiation pressure on the inside of the cavity (more than 1%). Shawyer says it is in accordance with Maxwell's equations, which is flat out wrong.Where is Shawyer wrong?1) Is the cutoff wavelength different at the small and big ends or not?2) Is the guide wavelength different at the small and big ends or not?3) Is the group velocity different at the small and big ends or not?4) Is the bounce force different at the small and big ends or not?5) Is the bounce force at the big end greater than at the small end or not?6) Is there a bounce force on the side walls or not?Just trying to understand where you believe Shawyer is wrong?Well, firstly, Shawyer has greater radiation pressure upon the wide end, but his drive is pushing narrow end forwards. Secondarily, yes, there is an interaction between the EM field and the walls, which results in a force on the side walls, equal to change in momentum of the EM field travelling down it, per time.
Quote from: txdrive on 05/19/2015 02:02 pmUltimately what Shawyer's and White's theories amount to, is that there is a radiation pressure imbalance on the inside of the cavity, resulting in a net force, which is a non small fraction of the total radiation pressure on the inside of the cavity (more than 1%). Shawyer says it is in accordance with Maxwell's equations, which is flat out wrong.Where is Shawyer wrong?1) Is the cutoff wavelength different at the small and big ends or not?2) Is the guide wavelength different at the small and big ends or not?3) Is the group velocity different at the small and big ends or not?4) Is the bounce force different at the small and big ends or not?5) Is the bounce force at the big end greater than at the small end or not?6) Is there a bounce force on the side walls or not?Just trying to understand where you believe Shawyer is wrong?
Ultimately what Shawyer's and White's theories amount to, is that there is a radiation pressure imbalance on the inside of the cavity, resulting in a net force, which is a non small fraction of the total radiation pressure on the inside of the cavity (more than 1%). Shawyer says it is in accordance with Maxwell's equations, which is flat out wrong.
CofM requires if the EM waves pushes more on the on the big end than the small end, the EM Drive frustum pushes back in the opposite direction of the imbalance. Momentum transfer is not one sided. If the EM Drive moved toward the big end, then CofE would be violated as only a one sided push.
Both Shawyer & the Chinese claim their many physical devices produce thrust and the measurement of that thrust is in agreement with their theoretical calculations. Both also claim no new physics is needed and CofE / CofM are conserved.I mean you say it can't work as they claim, yet it does and the measured thrust from many devices, measured in different ways, in different labs, in different countries all closely matched what their theory says the thrust should be.With respect, just maybe your explanation / understanding of what is happening inside the frustum is not at the same level as Shawyer or the Chinese?
We could pull it behind my 65 Pontiac Catalina. NASA has already proven that a 421 powered Pontiac will make things fly.http://www.dfrc.nasa.gov/Gallery/Movie/M2-F1/HTML/EM-0020-02.html
Quote from: LasJayhawk on 05/19/2015 05:50 pmWe could pull it behind my 65 Pontiac Catalina. NASA has already proven that a 421 powered Pontiac will make things fly.http://www.dfrc.nasa.gov/Gallery/Movie/M2-F1/HTML/EM-0020-02.htmlI thought my brain was being warped at the Super Conductor Super Collider, but this is a lot of fun. Love the pool of thoughts and ideas here it keeps me young and thinking. If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too. I have a 2500 sq ft shop with all kind of toys for metal and electronics left over from my business. I'm not the kind to just throw it together and there is a lot of research yet to be done. And there will be shielding!
If you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too.
Quote from: TheTraveller on 05/19/2015 06:30 pmBoth Shawyer & the Chinese claim their many physical devices produce thrust and the measurement of that thrust is in agreement with their theoretical calculations. Both also claim no new physics is needed and CofE / CofM are conserved.I mean you say it can't work as they claim, yet it does and the measured thrust from many devices, measured in different ways, in different labs, in different countries all closely matched what their theory says the thrust should be.With respect, just maybe your explanation / understanding of what is happening inside the frustum is not at the same level as Shawyer or the Chinese?Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits? This is all standard physics, supported by a century of experiments all conducted with far more precision and rigor than anything published on the EM drive.Incidentally, after doing a brief literature search, I have attached an experiment performed in the early 90's on a superconducting frustrum cavity, with a Q of at least 20,000. The paper is nice in that it gives explicit formulae for the EM fields in such a cavity. Their classical model fits the data perfectly. I might also note that they didn't see the thing shoot out of their dewar...
Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits?
Quote from: SeeShells on 05/19/2015 06:53 pmIf you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too. I think weight is a consideration, so I've crossed off steel. Also copper can not be anodized with silver, though there may be other techniques that can plate it. Silver will raise the Q factor as I understand it. A copper/aluminum alloy can be anodized with silver, as can aluminum itself. For these reasons I've settled on aluminum until I find reason to pick something else.Also 3D printing allows for additional weight savings, some of the parts can have internal cavities. 3D printing can be done at a resolution of 20 microns.
Quote from: phaseshift on 05/19/2015 06:40 pmA thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. Briefly they claim an additional finite dimension between our brane (weak/Tev) and a gravity brane (strong) where gravity actually exists. The distance between these branes is the reason that gravity is such a comparatively weak force. The length of this 4th spacial dimension has an upper limit of somewhat less than 1 millimeter (otherwise we would have seen its effects long ago). The force of gravity on the gravity brane is expected to be 16 orders of magnitude greater than it is on our brane....For whatever it's worth, a short note that Dr. White and Paul March both have invoked a (4+1) brane of spacetime in their explanation and papers.
A thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. Briefly they claim an additional finite dimension between our brane (weak/Tev) and a gravity brane (strong) where gravity actually exists. The distance between these branes is the reason that gravity is such a comparatively weak force. The length of this 4th spacial dimension has an upper limit of somewhat less than 1 millimeter (otherwise we would have seen its effects long ago). The force of gravity on the gravity brane is expected to be 16 orders of magnitude greater than it is on our brane....
Quote from: phaseshift on 05/19/2015 07:10 pmQuote from: SeeShells on 05/19/2015 06:53 pmIf you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too. I think weight is a consideration, so I've crossed off steel. Also copper can not be anodized with silver, though there may be other techniques that can plate it. Silver will raise the Q factor as I understand it. A copper/aluminum alloy can be anodized with silver, as can aluminum itself. For these reasons I've settled on aluminum until I find reason to pick something else.Also 3D printing allows for additional weight savings, some of the parts can have internal cavities. 3D printing can be done at a resolution of 20 microns.20 microns is 0.0008 of an inch and quite impressive (I built and designed XYZand T semiconductor machines with an positional accuracy of .25 um across 300mm) Is the price dropped low enough vs the real advantages of just using digital micrometers and good machining practices? To me nothing is really set in stone in the cavity designs and it seems like every day some new revelation pops up. Has 3D printing (with metals or conductors) dropped that low? I at least want to built it somewhat modular and that can allow design changes.
Quote from: squid on 05/19/2015 06:51 pmQuote from: TheTraveller on 05/19/2015 06:30 pmBoth Shawyer & the Chinese claim their many physical devices produce thrust and the measurement of that thrust is in agreement with their theoretical calculations. Both also claim no new physics is needed and CofE / CofM are conserved.I mean you say it can't work as they claim, yet it does and the measured thrust from many devices, measured in different ways, in different labs, in different countries all closely matched what their theory says the thrust should be.With respect, just maybe your explanation / understanding of what is happening inside the frustum is not at the same level as Shawyer or the Chinese?Or perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits? This is all standard physics, supported by a century of experiments all conducted with far more precision and rigor than anything published on the EM drive.Incidentally, after doing a brief literature search, I have attached an experiment performed in the early 90's on a superconducting frustrum cavity, with a Q of at least 20,000. The paper is nice in that it gives explicit formulae for the EM fields in such a cavity. Their classical model fits the data perfectly. I might also note that they didn't see the thing shoot out of their dewar...Guess you have not read the Chinese data:http://www.emdrive.com/NWPU2010translation.pdfhttp://www.emdrive.com/NWPU2010testresults.pdfhttp://www.emdrive.com/yang-juan-paper-2012.pdfThe thrust measured was not the EagleWorks mosquito landing on your arm level. Maybe read the papers before claimingQuoteOr perhaps they are all making basic mistakes in their sloppy experimental setups, pumping kW of microwave power into poorly shielded cavities and reporting thrusts near their error limits?as a quick way to dismiss their results.
Quote from: phaseshift on 05/19/2015 07:10 pmQuote from: SeeShells on 05/19/2015 06:53 pmIf you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too. I think weight is a consideration, so I've crossed off steel. Also copper can not be anodized with silver, though there may be other techniques that can plate it. Silver will raise the Q factor as I understand it. A copper/aluminum alloy can be anodized with silver, as can aluminum itself. For these reasons I've settled on aluminum until I find reason to pick something else.Also 3D printing allows for additional weight savings, some of the parts can have internal cavities. 3D printing can be done at a resolution of 20 microns.Both brass and copper take to electroplating with silver nicely and would provide a higher Q than bare copper.Keep in mind that any metal can be plated with the right combination. A chrome car bumper was steel, plated with copper, plated with nickel, plated with chrome, the nickel won't plate very well directly to steel...
Quote from: Rodal on 05/19/2015 06:47 pmQuote from: phaseshift on 05/19/2015 06:40 pmA thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.
Quote from: phaseshift on 05/19/2015 06:40 pmA thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.
A thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.
Quote from: phaseshift on 05/19/2015 07:26 pmQuote from: Rodal on 05/19/2015 06:47 pmQuote from: phaseshift on 05/19/2015 06:40 pmA thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.I have all of her books (4 I think, or is it 3?). In Warped Passages I swear I remember her mentioning the possibility of inflating the 4sd (4th spatial dimension) - though there was no known mechanism. Just like there is no known physical mechanism for the inflationary period of the Universe.
Quote from: Rodal on 05/19/2015 06:47 pmQuote from: phaseshift on 05/19/2015 06:40 pmA thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.I have all of her books (4 I think, or is it 3?). In Warped Passages I swear I remember her mentioning the possibility of inflating the 4sd (4th spatial dimension) - though there was no known mechanism. Just like there is no known physical mechanism for the inflationary period of the Universe.
Quote from: phaseshift on 05/19/2015 06:40 pmA thought experiment:Many physicists postulate that we live in a 3+1 deSitter space, and specifically I refer to Lisa Randall, Raman Sundrum http://arxiv.org/abs/hep-ph/9905221. I have Warped Passages by Lisa Randall, I need to get it out and re-read it, she is one of my heroes and if I believe (need to look again) she finds quasicrystals might have an underlying structure into other dimensions. Whoa! Ok need to sit in my hot tub and think some.I have all of her books (4 I think, or is it 3?). In Warped Passages I swear I remember her mentioning the possibility of inflating the 4sd (4th spatial dimension) - though there was no known mechanism. Just like there is no known physical mechanism for the inflationary period of the Universe.
Quote from: LasJayhawk on 05/19/2015 07:34 pmQuote from: phaseshift on 05/19/2015 07:10 pmQuote from: SeeShells on 05/19/2015 06:53 pmIf you use solid copper sheeting for the body of the EM device and that seems to be because of it's thermal and electrical conductivity, couldn't you use a different extruded metal? Extruded Brass comes to mind, 90% copper and 10% tin. Or steel? Unless someone can provide me with as reason why I should just use copper sheeting. Yes, I'm thinking about building one too. I think weight is a consideration, so I've crossed off steel. Also copper can not be anodized with silver, though there may be other techniques that can plate it. Silver will raise the Q factor as I understand it. A copper/aluminum alloy can be anodized with silver, as can aluminum itself. For these reasons I've settled on aluminum until I find reason to pick something else.Also 3D printing allows for additional weight savings, some of the parts can have internal cavities. 3D printing can be done at a resolution of 20 microns.Both brass and copper take to electroplating with silver nicely and would provide a higher Q than bare copper.Keep in mind that any metal can be plated with the right combination. A chrome car bumper was steel, plated with copper, plated with nickel, plated with chrome, the nickel won't plate very well directly to steel...Yes, electroplating is the way to go (there is so much to learn here) - aluminum still seems the best choice for its lower weight. I see that copper can also be 3D printed: http://3dprint.com/59881/nasa-3d-prints-copper-rocket/.
How about extrapolating/interpolating downward by calculating dimensions from resonant frequencies of these test articles? Use that interpolation to select a smaller sized set of cavity dimensions and scale up the frequencies to get that thrust signal out of the "iffy" zone?