Quote from: Notsosureofit on 02/17/2015 11:36 am....This does fit (as far as I've gotten) the concept of a self-accelerating Dirac wavepacket (which does conserve momentum)....Please tell us more when you have a chance about the <<self-accelerating Dirac wavepacket (which does conserve momentum)>> as conservation of momentum has been the biggest problem of the scientific media (Prof. Baez and Sean Carroll for example) and with the serious science-fiction media (Greg Egan) with the EMDrive. How does momentum get conserved in the EMDrive when there is nothing coming out of the EM Drive? http://physics.stackexchange.com/questions/160702/self-accelerating-wavepackets-what-are-they-and-can-they-impulse-a-spaceshiphttp://www.nature.com/nphys/journal/vaop/ncurrent/fig_tab/nphys3196_F1.htmlhttp://newsoffice.mit.edu/2015/self-accelerating-particles-0120Or are you considering that evanescent waves coming out of the EM Drive in outer space (with no fields or matter nearby to interact with) are responsible for conservation of momentum with an effectiveness much greater than a photon rocket?
....This does fit (as far as I've gotten) the concept of a self-accelerating Dirac wavepacket (which does conserve momentum)....
Quote from: aero on 02/17/2015 09:51 pm...So what do you propose as a resolution to your critique?Same thing I proposed here:http://forum.nasaspaceflight.com/index.php?topic=36313.msg1332813#msg1332813Quote from: Rodal on 02/17/2015 03:00 pm.. it is critical, to assess results of a numerical solution, to compare the results of a numerical solution (for example Finite Difference method) to an exact solution. In this case, an exact solution to a cylindrical cavity exists (http://en.wikipedia.org/wiki/Microwave_cavity#Cylindrical_cavity), and it would be worthwhile to compare how far is the MEEP solution for a resonant cylindrical cavity, say of a diameter=Sqrt[BigDiameterOfTruncatedCone * SmallDiameterOfTruncatedCone]=0.21060 m and same axial length, with the same material inputs and mesh as used for the Finite Difference solution of the Truncated Cone. ....I propose a MEEP analysis for a resonant cylindrical cavity (no dielectric), with diameter=Sqrt[BigDiameterOfTruncatedCone * SmallDiameterOfTruncatedCone] and same axial length=0.2286 m as the NASA cavity, with the same material inputs and mesh as you used for the Finite Difference solution of the Truncated Cone. Actual geometry Large OD : 11.00 " (0.2794m), Small OD: 6.25" (0.1588 m)Length : 9.00 " (0.2286m) Geometric Mean Diameter: 0.2106056741875679 mIf the MEEP mesh for the truncated cone cannot be used to obtain a MEEP solution close to the exact solution for a cylindrical cavity of similar dimensions (an easier problem to solve than the truncated cone), then that mesh and solution (2D?) cannot get a reliable solution for the EM Drive truncated cone, concerning EM Drive for space flight applications. (The cylindrical cavity is an easier problem because the mode shapes are either purely resonating (real solutions) or evanescent (imaginary solutions) while for a truncated cone there are modes that go from resonating to evanescent, and because the truncated cone displays interesting attenuation and focusing properties).
...So what do you propose as a resolution to your critique?
.. it is critical, to assess results of a numerical solution, to compare the results of a numerical solution (for example Finite Difference method) to an exact solution. In this case, an exact solution to a cylindrical cavity exists (http://en.wikipedia.org/wiki/Microwave_cavity#Cylindrical_cavity), and it would be worthwhile to compare how far is the MEEP solution for a resonant cylindrical cavity, say of a diameter=Sqrt[BigDiameterOfTruncatedCone * SmallDiameterOfTruncatedCone]=0.21060 m and same axial length, with the same material inputs and mesh as used for the Finite Difference solution of the Truncated Cone. ....
....As you must know, there are several more-or-less independent modules in meep. The core FDTD algorithm that we should be concerned about is not the same as the Harminv algorithm which determines resonance frequencies and as you know, is suspect, at least by me and Dr. Dominic and I think, yourself. Proving again that the Harminv module is suspect will not show anything one way or the other about the core FDTD algorithm or the Flux and Forces modules. ....
Quote from: Rodal on 02/17/2015 01:17 pmQuote from: Notsosureofit on 02/17/2015 11:36 am....This does fit (as far as I've gotten) the concept of a self-accelerating Dirac wavepacket (which does conserve momentum)....Please tell us more when you have a chance about the <<self-accelerating Dirac wavepacket (which does conserve momentum)>> as conservation of momentum has been the biggest problem of the scientific media (Prof. Baez and Sean Carroll for example) and with the serious science-fiction media (Greg Egan) with the EMDrive. How does momentum get conserved in the EMDrive when there is nothing coming out of the EM Drive? http://physics.stackexchange.com/questions/160702/self-accelerating-wavepackets-what-are-they-and-can-they-impulse-a-spaceshiphttp://www.nature.com/nphys/journal/vaop/ncurrent/fig_tab/nphys3196_F1.htmlhttp://newsoffice.mit.edu/2015/self-accelerating-particles-0120Or are you considering that evanescent waves coming out of the EM Drive in outer space (with no fields or matter nearby to interact with) are responsible for conservation of momentum with an effectiveness much greater than a photon rocket?This is certainly interesting but there are no "specially engineered phase masks" in Emdrive.Same people: http://arxiv.org/pdf/1205.2112.pdf
It has been recently argued that thequantum vacuum can possess momentum
This is a goldmine of information concerning non-reciprocal materials!http://arxiv.org/abs/1211.0530The visual is to help communicate the concept.
QuoteIt has been recently argued that thequantum vacuum can possess momentum
I've tried to understand the totality of the emdrive mystery in a lot of different ways ranging from it being pure bs to some quirk with inertia. The only way it makes sense is to apply that "momentum from the qv" theory I've been going on about. It is the only one left that still passes the smell test and doesn't try and overturn established science. It seems like a perfect fit for the conditions and two unconnected teams of researchers make the same claims. Most importantly, it makes falsifiable predictions.
Quote from: Mulletron on 02/18/2015 07:37 amI've tried to understand the totality of the emdrive mystery in a lot of different ways ranging from it being pure bs to some quirk with inertia. The only way it makes sense is to apply that "momentum from the qv" theory I've been going on about. It is the only one left that still passes the smell test and doesn't try and overturn established science. It seems like a perfect fit for the conditions and two unconnected teams of researchers make the same claims. Most importantly, it makes falsifiable predictions.Except that it *does* "try and overturn established science". Momentum from the quantum vacuum is not compatible with generally accepted physics.Unconnected teams can easily be mislead by similar mistakes. Just look at how many independent observers claimed to see canals on the surface of Mars when they were on the edge of the signal/noise boundary of optical telescopes.
Well it has been accepted for publication at least. http://iopscience.iop.org/0953-8984/page/Forthcoming%20articles#Special_isCasimir_foAnd the other citations are already published. http://lpm2c.grenoble.cnrs.fr/spip.php?page=publications&id_auteur=18&clepubli=van%20Tiggelen&lang=frSo we're not dealing with a crank here.
Folks:While you all talk about various ways to accomplish the E&M simulations of these frustum cavities, I thought you might like to take a look at the COMSOL derived resonances of the Eagleworks Lab's copper frustum resonant cavity driven with a ~16mm OD loop antenna located 15% up the side wall of the frustum from the large OD end of the cavity. BTW, the EMPower amplifiers were delivered to the Lab yesterday and I'll be calibrating the power metering for one that was installed yesterday on the torque pendulum.Best, Paul M,
Ok, maybe I'm a bit slower than I ought to be lately, but are you guys telling us that they are, essentially, developing a propellentless thrust system based on a RADAR SYSTEM?
Quote from: JasonAW3 on 02/18/2015 01:19 pmOk, maybe I'm a bit slower than I ought to be lately, but are you guys telling us that they are, essentially, developing a propellentless thrust system based on a RADAR SYSTEM?You never noticed that the ship rocks harder when the radars are turnin' and burnin'? Shoot, they should just sector SPY back aft and cut the engines. :-) http://en.wikipedia.org/wiki/Arleigh_Burke-class_destroyerBased on electromagnetic waves. Waveguide are found in numerous applications besides radars. Sorry back on topic...