Hi guys. The people who are working on the warp theory should look at this paper: http://arxiv.org/pdf/1505.06917v1.pdf
No, I'm saying that the fault is because the big end is closed! If you had resonance on the cone without closing the big end, like rubbing your finger on the rim of a champagne glass, it would be a thruster. As it is now, it's just an energy storage device and possibly an inertial-damper. Todd
Quote from: frobnicat on 06/24/2015 12:28 am... em drive on a wheel at stationary tangential speed and stationary thrust (for stationary power) ...You do understand that for a truly static EMDrive it will NOT move?
... em drive on a wheel at stationary tangential speed and stationary thrust (for stationary power) ...
Shawyer in his Force measurement document makes that very clear.The EMDrive operates in 1 of 3 mode:1) Do Nothing - no externally applied forces 2) Motor Mode - externally applied force moving the cavity big end toward small end.3) Generator Mode - externally applied force trying to move the cavity small end toward big end.The Energy for the Motor Mode generated Force to do Work over Distance comes from newly created microwave energy, powered by increased energy draw on the power supply.
Hook an EMDrive to a rotary wheel and feed it to a generator is not a source of free energy as the energy necessary to turn the generator under load comes from the EMDrives primary electrical power supply.
It is possible that pushing it backwards offers resistance such that it appears more massive, where pushing it forward it appears less massive and tends to accelerate easier. But who's going to give a satellite a "push" in space?Todd
Frankly, between the proposal that the EM Drive somehow "knows" its velocity so that it cannot become a free-energy machine and this proposal that the EM Drive has to have an unspecified level of vibration amplitude and frequency to exert a force... well I better stop here.
This sounds like the cavity is another version of the Woodward , Mach-Lorentz effecthttp://www.centauri-dreams.org/?p=1324http://nextbigfuture.com/2012/07/latest-woodward-mach-effect-propulsion.htmlhttp://nextbigfuture.com/2014/12/significant-resources-to-make-mach.html
I am not a Shawyer fan but the Traveller defense could be not so crazy, look at the following paper:Motion induced radiation from a vibrating cavityhttp://arxiv.org/abs/quant-ph/9606029We study the radiation emitted by a cavity moving in vacuum. We give a quantitative estimate of the photon production inside the cavity as well as of the photon flux radiated from the cavity. A resonance enhancement occurs not only when the cavity length is modulated but also for a global oscillation of the cavity. For a high finesse cavity the emitted radiation surpasses radiation from a single mirror by orders of magnitude.
Shawyer has made a point that he doesn't want to use dielectric inserts because they reduce the thrust force and Yang has not ever used any dielectric inserts in her reported experiments. So, those who claim the highest thrust forces use no dielectric insert whatsoever.How does a microwave cavity with no dielectric insert "sound like ... another version of the Woodward , Mach-Lorentz effect" Where is the Woodward-Mach effect coming from in such a cavity with no dielectric insert
Quote from: OttO on 06/24/2015 08:51 amI am not a Shawyer fan but the Traveller defense could be not so crazy, look at the following paper:Motion induced radiation from a vibrating cavityhttp://arxiv.org/abs/quant-ph/9606029We study the radiation emitted by a cavity moving in vacuum. We give a quantitative estimate of the photon production inside the cavity as well as of the photon flux radiated from the cavity. A resonance enhancement occurs not only when the cavity length is modulated but also for a global oscillation of the cavity. For a high finesse cavity the emitted radiation surpasses radiation from a single mirror by orders of magnitude.Amazing!.. Is this IT then?!
@rfmwguy - some images https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxbUxsM0lVTGVkemVTX1RaMlZJb001NHVaUDRvYUtjS0lIbjdIcUNkX0k&usp=sharinganyone who has the link can view?I had trouble finding resonance and basically failed. My excuse is that I ran out of daylight.Driving at 2.45 GHz I got Q's of 145 at both 2.40189260E+009 and 2.64320588E+009 Hz.Driving at the 2.40 GHz I got a Q of 100 and no other resonancesDriving at 2.64 GHz I got Q = 2000 at 2.40 GHz so I switched back to that number but the resonance went away.So these images are from the cavity driven at 2.64 Ghz and so perhaps not meaningful. I did use the full 15 digits computed, not the 3 digits used here. I probably need to play some more and decrease the bandwidth of the search for resonance. Maybe I'll try that ... later.These images are twice as dense as before. Ten images per cycle instead of five.
Quote from: aero on 06/25/2015 12:45 am@rfmwguy - some images https://drive.google.com/folderview?id=0B1XizxEfB23tfmcxbUxsM0lVTGVkemVTX1RaMlZJb001NHVaUDRvYUtjS0lIbjdIcUNkX0k&usp=sharinganyone who has the link can view?I had trouble finding resonance and basically failed. My excuse is that I ran out of daylight.Driving at 2.45 GHz I got Q's of 145 at both 2.40189260E+009 and 2.64320588E+009 Hz.Driving at the 2.40 GHz I got a Q of 100 and no other resonancesDriving at 2.64 GHz I got Q = 2000 at 2.40 GHz so I switched back to that number but the resonance went away.So these images are from the cavity driven at 2.64 Ghz and so perhaps not meaningful. I did use the full 15 digits computed, not the 3 digits used here. I probably need to play some more and decrease the bandwidth of the search for resonance. Maybe I'll try that ... later.These images are twice as dense as before. Ten images per cycle instead of five.Thanks aero, well done. Unfortunately I am stuck at driving at 2.45 ghz and not 2.64...fortunately I have yet to cut the frustum, meaning I can tweak the small and big diameters from 6.25 and 11.01. Is it easy to plug in the slightly larger diameters for 2.45 ghz resonance?. Not wanting to load u down, but 2k Q is better than 100. 6.735 in small diameter and 11.864 in large diameter, length can stay the same. Just wanting to know if resonance occurs...no pics needed. Thanks in advance...last favor to ask as I am meepless
Quote from: WarpTech on 06/24/2015 05:41 pmIt is possible that pushing it backwards offers resistance such that it appears more massive, where pushing it forward it appears less massive and tends to accelerate easier. But who's going to give a satellite a "push" in space?ToddIf that is the case, then just combine it with a traditional rocket (e.g. a photon rocket or ion thruster); the drive should lower the cost of escaping a gravity well. QV fluctuations alone might even accelerate it in its preferred direction.This also means that some of the experiments we've seen could be flawed by only testing it at ~9.8m/s2 versus momentum imparted by vibrations and atmosphere. Rather than look for the drive to start moving on a rotor, for example, we should start it at a constant velocity and see how/whether it resists various magnitudes of braking and/or acceleration. Then try it in the other direction to make sure it does not resist as much.Quote from: Rodal on 06/24/2015 07:32 pmFrankly, between the proposal that the EM Drive somehow "knows" its velocity so that it cannot become a free-energy machine and this proposal that the EM Drive has to have an unspecified level of vibration amplitude and frequency to exert a force... well I better stop here. The point is that it would not exert any force at all -- no more than a balloon does to rise in the air. In an atmosphere, it will be buoyant because it only resists change in momentum in one direction. Maybe even with QV fluctuations, although not as dramatically.That said, a device with constant mass that can resist a change in momentum in one direction but not as much in the other, assuming that the resistance is greater than a photon rocket, sounds quite exotic. I'd love to hear someone familiar with the equations chime in as to whether this is remotely reasonable.
Is the MEEP model's finite difference grid fine enough and the MEEP eigensolution HarmInv well-conditioned enough to successfully predict the frequencies measured by NASA and other experimenters, using their geometrical dimensions?@ RodalDon't you mean, "The frequencies that COMSOL indicated that they should use? And the answer is that Harminv only comes close. And to the other 1,499,999 readers of this thread, I apologize for my rant.
I was able to confirm that it is RFI affecting the scale causing the apparent changes in force. I used a rubber duck antenna suspended above the scale and was able to reproduce the ~30mg change with 30mw of net power, which seems like a plausible leakage value from the adjustable end which is not well sealed. That end is closest to the scale in the "Up" orientation that produced the largest force changes.
Quote from: Rodal on 06/25/2015 01:49 amShawyer has made a point that he doesn't want to use dielectric inserts because they reduce the thrust force and Yang has not ever used any dielectric inserts in her reported experiments. So, those who claim the highest thrust forces use no dielectric insert whatsoever.How does a microwave cavity with no dielectric insert "sound like ... another version of the Woodward , Mach-Lorentz effect" Where is the Woodward-Mach effect coming from in such a cavity with no dielectric insert No not the dielectrics, thats been covered before. Im refering to the "push-against-inertia"(generator mode) / "pull-when-assisted (motor) concept. If it realy operates with the ratchet like effect as stated then it is "similar" to Woodward's concept, just different in elementary design. STAIF 2006 doc says "What if you can make the mass of a capacitor fluctuating and act on it in a direction when it is heavier and in the opposite direction when it is lighter?"As far as I know Woodward started with (or later on created a test rig) based on capacitors, looking for inertial responses.