@RodalI think the answer to your thrust descripancy between the Cannae and the Tapered Frustum devices may be partly answered by the size of the dielectric. According to the pictures and comsol models in the paper the size of the dielectric in the Cannae device has to be much smaller than the die electric in the Tapered Frustum.
@Rodal.....As for your question about the thrust and specific force numbers reported in the Deck for Shawyer's EmDrive. It is my understanding from second and third hand information that while Dr. White originally attempted to replicate Shawyer's device, they failed to get positive results. ...So if the information is accurate then its most likely that the numbers on slide 40 of that deck are coming from one of Shawyer's papers or the Chinese papers (I have yet to double check that).
If we could use nuclear rockets, other choices would be availabe for our propulsion needs, but sadly the nuclear propulsion venue is not available to the US space program due to political issues we all know of, unless of course a fusion power breakthrough shows up on our doorsteps...
As someone said before and in agreement on the experimentalist side of things...Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust? We wouldn't need vacuum chambers or any nonsense.Why not?
Quote from: RotoSequence on 09/13/2014 07:23 pm...why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?Seriously, this time:The cost and difficulty of scaling to that degree is prohibitive.
...why not build a 33 kilowatt device, place it on an old fashioned weighing scale, and wow the world with a whole pound of thrust?
Quote from: IslandPlaya on 09/15/2014 12:04 amQuote from: Rodal on 09/15/2014 12:00 amQuote from: IslandPlaya on 09/14/2014 11:57 pmAs someone said before and in agreement on the experimentalist side of things...Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust? We wouldn't need vacuum chambers or any nonsense.Why not?Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or no?Ok, start at 1KW then 10KW then 100KW...The point is its much easier (I think) to construct higher power devices than to detect low thrust levels.If a 1KW device was to slide down an air-track then the world would change...OK I completely agree with you and JohnFornaro on that. Now,Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or not? Did Dr. White's lab test the Shawyer/SPR Ltd.'s device, yes or not?Can someone in this forum answer that, please ?
Quote from: Rodal on 09/15/2014 12:00 amQuote from: IslandPlaya on 09/14/2014 11:57 pmAs someone said before and in agreement on the experimentalist side of things...Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust? We wouldn't need vacuum chambers or any nonsense.Why not?Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or no?Ok, start at 1KW then 10KW then 100KW...The point is its much easier (I think) to construct higher power devices than to detect low thrust levels.If a 1KW device was to slide down an air-track then the world would change...
Quote from: IslandPlaya on 09/14/2014 11:57 pmAs someone said before and in agreement on the experimentalist side of things...Why doesn't someone get a bloody big 100Kw setup of the devices discussed and measure thrust? We wouldn't need vacuum chambers or any nonsense.Why not?Do we need to go to 100kW ? Does the Shawyer/SPR Ltd.'s device have a thrust orders of magnitude (400 to 4250 times higher) higher than Cannae device -as quoted by Dr. White- yes or no?
Quote from: Nathan on 04/18/2009 02:36 pmQuoteQuoteEM-Drive is not fake science. They have a WORKING prototype and are moving towards a flight test in 2009. www.emdrive.com. This uses actual physics and obeys all the convervation laws.I am NOT impressed by this site. It states that just like a laser ring gyro is a closed system and can measure rotation rate, this drive is a closed system that can produce force. Newton and all have NO problem with a closed system measuring rotation rate. No need to introduce Special Theory effects to explain this. Explaining away the closed system problem by using the laser ring gyro as an analogy tells me these people are incorrect.However I do hope I am wrong and they produce a really nice rocket engine someday. I for one will not be investing my money in this technology.Danny DegerP.S. Maybe there is some change of momentum of the photons that balances the change of momentum of the rocket. This would make the device not violate the law of the conservation of momentum.I took me a while to understand how it works. There is a basic property of a waveguide that describes how the group velocity of a wave changes as the size of the waveguide changes. For the em-drive it is this that creates the force imbalance on the end walls of the cavity. In terms of momentum, if there are two equal masses and the total momentum p=p1-p2 then p is non zero when the velocities of the particle colliding at each end of the waveguide differ. The slope of the walls of the cavity ensure the collisions with the walls along the length result in a nonlinear force ie: the differing group velocities along the length of the sloping cavity ensure the particles don't just bounce around inside the cavity canceling each others forces totally out. One uses the law of relativistic velocity addition to see that there is forward motion when the thruster is viewed by an outside observer (thus an open system).To illustrate:If one fires two opposing canons within a closed box the impact of the canonballs against the walls will cancel out to result in zero motion. If either the velocity or the mass of one of the balls changes en-route to the wall then the impacts will not cancel out and there will be motion. The trick then is to deal with the lost mass or velocity. It has to have gone somewhere. From the point of view of momentum; The em-drive looks at the change in velocity whereas the woodward drive looks at the change in mass. The both deal with the imbalance in different ways. EM-drive uses the properties of waveguides and relativity whereas woodward's drive uses machian mass fluctuations and a rectifier.When one accounts for the energy absorbed into the system to create the motion then one retains conversation of energy. Same for momentum.So I think I understand. Took me a while but I think I'm there. And it is basic physics! It USES newton laws. It just needed a different perspective.Nathan:A major problem with Shawyer’s waveguide explanation is that his theoretical proof does not provide an explanation for the magnitude of the reaction forces reported. Photon rockets of any stripe with only several hundred watts of input power can't generate thrusts measured in milli-Newtons. Instead they can only produce pico to nano-Newtons of thrust from their local power supplies, unless they are also inadvertently tapping into a higher dimensional energy manifold as do Woodward's devices with the cosmologically derived gravinertial field. However, Shawyer first has to replicate his posted video experiment in a hard vacuum (<1x10-6 Torr) and get the same results, thus precluding possible ion wind or cooling fan generated thrusts before we worry too much about his proposed theoretical approach. If he does get the same reported thrust in a vacuum though, then my bet is still on Sonny White's QVF explanation being more accurate than Shawyer’s.BTW, as noted by GI-Thruster, I need to find the time and resources to replicate my Mach-2MHz experiment and/or exercise my new MLT-2009 test article in a hard vacuum, before we can take its results to be anything more than strongly suggestive that M-E based MLTs work as advertised. Alas, that next step for me has proven problematic so far...
QuoteQuoteEM-Drive is not fake science. They have a WORKING prototype and are moving towards a flight test in 2009. www.emdrive.com. This uses actual physics and obeys all the convervation laws.I am NOT impressed by this site. It states that just like a laser ring gyro is a closed system and can measure rotation rate, this drive is a closed system that can produce force. Newton and all have NO problem with a closed system measuring rotation rate. No need to introduce Special Theory effects to explain this. Explaining away the closed system problem by using the laser ring gyro as an analogy tells me these people are incorrect.However I do hope I am wrong and they produce a really nice rocket engine someday. I for one will not be investing my money in this technology.Danny DegerP.S. Maybe there is some change of momentum of the photons that balances the change of momentum of the rocket. This would make the device not violate the law of the conservation of momentum.I took me a while to understand how it works. There is a basic property of a waveguide that describes how the group velocity of a wave changes as the size of the waveguide changes. For the em-drive it is this that creates the force imbalance on the end walls of the cavity. In terms of momentum, if there are two equal masses and the total momentum p=p1-p2 then p is non zero when the velocities of the particle colliding at each end of the waveguide differ. The slope of the walls of the cavity ensure the collisions with the walls along the length result in a nonlinear force ie: the differing group velocities along the length of the sloping cavity ensure the particles don't just bounce around inside the cavity canceling each others forces totally out. One uses the law of relativistic velocity addition to see that there is forward motion when the thruster is viewed by an outside observer (thus an open system).To illustrate:If one fires two opposing canons within a closed box the impact of the canonballs against the walls will cancel out to result in zero motion. If either the velocity or the mass of one of the balls changes en-route to the wall then the impacts will not cancel out and there will be motion. The trick then is to deal with the lost mass or velocity. It has to have gone somewhere. From the point of view of momentum; The em-drive looks at the change in velocity whereas the woodward drive looks at the change in mass. The both deal with the imbalance in different ways. EM-drive uses the properties of waveguides and relativity whereas woodward's drive uses machian mass fluctuations and a rectifier.When one accounts for the energy absorbed into the system to create the motion then one retains conversation of energy. Same for momentum.So I think I understand. Took me a while but I think I'm there. And it is basic physics! It USES newton laws. It just needed a different perspective.
QuoteEM-Drive is not fake science. They have a WORKING prototype and are moving towards a flight test in 2009. www.emdrive.com. This uses actual physics and obeys all the convervation laws.I am NOT impressed by this site. It states that just like a laser ring gyro is a closed system and can measure rotation rate, this drive is a closed system that can produce force. Newton and all have NO problem with a closed system measuring rotation rate. No need to introduce Special Theory effects to explain this. Explaining away the closed system problem by using the laser ring gyro as an analogy tells me these people are incorrect.However I do hope I am wrong and they produce a really nice rocket engine someday. I for one will not be investing my money in this technology.Danny DegerP.S. Maybe there is some change of momentum of the photons that balances the change of momentum of the rocket. This would make the device not violate the law of the conservation of momentum.
EM-Drive is not fake science. They have a WORKING prototype and are moving towards a flight test in 2009. www.emdrive.com. This uses actual physics and obeys all the convervation laws.
Quote from: mlorrey on 04/17/2009 09:24 pmQuote from: gospacex on 04/17/2009 08:57 pmQuote from: Star-Drive on 04/14/2009 07:14 pmSo what do you consider “substance” in regards to proving these observed M-E effects are REAL? Supporting experimental data from two or more different sources used to be considered substantiating support, but apparently that is no longer the case in 2009. So what will it take to prove the point to you and the rest of the skeptics in the world that the M-E or its QVF cousin is real and usable?I am not a sceptic, I would be *happy* if someone will prove that 3rd law of Newton can be worked around.It can be the case that the idea, being rather radical, does require verification by more than one team. Extraordinary claims do require extraordinary evidence, in this case, reproduction of the effect by multiple teams.Do not assume that "they" (meaning scientific community) have ill intentions. No amount of complaining that "they" don't take it seriously would help. Ony more independent verifications will.Firstly, please stop asserting that M-E gets 'around' Newtons third law any more than a game of tug-of-war does. The M-E reacts against the rest of the universe, period. While I understand thats a bit big of a concept for some folks, honestly though, it shouldn't be for anybody who has moved beyond the idea that anything outside our solar system is just little light bulbs on a big sphere.By what mechanism is it reacting against the rest of the universe? Why do other devices not react with the rest of the universe like this? Why is this one special? How can it instantaneously signal the rest of the universe to react? Saying it is so doesn't make it so.
Quote from: gospacex on 04/17/2009 08:57 pmQuote from: Star-Drive on 04/14/2009 07:14 pmSo what do you consider “substance” in regards to proving these observed M-E effects are REAL? Supporting experimental data from two or more different sources used to be considered substantiating support, but apparently that is no longer the case in 2009. So what will it take to prove the point to you and the rest of the skeptics in the world that the M-E or its QVF cousin is real and usable?I am not a sceptic, I would be *happy* if someone will prove that 3rd law of Newton can be worked around.It can be the case that the idea, being rather radical, does require verification by more than one team. Extraordinary claims do require extraordinary evidence, in this case, reproduction of the effect by multiple teams.Do not assume that "they" (meaning scientific community) have ill intentions. No amount of complaining that "they" don't take it seriously would help. Ony more independent verifications will.Firstly, please stop asserting that M-E gets 'around' Newtons third law any more than a game of tug-of-war does. The M-E reacts against the rest of the universe, period. While I understand thats a bit big of a concept for some folks, honestly though, it shouldn't be for anybody who has moved beyond the idea that anything outside our solar system is just little light bulbs on a big sphere.
Quote from: Star-Drive on 04/14/2009 07:14 pmSo what do you consider “substance” in regards to proving these observed M-E effects are REAL? Supporting experimental data from two or more different sources used to be considered substantiating support, but apparently that is no longer the case in 2009. So what will it take to prove the point to you and the rest of the skeptics in the world that the M-E or its QVF cousin is real and usable?I am not a sceptic, I would be *happy* if someone will prove that 3rd law of Newton can be worked around.It can be the case that the idea, being rather radical, does require verification by more than one team. Extraordinary claims do require extraordinary evidence, in this case, reproduction of the effect by multiple teams.Do not assume that "they" (meaning scientific community) have ill intentions. No amount of complaining that "they" don't take it seriously would help. Ony more independent verifications will.
So what do you consider “substance” in regards to proving these observed M-E effects are REAL? Supporting experimental data from two or more different sources used to be considered substantiating support, but apparently that is no longer the case in 2009. So what will it take to prove the point to you and the rest of the skeptics in the world that the M-E or its QVF cousin is real and usable?
Quote from: aero on 11/14/2012 04:26 pmJohn - You're grasping at straws. The topic is Propellantless Field Propulsion and application. The test stand has no bearing on the topic beyond giving assurances that the thrust measurements were accurately made. Any good test stand will do, even a pendulum. Aero: ... The common wisdom is that EM drive does not work. In the case of Woodward's work, and probably Shawyer's as well, the test stand is almost as important as the tested device itself, since the expected forces are thought to be very low in the experiments demonstrated.Woodward and Paul March have gone to great lengths to account for spurious outside signals, and even now, can barely ascertain the output of his device from noise.A pendulum will most assuredly not work. ... The measurement of the forces is key, until such time as they float one of these devices out on the conference room table. ...
John - You're grasping at straws. The topic is Propellantless Field Propulsion and application. The test stand has no bearing on the topic beyond giving assurances that the thrust measurements were accurately made. Any good test stand will do, even a pendulum.
The test stand is very important. If I might repeat myself: It would be nice to read more of Rodal's analysis of the testing mechanism.
Quote...Newton and all have NO problem with a closed system measuring rotation rate. ...Danny Deger
...Newton and all have NO problem with a closed system measuring rotation rate. ...Danny Deger
Paul March's Woodward-Effect devices were tested in a completely different set-up (using a load cell instead of an inverted torsion pendulum).
QuotePaul March's Woodward-Effect devices were tested in a completely different set-up (using a load cell instead of an inverted torsion pendulum).Maybe Paul March would test the Tapered (Frustum) Cavity using his set-up. That should also work to provide valid comparison between the two devices.
Why haven't Paul March's Woodward-Effect devices been tested in NASA/Dr. White's Eagleworks inverted torque pendulum and reported?
If people think there is some ongoing conspiracy or that scientific breakthrough about interstellar travel has been achieved, it's entirely different topics from EMDrive purpose (or btw Cannae) which aims only as replacing auxiliary propulsion systems on satellites.
Quote from: Rodal on 09/15/2014 05:59 pmWhy haven't Paul March's Woodward-Effect devices been tested in NASA/Dr. White's Eagleworks inverted torque pendulum and reported? @Rodal: My feeling is that you try to find too much meaning in this whole thing. After all, there is no scientific or engineering breakthrough described in the Dr White paper, just a report on some exotic experimentations with anomalous results. I see it as some "food for thought" paper. Indeed as Paul March said, there is a "pay the bills" aspect intended for NASA managers and certainly not for scientists. This gives a specific style to the writing, which you would not find in a more traditionaly formated paper. Every organisation has its own culture and quirks....
Here is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive
Quote from: sanman on 08/08/2014 02:30 amI, for one, am glad if the NASA team's test results announcement has created a flutter. At least this will encourage more experts to get involved in coming up with either a definitive proof or disproof on this matter. At least one way or the other, the matter can then be settled.It's already considered settled by mainstream science: there is nothing there. Mainstream scientists have already looked into the EmDrive years ago and convinced themselves it doesn't work.
I, for one, am glad if the NASA team's test results announcement has created a flutter. At least this will encourage more experts to get involved in coming up with either a definitive proof or disproof on this matter. At least one way or the other, the matter can then be settled.
Quote from: aero on 08/07/2014 06:33 pmHere is an article with a more accepting slant. Still has errors but what can you do. The tests were NOT performed in vacuum.http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-driveI have been trying to find out whether some of the tests were preformed in a vacuum. From the paper, it sounds as though some of them were not -- but why have the detailed description of the evacuation process if none of them were? Can anyone shed any light?Also, my understanding is that this technology could fit on a cubesat, presumably that would be a fairly cheap test?
A) There is a claim that there can be rocket propulsion produced without on-board propellant and without an outside force propelling it (i.e. solar propulsion, electrodynamic tethers, etc.)