Quote from: TheTraveller on 05/26/2015 09:59 pmIn Shawyers Flight Thruster test the reported max thrust achieved was around 170mN. ...That is approx 17 gf. Is a bit over the weight of 2 x US dollar coins. If I put them in your outstretched palm, could you feel the weight? Sure it is not a kg but the level is significant and not what some mosquito produces when it lands on your arm.Traveller, do you know how Shawyer actually measured thrust, because according to his EmDriveForceMeasurement.pdf and due to his strange interpretation of action and reaction, he believes that direct measurement of the thrust from a non-accelerating EmDrive is impossible, and the test rigs discussed here, including Iulian's balance, should not measure any thrust at all.Quote from: Pg. 2The most important point to be made, is that to measure force, the cavity must experience acceleration. In a fully restrained cavity, thrust and reaction force cancel out. ...Clearly, in a static situation, where T and R both exist as forces, they will cancel out. Thus any attempt to measure them by simply placing the thruster vertically on a set of scales will fail. If however the thrust is sufficient such that a = -g, then the thruster could be made to hover above the scales. ...In free space, the thruster will simply accelerate at a m/s/s, and R will not be measurable. To measure R it is necessary to restrain the thruster against a fixed reference point.However at rest, no force can be measured as R will cancel out T as in Fig 1. ...and most importantlyQuote from: Pg. 3A number of methods have been used in the UK, the US and China to measure the forces produced by an EmDrive thruster. In each successful case, the EmDrive force data has been superimposed on an increasing or decreasing background force, generated by the test equipment itself.Indeed, in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured. This was clearly a result of attempting to measure the forces on a fully static thruster, where T and R cancel each other.Does that mean that Shaywer's device includes actuators which accelerate the drive, and the measured thrust is extracted from the signal by subtracting the expected contribution of those actuators?~Kirk
In Shawyers Flight Thruster test the reported max thrust achieved was around 170mN. ...That is approx 17 gf. Is a bit over the weight of 2 x US dollar coins. If I put them in your outstretched palm, could you feel the weight? Sure it is not a kg but the level is significant and not what some mosquito produces when it lands on your arm.
The most important point to be made, is that to measure force, the cavity must experience acceleration. In a fully restrained cavity, thrust and reaction force cancel out. ...Clearly, in a static situation, where T and R both exist as forces, they will cancel out. Thus any attempt to measure them by simply placing the thruster vertically on a set of scales will fail. If however the thrust is sufficient such that a = -g, then the thruster could be made to hover above the scales. ...In free space, the thruster will simply accelerate at a m/s/s, and R will not be measurable. To measure R it is necessary to restrain the thruster against a fixed reference point.However at rest, no force can be measured as R will cancel out T as in Fig 1. ...
A number of methods have been used in the UK, the US and China to measure the forces produced by an EmDrive thruster. In each successful case, the EmDrive force data has been superimposed on an increasing or decreasing background force, generated by the test equipment itself.Indeed, in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured. This was clearly a result of attempting to measure the forces on a fully static thruster, where T and R cancel each other.
Quote from: kdhilliard on 05/26/2015 10:55 pmQuote from: TheTraveller on 05/26/2015 09:59 pmIn Shawyers Flight Thruster test the reported max thrust achieved was around 170mN. ...That is approx 17 gf. Is a bit over the weight of 2 x US dollar coins. If I put them in your outstretched palm, could you feel the weight? Sure it is not a kg but the level is significant and not what some mosquito produces when it lands on your arm.Traveller, do you know how Shawyer actually measured thrust, because according to his EmDriveForceMeasurement.pdf and due to his strange interpretation of action and reaction, he believes that direct measurement of the thrust from a non-accelerating EmDrive is impossible, and the test rigs discussed here, including Iulian's balance, should not measure any thrust at all.Quote from: Pg. 2The most important point to be made, is that to measure force, the cavity must experience acceleration. In a fully restrained cavity, thrust and reaction force cancel out. ...Clearly, in a static situation, where T and R both exist as forces, they will cancel out. Thus any attempt to measure them by simply placing the thruster vertically on a set of scales will fail. If however the thrust is sufficient such that a = -g, then the thruster could be made to hover above the scales. ...In free space, the thruster will simply accelerate at a m/s/s, and R will not be measurable. To measure R it is necessary to restrain the thruster against a fixed reference point.However at rest, no force can be measured as R will cancel out T as in Fig 1. ...and most importantlyQuote from: Pg. 3A number of methods have been used in the UK, the US and China to measure the forces produced by an EmDrive thruster. In each successful case, the EmDrive force data has been superimposed on an increasing or decreasing background force, generated by the test equipment itself.Indeed, in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured. This was clearly a result of attempting to measure the forces on a fully static thruster, where T and R cancel each other.Does that mean that Shaywer's device includes actuators which accelerate the drive, and the measured thrust is extracted from the signal by subtracting the expected contribution of those actuators?Not at my laptop. I have images of each case below. He has placed them directly on scales, hung them from springs above scales, used balance beams with scales, plus he used a rotary air bearing system to show true acceleration. Seems his preferred method is to work either against gravity (small end pushing up) or with gravity (small end pushing down).
Quote from: TheTraveller on 05/26/2015 09:59 pmIn Shawyers Flight Thruster test the reported max thrust achieved was around 170mN. ...That is approx 17 gf. Is a bit over the weight of 2 x US dollar coins. If I put them in your outstretched palm, could you feel the weight? Sure it is not a kg but the level is significant and not what some mosquito produces when it lands on your arm.Traveller, do you know how Shawyer actually measured thrust, because according to his EmDriveForceMeasurement.pdf and due to his strange interpretation of action and reaction, he believes that direct measurement of the thrust from a non-accelerating EmDrive is impossible, and the test rigs discussed here, including Iulian's balance, should not measure any thrust at all.Quote from: Pg. 2The most important point to be made, is that to measure force, the cavity must experience acceleration. In a fully restrained cavity, thrust and reaction force cancel out. ...Clearly, in a static situation, where T and R both exist as forces, they will cancel out. Thus any attempt to measure them by simply placing the thruster vertically on a set of scales will fail. If however the thrust is sufficient such that a = -g, then the thruster could be made to hover above the scales. ...In free space, the thruster will simply accelerate at a m/s/s, and R will not be measurable. To measure R it is necessary to restrain the thruster against a fixed reference point.However at rest, no force can be measured as R will cancel out T as in Fig 1. ...and most importantlyQuote from: Pg. 3A number of methods have been used in the UK, the US and China to measure the forces produced by an EmDrive thruster. In each successful case, the EmDrive force data has been superimposed on an increasing or decreasing background force, generated by the test equipment itself.Indeed, in the UK when the background force changes were eliminated, in an effort to improve force measurement resolution, no EmDrive force was measured. This was clearly a result of attempting to measure the forces on a fully static thruster, where T and R cancel each other.Does that mean that Shaywer's device includes actuators which accelerate the drive, and the measured thrust is extracted from the signal by subtracting the expected contribution of those actuators?
...I think it speaks for itself how much attention the scientific and engineering community are paying to this work. There certainly won't be any increase thrust, as any such thrust was due to thermal or electronic noise in the first place. The experimental method is botched, and the data is incomprehensible (the error bars are far too large to make any justifiable conclusions). Also, none of it has even been peer-reviewed and the researchers don't seem to be interested in repeatability or having other researchers take a much deeper look at their work. The fact that my previous post was "widely reported" and deleted just shows how incredibly sensitive they and their supporters are to any criticism.
BTW The entire bread crumb thing makes me cringe.So many times I've seen the case of a deluded researcher giving hints that, in retrospect, say: 'I don't know the answer, but I'm going to drop my hunches as if I know, and then take the credit when you find something interesting.' That's really been the trend in any kind of bogus technology guru situation. No offense to The Traveler -- just a heads up that the breadcrumb thing is a trope of rag-trade paperbacks and soap operas to get you to stick around after the ad-break/chapter. But good luck if you are able to get a head start before his peer reviewed paper comes out (that's a thing right? Aside from EW's forthcoming publication?). I think, with Shawyer at least, a good dollop of blind faith is required to remain satisfied.
Quote from: WarpTech on 05/26/2015 03:34 am...Therefore, any propellant-less propulsion device, must have some means of becoming depolarized. In the case of the frustum, stored energy is lost to heat as well as thrust, and this eventually depolarizes it so it can be re-charged and thrust again. Once again, it can only work in a pulsed mode, when power is ramping up and down quickly.ToddWhat do people think of the idea of driving the EM Drive with a TEmnp mode (transverse electric mode) such that the axial field is magnetic along the longitudinal direction.
...Therefore, any propellant-less propulsion device, must have some means of becoming depolarized. In the case of the frustum, stored energy is lost to heat as well as thrust, and this eventually depolarizes it so it can be re-charged and thrust again. Once again, it can only work in a pulsed mode, when power is ramping up and down quickly.Todd
Then the idea would be to make the EM Drive more of a "one-way" street (1-way directional waves rather than a 2-way street with standing waves) by placing tiny ferrite beads (magnets) along so as to minimize reflections (as done in the solid state ruby maser).The number and size of the ferrite beads would control the fine tradeoff between Q resonance (needed for reverberation) and directionality (needed for thrust).
Perhaps this would allow the use of a cylindrical waveguide (instead of a truncated cone), one could control the amount of reflections by the size and number of ferrite beads along the axis. (The size of the ferrite bead could be functionally graded such that the size of ferrite would monotonically increase in one direction, for example).Also the use of a solid state material (such as the ruby used in the ruby maser) that can emit in a very wide range of microwave frequencies may allow much higher power to thrust force conversion.Please notice as per the history of the Ruby Maser chart, that many Ruby Masers operated at similar microwave frequencies (2.4 GHz) as used for magnetrons for home cooking microwave ovens:
Quote from: Rodal on 05/26/2015 05:08 pmQuote from: WarpTech on 05/26/2015 03:34 am...Therefore, any propellant-less propulsion device, must have some means of becoming depolarized. In the case of the frustum, stored energy is lost to heat as well as thrust, and this eventually depolarizes it so it can be re-charged and thrust again. Once again, it can only work in a pulsed mode, when power is ramping up and down quickly.ToddWhat do people think of the idea of driving the EM Drive with a TEmnp mode (transverse electric mode) such that the axial field is magnetic along the longitudinal direction.This would be a solenoid, aka transformer primary or coupled inductor oriented axially with the frustum. It is a straightforward design I have been considering...QuoteThen the idea would be to make the EM Drive more of a "one-way" street (1-way directional waves rather than a 2-way street with standing waves) by placing tiny ferrite beads (magnets) along so as to minimize reflections (as done in the solid state ruby maser).The number and size of the ferrite beads would control the fine tradeoff between Q resonance (needed for reverberation) and directionality (needed for thrust).How? Any magnetic material along the axis will transfer momentum forward to the frustum, but only at the expense of recoiling momentum toward the rear. If they are physical attached to one another, the result should be nil. QuotePerhaps this would allow the use of a cylindrical waveguide (instead of a truncated cone), one could control the amount of reflections by the size and number of ferrite beads along the axis. (The size of the ferrite bead could be functionally graded such that the size of ferrite would monotonically increase in one direction, for example).Also the use of a solid state material (such as the ruby used in the ruby maser) that can emit in a very wide range of microwave frequencies may allow much higher power to thrust force conversion.Please notice as per the history of the Ruby Maser chart, that many Ruby Masers operated at similar microwave frequencies (2.4 GHz) as used for magnetrons for home cooking microwave ovens:It's still beyond my comprehension at the moment. I'll give it some thought and do some research.Todd
Interesting. Do you then agree that his EmDriveForceMeasurement.pdf suggests that with such methods no EmDrive force would be measured?~KirkP.S. On a personal note, I hope you know that no one here is calling on you to defend Shawyer's position. You just seem to be the one most familiar with his work. I find his treatment of action-reaction to be very confusing, and I'd appreciate any breadcrumbs I get from you which would help explain just what he is thinking.
(...)It is not a closed system violating CoM, it is an open-system, separating forward and reverse propagating electromagnetic momentum by frequency, with the dispersive cavity then selectively dissipating and radiating the sorted momentum as heat.As, I know, this has been espoused by some here prior. I'm just kind of slow on the uptake.So why would a Peltier cooler generate thrust? An electric current drags high-frequency (hot) phonons from one end and leaving low-frequency (cold) phonons on the other. Kind of the same thing, in another media and operating regime. Or something like that.I googled "Peltier Thrust" and found this:http://www.theavalonfoundation.org/docs/peltier.htmlHal Puthoff mentioned. Usual suspect?So, pending more evidence, at this time I'm persuaded this is a thermodynamic rather than a qv warping/compressing phenomena. I change my mind often about this stuff over the last couple weeks. If true, it precludes some exciting and energetic plasma applications.
Quote from: kdhilliard Interesting. Do you then agree that his EmDriveForceMeasurement.pdf suggests that with such methods no EmDrive force would be measured?~KirkP.S. On a personal note, I hope you know that no one here is calling on you to defend Shawyer's position. You just seem to be the one most familiar with his work. I find his treatment of action-reaction to be very confusing, and I'd appreciate any breadcrumbs I get from you which would help explain just what he is thinking.To be free to move or not is a relative term. How much movement is free to move? Bolt it to a satellite and it will not move relative to the satellite. Sit it on a scale and it can press down, move a micron and generate a force. Sometime Roger Shawyer is not the best of technical writers and you need to do a bit of head scratching to understand his point of view.I have no issues with the measurement paper and using scales to measure the force as the EM Drive does move on a scale, even if you can't see it.
Quote from: TheTraveller on 05/27/2015 12:22 amQuote from: kdhilliard Do you then agree that his EmDriveForceMeasurement.pdf suggests that with such methods no EmDrive force would be measured?To be free to move or not is a relative term. How much movement is free to move? Bolt it to a satellite and it will not move relative to the satellite. Sit it on a scale and it can press down, move a micron and generate a force. Sometime Roger Shawyer is not the best of technical writers and you need to do a bit of head scratching to understand his point of view.I have no issues with the measurement paper and using scales to measure the force as the EM Drive does move on a scale, even if you can't see it.Fortunately we have the field of Mechanics that has answered this question. ...
Quote from: kdhilliard Do you then agree that his EmDriveForceMeasurement.pdf suggests that with such methods no EmDrive force would be measured?To be free to move or not is a relative term. How much movement is free to move? Bolt it to a satellite and it will not move relative to the satellite. Sit it on a scale and it can press down, move a micron and generate a force. Sometime Roger Shawyer is not the best of technical writers and you need to do a bit of head scratching to understand his point of view.I have no issues with the measurement paper and using scales to measure the force as the EM Drive does move on a scale, even if you can't see it.
Do you then agree that his EmDriveForceMeasurement.pdf suggests that with such methods no EmDrive force would be measured?
The answer is that there is no such Infinitely stiff material in our Universe.