Potomic... I am somewhat confused by your rational for not pursuing this exp. As I understand it a torsion wire would not be subject to the stiction error of scales. You would be looking for rotation in the wire larger than any back and forth motion produced by the drive. The won't be any stiction in a torsion wire since there is nothing to slip against or to stick to.What am I missing?
I noticed the rubber pad was absent in the "null" device constructed by Woodward. If the Mach Effect Thruster is basically a Harry Bull Reaction Motor, then it needs the rubber pad to "work."
Quote from: Tcarey on 10/24/2017 06:11 pmPotomic... I am somewhat confused by your rational for not pursuing this exp. As I understand it a torsion wire would not be subject to the stiction error of scales. You would be looking for rotation in the wire larger than any back and forth motion produced by the drive. The won't be any stiction in a torsion wire since there is nothing to slip against or to stick to.What am I missing?Here is the pertinent part copied from the link above:"Even with this arrangement, self-deception can occur, as in Henry Bull's impulse engine of 1935. You can read about it in Popular Science Monthly, Jan 1935, p. 27: Harry W. Bull: Reaction Motor. His device was in an enclosed box, and suspended from wires as a pendulum. Inside the box two weights were driven by electromagnets, one weight making an inelastic impact with a spring, the other making a nearly elastic metal-to-metal impact. When running, the box containing the device moved to the side. Why? Due to the asymmetric motion inside the box, the center of mass of the box and its contents shifts relative to the box. But the center of mass must still remain where it was before (relative to the laboratory). So the box moves aside, while its center of mass stays put. Newton's laws were working properly, as they always do."
OK, I stated in the EMDrive thread that I planned to do some Dean Drive experiments. The purpose was to try to investigate whether the Dean Drive effect was what really happening in the Mach Effect Thruster (MET or MEGA drive). My instinct told me that it was. (Side note: I have good physics instincts. Last time I thought NASA EW's 2014 experiment had not accounted for Lorentz force caused by ground loop DC current, and I experimentally showed that a similar construction had large Lorentz force up to a hundred micro-Newtons. A pdf document about it is downloadable from https://arxiv.org/abs/1510.07752) This time, I planned to experiment with MEGA. I planned to first reproduce "their" MEGA results, ideally with "their" MEGA device; then I plan to place the entire thing (stand, counterweight, beam, bearing, MEGA, power supply etc) in a sealed box, hang the box under a thin piano wire, control the device on and off with optical or RF switch, then measure the rotation of the piano wire. If the thrust was true, the wire would rotate, at least to an angle. If the thrust was not there, it would not rotate.I thought this was a good plan. Triggered by Monomorphic's post about his new E-10 bearing today, I started to do some on-line research to prepare for my experiment. To my disappointment, I found that my experiment will not bring in anything new. Here is why.I started from searching "metal spring dissipation", for differential dissipation between the cases when the spring was compressed quickly and slowly. This kind of asymmetrical movement, present in previous MEGA experiment, might have caused the "thrust", much like what happened in Dean Drive. I found some interesting documents, such as "Anomalous low frequency dissipation processes in metal springs" by Riccardo DeSalvo, "Dissipation processes in Metal springs" by Arianna Di Cintio, "The Elastic Hysteresis of Steel" by Bertram Hopkinson and G. Trevor Williams. And finally I found this page: https://www.lhup.edu/~dsimanek/museum/test-pm.htm. They quoted an article http://www.rexresearch.com/bull/1bull.htm about Harry W. BULL's "Reaction Motor". See how similar it is to MEGA! Quote:"Balance scales and even electronic balances can also be fooled by vibrations, due to mechanical "stiction" (the "stick and slip" phenomenon of friction). The scale itself is affected by nonlinear phenomena in its mechanism, and these can often display resonance peaks, dependent on the frequency of the vibrations. So a running motor on a balance scale may indeed seem to weigh less when it's running. That has fooled many people, and is one of the reasons for the strange results when Norman Dean demonstrated his "reactionless" drive of the early 1960s."I lost the interest in performing the said experiment in the beginning of this post. Would my experiment add more evidence to science? I guess the answer is "No". That web page had summarized well the existing evidence. All my experiment would be able to show had been shown. I write down this post to wrap up my short-lived interest in MET. By the way, I am interested in AI and I have been three years into it.
So I am very curious about your thought process here. Especially since they have presented experimental results showing not only thrust but also no thrust with the exact same stack configuration that has depolarized (IIRMC). I n addition their test results I believe also cover the case where the stack is driven outside of the correct frequency. Finally, the paper your referring to is talking about what looks like a different set of tests.editMost importantly I dont believe the paper explain why the measured thrust results match the predicted thrust scaling from the theoretical derivation.If your going to argue that the effect is not real or is something else then you would need to provide an explaination for the results in section 2 of Theory of mach effect thrust II, and I am not finding that in the paper you quoted
Quote from: birchoff on 10/25/2017 12:03 amSo I am very curious about your thought process here. Especially since they have presented experimental results showing not only thrust but also no thrust with the exact same stack configuration that has depolarized (IIRMC). I n addition their test results I believe also cover the case where the stack is driven outside of the correct frequency. Finally, the paper your referring to is talking about what looks like a different set of tests.editMost importantly I dont believe the paper explain why the measured thrust results match the predicted thrust scaling from the theoretical derivation.If your going to argue that the effect is not real or is something else then you would need to provide an explaination for the results in section 2 of Theory of mach effect thrust II, and I am not finding that in the paper you quotedSome articles referred by "Theory of mach effect thrust II" are not downloadable. I think one needs to look into details to figure out why there is no thrust if the stack is depolarized, or is driven with different frequency. I think I will need to see and manipulate the experiment myself if I want to get a better understanding why. There are multiple possible reasons, for example, the frequency may need to be close to the resonance frequency of the system. Also I'd like to see they do the experiment I planned (sealed box with everything hanging under a wire). I generally lost interest to do that myself.
Honestly, I don't care if you have personally lost interest. I am just pointing out that if you want to show that the experimental results are being incorrectly interpreted. You have to do way more than you have done so far, otherwise, all you have is a belief that the measured effect is something else.Basically, I am asking for critics to do the same thing they ask others to do. If a critic isn't willing to do that when the person/team proposing a new idea has done the work to show agreement with their theory so far. I have a hard time taking the critics seriously.P.S. please also keep in mind that it looks like between estes park last year and the NIAC presentation a lot more experimental runs have been performed that continue to show strong agreement with the predicted scaling.
Anyway, I am out of this MET business and it is my belief that it will not go too far.
Quote from: birchoff on 10/25/2017 03:47 amHonestly, I don't care if you have personally lost interest. I am just pointing out that if you want to show that the experimental results are being incorrectly interpreted. You have to do way more than you have done so far, otherwise, all you have is a belief that the measured effect is something else.Basically, I am asking for critics to do the same thing they ask others to do. If a critic isn't willing to do that when the person/team proposing a new idea has done the work to show agreement with their theory so far. I have a hard time taking the critics seriously.P.S. please also keep in mind that it looks like between estes park last year and the NIAC presentation a lot more experimental runs have been performed that continue to show strong agreement with the predicted scaling.We direct our limited resources (time, brain capacity...) based on our own judgement. Calling it belief is not too inaccurate. Anyway, I am out of this MET business and it is my belief that it will not go too far.
Due to the asymmetric motion inside the box, the center of mass of the box and its contents shifts relative to the box. But the center of mass must still remain where it was before (relative to the laboratory). So the box moves aside, while its center of mass stays put. Newton's laws were working properly, as they always do."
Quote from: Monomorphic on 10/24/2017 06:17 pm Due to the asymmetric motion inside the box, the center of mass of the box and its contents shifts relative to the box. But the center of mass must still remain where it was before (relative to the laboratory). So the box moves aside, while its center of mass stays put. Newton's laws were working properly, as they always do."I've constructed a couple of "asymmetric shakers" to test whether a Harry Bull Reaction Motor can produce similar "thrust" signatures as a Mach Effect Thruster (MET) using a torsional pendulum. It is a very straightforward design having a vibrator-weight-spring/damper internal configuration. Two models have been produced, a 0.5W version and a 5.0W version. There is just enough room on my torsional pendulum to mount these one at a time for testing. Both models are capable of vibrating from 31 Hz to 64,000 Hz.
Can you share your design? Are these vibrators PZT based or electromagnetic solenoid? What makes it "asymmetrical"?
His device was in an enclosed box, and suspended from wires as a pendulum. Inside the box two weights were driven by electromagnets, one weight making an inelastic impact with a spring, the other making a nearly elastic metal-to-metal impact. When running, the box containing the device moved to the side. Why? Due to the asymmetric motion inside the box, the center of mass of the box and its contents shifts relative to the box. But the center of mass must still remain where it was before (relative to the laboratory). So the box moves aside, while its center of mass stays put.
Based on the experiences of the NASA Breakthrough Propulsion Physics Project, suggestions areoffered for constructively responding to proposals that purport breakthrough propulsion using mechanicaldevices. Because of the relatively large number of unsolicited submissions received (about 1 perworkday) and because many of these involve similar concepts, this report is offered to help the would-besubmitters make genuine progress as well as to help reviewers respond to such submissions. Devices thatuse oscillating masses or gyroscope falsely appear to create net thrust through differential friction or bymisinterpreting torques as linear forces. To cover both the possibility of an errant claim and a genuinediscovery, reviews should require that submitters meet minimal thresholds of proof before engaging infurther correspondence; such as achieving sustained deflection of a level-platform pendulum in the caseof mechanical thrusters.
What am I missing?