Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/I'm interested in funding a private sector test of this tech. Does anyone here have the capabilities of assembling a team that can create a testable EMDrive? If so, lets talk budget.Thanks,Jordan Greenhall
They say this thing needs to be tested in space. Is that because it needs 0 g? What about testing it on an air track where there is almost no friction?
Quote from: Rodal on 11/12/2014 09:33 pmI received another very interesting e-mail from Bob Ludwick, that I reproduce below:From: Robert LudwickSent: Wednesday, November 12, 2014 1:54 PMTo: Dr. J. RodalSubject: Testing the EmDriveHello Dr. RodalAlthough thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. i. e. A. Establish the resonant frequency (s) and bandwidths of the thruster.B. Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.C. Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.D. Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize. Measure the residual thermal/magnetic/whatever ‘thrust’.E. Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency. F. For each frequency step, record forward and reflected power from the thruster.G. After allowing for mechanical settling time, record the thrust.H. Go to the next frequency and repeat. If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it. If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the testIt DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one. Power meters, too.I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets. Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP. I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not. And I would insist in more than one ‘fail’ before I called a halt. Frankly, doing so should be cheap AND fast. And the stakes are enormous.Bob LudwickI completely agree with this except I would note that there is very serious challenge in the notion of changing frequency and NOTHING else. Dr. Ludwick points this out, and I agree with him though I'm not sure how one would do what he suggests.
I received another very interesting e-mail from Bob Ludwick, that I reproduce below:From: Robert LudwickSent: Wednesday, November 12, 2014 1:54 PMTo: Dr. J. RodalSubject: Testing the EmDriveHello Dr. RodalAlthough thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. i. e. A. Establish the resonant frequency (s) and bandwidths of the thruster.B. Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.C. Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.D. Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize. Measure the residual thermal/magnetic/whatever ‘thrust’.E. Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency. F. For each frequency step, record forward and reflected power from the thruster.G. After allowing for mechanical settling time, record the thrust.H. Go to the next frequency and repeat. If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it. If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the testIt DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one. Power meters, too.I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets. Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP. I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not. And I would insist in more than one ‘fail’ before I called a halt. Frankly, doing so should be cheap AND fast. And the stakes are enormous.Bob Ludwick
Oh, I can assemble a team, all right.
No1) They did not specify (in the "Anomalous ... " report) the Q before or after removing the dielectric2) They did test (removing the dielectric) very early in the testing program3) They did specify the frequency at which they performed this test (removing the dielectric) and it was a frequency much higher than for the other reported tests. Therefore these tests (removing the dielectric) are highly questionable. 4) Furthermore @Mulletron's concerns regarding resonance before and after are well thought out.
Quote from: Rodal on 11/13/2014 05:45 pmNo1) They did not specify (in the "Anomalous ... " report) the Q before or after removing the dielectric2) They did test (removing the dielectric) very early in the testing program3) They did specify the frequency at which they performed this test (removing the dielectric) and it was a frequency much higher than for the other reported tests. Therefore these tests (removing the dielectric) are highly questionable. 4) Furthermore @Mulletron's concerns regarding resonance before and after are well thought out. No. The dielectric slows the em through it, so the chamber is effectively a higher frequency chamber without it. It is presuming the folks at Eagle are stupid in the extreme to think they would not note this most obvious issue.
I'm pretty sure they were specific that the Q was measured to be very high without the dielectric , which was I believe the first way they tested it.
Posting this again.https://www.fourmilab.ch/gravitation/foobar/This is a DIY on how to build your own torsion balance at home. This setup is sensitive enough to measure the gravitation between chunks of lead. Good enough to measure "anomalous thrust" if you so desire to build your own test article.
Quote from: Mulletron on 11/13/2014 07:43 pmPosting this again.https://www.fourmilab.ch/gravitation/foobar/This is a DIY on how to build your own torsion balance at home. This setup is sensitive enough to measure the gravitation between chunks of lead. Good enough to measure "anomalous thrust" if you so desire to build your own test article.Good info. The classical Cavendish setup.No Christmas-tree with hanging ornaments setup.No 1.5 by 1.5 inch Faztek long cantilevered beam sticking out with the EM Drive at the end. No C-Flex Riverhawk with uncertain spring constant.
You seem to have information from other sources that does not emanate from the "Anomalous..." report:Where in the report are they so specific concerning the Q measured to be very high without the dielectric?Please give the page in where that is stated
Hi all, I came here from a reddit post regarding the EM drive: http://www.reddit.com/r/EmDrive/comments/2ih0mh/rapid_spread_of_emdrive_technology_by_the_diy/I'm interested in funding a private sector test of this tech. Does anyone here have the capabilities of assembling a team that can create a testable EMDrive? If so, lets talk budget.
Quote from: JohnFornaro on 11/13/2014 06:05 pmOh, I can assemble a team, all right.1) What kind of a team can you assemble?2) Who is on your team?
The sweeping methodology sounds nice, but a "simple" longer power on test could learn a lot too. What is the record of time with power on for any of the propellentless devices so far ?
Quote from: JohnFornaro on 11/13/2014 06:05 pmOh, I can assemble a team, all right.What kind of a team can you assemble?Who is on your team?
This is an example of why I continue to insist on the paramount importance of stating principles in English before devolving to math. Everything that needs to be said, and that has to be saod. should be reduced to English.
All it takes is three hundred years to start colonizing the solar system. Why haven't we? We're being kept on planet.
Quote from: Ron Stahl on 11/12/2014 10:24 pmQuote from: Rodal on 11/12/2014 09:33 pmI received another very interesting e-mail from Bob Ludwick, that I reproduce below:From: Robert LudwickSent: Wednesday, November 12, 2014 1:54 PMTo: Dr. J. RodalSubject: Testing the EmDriveHello Dr. RodalAlthough thrust without throwing something out the back is at least improbable (I am of course rooting for the improbable.), I think that the testing problem (to rule out heat artifacts) could be resolved by the test plan I proposed awhile back. i. e. A. Establish the resonant frequency (s) and bandwidths of the thruster.B. Select a test frequency range that is at least double the bandwidth of the thruster, so that the start and stop frequencies are well outside the high Q region of the thruster.C. Select frequency steps so that you are guaranteed AT LEAST ten steps in the high Q region of the thruster.D. Set the test frequency to the start frequency, turn on the power amplifier, and wait 5 minutes or so for any thermal and current/magnetic field effects to stabilize. Measure the residual thermal/magnetic/whatever ‘thrust’.E. Start the frequency sweep, with dwell times on each frequency long enough for the mechanical system to settle. Change NOTHING other than frequency. F. For each frequency step, record forward and reflected power from the thruster.G. After allowing for mechanical settling time, record the thrust.H. Go to the next frequency and repeat. If there is any ‘anomalous’ thrust related to thruster Q this procedure will detect it. If the ‘thrust’ is due to thermal effects, it should remain constant throughout the test, as the power/current will be constant throughout the testIt DOES require a highly stable, computer controlled signal source rather than a VCO with a knob, but those, including those suitable for testing superconducting cavities, are available from any equipment rental place (such as ElectroRent) if the lab is too cheap to buy one. Power meters, too.I am completely baffled at the apparent disinterest of people and organizations who should be foaming at the mouth at the prospect of getting their hands on a relatively simple device that can convert microwave power into translational motion at efficiencies orders of magnitude better than simple photon rockets. Apparently they have decided that it is prima facie impossible and therefore don’t want to waste any time or money in finding the problems in some fringe PhD’s test setup.On the other hand, if I were controlling the budget for spaceships in any form and was aware that at least three disparate groups had detected thrust from EmDrive-like devices, I would want to confirm or refute this thing ASAP. I’d have lab crews—more than one, at different labs, using different equipment--working overtime until I knew, one way or another, whether it was real or not. And I would insist in more than one ‘fail’ before I called a halt. Frankly, doing so should be cheap AND fast. And the stakes are enormous.Bob LudwickI completely agree with this except I would note that there is very serious challenge in the notion of changing frequency and NOTHING else. Dr. Ludwick points this out, and I agree with him though I'm not sure how one would do what he suggests.Bob Ludwick answered as follows:From: Robert Ludwick Sent: Wednesday, November 12, 2014 7:05 PMTo: Dr. J. RodalSubject: Re: Testing the EmDriveAs for the difficulty of changing the frequency and nothing else, I don’t see it, but maybe I don’t understand the problem that is being referred to. To run the test, you turn on the amplifier and all the test equipment, let it stabilize (Normally, in the labs I worked in, the sig gens et all remained powered up 24/7/365, so they didn’t require stabilization time.), and click ‘Run’ on the control computer. The control program which you have written will ask for the start frequency, the stop frequency, the frequency step size, and the desired output level for the signal generator driving the power amplifier. Once those have been entered, the computer will just execute the steps I have outlined. Of course if you define ‘change nothing’ rigorously enough, it becomes difficult, but for the purposes of this exercise, changing the output frequency of the signal generator is done via software commands and occurs in microseconds, typically, the drive is leveled to small fractions of a dB by the sig gen leveling circuits, and over narrow sweep ranges the variations in the current drawn by the amplifier are negligible, as are its variation in output level (which are monitored by the power meter and recorded). So at least to a first approximation, ‘changing nothing' should be pretty simple. The program should run to completion, in a time depending on the number of steps and the settling time allowed for each step. As the program runs, the computer plots a running graph of measured thrust vs frequency (while saving ALL data to a test file), so that the operator can see what’s happening in real time. The thrust measurement in the torsional pendulum should occur under computer control, without any operator intervention, once the procedure is known. The only ‘moving part’ during the whole procedure is whatever mechanical movement occurs in the torsional pendulum as a response to the (hopefully) varying thrust as the frequency sweeps through thruster resonance.The point is, with all the gory details coming with getting the thrust data back from the torsional pendulum, with my procedure everything should be steady state EXCEPT for the response of the thruster as the drive frequency sweeps through the high Q part of its frequency response. There are no moving parts and no transients. The current (and associated magnetic fields) to the amplifier should remain constant and the amplifier power into the thruster, and thus its heating effect, should remain constant within small fractions of a dB. You don’t have to worry about what material the end caps are made of, their temperature response curves, or any other material properties of the thruster, unless the measured thrust does in FACT vary with the Q at the drive frequency. At that point, physicists need to figure out what is REALLY going on. On the other hand, if, after it is powered up and allowed to achieve its steady state temperature, it just hangs there doing nothing as the sig gen is stepped through the frequency of peak Q, we can all go home.