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#420
by
oyzw
on 12 Sep, 2018 09:34
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#421
by
Peter Lauwer
on 12 Sep, 2018 10:15
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...
Of particular interest to this forum is the story Martin Tajmar and his students told me of Roger Shawyer's visit to their lab. They asked Roger for an older device to test and Roger told them he would only loan them a device if they report some positive results BEFORE they get the device. They refused of course.
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Sounds rather typical. Funny though, how he managed to fool us (well, at least some of us) for almost 20 years.
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#422
by
MineCanary
on 12 Sep, 2018 12:57
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As a longtime lurker, that's evidence enough for me to call it. Emdrive doesn't work. This is of course still wonderful science, as discovering what does and doesn't work are BOTH contributing to the body of knowledge of this wacky reality we live in. Congrats and well done to all, especially Monomorphic who has kept us all 'in the passengers seat' during this ride. It's been a great ride indeed!
Looks like its 'generation ships' to the stars.. or I wonder how cryogenics are going..
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#423
by
PotomacNeuron
on 12 Sep, 2018 13:48
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...
Of particular interest to this forum is the story Martin Tajmar and his students told me of Roger Shawyer's visit to their lab. They asked Roger for an older device to test and Roger told them he would only loan them a device if they report some positive results BEFORE they get the device. They refused of course.
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Did Mr. Shawyer mean that he would only loan his device to Dr. Tajmar if they reported some positive results WITH THEIR OWN DEVICES before hand? I now think this is what he meant. If so, "BEFORE" should not be emphasized. It led me to interpret the story in an uncomfortable way yesterday.
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#424
by
Jim Davis
on 12 Sep, 2018 13:58
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Funny though, how he managed to fool us (well, at least some of us) for almost 20 years.
You can't put this all on Shawyer. A lot of us were thinking with our hearts instead of our heads. We were all to eager to buy what he was selling.
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#425
by
meberbs
on 12 Sep, 2018 14:24
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...
Of particular interest to this forum is the story Martin Tajmar and his students told me of Roger Shawyer's visit to their lab. They asked Roger for an older device to test and Roger told them he would only loan them a device if they report some positive results BEFORE they get the device. They refused of course.
...
Did Mr. Shawyer mean that he would only loan his device to Dr. Tajmar if they reported some positive results WITH THEIR OWN DEVICES before hand? I now think this is what he meant. If so, "BEFORE" should not be emphasized. It led me to interpret the story in an uncomfortable way yesterday.
There is no comfortable interpretation of that. If they had an emDrive that produced positive results, there wouldn't be much need to borrow an old drive from Shawyer. This restriction guarantees that under the assumption that the emDrive doesn't work, no one would be allowed to test Shawyer's device if their setup is capable of disproving it. If the emDrive did work, then this restriction is just a pointless obstacle, slowing down efforts to validate Shawyer's claims. Even if it wasn't meant as a request to fabricate data, it is a completely unscientific approach, and difficult to see why anyone would ask for that restriction unless they knew their device did not work and were trying to hide that.
Bottom line, the word "before" is important, and deserves to be emphasized. (Note that "after" would actually have been worse, since it would directly be a request to fake results if they came back negative.)
In contrast, we have examples such as the data being presented at the conference in Estes of people actually following good scientific process, and coming to unbiased results.
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#426
by
TheTraveller
on 12 Sep, 2018 14:42
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Of particular interest to this forum is the story Martin Tajmar and his students told me of Roger Shawyer's visit to their lab. They asked Roger for an older device to test and Roger told them he would only loan them a device if they report some positive results BEFORE they get the device. They refused of course.
...
Did Mr. Shawyer mean that he would only loan his device to Dr. Tajmar if they reported some positive results WITH THEIR OWN DEVICES before hand? I now think this is what he meant. If so, "BEFORE" should not be emphasized. It led me to interpret the story in an uncomfortable way yesterday.
In email corro with Roger about this. Was told what Jamie reported was accurate.
However.......
It is my understanding that Tajmar's group needed to show they had followed Roger advise, built an EmDrive and thrust measurement system as per what he shared. Once they had achieved that goal and measured thrust, he would then loan them an EmDrive to test.
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#427
by
flux_capacitor
on 12 Sep, 2018 15:02
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Thank you PotomacNeuron. Yesterday I was disgusted too about Shawyer's behavior after I read that sentence like you at first glance, i.e. that the condition to loan that older thruster was that Tajmar had to report positive results of this old device BEFORE he could actually hold it in his hands. It was so nonsensical and unethical I was baffled. You restored the correct meaning, its more logic now.
However meberbs makes a point in that it is a faulty logic. He states that Shawyer only wants to loan devices that can be "proven to work" on badly designed test stands. According to meberbs, a badly designed test stand is an apparatus that would detect spurious forces where there are no genuine thrust. If so, Shawyer would obtain guarantees in advance that his own cavity, would show some "thrust" on Tajmar's test rig, whereas it is not true.
But TheTraveller has another point of view, where he assumes that Shawyer doesn't want to loan devices that could not be properly tested on badly designed test stands. According to TT, a badly designed test stand is an apparatus that would not detect any genuine thrust yet present, for lack of sensitivity or any technical "prerequisite" mandatory according to SPR theory.
These two points of view cannot converge.
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#428
by
PotomacNeuron
on 12 Sep, 2018 15:36
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Thank you PotomacNeuron. Yesterday I was disgusted too about Shawyer's behavior after I read that sentence like you at first glance, i.e. that the condition to loan that older thruster was that Tajmar had to report positive results of this old device BEFORE he could actually hold it in his hands. It was so nonsensical and unethical I was baffled. You restored the correct meaning, its more logic now.
However ...
Years ago I tried to sell an imported product in the US. I asked somebody famous to review it. He promised not to say bad words about it, to my (a little bit) surprise. So I guess maybe it is a norm in business, though it might not be acceptable in science.
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#429
by
Peter Lauwer
on 12 Sep, 2018 16:24
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Funny though, how he managed to fool us (well, at least some of us) for almost 20 years.
You can't put this all on Shawyer. A lot of us were thinking with our hearts instead of our heads. We were all to eager to buy what he was selling.
And even now, with only some vague descriptions of results of a few limited tests, our approach does not seem very solid.
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#430
by
moreno7798
on 12 Sep, 2018 17:02
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It would be interesting to hear from Dr. Harold White from NASA's Eagleworks.
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#431
by
DamianM
on 12 Sep, 2018 17:10
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I saw your video with this thing skipping across a tabletop. You attribute its movement to friction. Have you tried it on the same tabletop with friction defeated? Maybe put on a freewheeling toy plastic car. Properly assembled and lubricated, there should not be a preferential direction to the friction of the wheels/axles of the toy car.
Yes, I built a little toy car out of some legos. It's not exactly friction free so occasionally it will move to one side or the other, but overall it stays in the same place. I also recorded the device in slow motion attached to some springs. If you watch the bottom right corner of the oscillator, you can see how it displaces to the right more than the left of equilibrium. This anharmonic displacement is at the same frequency as the oscillation, but it is only a 2 DOF oscillator. I think at least three masses are required for Mach/Henry Bull-like displacements, plus some other anelastic effects.
It is worth considering the inerter...
http://imik.wip.pw.edu.pl/zmitu/images/Publikacje/Seminaria/mechanika_energetyczna_zastosowanie.pdfhttp://www.kms.polsl.pl/mi/pelne_18/01_18_49.pdfDevice for efficient self-contained inertial vehicular propulsion
https://patents.google.com/patent/US9995284B1/en?inventor=Gottfried+Gutsche
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#432
by
tchernik
on 12 Sep, 2018 17:29
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Funny though, how he managed to fool us (well, at least some of us) for almost 20 years.
You can't put this all on Shawyer. A lot of us were thinking with our hearts instead of our heads. We were all to eager to buy what he was selling.
And even now, with only some vague descriptions of results of a few limited tests, our approach does not seem very solid.
Given the lack of other clear results, if Tajmar or other professional team disprove it, my take will be that the phenomenon doesn't exist (any thrust is just noise) or it's too weak to be taken clearly and unmistakably out of the noise background.
Which for all purposes, will make it non existing for mainstream physics and stay on the fringe as long as such situation doesn't change.
Well, a pity. But this really wasn't an unexpected outcome.
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#433
by
cvbn
on 12 Sep, 2018 20:20
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But even if Emdrive does not work as intended, couldn't these 'artifacts', which were so difficult to get rid of, and which caused the apparent thrust, be used to propel LEO satellites (assuming that these artifacts are the result of interaction with Earth's magnetic field)?
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#434
by
Donosauro
on 12 Sep, 2018 22:00
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But even if Emdrive does not work as intended, couldn't these 'artifacts', which were so difficult to get rid of, and which caused the apparent thrust, be used to propel LEO satellites (assuming that these artifacts are the result of interaction with Earth's magnetic field)?
The magnetic artifacts caused by interactions with the Earth's magnetic field were torques. Some satellites have used those for attitude control from the early days of artificial Earth satellites. Magnetic thrust forces would, sadly, be many orders-of-magnitude smaller.
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#435
by
Monomorphic
on 13 Sep, 2018 00:11
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I have just learned from Mike McDonald from the US Navy Emdrive group that he is also reporting negative results.
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#436
by
oyzw
on 13 Sep, 2018 01:23
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I have just learned from Mike McDonald from the US Navy Emdrive group that he is also reporting negative results.
The US Navy Emdrive also looks like the TE012 or TE013 module. The magnetic field is shielded by a magnetic conductive steel. Your cavity test has a force of 7uN, and my cavity has a force of only 0.7uN. The other conditions are the same, indicating that the source of force is not external interference, but the cavity itself. Professor Yang Wei told me that her whole thruster design is in accordance with Mr. Shawyer's suggestion that the direction of the cavity thrust is fluctuating. She provided the whole system to me free of charge, but I don't have a laboratory. I am considering further improving her thruster program.
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#437
by
oyzw
on 13 Sep, 2018 01:44
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Recently, with the in-depth analysis of Professor Yang Lan, I learned that her suspension oscillating thruster was directly guided by Mr. Shawyer during the design process. During the test period, the device was placed in multiple orientations, such as north and south. Things and so on. No significant differences were found in the thrust of the device.
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#438
by
RotoSequence
on 13 Sep, 2018 01:51
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Unless someone can demonstrate a rebuttal, in the form of a device that shows a thrust signal, in an apparatus with as much attention to noise control as Monomorphic's has, I see little reason to hope that these tiny, errant signals are anything but noise.
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#439
by
meberbs
on 13 Sep, 2018 02:49
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...According to meberbs, a badly designed test stand is an apparatus that would detect spurious forces where there are no genuine thrust. ...
... According to TT, a badly designed test stand is an apparatus that would not detect any genuine thrust yet present, for lack of sensitivity or any technical "prerequisite" mandatory according to SPR theory.
These two points of view cannot converge.
As far as them being effectively opposite definitions, then that is correct that these points of view can't converge.
Really both validly describe a different type of "bad" test stand. TT's version of a bad test stand can be eliminated without first putting an emDrive on the stand though. The sensitivity of the measurement device to small forces is something that is measured by any good experiment to calibrate the instrument. (And Shawyer has claimed forces with even his early drives orders of magnitude above the sensitivities of recent tests.) Any "prerequisites" can be explicitly stated and accounted for. (e.g. if it needs an initial acceleration, a controlled "tap" can be generated, even if you decide to ignore accelerations from gravity and Earth's rotation for some reason.)
