EM Drive

Point out news stories, on the net or in mainstream media, related to polywell fusion.

Moderators: tonybarry, MSimon

Post Reply
Skytreker
Posts: 13
Joined: Sun Dec 30, 2007 8:10 pm

Post by Skytreker »

GIThruster wrote:It violates conservation,. That's why the Brits stopped backing it and let the Chinese have it--for a distraction. I should note though, that it ought to produce thrust according to Sonny White's QVF model, which is why he and Paul March built one.
Doesn't the Gyroscopic Inertial Thruster also violate conservation ? :P

GIThruster
Posts: 4686
Joined: Tue May 25, 2010 8:17 pm

Post by GIThruster »

Yes, it does. That's why physicists and others who know, know there is no point in testing GIT's or Shawyer Resonators.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

Carl White
Posts: 334
Joined: Mon Aug 24, 2009 10:44 pm

Post by Carl White »

GIThruster wrote:Yes, it does. That's why physicists and others who know, know there is no point in testing GIT's or Shawyer Resonators.
There's nothing wrong with questioning assumptions. It's a healthy thing for science, in fact.

I'd like to see a small part of the overall science budget devoted to finding new ways of testing old assumptions (such as Conservation of Energy). The EM drive would seem to fit the bill.

In fact, it would seem ludicrous if Shawyer actually did produce positive results (as he claimed to) which were then thrown out (i.e. budget discontinued) because "scientists" protested that they don't conform to theory. That's exactly the reverse of the scientific process.

GIThruster
Posts: 4686
Joined: Tue May 25, 2010 8:17 pm

Post by GIThruster »

Well there have been many, many devices like the GIT that have been tested despite they all violate conservation. Just how many tests do there need to be?

The Shawyer resonator finally went unfunded in the UK because of lack of results and an obvious flaw in the theory based upon Shawyer's misunderstanding of what "group velocity" entails. IIUC it is however still being funded, though now in China. The Brits have clearly wised up.

And yes, there is a model that could replace Shawyer's about why he got thrust. Sonny White's QVF model says he should have gotten thrust, and this is why he and Paul March built a Shawyer resonator of their own. It likewise did not produce thrust.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

AcesHigh
Posts: 652
Joined: Wed Mar 25, 2009 3:59 am

Post by AcesHigh »

GIThruster wrote:Sonny White's QVF model says he should have gotten thrust, and this is why he and Paul March built a Shawyer resonator of their own. It likewise did not produce thrust.
in other words, Sonny White´s QVF model is wrong.

GIThruster
Posts: 4686
Joined: Tue May 25, 2010 8:17 pm

Post by GIThruster »

I don't think the failure of the resonator Sonny and Paul built falsifies Sonny's model. Sonny's model flexed and changed with the data as it came in from the experiment on the resonator. As the work progressed and no thrust developed, I think Sonny proposed that the presence of matter in the resonator was choking off the virtual e-p pair production by limiting the voltage they could use, or some such. The final claim on the resonator experiment was that they could not draw high enough vacuum in the resonator chamber because the vapor pressure of copper is too high.

Paul can explain the details but the issues I have with this are that:

a) I think Shawyer used copper so he could not have pulled more vacuum than Paul and Sonny did. If Sonny's explanation for why they didn't get thrust obtains, then Sonny's explanation for thrust from Shawyer fails.

b) I think Sonny's current QVF model and the warp interferometry experiment are not contingent on such extremely high vacuum, so it appears Sonny has abandoned this previous explanation.

These are more questions than answers. I'm just saying Paul will need to answer your question but these are the questions I'd add onto yours. It is however not true that the result from Sonny and Paul's resonator is characterized by them as a null result but rather as inconclusive for lack of enough vacuum. I think they pulled E-6T and decided they'd need more.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

paulmarch
Posts: 155
Joined: Tue Sep 08, 2009 7:06 pm
Location: Friendswood, TX USA

Post by paulmarch »

GIThruster wrote:I don't think the failure of the resonator Sonny and Paul built falsifies Sonny's model. Sonny's model flexed and changed with the data as it came in from the experiment on the resonator. As the work progressed and no thrust developed, I think Sonny proposed that the presence of matter in the resonator was choking off the virtual e-p pair production by limiting the voltage they could use, or some such. The final claim on the resonator experiment was that they could not draw high enough vacuum in the resonator chamber because the vapor pressure of copper is too high.

Paul can explain the details but the issues I have with this are that:

a) I think Shawyer used copper so he could not have pulled more vacuum than Paul and Sonny did. If Sonny's explanation for why they didn't get thrust obtains, then Sonny's explanation for thrust from Shawyer fails.

b) I think Sonny's current QVF model and the warp interferometry experiment are not contingent on such extremely high vacuum, so it appears Sonny has abandoned this previous explanation.

These are more questions than answers. I'm just saying Paul will need to answer your question but these are the questions I'd add onto yours. It is however not true that the result from Sonny and Paul's resonator is characterized by them as a null result but rather as inconclusive for lack of enough vacuum. I think they pulled E-6T and decided they'd need more.
Ron:

The reason we did not have any hope of seeing any measured thrust in this 1998 test series was that the coaxial resonant cavity we were using running at 146 MHz developed an internal glow discharge, AKA electrical plasma, that clamped the expressed E-field voltage at the open end of the 1/4 wave coaxial center rod to ~105V when we tried to pump the resonant cavity down to a vacuum level of 1x10^-5 Torr. Per the QVF thrust predication, we needed to generate a voltage of ~1.5 kVp at this location to see measureable thrust levels of ~500-to-1,000 uN. At the obtained 105V-p voltage, the predicted QVF thrust levels was only a few uN, which was WAY below the A-Frame pendulum’s thrust detection noise platform that we were using at the time. This plasma voltage clamping effect is a well-known phenomenon and was utilized in gas regulator tubes like the OC3 back when vacuum tubes were King. So in summation, we could not prove or disprove the QVF conjecture at the time because we never reached the required operating conditions needed to express an observable signal per predictions with our measurement equipment at hand, so the validity of the QVF conjecture in our minds still remains an open one.

BTW, we were informed by vacuum experts at LM Sunnyvale that it would take a vacuum level of 1x10^-7 Torr to extinguish the glow discharge plasma in our resonant cavity, which is similar to the vacuum levels found in commercial vacuum relays and vacuum capacitors. (Something about the minimum mean free path for the ions in the plasma...) This was a feat we were never able to accomplish with the outgassing copper resonant cavity with solder joints we had built and the small 90 l/s turbo pump we had at our disposal at the time. Lesson learned was have the $$$ to use stainless steel vacuum chambers with bigger turbo pumps and be very particular about outgassing issues in the materials used in your test articles.

See: http://en.wikipedia.org/wiki/Voltage-regulator_tube

Best,
Paul March
Friendswood, TX

DeltaV
Posts: 2245
Joined: Mon Oct 12, 2009 5:05 am

Post by DeltaV »

Propellentless Space Propulsion Research Continues
November 05, 2012

David Hambling London

Chinese scientists appear to have validated a propellentless space propulsion technology previously branded as impossible. Based on earlier British research, it is averred that the EmDrive concept provides sustained thrust at low cost and weight, but this has yet to be accepted even as a workable theory by the wider propulsion community.
The latest paper, “Net Thrust Measurement of Propellentless Microwave Thruster,” is in the June edition of the journal Acta Physica Sinica published by the Chinese Academy of Sciences. Yang's team used a magnetron as a 2.45 GHz microwave source and produced a measured thrust of up to 720 mN from 2.5 kw of input power. On the surface, this appears to be a peer-reviewed validation of the science.
http://www.emdrive.com/yang-juan-paper-2012.pdf

Hat tip to NSF.

GIThruster
Posts: 4686
Joined: Tue May 25, 2010 8:17 pm

Post by GIThruster »

The reason the Brits stopped funding this is it is based upon a misunderstanding of what "group velocity" entails, and is a violation of conservation. Unless you see real peer review of both the theory and the lab tests, I would not believe anything that comes out of China on this issue. Just as with the HFGW nonsense the Chinese have picked up, this should be ignored.

I would however note that since the Chinese have clearly demonstrated their willingness to pursue these useless technologies, it should be a no-brainer that they are pursuing M-E tech as well, and with these resources, we should expect them to be significantly in advance of Woodward.
"Courage is not just a virtue, but the form of every virtue at the testing point." C. S. Lewis

paperburn1
Posts: 2466
Joined: Fri Jun 19, 2009 5:53 am
Location: Third rock from the sun.

Post by paperburn1 »


chrismb
Posts: 3161
Joined: Sat Dec 13, 2008 6:00 pm

Post by chrismb »

Image

Of course it can be made to appear to generate thrust!! - It is a static electrical source feeding a current through a circuit in a mobile frame of reference!

...Same issue as these other attempts at defeating the well-known scientific principles of momentum...

Pick the simplest explanation - until there is exceptional cause to presume otherwise then trust the physics that has informed mankind thus far sufficiently to sent spacecraft beyond this solar system. Conservation of momentum has never yet failed to explain an established, repeatable phenomenon. Why start here when there is already a perfectly good explanation for any observed thrust, that fits known principles?

DeltaV
Posts: 2245
Joined: Mon Oct 12, 2009 5:05 am

Post by DeltaV »

How's the_poster_formerly_known_as_chrismb's UFO progressing?

Image

chrismb
Posts: 3161
Joined: Sat Dec 13, 2008 6:00 pm

Post by chrismb »

per tax-payers and/or investors' dollar input; it has made infinite progress - more than any other current project discussed here.

Quoting objective outcomes is immaterial on this forum, which has become 'faith-based' and is assessed according to homage paid to the words of an ordered hierarchy of priest-hood ascribed to those who ordain over the sacraments of the mysticisms of their respective experiments.

Objective, scientific debate is welcome on this experiment at fusor.net . This forum is no place for such debates with its current congregation diligently at worship.

DeltaV
Posts: 2245
Joined: Mon Oct 12, 2009 5:05 am

Post by DeltaV »

Amen and pass the Boron 11.

Carl White
Posts: 334
Joined: Mon Aug 24, 2009 10:44 pm

Post by Carl White »

A Wired article about the EM Drive has appeared:

http://www.wired.co.uk/news/archive/201 ... old-fusion

The Chinese group reports achieving about 720 mN of thrust at a power level of about two kilowatts.

It says there may (again, may) be a demonstration at an aerospace conference this year.

It points to the translated paper already mentioned by DeltaV:

http://www.emdrive.com/yang-juan-paper-2012.pdf

Post Reply