EM Drive

[ScottL]

https://www.reddit.com/r/EmDrive/comments/5jf32j/eaglework_paper_contains_major_flaws/

Reddit user Eric1600 has a pretty indepth analysis of the EagleWorks experiment and some issues they appear to have overlooked. I know Paul ventures here on occasion, so hopefully this can come to his attention.

Given the magnitude of the signal they're trying to observe, thermal expansion of the test rig could plausibly account for the signal seen.

I'm thinking there is a whole host of issues. Arstechnica also ran a piece on the test and its lack of details. I just don't see anything in the paper that impresses me or gives me "well maybe they got something." Looks like a lot of slop to me, but then, I'm not a physicist, just an engineer.

[D Tibbets]

In this long thread, this may have been linked before, but I found this to be informative and gives a useful perspective as to it's potential usefulness.

https://www.youtube.com/watch?v=JGcvxg7jJTs

Dan Tibbets

[Diogenes]

Emdrive inventor Shawyer patenting new approach and has bigger claims

Here is part of Shawyers most recent presentation and his patent application.

First generation emdrive- Original low thrust technology for inorbit satellite applications. Reported to be operational in US and China. NASA eagleworks has a peer reviewed report of 1.2 millinewtons per kilowatt of thrust from a first generation emdrive.

Second Generation emdrive
High thrust, low acceleration, superconducting technology. Space and Marine applications.
Under development in UK and US. Nextbigfuture notes that no report of a superconducting Emdrive having official performance measurements. If a superconducting Emdrive works as claimed then the amount of thrust would be definitive.

Third Generation emdrive – Shawyers new design.
High thrust. High acceleration, superconducting technology. Theoretical work reported in US, China and UK. Aerospace applications including Launch Vehicles and Personal Air Vehicles.

https://www.nextbigfuture.com/2017/08/e ... laims.html



Claims without data? This sounds like "Rossi" territory. All hype and no proof.

[ScottL]

Yeah, this whole topic is done at this point.

Shawyer makes claim for 20+ years.
Prof. Yang publishes results of a poorly done experiment seemingly confirming above claims.
EagleWorks joins the effort. First attempt, null result.
Media sensationalizes as media does.
"Believers" in the EmDrive start to appear without any physics (or science in general) background trying to be armchair scientists.
DIYers come out of the woodwork trying to use magnetrons to experiment.
Forum poster on NSF and reddit starts to make extraordinary claims, fails to produce evidence of said claims, disappears for a few months.
EagleWorks sets up Vacuum test, non-vacuum rated equipment fails, results still make it up on the web. Experiment still has serious design issues.
Some fail and realize why, others fail and refuse to accept why.
Prof. Tajmar tries his hand at an EmDrive only to decide his setup is insufficient and results would ultimately be inconclusive.
Prof. Yang alters experiment to move power source onto device instead of feeding it along the balance arm, measurement disappears. Publishes new results, believers won't accept results.
EagleWorks fails to publish to any physics journals, decides to target engineering journals and successfully publishes in a propulsion journal.
EagleWorks results are pretty heavily critique'd in the physics community as well as the amateur physics communities for issues with design.
Skeptics chalk the claims up to noise in the way of thermal effects, lorentz forces, poor grounding, and other issues.
Forum poster on NSF and reddit reappears with even greater claims. Starts spreading false rumors about EmDrive testing on the X37-B and in China.
Most folks have moved on, but there are still hold-outs.
Shawyer doubles down on claims....


Rossi is still better at this game than Shawyer will ever be.

[RERT]

Except that Shawyer has (probably) sunk his own money into his company, along with that of other people willing to give him indefinite term, interest free loans - close friends. He has been paying back for a couple of years, as disclosed in related party transactions. Read the last 10 years accounts, they are public documents, https://beta.companieshouse.gov.uk/company/04097991

Also, I object to what you say about B37b testing. I made that conjecture up myself, here at Polywell, many months ago...

(The link was wrong above for a minute until I fixed it)

[ScottL]

Except that Shawyer has (probably) sunk his own money into his company, along with that of other people willing to give him indefinite term, interest free loans - close friends. He has been paying back for a couple of years, as disclosed in related party transactions. Read the last 10 years accounts, they are public documents, https://beta.companieshouse.gov.uk/company/04097991

If I'm not mistaken, he is part of 2 separate companies. One seemingly breaks even and the other I'm not sure about. He is reported tied to Gilo Industries, but the details are anyones guess. Ultimately his claims don't seem to pan out. Even those who are pro the idea of the EmDrive have given up on Shawyers theories.

Also, I object to what you say about B37b testing. I made that conjecture up myself, here at Polywell, many months ago...

I don't believe I was talking about you nor was I aware of you thinking it. I don't believe you went around to various news sites to peddle this rumor, stating it as fact instead of conjecture like the poster I'm talking about who did this about November of last year.

[ladajo]

The only X-37B drive testing that has been made public is potentially Ion Thruster work, as far as I know. Something probably along the lines of VASIMR. I recall seeing an article on it somewhere. No time to hunt it down right now.
I do recall someone running around saying that the AF and DARPA was testing EM on orbit at some point, and thinking they were full of it. It was not TRL mature enough, and remains so as far as I know. While on orbit is a great test regime, you need to be ready to do it, and I don't think we are there yet.

[ScottL]

The only X-37B drive testing that has been made public is potentially Ion Thruster work, as far as I know. Something probably along the lines of VASIMR. I recall seeing an article on it somewhere. No time to hunt it down right now.
I do recall someone running around saying that the AF and DARPA was testing EM on orbit at some point, and thinking they were full of it. It was not TRL mature enough, and remains so as far as I know. While on orbit is a great test regime, you need to be ready to do it, and I don't think we are there yet.

Nailed it on the head. I think in January of 2016 it was announced that the X-37B would be testing an ion thruster. Shortly after China made a similar statement that they too would be testing an ion thruster in October 2016. In November of 2016, an individual who posts at NSF and on Reddit started spreading the rumor that an EmDrive had been tested in China. At the time, I could understand the mix-up because the picture most commonly used in EmDrive articles is actually an ion thruster, not an EmDrive. A day or two after this individual made these remarks on NSF and Reddit, Ibtimes published articles stating that a source has told them that the U.S. has tested an EmDrive on the X-37B and that China has tested one this past October. Eventually the individual confirmed themselves as the source for at least one of the articles. Of course, they had no proof of their claims. As a matter of fact a link to a Chinese State run news article was put forth as the proof. Google translate only does so much with Chinese and even then there was nothing to infer the EmDrive had ever been tested in space. The article in question was talking about their successful test of an ion drive which (paraphrasing) could lead to future tests of theoretical drives such as the EmDrive, etc. At this point in time though, there is no evidence to suggest that any of the claims are legitimate. If anything, the hyper has started dying off and people have begun moving on.

[RERT]

I agree Shawyers theory appears to be rubbish.

My opinion on the accounts is that Shawyer has spent many years and many hundreds of thousands of pounds testing his concept. He should know if it works or not. He is either right, criminal, or delusional.

The remark about the B37b was meant to be mildly humorous. I did make a post many months ago that effect. It was based on the reports that BEFORE ion thruster work, the B37b flew missions which lasted for multiples of the scheduled duration. (Sounds like a propellant less thruster to me...) These were said to be testing advanced propulsion, and the timing was roughly when Shawyer claims that the Boeing relationship closed off. A supporter would conclude that a flight test had been successful, and the program had 'gone dark'.

It was humorous because I didn't really get upset that you had failed to note my priority on the rumour...

(Revision: i just looked it up - my post was on this thread 24 Aug 2016)

[ScottL]

I agree Shawyers theory appears to be rubbish.

My opinion on the accounts is that Shawyer has spent many years and many hundreds of thousands of pounds testing his concept. He should know if it works or not. He is either right, criminal, or delusional.

The remark about the B37b was meant to be mildly humorous. I did make a post many months ago that effect. It was based on the reports that BEFORE ion thruster work, the B37b flew missions which lasted for multiples of the scheduled duration. (Sounds like a propellant less thruster to me...) These were said to be testing advanced propulsion, and the timing was roughly when Shawyer claims that the Boeing relationship closed off. A supporter would conclude that a flight test had been successful, and the program had 'gone dark'.

It was humorous because I didn't really get upset that you had failed to note my priority on the rumour...

(Revision: i just looked it up - my post was on this thread 24 Aug 2016)

Pretty good prediction of what the "believers" would claim I'd say, nice job. If I remember correctly, Boeing bowed out in 2012 officially stating that they were no longer pursuing the EmDrive research or any business relationship with Shawyer. I think Shawyer is probably a little bit delusional. There are countless incidents where people claim to have seen a small measurement and believe that it can be amplified when in fact we all know it to be noise. I think Shawyer is one of these individuals. He has fooled himself with shoddy engineering work and thinks he can scale it.

[Carl White]

An attempt to give the EM Drive a theoretical basis has been published in the Journal of Applied Physical Science International (couldn't find an impact factor, can anyone confirm this is a "real journal"?):

http://www.ikpress.org/abstract/6485

Here we present a possible explanation for the observed thrust based on the conceptual framework of Eurhythmic Physics, a kind of pilot-wave theory aiming at bridging the gap between quantum and macroscopic systems. Applied to the present system, a generalized guidance condition could explain the claimed absence of reaction of the material of the drive on the enclosed fields.

[williatw]

An attempt to give the EM Drive a theoretical basis has been published in the Journal of Applied Physical Science International (couldn't find an impact factor, can anyone confirm this is a "real journal"?)

Just out of curiosity...is it reasonably possible that both EM Drive & Mach Thruster drive will turn out to work? Or are their "theories" of operation in some way incompatible?

[Carl White]

Just out of curiosity...is it reasonably possible that both EM Drive & Mach Thruster drive will turn out to work? Or are their "theories" of operation in some way incompatible?

My understanding is that the proposed theory for the workings of the EmDrive involves rejecting wave-particle duality. In other words, it claims photons occupy a specific location in space at any given time and that something else (unspecified) is the source of strangeness.

The Mach Effect is based on Mach's Principle, which, put vaguely, is "mass out there influences inertia". So there doesn't seem to be much common ground.

Dr. Jean-Philippe Montillet has suggested that if the EmDrive works, it's because it is functioning as a capacitor and that the Mach Effect applies. Dr. Rodal of Heidi Fearn's MEGA team talks about that here: http://forum.nasaspaceflight.com/index.php?topic=40959.msg1588165#msg1588165.

Anyhow, I'm not the best person to ask. Maybe someone else can provide a better explanation.

[Maui]

A new attempt to validate/disprove EMDrive and Mach Effect has been attempted. Initial results published here:
https://www.researchgate.net/publicatio ... _Thrusters

In a nutshell: Previous promising EMDrive results are attributed to insufficient shielding on cables. Mach Effect results were a little more indeterminate, but also appears likely to be attributed to unintended electromagnetic or thermal interactions. (More tests to come)

[TDPerk]

RE by Maui » Fri May 18, 2018 10:25 pm

And because the work of Woodward, Fearn, and other work by Tajmar, et al, have no such thermal or magnetic interactions, this work even if replicable cannot impugn those results.