Em drives

[Urwumpe]

Sorry, but that is wrong:

Thrust was observed on both test articles, even though one of the test articles was designed with the expectation that it would not produce thrust. Specifically, one test article contained internal physical modifications that were designed to produce thrust, while the other did not (with the latter being referred to as the "null" test article).

There was no "test article #3" in the Brady paper.

What you mean is that one:

In addition, the test article was replaced by an RF load to verify that the force was not being generated by effects not associated with the test article.

That was done by calibration, but again says little about the experiment having no conventional physics cause. The RF load just stood in place of the experiment, but then, the parameters of this RF load and which assumptions had been behind scaling this RF Load is not known to me. But would be interesting.

 

[kamaz]

There was no "test article #3" in the Brady paper.

Test article #3 refers to the load resistor -- it was mounted in place of the test articles to investigate possible RF coupling effects -- and it predictably generated no thrust.

That was done by calibration, but again says little about the experiment having no conventional physics cause.

1. What is your proposed mechanism for the Cannae test articles producing thrust in vaccuum?

2. What is your proposed mechanism for tapered cavity test articles (section IV) producing thrust in vaccuum?

 

[Urwumpe]

1. What is your proposed mechanism for the Cannae test articles producing thrust in vaccuum?

2. What is your proposed mechanism for tapered cavity test articles (section IV) producing thrust in vaccuum?

The test was not done under vacuum conditions, but ambient air conditions.

Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level, within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure.

Their experiment procedure involved moving the test articles in and out of the test chamber for tuning, so they had decided against using vacuum.

And as explanation: The test was done in a stainless steel chamber and reached its peak performance at a specific frequency, using a metallic waveguide as "thruster". Thus, I would not even exclude simple induction as source of the force. The 4 µN thrust per kW RF power is also on the magnitude at which I would first-guess-timate such electromagnetic interaction between test article and test chamber.

The RF load has a different geometry and does not induce magnetic fields like the two test articles, which would then also explain the difference. That the non-slotted variant is more "powerful" than the slotted version is also explainable by that hypothesis.

But I would need much more information about the experiment to have a more solid hypothesis than this. But magnetic interactions between antennas are no new phenomena, so why should I not start there first?

 

[kamaz]

Possible. That would explain the thrust difference after rotating the test article.

The most interesting fact though is that the paper mentions that White's group has been investigating RF cavity thrusters since 2013.

 

[Urwumpe]

Possible. That would explain the thrust difference after rotating the test article.

The most interesting fact though is that the paper mentions that White's group has been investigating RF cavity thrusters since 2013.

Not really that interesting... A quick check on what Brady did in the past revealed research in optical neural networks. All seem to be in the more "experimental" field... could be part of a strategy to risk many boring experiments in different technologies for the single spectacular one. Or that they are just kept busy with such research to get a better "publication quota" in their institutes.

 

[kamaz]

The test was not done under vacuum conditions, but ambient air conditions.

Their experiment procedure involved moving the test articles in and out of the test chamber for tuning, so they had decided against using vacuum.

Where does it say that?

---------- Post added at 07:54 PM ---------- Previous post was at 07:51 PM ----------

Not really that interesting... A quick check on what Brady did in the past revealed research in optical neural networks.

So? If you looked through my publication history you'd find papers across 4 major fields.

 

[Urwumpe]

Where does it say that?

The abstract, I had also included it above:

Testing was performed on a low-thrust torsion pendulum that is capable of detecting force at a single-digit micronewton level, within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure...Integration of the two test articles and their supporting equipment was performed in an iterative fashion between the test bench and the vacuum chamber. In other words, the test article was tested on the bench, then moved to the chamber, then moved back as needed to resolve issues. Manual frequency control was required throughout the test.

Tells a story. :lol:

---------- Post added at 09:01 PM ---------- Previous post was at 08:55 PM ----------

So? If you looked through my publication history you'd find papers across 4 major fields.

Still much more than mine. :thumbup:

 

[Face]

So? If you looked through my publication history you'd find papers across 4 major fields.

Kamaz, I tried to find your real name in order to find those papers, but it is not shown in your profile nor in the nearest source code I could find (VNCMFD). "Kamaz" alone brings up too much hits on Google. Could you please give a link to your publications?

 

[kamaz]

Kamaz, I tried to find your real name in order to find those papers, but it is not shown in your profile nor in the nearest source code I could find (VNCMFD). "Kamaz" alone brings up too much hits on Google. Could you please give a link to your publications?

That's intended. I do not want my pseudonymous identity to be too easy to match to my name. Check your PM

 

[Andy44]

By the way, please keep in mind that the most damaging fraudulent paper in modern science made it through peer review. Someone even managed to put a fraudulent paper into Nature.

Peer review is like a water filter. It's not 100% effective in cleaning water, but it's much better than no filter at all.

 

[kamaz]

The problem with peer review is that the reviewer only has the paper to work with. The reviewer can check your maths and your conclusions, but he does not have experimental data, so he cannot check those. Which is exactly how a scientific fraud is done: one generates a plausible looking set of data and writes a paper around it -- the reviewer is none the wiser. Schon only got caught because he made a mistake doctoring his data sets, and that was only discovered because he made an otherwise innocent and common error of putting a graph from one paper into another. If he was more careful, he could go on for a few more years. Mind you, he would still get caught -- independent verification is still king even if it takes years -- but possibly after having received a Nobel prize. Now that would be an embarassment...

Bottom line is, if you are suspecting outright intentional fraud, then peer review is not the tool to catch it. You must rely only on (failure of) independent experimental reproduction and/or forensic statistics.

 

[boogabooga]

I don't suspect fraud in the NASA team's results, I suspect experimental error. Specifically, force balance when ALL environmental interactions are accounted for. That is precisely the kind of thing peer review could help.

I am suspicious of shady activity on the "inventor's" website where relevant pages of information disappear just as interest increases, etc.

I realize that it is not consistent to allow an independent team to try to verify, (or not) your claims if you are a fraud. However, I do not know what goals individuals might have. For example, if the purpose of some hypothetical fraud was only to generate media hype for some reason, then having results like this study generated would certainly count as a success.

Keep in mind that even when frauds are called out, a subset of the population will not only still believe the fraud, but consider the fraudster a hero who is being persecuted by the greedy "mainstream". Perhaps if you were counting on maintaining funding from such individuals...

 

[Urwumpe]

The problem with peer review is that the reviewer only has the paper to work with. The reviewer can check your maths and your conclusions, but he does not have experimental data, so he cannot check those. Which is exactly how a scientific fraud is done: one generates a plausible looking set of data and writes a paper around it -- the reviewer is none the wiser.

Which is why it is absolutely normal to reproduce the experiments in a paper and peer review them to get your own data. Also, some many papers have the data for download near them, and I know only few reasons why scientists refuse giving you their data for further research. Mostly commercial reasons.

Peer review is more than just getting accepted into a journal. In fact, you can publish a lot of stuff in quite popular journals without EVER getting any review before publication.

Peer review of your work even takes place, when you are already long dead. unless you work a company - in that case, you can only hope for peer review inside the company, your work will rarely be published for peer review. You only present them at conferences for letting your employer look good and attract new scientists for your companies work.

What you have right is the order of peer review:

First formal (you can already find bad work by only looking how citations are used), then abstract, then content and references, then data.

---------- Post added at 11:06 PM ---------- Previous post was at 11:03 PM ----------

I don't suspect fraud in the NASA team's results, I suspect experimental error. Specifically, force balance when ALL environmental interactions are accounted for. That is precisely the kind of thing peer review could help.

I don't even see experimental error there. NASAs team does not claim much there, which really deserves error as label. Maybe "happy little accidents", as Bob Ross would say.

Only the jump to the conclusion, that the hypothesis is potentially proven, despite the experiment contradicting the predictions, and proving a hypothesis, that the paper does not even seem to explain (the abstract already gives hints there) so you can understand why this conclusion was logically derived is really bad sloppy science.

But I have seen much worse there than that, really.

 

[kamaz]

Which is why it is absolutely normal to reproduce the experiments in a paper and peer review them to get your own data.

I have written for reviewed journals, I work with people who do reviews, I have worked as an editor. I have yet to see a case where a reviewer would attempt to verify the experiment himself.

OTOH once the paper is out there, then someone will attempt to replicate results and this is where you have actual control. Here is a typical example of a fraud which was caught because results could not be reproduced, despite the fact that study made it into Nature. From this point of view, it doesn't actually matter if you publish in a journal, at a conference, or put a preprint on arxiv. Get the paper out there so people can read it and see if they are able to reproduce.

I don't suspect fraud in the NASA team's results, I suspect experimental error. Specifically, force balance when ALL environmental interactions are accounted for.

Having read the paper, I have one major objection which is that the test was not done in a vaccuum. Besides that, I'd say that due diligence was done in this area. To wit:

However, one visible affect to the seismic environment is the periodic (about one-third to one-quarter Hertz) perturbation created by the waves from the Gulf of Mexico (about 25 miles southeast of Johnson Space Center), especially on windy days. According to local geologists, these low frequency waves propagate inland as far as 100 miles. A less predictable and higher impact seismic disturbance is the equipment and activity in the areas adjacent to the Eagleworks Lab test area, including a building air handler, an elevator, and employee foot traffic. In order to minimize impacts of all vibration sources, the table is floated on its pneumatic vibration isolation piers.

(Cool story: People doing Atomic Force Microscopy can tell you who was walking in the corridor by looking at the seismic signature embedded in the scan. I was in one AFM lab which was carved into the granite rock precisely for this reason.)

That is precisely the kind of thing peer review could help.

No. The best way to rule out experimental error is for someone else to repeat the experiment on his own test rig. If there is a problem with the rig itself, it's very unlikely the exact same problem would be present in an independently constructed rig.

 

[Urwumpe]

actually, I remember that a micrometer coordinate measuring equipment was installed on a heavy granite block and a pneumatic table to prevent the traffic from the nearby city roads from ruining the measurements... the problems can be much more trivial than waves on the shore.

 

[boogabooga]

http://scienceblogs.com/principles/2014/08/04/impossible-thruster-probably-impossible/

 

[Urwumpe]

So they used a measurement technology at ambient pressure, that can easily be disturbed by even light airflows?

 

[kamaz]

http://scienceblogs.com/principles/2014/08/04/impossible-thruster-probably-impossible/

It’s almost certainly an experimental error of some sort, most likely a thermal air current due to uneven heating

Force produced with a load resistor placed in palce of the test article was 9uN (vs. 49uN with the test article). If the effect is due to heat, then the force produced with the resistor should be larger, as the resistor dissipates all of received RF energy as heat. Further, air circulation for the "slotted" test article will be different then for the "unslotted" test article, so produced force should be different -- but both test articles produced the same force.

As for the sea waves and the shape of local gravity fields. The former can be treated as random disturbance, so after doing several measurements the effect will average out. The latter is not a factor, because it is constant -- and there is a graph in the paper showing the displacement value while switching the RF source on and off -- the displacement clearly increases when the RF source is on.

Yes, the data is noisy, but it's not really that bad -- the noise is about 1/5 of the claimed effect.

 

[Urwumpe]

Force produced with a load resistor placed in palce of the test article was 9uN (vs. 49uN with the test article). If the effect is due to heat, then the force produced with the resistor should be larger, as the resistor dissipates all of received RF energy as heat.

Further, air circulation for the "slotted" test article will be different then for the "unslotted" test article, so produced force should be different -- but both test articles produced the same force.

Please read the reference about the "torsion pendulum"

http://en.wikipedia.org/wiki/Torsion_pendulum#Torsion_balance

http://hdl.handle.net/2060/20030025383

 

[kamaz]

...And?