Em drives

[jedidia]

Well, my physics are somewhat rusty (plus it's bedtime), of course an acceleration of 20.19 m/s^2 does not result in an altitude of 20.19 m after one second, that would be velocity. the altitude reached is only 10.095 m :facepalm:

That's still a workload of 98.998 kJ though, so the point still stands.
Also, slightly concerned noone has caught my mishap. You're slacking, guys! :lol:

Earth's gravity exerts pull of 10N/kg. Hovering (a.k.a. anti-gravity) requires you to exert 10N/kg in the opposite direction.

Don't quite see what that's got to do with my calculation. I subtracted earth acceleration (otherwise the result would be even worse), and for the calculation of work gravity is already taken into acount AFAIK.

 

[Urwumpe]

Indeed. What is actually dubious in this argument is the 30kN/kW figure.

Well, you can produce 30 kN thrust with 1 kW of exhaust power... you only need an ISP of 1/30 m/s ...

 

[Quick_Nick]

Here's the video. Doesn't say much. Apparently the numerical method results are indeed about this unbalanced force. And again, the test NASA did should not have produced thrust with the unslotted cavity if this guy was right about the mechanism.

[ame="http://vimeo.com/29840866"]QDrive Introduction Part 2 on Vimeo[/ame]

The general idea seems to be:

 

[boogabooga]

One runs a business and the others run scientific tests.

One is a group of respectable engineers and the other is likely a fraud (In my opinion).

Some perspective:
http://space.io9.com/a-new-thruster...articles-or-1615361369/1615513781/+rtgonzalez

 

[Quick_Nick]

One is a group of respectable engineers and the other is likely a fraud (In my opinion).

Some perspective:
http://space.io9.com/a-new-thruster...articles-or-1615361369/1615513781/+rtgonzalez

I don't know about a fraud as much as confused.

And Sean Carroll criticizing unconventional physics? I think the whole of his work goes against mainstream physics.

 

[kamaz]

One is a group of respectable engineers and the other is likely a fraud (In my opinion).

But what you have here is that a group of respectable engineers has tested a device made by likely a fraud and found that the device indeed works.

Some perspective:
http://space.io9.com/a-new-thruster...articles-or-1615361369/1615513781/+rtgonzalez

From the article:

[Thrust] occurs even for the test article that wasn't supposed to produce any thrust at all

It appears that Mr. Carroll did not read the research he is commenting on. There were 3 test articles:

asymmetric - this was supposed to produce thrust under both Fetta's and White's theory
symmetric - this was supposed to produce thrust under White's theory, but not under Fetta's theory
control - this was not supposed to produce thrust under any theory

Both asymmetric and symmetric articles produced thrust. Control article produced no thrust.

The logical conclusion is that the device works, it just doesn't work the way Fetta imagines it does. It maybe works the way White thinks it does.

 

[Urwumpe]

But what you have here is that a group of respectable engineers has tested a device made by likely a fraud and found that the device indeed works.

Lets stop the analysis already at this point: Did it really work?

Something was measured. Now, what was measured and how this was caused, are not that easily answered. It actually, if you read carefully, worked completely unlike the predictions.

Is the fact that the control device produced zero force really a sign, that the measurements of a force by the other two articles produced thrust?

Important is also: Can't this force be also explained by more mundane effects, for example Earths magnetic field?

 

[Quick_Nick]

They had an entire year to consider Earth's magnetic field, etc. before publishing.
That's still easily the case though.

We still don't have results from January as far as I know. Maybe that will be published soon. (And maybe it will be inconclusive)

 

[Urwumpe]

They had an entire year to consider Earth's magnetic field, etc. before publishing.
That's still easily the case though.

We still don't have results from January as far as I know. Maybe that will be published soon. (And maybe it will be inconclusive)

Its not just that simple - you can have interactions within the experiment set-up, which would not take place in space.

 

[boogabooga]

They had an entire year to consider Earth's magnetic field, etc. before publishing.
That's still easily the case though.

The Joint Propulsion Conference is not peer reviewed. The standards for publication are fairly low. Think of it as an opportunity for old colleagues from across the country to come together for cocktails after giving a 15 minute power point each. The "published" testing was preliminary.There is no requirement that they rigorously ruled out experimental error.

Researchers made a little gizmo with all sorts of electromagnetic fields zipping about. I find it far more likely that when all interactions with the environment are considered, the forces will balance- which has NOT been ruled out at this point.

 

[kamaz]

The Joint Propulsion Conference is not peer reviewed.

So what? You realize that there were several people in the room who will rush to replicate this as soon as they get back to the office, particularly because the gizmos are quite simple and they were being passed around? This is the last thing you want if you are trying to pull a fraud.

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.

 

[Urwumpe]

So what? You realize that there were several people in the room who will rush to replicate this as soon as they get back to the office, particularly because the gizmos are quite simple and they were being passed around? This is the last thing you want if you are trying to pull a fraud.

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.

So, mixing science and magic is OK, if it isn't peer reviewed?

Also: If it would be "quite simple" we would already have it for 200 years and complain about it. The little information about the experiment setup suggests that it is everything BUT simple.

 

[kamaz]

Lets stop the analysis already at this point: Did it really work?

The inventor claimed that his experimental setup produces a force.

NASA replicated his setup and found that the setup indeed produces a force.

It is not known at this point if the force was indeed produced by the device itself, or by some unaccounted for coupling in the experimental setup. This is why it should be investigated further.

 

[Urwumpe]

The inventor claimed that his experimental setup produces a force.

NASA replicated his setup and found that the setup indeed produces a force.

It is not known at this point if the force was indeed produced by the device itself, or by some unaccounted for coupling in the experimental setup. This is why it should be investigated further.

NASA also modified his set-up, beyond what the inventor claimed could work and produced a force. Only the Null-test produced no detectable force, which means that some reasons for the force can be excluded.

 

[kamaz]

Please excuse me for being nosy, but have you actually read the Brady et.al. paper?

Because I am looking at it right now, and inventor's claims as to what should work have no bearing on the results.

---------- Post added at 05:31 PM ---------- Previous post was at 05:25 PM ----------

That's my point. The simulation will only include "conventional" physics. If "unconventional" physics appear in the simulation, it's because the simulation was already programmed to include it.

You can't use a simulation of conventional physics as a validation of unconventional physics.

The paper says that the numerical simulation was used to determine the electromagnetic field distribution inside the test article. No new physics here.

 

[boogabooga]

The inventor claimed that his experimental setup produces a unbalanced force.

NASA replicated his setup and found that the setup indeed produces a force.

FTFY

It is not known at this point if the force was indeed produced by the device itself, or by some unaccounted for coupling in the experimental setup.

That is exactly true. But now is the pesky matter of the burden of proof. Simply producing a force on a test rig is not sufficient. For the fourth time, until it can be shown that there was not a coupling with the setup, environment, etc. and thus a violation of conservation of momentum, this simply does not deserve the hype that it is getting.

This is why it should be investigated further.

Sure, investigate away. If you have the time and the money, why not.

BTW, just because a few frauds have slipped through peer review, does not mean that research that has not been per reviewed should be assumed to be as good as research that has.

The paper says that the numerical simulation was used to determine the electromagnetic field distribution inside the test article. No new physics here.

I was referring to claims made not in the paper but on his website, which has since been mysteriously taken down.

 

[kamaz]

and thus a violation of conservation of momentum

Per this paper on White's theory there is no violation of conservation of momentum any more then there is in case of a paddle boat.

Fetta's theory of device operation would require violating conservation of momentum, but the experiment has showed that it is incorrect. (Surprise!)

 

[Urwumpe]

Please excuse me for being nosy, but have you actually read the Brady et.al. paper?

I have only the abstract available.

But I had understood it wrong: I thought that they tested three devices, but in reality they only tested a Cannae and the Null article and BOTH produced thrust.

The cannae thruster 30-50 µN, the null article designed to produce no force at all produced 90 µN!

Case closed for me. The experiment design was wrong, and a new experiment has to be devised.

The jumping to conclusion "Quantum Vacuum Plasma potentially exists" is bad science: Better would be the formulation: "Quantum Vacuum Plasma hypothesis was invalidated by the experiment results"

 

[kamaz]

But I had understood it wrong: I thought that they tested three devices, but in reality they only tested a Cannae and the Null article and BOTH produced thrust.

Incorrect. There were 3 test articles. 2 test articles were provided by Cannae. The articles were the same, except that one of the had holes on one side the RF cavity. The third article was a 50 ohm resistor. Only the third article produced no thrust.

The test article is a short, wide cylinder. During the test, the device is mounted horizontally ('cause gravity). Fetta (Cannae) theorized that the device works by having particles bouncing off between the "left" and "right" walls of the cylinder back and forth. However, in such case the net force is zero, because the force exerted on the left plate is the same as the force exerted on the right plate. (This is test article #2, a.k.a. "unslotted"). So he had another article, which had holes drilled in the "right" plate, permitting particles to escape. If the holes were, say, 20% of the plate surface, then the force on one plate would be reduced by 20% -- as 20% of particiles would escape through the holes -- and this would produce thrust. (This is test article #1, a.k.a. "slotted").

Test article #1 produced 40.0uN of thrust on average, test article #2 produced 40.7uN of thrust on average. Since there's some spread in the data from run to run, it looks like both articles produced the same thrust.

Test article #3 (a.k.a. resistor) produced no thrust. (This is not entirely true -- the authors say that they have measured 9uN of force in the configuration involving the resistor due to magnetic field from the feed cable pushing the torsion pendulum, so they have substracted 9uN from all results.)

Most of the confusion stems from the fact that the abstract refers to the "unslotted" article as null. This is because it was a null for Fetta's theory that the thrust is produced by holes in the wall of the RF cavity.

 

[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.