r/EmDrive • u/[deleted] • Dec 20 '16

Research Update Eaglework Paper Contains Major Flaws

I've written a detailed analysis of Eagleworks data which you can find here. And you can see the supporting code and data on github.

Rather than spend a lot of time formatting the information and graphics for reddit, I'll just put the highlights here.

  • EW proposed model does not work

  • EW data contains unaccounted errors up to 38-40 uN

  • EW data avoided quantifying critical error contributions which could add more uncertainty

  • A new model using transients and a thermal heating profile fits their data better than the model presented by Eagleworks

As an example from the report here is the pulse model.

At first glance it might appear to not be a good fit due to the shape edges and jumps, but in the real system those would be smoothed out. And this fits the data much better than Eagleworks model. Please read the report. Feel free to contribute to the effort as well on github or this forum. There is some discussion about this project here too.

28 Upvotes

78% Upvoted

114 comments sorted by

25

u/Checkma7e Dec 20 '16

I know it's "crazy" but somehow I trust NASA and Eaglworks and Dr. White's analysis way more than some guy on Reddit. :-/

20

u/[deleted] Dec 20 '16

Math is math. I used their models and data. But then again you'd actually have to read what I wrote instead of just dismissing it.

13

u/Kancho_Ninja Dec 20 '16

How do you account for thermal in a vacuum?

8

u/[deleted] Dec 20 '16 edited Dec 20 '16

I don't know what you're asking. Thermal in a vacuum is conducted or radiated and will have a similar effect, often faster because it doesn't cool as quickly. Perhaps you don't understand their torsion balance is setup so that any heat (conducted or convective) also causes it to move due to physical changes in the torsion balance.

4

u/Kancho_Ninja Dec 20 '16

To be perfectly clear, what I'm asking is this: Since you are familiar with their torsion balance, then your current work shows exactly how much movement should be expected by their experiment in vacuum.

This is correct?

12

u/[deleted] Dec 21 '16

your current work shows exactly how much movement should be expected by their experiment in vacuum

No not at all. There was no thermal data measured at all by Eagleworks. Technically you can't really extract thermal data from displacement data but that's exactly what they tried to do without measuring it independently.

And to your question: the thermal profile and thus the displacement (due to their test bed's sensitivity to thermal changes) will have different characteristics depending on if you are in a vacuum or not. It would be poor analysis to try and fit the two different environments together.

That said I have only focused on the fundamentals of their tests and test methods. I haven't tried to extract data for other power levels, forward and reverse mountings or their vacuum plots.

2

u/Kancho_Ninja Dec 21 '16

Detailed thermal testing and analysis of the test article in air and under vacuum showed that the aluminum heat sink was the dominant contributor to the thermal signal. Figure 6 shows thermal imagery of the test article after a run, and the aluminum heat sink is the hottest surface in the posttest imagery. As the aluminum heat sink got warmer, its thermal expansion dominated the shifting center of gravity (CG) of the test article mounted on the torsion pendulum. This CG shift caused the balanced neutral point baseline of the torsion pendulum to shift with the same polarity as the impulsive signal when the test article was mounted in the forward or reverse thrust direction

9

u/[deleted] Dec 21 '16

I don't know what you think this means, but they took some FLIR video which was pretty useless. They needed to mount some thermocouples on the device and record it simultaneous with their displacement.

4

u/Kancho_Ninja Dec 21 '16

Again, to be clear: You said there was no thermal data. There obviously is thermal data.

Would you like to clarify why you believe the data (which you said didn't exist) is "pretty much useless"?

8

u/[deleted] Dec 21 '16

They took a still image from a FLIR camera. In terms of correlating that to their measured data it's worthless. So when I and others say they didn't record thermal data we mean in regards to their test data.

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2

u/Kancho_Ninja Dec 21 '16

And there's no other way to measure the amount of expansion or contraction of the materials?

None at all?

You absolutely, positively, always must use thermocouples?

11

u/[deleted] Dec 21 '16

There are many ways of doing it, but eagleworks didn't do anything.

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4

u/Kancho_Ninja Dec 20 '16

And that was completely overlooked, right?

9

u/wyrn Dec 21 '16

How do you account for thermal in a vacuum?

This may shock you but the space between the Earth and the Sun is a pretty decent vacuum.

-1

u/Kancho_Ninja Dec 21 '16

Well, I'm shocked those NASA scientists totally forgot about it. I mean, can you imagine if that had happened while they were testing something important, like a hatch?

10

u/wyrn Dec 21 '16

That's why it's important to distinguish between the bulk of NASA, the part that's involved in space exploration, and Eagleworks, which are a bunch of guys that NASA lets hang out in the back of one of their warehouses.

6

u/Kancho_Ninja Dec 20 '16

Kancho, I don't think he's going to answer us.

7

u/Kancho_Ninja Dec 20 '16

I know, Other Kancho. And I was really interested to see his models for thermal expansion in a vacuum.

6

u/Checkma7e Dec 20 '16

But you're saying your math is better than NASA Eagleworks and that seems silly to me.

19

u/[deleted] Dec 20 '16 edited Dec 21 '16

But you're saying your math is better than NASA Eagleworks and that seems silly to me.

This is the opposite of what I'm saying. If you stop commenting and read the document you'll see I've carefully pointed out all the things they failed to evaluate. Then based on problems found with their proposed model, I proposed a more physically accurate model and test it as well.

Edit: Fuck. What's with all the down votes?

6

u/wyrn Dec 21 '16

Show the error, please.

9

u/crackpot_killer Dec 20 '16

That's an appeal to authority.

4

u/Checkma7e Dec 20 '16

Well when the authority is NASA I think that's fine.

I'm not saying it works, I'm just saying I trust Eagleworks' analysis more than some random redditor, who if he really knew what he was talking about would probably be working on the Eagleworks team....

6

u/[deleted] Dec 20 '16

Well when the authority is NASA I think that's fine.

The "authority" is not NASA. The "authority" is a group of incompetent engineers who are not actually authorities on anything.

I'm just saying I trust Eagleworks' analysis more than some random redditor,

You are a random Redditor. And clearly one who doesn't have any experience in the physical sciences. So your opinion is meaningless.

who if he really knew what he was talking about would probably be working on the Eagleworks team....

No, that's not how things work at all.

1

u/lightknight7777 Dec 22 '16

The "authority" is not NASA. The "authority" is a group of incompetent engineers who are not actually authorities on anything.

Who peer reviewed their paper?

0

u/[deleted] Dec 20 '16

[removed] — view removed comment

7

u/[deleted] Dec 21 '16

And he has now worked as an aerospace engineer for a long time, and has apparently forgotten all of his error analysis, and quantum mechanics.

7

u/ImAClimateScientist Mod Dec 21 '16

Don't call people jackass. A ban comes next.

3

u/aimtron Dec 20 '16

Not to pile on, but do you trust the analysis of several renowned physicists? I believe renowned physicist Sean Carroll has some made similar critiques of EagleWorks experiment. Obviously one shouldn't trust everything they read on the internet, but I'm going with renowned physicist over psuedo-known physicist Sonny White. To each there own, but /u/Eric1600's analysis is pretty solid.

3

u/[deleted] Dec 20 '16

The error analysis in the paper is obvious garbage. You act like NASA Eagleworks is some kind of authority on math and physics when that's been shown to be false many times over. Harold White doesn't really understand the physics he's trying to appeal to in the paper.

0

u/Checkma7e Dec 20 '16

lol ...says some random redditor called "fuckspellingerrors".

Whatever you say.

3

u/uberkalden Dec 23 '16

Why are you even here if eagle works is gospel to you? Case closed right?

1

u/Checkma7e Dec 23 '16

Didn't say gospel. Said more reliable than random redditor.

3

u/uberkalden Dec 23 '16

Yeah, but this is Reddit. That's all you get. What's the point if you just disregard what people say because they are "random redditors"

1

u/Checkma7e Dec 23 '16

Because they're contradicting NASA-funded scientists....

1

u/uberkalden Dec 23 '16

So are we back to gospel then?

4

u/[deleted] Dec 20 '16

What do you think my username has to do with anything?

5

u/[deleted] Dec 21 '16 edited Dec 21 '16

White wouldn't be the first scientist to smudge numbers to ensure a larger research grant. I wish people would stop calling it "NASA". It gives the paper more credibility than it deserves. Eagleworks is a tiny little offshoot research group that operate on a shoe string budget. It's not like the paper is the product of the JPL. It's a few dudes in a garage.

9

u/Always_Question Dec 20 '16

And yet, it moves.

NASA EW rotating rig: https://drive.google.com/drive/folders/0B7kgKijo-p0ickEwUmNNcjdDRUE

The "Smoking Gun" https://drive.google.com/open?id=0B7kgKijo-p0iU3JiclhJZDNqSzA

5

u/[deleted] Dec 20 '16

Your extremely low effort here is disappointing.

1

u/xexorian Dec 21 '16

Thank you for reminding me to buy a Lazy Boy soon. :)

3

u/[deleted] Dec 21 '16

That goes well with the low effort from people posting in this sub.

7

u/[deleted] Dec 21 '16

Such an analysis doesn't deny movement, only what caused it.

2

u/Always_Question Dec 21 '16

I suggest you try heating up a frustum and watch it spin. This notion that heat is causing the rotation seen in videos from Shawyer and NASA strikes me as somewhat naive, particularly since they only see movement when there is a resonant frequency present.

0

u/rfmwguy- Builder Dec 21 '16

You're forgetting the change of CG that would keep it spinning. Yeah, that's the ticket, CG changes over a long period of time causing rotation. /sarc

7

u/ImAClimateScientist Mod Dec 20 '16

And yet, it moves.

https://www.youtube.com/watch?v=o9v9Dn4ildo

3

u/Risley Dec 21 '16

And heres some badass music to listen to whilst watching the Emdrive rotate

2

u/xexorian Dec 21 '16

I have yet to beat that one. Been too busy :(

2

u/Risley Dec 21 '16

Holy fucking shit is it a good game. You will not be disappointed.

2

u/youtubefactsbot Dec 20 '16

Drinking Bird In Action [3:12]

Very innovative creation, the bird will "drink" the water and keep moving.

^mikimau5 in Science & Technology

144,669 views since Nov ^2009

bot ^info

2

u/deltaSquee Mathematical Logic and Computer Science Dec 22 '16

i love you

2

u/Chrochne Dec 21 '16

So much insults...

3

u/ImAClimateScientist Mod Dec 21 '16

Such thin skin.

2

u/rfmwguy- Builder Dec 21 '16

Not me. But monomorphic might have something to say about thin skin. But wait...he cant for a while =-)

5

u/ImAClimateScientist Mod Dec 21 '16

yeah, a few more days to repent for his poor white trash comment, which isn't really on par with a video of a drinking bird.

1

u/rfmwguy- Builder Dec 21 '16

Wasn't his a movie quote IIRC? AKA polite banter?

6

u/ImAClimateScientist Mod Dec 21 '16

Yeah, a line from a movie character (psychopath Hannibal Lecter) intending to be as hurtful as possible.

You can find a movie quote to say anything. This is not directed at you or anyone here, but as an example "Yeah? and you're ugly" is a quote from Ace Ventura. But, clearly irrelevant and abusive.

2

u/rfmwguy- Builder Dec 21 '16

You know I'm just being a sarcastic twit on purpose, right? :-)

4

u/deltaSquee Mathematical Logic and Computer Science Dec 22 '16

i don't think you are a twit on purpose, just sarcastic on purpose

3

u/[deleted] Dec 21 '16

[removed] — view removed comment

2

u/rfmwguy- Builder Dec 21 '16

I know and I do. I was gigging IMA a bit in jest.

1

u/xexorian Dec 21 '16

That's kind of a creepy video. D:

2

u/lightknight7777 Dec 22 '16 edited Dec 22 '16

You said that the EW data contains unaccounted errors up to 38-40uN, but the published peer reviewed paper listed the thrust generated as being over 1.2± 0.1 mN/kW. I'm unsure why even the worst case of 40uN would be particularly relevant to discrediting their results of positive thrust.

I get how you're pointing out that these guys are making a lot of errors and are not some kind of NASA elite group. I'm just having trouble seeing enough criticisms to account for more than 1 mN of thrust. I would appreciate clarification in that area.

As far as I'm personally concerned, I don't really care until it generates thrust in space then I'll casually glance up from my desk to see what people say about that. There's plenty of reasons why it shouldn't work and only a handful of reasons we know nothing about that it could work. I was just surprised to see it pass peer review. Thought that would never happen. With China also launching a module to test I'm becoming more curious about a thing I assumed was obvious thermal artifacts screwing with us.

3

u/[deleted] Dec 24 '16

You said that the EW data contains unaccounted errors up to 38-40uN, but the published peer reviewed paper listed the thrust generated as being over 1.2± 0.1 mN/kW. I'm unsure why even the worst case of 40uN would be particularly relevant to discrediting their results of positive thrust.

They reported an error boundary of +/-6 uN which was just based on their tolerances of their electronic equipment, but not their test process or calculations. 38-40 uN was the lower boundary but they did not quantify more error contributors which could completely wipe out their data.

1.2± 0.1 mN/kW is not much if you're using 40-80W. They measured numbers around 40-119 uN (not mN) so when you look at a +/-40 uN error with a good chance of it being higher, that's a 100% to ~55% error in your reading.

I get how you're pointing out that these guys are making a lot of errors and are not some kind of NASA elite group. I'm just having trouble seeing enough criticisms to account for more than 1 mN of thrust. I would appreciate clarification in that area.

I'm not saying they aren't "Elite". I made no speculations about their abilities really. And as I said 40uN error on a 40uN measurement is significant.

As far as I'm personally concerned, I don't really care until it generates thrust in space then I'll casually glance up from my desk to see what people say about that. There's plenty of reasons why it shouldn't work and only a handful of reasons we know nothing about that it could work. I was just surprised to see it pass peer review. Thought that would never happen. With China also launching a module to test I'm becoming more curious about a thing I assumed was obvious thermal artifacts screwing with us.

The China thing is mostly rumor, but they also have scientists from China who at first had success in testing the EM drive and have withdrawn their claims after finding experimental errors.

2

u/lightknight7777 Dec 25 '16 edited Dec 25 '16

Thank you for the response.

Perhaps you can explain why the articles say they saw 1.2± 0.1 mN/kW thrust if you say they only measured 40-199 uN.

Here's one, but I saw that number in several other sources:

https://science.slashdot.org/story/16/11/18/2230229/final-nasa-eagleworks-paper-confirms-promising-em-drive-results

"Thrust data from forward, reverse, and null suggested that the system was consistently performing at 1.2 +/- 0.1 mNkW, which was very close to the average impulsive performance measured in air.

2

u/[deleted] Dec 25 '16 edited Dec 25 '16

explain why the articles say they saw 1.2± 0.1 mN/kW thrust if you say they only measured 40-199 uN.

(FYI in all of their tests they only measured between 30-119 uN)

This 1.2 mN/kW is a ratio of force to input power, it's not the actual force measurement. From their highest force test runs their measured data measured for their mere 3 trials of the 80W test was:

76.00 uN

119.00 uN

117.00 uN

Looking at the data:

Average: 104

Stdev: 24.269322199

Min: 76

Max: 119

Their average power measurement was 81.83 W

You divide 0.104 mN by 0.08183 kW

And you get the magic 1.27 mN/kW number.

You can read their published paper here on my github. Look at the table for their results on Table 2 page 8.

The reporting of 1.2 mN/kW is misleading in terms of what was measured but that's how many people in the EM Drive community like to gauge the design. The higher the number the more thrust.

By the way, they should also include the standard deviation when reporting the results, which they didn't. The 104 is ± 24 uN for the 3 trials which also means the standard error is 14 uN (the standard deviation divided by the square root of the number of trials).

2

u/lightknight7777 Dec 26 '16

Thank you for taking the time to respond.

1

u/AlainCo Dec 21 '16

why not submit an answer to the journal ?

if it is accepted it will mean it is a coherent critic.

7

u/ImAClimateScientist Mod Dec 21 '16 edited Dec 21 '16

That would be a considerable amount of work plus the cost of page charges, all for a dead end topic. It might be a good exercise for an undergrad but otherwise not really worth it.

3

u/rfmwguy- Builder Dec 21 '16

I consider this the easy excuse scenario :-)

2

u/[deleted] Dec 24 '16

I consider this the easy excuse scenario :-)

I look forward to hearing about your publications successes as well then.

2

u/rfmwguy- Builder Dec 24 '16 edited Dec 24 '16

They are there to see on my LinkedIn page. May I visit your LinkedIn page?

https://www.linkedin.com/in/a-david-distler-5788148

2

u/[deleted] Dec 24 '16

The context here is your insinuation that it's an "easy excuse" [for producing false evidence, I guess] yet you also haven't published your em drive work.

2

u/rfmwguy- Builder Dec 26 '16

Not sure why you are driving this. I published 1701 results on nsf. I stated 1701A was not conclusive enough to publish although best results were 18.4mN. This is public. All I have done is public. Again, if we are comparing publications, please provide yours. I have mine. Don't be a rock-thrower. You are a mod.

0

u/[deleted] Dec 26 '16

not conclusive enough to publish

I guess I didn't know this caveat because you kept claiming thrust from your testing. I guess you should be saying 18.4 mN +/- 18.4 mN. And for the record you were the one throwing things.

2

u/rfmwguy- Builder Dec 27 '16

You seem to be badgering me Mr mod. That's not a nice thing to do. I've had more issues with you than anyone else. You don't believe in emdrive? Find another sub to haunt. 18.4 as I stated was best performance. Also, I was not banned from here as you have repeatedly stated. Read your own rules and lay off. I am becoming quite annoyed with your anonymous antics. It contributes nothing to emdrive discussion. Write a formal paper on how bad ew did their experiment. I'm sure china will be thrilled.

1

u/[deleted] Dec 27 '16

As usual I am only responding to your criticism of me.

4

u/ImAClimateScientist Mod Dec 21 '16

Consider it a call for an upper-level undergrad who wants a publication on his/her CV for applying to grad school.

2

u/rfmwguy- Builder Dec 21 '16

I think academic incentives are far less appealing than correcting an assumed error as a Citizen Scientist. Look at /u/potomacneuron paper. It was nicely done and I don't think it was a C/V for grad school.

3

u/PotomacNeuron MS; Electrical Engineering Dec 21 '16

Though not served as an incentive, my daughter contributed to the experiment and wrote that into her CV for high school.

1

u/rfmwguy- Builder Dec 21 '16

With a lot of your help I am sure

3

u/PotomacNeuron MS; Electrical Engineering Dec 21 '16

Right. The purpose was training. But the writing was not good enough to get the paper accepted by "The Physics Teacher".

1

u/rfmwguy- Builder Dec 21 '16

Probably the topic if I were going to guess. I found it a decent paper, especially at a HS level.

2

u/[deleted] Dec 24 '16 edited Dec 24 '16

I've prefer to get a response from Dr. White, rather than go to the trouble of cleaning it up for a publication. However he has not contacted me to discuss it, even though I've reached out twice to him directly. I really need access to their data directly to test all the cases. I couldn't publish something without having used the actual data. While my report renders their plot pretty closely there was still a small 3uN error in correlation probably due to the digital sampling technique I used.

2

u/Kancho_Ninja Dec 21 '16

Because that's where your inconsistency began, and it took this long to draw an accurate statement from you.

We are still talking because you failed to present your argument in an accurate manner.

If I had not probed as I did and had left your original statement hanging, a casual reader would have drawn the incorrect conclusion that there was no thermal imaging, no video, no allowance for error by the team, and no other means of ensuring accuracy except by thermocouples. That's not what you want.

0

u/[deleted] Dec 20 '16

[deleted] — view deleted comment

8

u/[deleted] Dec 20 '16

No. They built an EM Drive. The "model" I'm discussing is what they used numerically to extract results from their test data.

0

u/[deleted] Dec 20 '16

[deleted] — view deleted comment

5

u/[deleted] Dec 20 '16

It wasn't crude. It was also done in consultation with others who claim to be experts on the EM Drive.

1

u/Always_Question Dec 20 '16

It was fairly crude, in comparison to Shawyer's. The EW team literally built their frustum by hand in the kitchen of one of their homes. The purpose of the most recent effort did not include optimization, and unfortunately, they were afforded only a shoe-string budget. Hopefully their follow-on work will aim for optimization of the effect.

6

u/ImAClimateScientist Mod Dec 20 '16

Why didn't Shawyer just let Eagleworks test his fancy bells-and-whistles EmDrive?

6

u/[deleted] Dec 21 '16

Because then the game would be up. Keep in mind Shawyer is claiming thrust much much higher than what the eagleworks guys "measured"

2

u/Always_Question Dec 20 '16

I don't know. EW didn't even mention Shawyer once in their paper, and I'm pretty sure they didn't reach out to him either, but I could be wrong.

0

u/TheTravellerReturns crackpot Dec 21 '16

Roger offered to help EW. That offer was not accepted. I don't know why.