Cannae/EmDrive

[Frozen_Heart]

Would increasing the power level increase the thrust?

[andrew123]

Would increasing the power level increase the thrust?

We don't have much info one the drive (It's purely theoretical), but from the known info, yes.

I can already envisage the US Air Force dreaming up some... peacekeeping... platforms.

EDIT: And with their resurgent military, the Japanese.

Edited October 31, 2014 by andrew123

[KerikBalm]

We don't have much info one the drive (It's purely theoretical), but from the known info, yes.

I believe you mean hypothetical... or not even that, just speculation.

The closest thing to a theory to explain how it might work was disproved when there was no difference with the null test article.

There is no theory behind it.

[Frozen_Heart]

Does anyone know if they plan to try and test it again?

[Northstar1989]

Does anyone know if they plan to try and test it again?

NASA has definitive plans to continue testing the device. No idea how well they're sticking to their original timeline though...

Regards,

Northstar

[SamSilver]

Sigh...I dislike having to be that guy in threads like these. But there are some extraordinary claims being accepted at face value here, and as an experimental physicist I have a hard time letting them just slide.

When I first read this report in August, the fact that the "null" device produced a comparable force to the "test" device was already a red flag. But if you want to claim that both devices are somehow equally-effective reactionless drives, a careful reading of the paper reveals a gaping hole in their experimental procedure.

A good deal of Section II discusses the vacuum chamber designed to house the experiment, and how it can achieve a vacuum down to 5 microTorr. This is crucial, because a reactionless drive must be demonstrated in a vacuum! Otherwise you are vulnerable to all kinds of unwanted effects. For instance, if you run the experiment in atmosphere and there are parts of the device that are warmer than others, the interaction with the air can produce a net force.

But...there is a crucial sentence buried in Section VI (summary and forward work):

Vacuum compatible RF amplifiers with power ranges of up to 125 watts will allow testing at vacuum conditions which was not possible using our current RF amplifiers due to the presence of electrolytic capacitors

So at the end of the paper, the authors let slip that they did not do the tests in vacuum conditions!

This renders the entire paper meaningless, since without a vacuum you can't credibly claim that torques this small are actually evidence of a working reactionless drive.

If these results can be convincingly reproduced in vacuum, I would change my mind. But we haven't heard anything new since August, and I would bet we won't see any such evidence anytime soon.

[Dodgey]

SamSilver read the OP, it addresses all of your concerns.

[Northstar1989]

Sigh...I dislike having to be that guy in threads like these. But there are some extraordinary claims being accepted at face value here, and as an experimental physicist I have a hard time letting them just slide.

When I first read this report in August, the fact that the "null" device produced a comparable force to the "test" device was already a red flag. But if you want to claim that both devices are somehow equally-effective reactionless drives, a careful reading of the paper reveals a gaping hole in their experimental procedure.

Sam, their not knowing *why* the device works changes nothing about the fact that it *does* work. Experimental Evidence trumps theory- I was quite clear about that in my OP... The "null" drive was not a control, anyways- just a test of a particular theory. As a fellow scientist, I invite you to actually carefully purview the evidence rather than just reading the abstract. You should know better than to judge a paper by an abstract if you are a fully-trained scientist.

A good deal of Section II discusses the vacuum chamber designed to house the experiment, and how it can achieve a vacuum down to 5 microTorr. This is crucial, because a reactionless drive must be demonstrated in a vacuum! Otherwise you are vulnerable to all kinds of unwanted effects. For instance, if you run the experiment in atmosphere and there are parts of the device that are warmer than others, the interaction with the air can produce a net force.

But...there is a crucial sentence buried in Section VI (summary and forward work):

So at the end of the paper, the authors let slip that they did not do the tests in vacuum conditions!

This renders the entire paper meaningless, since without a vacuum you can't credibly claim that torques this small are actually evidence of a working reactionless drive.

If these results can be convincingly reproduced in vacuum, I would change my mind. But we haven't heard anything new since August, and I would bet we won't see any such evidence anytime soon.

Read the Q&A I linked to in the OP before regurgitating points it (and I) quite clearly addressed. The following is a direct quote:

"While the original abstract says that tests were run "within a stainless steel vacuum chamber with the door closed but at ambient atmospheric pressure", the full report describes tests in which turbo vacuum pumps were used to evacuate the test chamber to a pressure of five millionths of a Torr, or about a hundred-millionth of normal atmospheric pressure."

Regards,

Northstar

[magnemoe]

So at the end of the paper, the authors let slip that they did not do the tests in vacuum conditions!

This renders the entire paper meaningless, since without a vacuum you can't credibly claim that torques this small are actually evidence of a working reactionless drive.

If these results can be convincingly reproduced in vacuum, I would change my mind. But we haven't heard anything new since August, and I would bet we won't see any such evidence anytime soon.

Makes some sense to test this way, if it did not produce any trust in atmosphere you drop it, if it produce something interesting you do an new test if not you can drop it after an cheap test.

[SamSilver]

Northstar,

I read both the OP and the report in detail. The main section of the paper describes the procedure for evacuating the chamber, meaning that they certainly did test that the chamber could be brought down to 5 millionths of a Torr. But they never state explicitly in that section that they actually ran these tests in vacuum.

And there are TWO places where they state that they didn't. Once in the original abstract, as you pointed out in the OP, and a second time in the conclusions. Here is the second mention once more:

Vacuum compatible RF amplifiers with power ranges of up to 125 watts will allow testing at vacuum conditions which was not possible using our current RF amplifiers due to the presence of electrolytic capacitors

They had to run the experiments at ambient pressure because their RF amplifiers could not be run in vacuum! Their amplifiers were built with electrolytic capacitors, which tend to go "boom" in vacuum (both destroying the amplifier and releasing chemicals that go on to contaminate your instruments and the vacuum system itself). I'm sorry, but as an experimental physicist it is clear to me that this work was not (and could not) be run in vacuum. The fact that a crucial point like this was obfuscated just goes to show how poorly written a paper this is.

I hate to be "that guy" who gets drawn into an online debate with a Believer, and I am pretty sure that nothing I write here will sway you. But as a member of the physics community, I feel obligated to answer extraordinary claims that I see voiced in a public forum. And now that I have done so, I feel that my duty is done.

Edited November 1, 2014 by SamSilver
omitted word

[SamSilver]

Oh, one more thing. Northstar wrote:

As a fellow scientist, I invite you to actually carefully purview the evidence rather than just reading the abstract. You should know better than to judge a paper by an abstract if you are a fully-trained scientist.

Yes, I have read the full paper multiple times, and found the evidence to be lacking. As a "fellow scientist", you should also know that extraordinary claims demand extraordinary evidence. Conversely, ordinary claims only demand ordinary evidence. Against their extraordinary claim of reactionless force, I propose a completely ordinary explanation (thermal interaction with ambient atmosphere), which is completely in line with what was reported in the paper.

(In case this was a question about my scientific qualifications, I have 25 years of experience working in experimental particle physics and helped design and build part of one of the Large Hadron Collider experiments. My main area of expertise is detector instrumentation and data acquisition.)

Edited November 1, 2014 by SamSilver
grammar fix

[andrew123]

Well, regardless of the poor experimental design, I still hope the research pans out...

... the implications for spacecraft could be huge.

[Frozen_Heart]

Though I still don't believe it really works. It is definitely worth thoroughly investigating on the off chance it does work.

Putting some microwaves into a copper tube shouldn't be too much for even NASA's measly budget.

[KerikBalm]

Sam, their not knowing *why* the device works changes nothing about the fact that it *does* work. Experimental Evidence trumps theory

There is no evidence that it does work.

Thrust and force are not the same thing.

Thrust in an atmosphere and thrust in space, are not the same thing.

A force was measured, there is currently no evidence that it can generate that force in a vacuum/space.

Therefore, your claim is BS.

[Leszek]

The way I see it, EmDrive is not very plausible. Perhaps it works, perhaps not. The test so far done are not definitive, you can think of them as preliminaries. They need to be tested and demonstrated in more complete and rigorous ways.

I am not an expert in the relevant physics but there is one big red flag that needs to be addressed, ALWAYS be wary of results near the margins of what we can detect. This lesson was learned from such examples as N Rays. http://en.wikipedia.org/wiki/N_ray (N Rays is also a good example for other lessons such as confirmation bias and the need for double blind tests.)

When EmDrive survives more experiments, we will have no choice but to accept that it works. Until then it is a candidate technology that currently works on ghosts and magic.

If you are a betting man, then go with scientific consensus. The device probably doesn't work. However do not forget there is no shame in suspending judgment on the matter until more data is in. Notice that I avoided saying outright it doesn't work.

[Northstar1989]

I read both the OP and the report in detail. The main section of the paper describes the procedure for evacuating the chamber, meaning that they certainly did test that the chamber could be brought down to 5 millionths of a Torr. But they never state explicitly in that section that they actually ran these tests in vacuum.

And there are TWO places where they state that they didn't. Once in the original abstract, as you pointed out in the OP, and a second time in the conclusions. Here is the second mention once more:

They had to run the experiments at ambient pressure because their RF amplifiers could not be run in vacuum! Their amplifiers were built with electrolytic capacitors, which tend to go "boom" in vacuum (both destroying the amplifier and releasing chemicals that go on to contaminate your instruments and the vacuum system itself). I'm sorry, but as an experimental physicist it is clear to me that this work was not (and could not) be run in vacuum. The fact that a crucial point like this was obfuscated just goes to show how poorly written a paper this is.

I hate to be "that guy" who gets drawn into an online debate with a Believer, and I am pretty sure that nothing I write here will sway you. But as a member of the physics community, I feel obligated to answer extraordinary claims that I see voiced in a public forum. And now that I have done so, I feel that my duty is done.

Sam, you may or may not be correct. I will admit the paper was obfuscated on the matter. It *is* possible that they ran *some* tests in vacuum, and other not, for instance (they actually tested multiple devices- the paper is on only *one* of those devices, whereas the Q&A refers to multiple).

Things are unclear- which is why I'm inclined to believe the writers of the Q&A, who (presumably) had greater access to the original authors than you or I do. They quite clearly state vacuum tests WERE performed.

I'm *NOT* stating the device works. It's inaccurate to categorize me as a "believer". My main gripe was that people dismissed the paper for completely illegitimate reasons- namely that "it's impossible so we won't believe it" (if you don't allow anything to challenge your dogma, your views can NEVER change- and may not necessarily be correct), and criticism by people who couldn't even be bothered to read the proper paper or do any background research, and didn't understand the purpose of the "null" device (they thought it was a negative control- which it was *not*).

The device MAY OR MAY NOT work. But it needs to be criticized for the RIGHT reasons. Mistakes the authors actually made- not ones we imagined. And the "extraordinary claims require extraordinary evidence" bit is in DIRECT contradiction to good science (where the evidence must come first) when used in the manner you and most people are using it. For one, your assumption that a claim is "extraordinary" is predicate on the verity of the law/theory which it contradicts in the first place. You CANNOT start from the perspective a theory is correct- even a very old and well-backed one. You MUST assume there is a possibility that all previous thought on a subject is wrong, and be open to change and innovation- and then CAREFULLY examine the evidence. THIS is good science.

Mind you I don't mean to pull your words out of context, but you and other physicists are overusing that simple, dogmatic statement. It *IS* possible there are exceptions to the Conservation of Momentum- just because we hadn't found them *yet* (or possibly, up until now- *if* the EmDrive/Cannae Drive pans out) doesn't mean they don't exist...

Regards,

Northstar

[Northstar1989]

Yes, I have read the full paper multiple times, and found the evidence to be lacking. As a "fellow scientist", you should also know that extraordinary claims demand extraordinary evidence. Conversely, ordinary claims only demand ordinary evidence. Against their extraordinary claim of reactionless force, I propose a completely ordinary explanation (thermal interaction with ambient atmosphere), which is completely in line with what was reported in the paper.

Sam, the evidence is clear-cut and simple. Yes, there are possible flaws/holes in it (thermal interactions with the atmosphere, *if* no tests were not really performed in a vacuum as the Q&A quite clearly states some, but not all tests *were*), but the evidence is not lacking- only imperfect. You, of all people should know better than to obfuscate words like this.

Or perhaps, maybe you don't. What you said next doesn't *necessarily* prove your perfection as a scientist:

(In case this was a question about my scientific qualifications, I have 25 years of experience working in experimental particle physics and helped design and build part of one of the Large Hadron Collider experiments. My main area of expertise is detector instrumentation and data acquisition.)

You've been in the field 25 years. You've helped build one of the most expensive, but conventional, experiments in existence. By all accounts, *you are an establishment man*.

Now I'm not saying that's *necessarily* a BAD thing- in fact in many ways it's not. It indicates you *clearly* know a thing or two. You can get stuff done relying on conventional theory, and have the achievements to prove it. You are probably highly-respected in your field.

BUT, in many fields, ESPECIALLY in physics, the major breakthroughs *HAVE NOT* come from establishment men. They are simply too deeply rooted in conventional ways of thinking, and incapable of seeing things from another perspective. Never forget that EINSTEIN was a mere patent-man. Stephen Hawkings was not always so famous as he was now- and at one time much of the physics community *laughed* at ideas like his. And there are countless more examples like that from other fields.

In my own field, Biology, I can think of quite a few prominent examples. Darwin, just for starters, was a mover and a shaker- NOT an establishment man. In fact, many of the prominent biologists of his time initially tried to DISCREDIT his ideas. They are now well-accepted as very firmly-established scientific fact.

In more recent times, and even more closely related to my sub-specialty in biology, the nature of Cancer and of Stem Cells have both been subject to exactly the same type of radical shake-ups not one, but SEVERAL times, and they will likely continue to be in the future. Old and well-established ideas simply CANNOT be blindly accepted as fact.

You can't get much more clear-cut in a violation of the Conservation of Momentum than a working reactionless propulsion drive. And *so far*, we have not one but *TWO* reactionless drives (the EMDrive and the Cannae Drive) that *DO* appear to work. Mind you, it *may* all turn out be bunk when they perform additional tests (such as new/better vacuum-tests). But you *CANNOT* simply shrug off such important evidence to the contrary of a well-established "Law", simply because the law is well-established.

Regards,

Northstar

[Northstar1989]

There is no evidence that it does work.

Thrust and force are not the same thing.

Thrust in an atmosphere and thrust in space, are not the same thing.

A force was measured, there is currently no evidence that it can generate that force in a vacuum/space.

Therefore, your claim is BS.

KerikBalm, be careful when throwing around terms like BS. Not only are they against the spirit of the forums, but if anything they would better be applied to simplistic dismissals of relatively clear-cut experiments.

It's true that other things can cause the force aside from thrust, but the experiments they performed *were* of the types normally used to try and measure thrust, and *did* appear to measure it.

Because certain precautions may or may not have been taken, it is impossible to know *for sure* if the results were valid yet. But simply saying "A appears to be Y, but A *could* be X; therefore A it *must* be X, and any claim that A is really Y is bogus" is terrible logic, and I think you know better.

Regards,

Northstar

P.S. Just a side-thought, but have you ever even considered that there might be active efforts to SUPPRESS this "discovery" (if it does turn out to be such), simply because it challenges the position of those who thought it impossible? I'm not talking a conspiracy-theory here, I'm talking about the repeatedly-observed tendencies of human beings in positions of power and authority to do everything they can to try and preserve that authority. Time and time again in human history, senior scientists have tried to suppress what turned out to be major scientific breakthroughs, simply because the breakthrough was perceived to challenge their authority by saying that they were actually *wrong* about certain things...

Edited November 2, 2014 by Northstar1989

[Northstar1989]

I hate to present so many walls of text, but there is one final story I want to relate, which might be enlightening to some of you guys...

My second semester of college, I took a physics course designed explicitly for physics majors (I had already demonstrated considerable talent in physics in a non-majors physics course my first semester. I was the *ONLY* non-physics major in the room, and in hindsight I do believe the professor was trying to gently recruit me to switch my major to physics, just as a later professor tried to do with psychology...)

The instructor of that course, a brilliant, quirky, but lovable elderly professor, said something *very* enlightening to the class, that I have always carried with me since. My paraphrasing may not quite do it justice, but I'll attempt to re-capture it below:

"The productivity of physicists declines SHAPLY after about age 30. Most of the major breakthroughs in the field have come from young, up-and-coming guys; NOT old-timers like myself. Why do you think that is? Part of it must be that we lose some of our creativity and mental vigor when we grow older, but I also do believe that part of it is that only the new guys have the capability to see things from a different perspective. Einstein was brilliant because he was the rare exception to this rule- he managed to maintain much of his creativity and innovative nature well into old age and eventually after many years being submerged in the field. I do believe that any good physicist needs to try and maintain a youthful optimism and skepticism of established concepts as well as a healthy respect for that which has already been studied before his time."

It may be enlightening to note that one of this professor's many areas of research- actually more of a "side project" to his main work dealing with high-powered lasers, was on the "quantum vacuum"- the state of a space when *all* particles are emptied out of it, and the occasional spontaneous appearance of particles within (and subsequent disappearance from) this space as predicted by the Heisenberg Uncertainty Principle (for more context, I advise carefully reading the Wikipedia article on Vacuum State).

He *firmly* believed in the existence of vacuum fluctuations, and was researching whether there were any potentially useful applications for them. I would *not* be surprised if he had at some point drawn up an idea for an EmDrive or Cannae Drive himself (as a way of acting on these vacuum fluctuations- one potential explanation of how the drive works that does *not* technically violate the Conservation of Momentum), and simply abandoned it as he thought nobody would believe or be willing to test the device...

The greatest struggle for researchers (in physics, or ANY field) with new and innovative ideas is the crushing weight of convention that attempts to stifle precisely those sorts of ideas. I may be biased as a young scientist, but I *strongly* believe that while such convention does have a role, senior scientists take it MUCH too far- probably based partially on their own self-interest, and partially on so many years of thinking a certain way about some subjects that they are unable to *truly* entertain any idea that runs contrary to that way of thinking...

The ignorance and inability to comprehend advanced science of the lay public is ALSO a major issue, but one to be expected- and I won't even bother commenting further on that...

Regards,

Northstar

Edited November 2, 2014 by Northstar1989

[N_las]

Northstar, as much as you repeat that those devices appear to work... The papers simply don't provide enough evidence. For starters, there is NO explanation given, not even a rough idea, how those devices should work. They only throw around words without any explanation. There is no theoretical estimation how high the thrust from the drive should be. From this perspective, the drive is just a random assortment of parts ...which by sheer luck works like an reactionless drive? There is only a miniscule force measured, which could come from a thousand different sources. Anybody who made a few proper scientific experiments during studying physics can tell: Such small forces can come from anywhere. For simple mechanical experiments like an undergrad would do, they are simple background noise and can be disregarded. If you really are planning to do an experiment to measure such small forces, 99% of the work behind experiment will consist of hunting down the most insignficant sources of noise and eliminating them. The biggest part of the paper would be a discussion of how one can be sure that the measured thrust is really real.

From the actual paper one can't draw the conclusion that the device works. Not even that is SEEMS to work.

BUT, in many fields, ESPECIALLY in physics, the major breakthroughs *HAVE NOT* come from establishment men. They are simply too deeply rooted in conventional ways of thinking, and incapable of seeing things from another perspective. Never forget that EINSTEIN was a mere patent-man. Stephen Hawkings was not always so famous as he was now- and at one time much of the physics community *laughed* at ideas like his. And there are countless more examples like that from other fields.

What do you mean "Einstein was a MERE patent-man"? He was a physicist with a degree. He just worked for some time at a patent office. Thats like saying: "This physicist worked at McDonalds once during his college time to earn some money. Therefore he wasn't an established physicist but a mere burger cook!"

And I am not even sure what you mean in regards to Hawking. Someone "laughed" at ideas like his?

Can you bring up an ACTUAL example an major breakthrough in physics that has come from an "unestablishment" guy? What do you even mean by that? Someone who didn't had a dregree in physics?

Because certain precautions may or may not have been taken, it is impossible to know *for sure* if the results were valid yet. But simply saying "A appears to be Y, but A *could* be X; therefore A it *must* be X, and any claim that A is really Y is bogus" is terrible logic, and I think you know better.

- A could be Y or X or Z or any number of things... There is really no proper control to know anything about what A is... The only thing we know is "we measured A"

- Therfore the claim "A appears to be Y" is bogus

P.S. Just a side-thought, but have you ever even considered that there might be active efforts to SUPPRESS this "discovery" (if it does turn out to be such), simply because it challenges the position of those who thought it impossible? I'm not talking a conspiracy-theory here, I'm talking about the repeatedly-observed tendencies of human beings in positions of power and authority to do everything they can to try and preserve that authority. Time and time again in human history, senior scientists have tried to suppress what turned out to be major scientific breakthroughs, simply because the breakthrough was perceived to challenge their authority by saying that they were actually *wrong* about certain things...

Do you have an actual example of that? It sounds like the plot of an interesting movie, but not like reality.

Edited November 2, 2014 by N_las

[Frozen_Heart]

the drive is just a random assortment of parts ...which by sheer luck works like an reactionless drive

Pretty much a K-drive then...

Edit: Surely if sure if thrust is dependent on power, they should just link one directly to a power station. If it punches through the roof its theory validated?

Edited November 2, 2014 by Frozen_Heart

[N_las]

Surely if sure if thrust is dependent on power, they should just link one directly to a power station. If it punches through the roof its theory validated?

That's the thing. If we would have a theoretical description of how the drives is supposed to work, then we could make considerations like that. But we have no possible way to know if and how the thrust depends on power, since there is no idea behind it. For all we know, the thrust could be greater the lower the input power. Or the thrust could be greater on sunday evenings and christmas.

Edited November 2, 2014 by N_las

[CptRichardson]

Let's say that this IS an atmospheric only thing if the worst case is true. That still provides much more available thrust to us if we can get superconducting versions work as experimental data suggests. Space becomes that much closer, as you now only have to provide rocket thrust above the bulk of the atmosphere, and you can theoretically speed up to nearly orbital velocities while at 10 miles up before pulling up in some crazy KSP-esque maneuver.

Even the worst case scenarios for this drive suggest that there is something incredibly useful to be gained from these things, and we would be fools to ignore them.

[N_las]

How is this the worst case? The worst case is, that the force is just an artifact in the experment. There is no experimental data that suggest a "superconducting version" would work better. There is no real explanation for how the effect should work. For all we know, a "superconducting version" could work worse not better.

There is "something incredibly useful to be gained" in every experiment. Nothing special about this one. It is just naive to EXPECT anything incredible.

[Guest]

What do you mean "Einstein was a MERE patent-man"? He was a physicist with a degree. He just worked for some time at a patent office. Thats like saying: "This physicist worked at McDonalds once during his college time to earn some money. Therefore he wasn't an established physicist but a mere burger cook!"

And I am not even sure what you mean in regards to Hawking. Someone "laughed" at ideas like his?

Can you bring up an ACTUAL example an major breakthrough in physics that has come from an "unestablishment" guy? What do you even mean by that? Someone who didn't had a dregree in physics?

He meant that until he started cranking out big theories, he had little impact on physics. If a physics student (or a guy who just finished studies) made a great discovery while still working at McDonald's, then you could say a similar thing. Einstein was not any sort of university professor when he first started on his theories. Northstar didn't meant "unestablished" as "lacking a degree", but rather "not known for other, prior achievements". And this is true. It does seem that scientist either makes a groundbreaking discovery (and spends life either polishing it or teaching it), or spends life teaching and making small steps confirming the already established theory. There is little middle ground in there, very few "old timers" actually came up with really new stuff.