Talk:EmDrive

Bloody biased article

This article is so biased that reaches the point of causing nausea... C'mon guys, is impossible to this point to look at the question without wanting to burn Shawyer alive because he committed the "heresy" of suggesting that what he is doing is not "magic"? What will you do after that, burn witches? I do not need to be a PhD to see what he suggests makes sense, deserves at least a "ok, let's try this and see what happens" rather than making ridiculous suggestions that he should be banished from the scientific community for trying.

Analysis

Can someone edit the analysis page, it was blatently written by someone who hasn't read either the New Scientist article or the more recent Eureka article. It doesn't violate either the conservation of momentum or energy, as it uses energy!

Every article on it specifically states that when the equipment accelerates it loses thrust. If anyone would like to check, this happens with every form of propultion and just because it doesn't spew matter out of it doesn't make it reactionless.

If it violated the conservation of energy, why would it take kilowatts of energy to run. If it actually violated the conservation of energy (like has never been claimed, and refuted in every article) it wouldn't take energy to run as you would be getting more energy out than in and at that point I doubt he'd need grants as he'd be able to make free energy and become the richest person on the planet after undercutting the prices of every power company.

The nice wholely verbose and highly infantile argument by 'Dr. John P. Costella' shows just how little attention he paid to the articles. He forgets fundamental facts of science, claiming he's disproved it by using particles to explain how a tapered WAVEguide won't work. Almost a century of physics was spent figuring out if light was a wave or a particle, and people won nobel prizes for proving both right.

He insults Shawyer, the absolute worst thing you can do when criticizing someone, all it screams is that Costella is incompitent and can't get enough evidence to prove his own point.

Costella is worse than a fraud, he's blatently ignorant.

Simply looking at the quantum theory of momentum disproves Costella, as it's based on waves not particles. He also completely ignores the conservation of four-momentum, which brings energy into the equation. As the equipment is storing aprox 17MW of energy, that should equate to the system gaining 0.002 grams in mass. However, there's no mention of basic theories that the EMdrive relies on.

Costella would have had a perfectly valid argument, without research, saying that Shawyers' apparatus could not gain more than 0.002 grams of thrust in any direction. Yet no, this Ph.D does zero research even though he claims to have gone on the 'net' to even look for something to disclaim Shawyer. This only serves to prove that Ph.D's are useless and can't even research after they've spent near a decade of their lives researching to get a Ph.D.

I don't have a Ph.D and it took me a few minutes to find a resonable basis for an argument AGAINST my point of view. So please, someone edit it before I delete the whole damn portion as being useless and bias as it's not an analysis at this point it's plain criticism. —Preceding unsigned comment added by 86.137.68.79 (talk) 20:48, 11 October 2007 (UTC)

Unfortunately, it violates conservation of momentum. It can be shown that if it violates that, then it inevitably violates conservation of energy as well, due to relativity considerations, in at least some inertial frames of reference. Shawyer tried to avoid that by asserting conservation of energy in his derivation, but because of lack of conservation of momentum, his derivation only holds in one reference frame, unlike Newtonian mechanics or Special Relativity, where it holds in all.WolfKeeper 02:11, 12 October 2007 (UTC)

The esoteric General Relativistic effect of asymmetric frame drag allows a very small force. It appears only in relation to the drag itself and not the energy expended. I have said before that Shaywer's theory is likely incorrect, but the effect he sees is a real esoteric frame drag. He postulates increasing efficiency to make cars float, for example. This is in error as it follows a failed theory. I predicted a five pound force as a sun probe. Near earth a small mass drag is far less. It does violate as with all drag. A photon has an odd property making only radiowave/light/etc. cause true asymmetry.

--74.9.129.85 (talk) 21:35, 10 March 2008 (UTC)

The creator asserts it does not violate the conservation of momentum or energy, the Wikipedia article asserts indirectly that it does by labeling it a reactionless drive (which the creator also disputes) and proceeding with criticism on that front without any citation of analysis of the actual drive or mathematics itself. That is why this section is original research, that is why this section is biased POV, that is why the Analysis section should be removed. If someone wants this information so badly, they should find some analyses of the drive and its theoretical underpinnings and write a wikipedia article on the controversy directly and actually cite it. Unless someone here can create a detailed analysis based on actual information and post it on their own site, they are playing armchair science critic and that's POV. This isn't even about whether or not the drive even works theoretically.

Whatever Costella's credentials and background, he is entirely correct and this Wiki entry should be deleted as being an 'accessory before the fact' in a blatant fraud. Moreover, it is a very sad modern trend that those with no knowledge of physics (but a great fondness for philosophical double-talk) defend crackpots in a knee-jerk manner and simultaneously accuse experts of - in effect - being brainwashed by their own expertise. Defenders of the concept should ask themselves how the situation differs from the old kindergarten puzzle about whether one can reduce the postage on a package of bees by stirring them into flight before putting it onto the scales. It doesn't: microwaves are not 'magic', and relativistic arguments change nothing. Also, those who cite quantum mechanics should check out what the 'correspondence principle' implies. Magazines such as New Scientist and Wired should be censured for even mentioning Shawyer; his only proper place is in the pages of Fortean Times or some ufology fanzine. Above all, (more) questions should be asked in Parliament about the quarter of a million pounds of public money which has already been squandered on this nonsense. — Preceding unsigned comment added by 81.147.128.77 (talk) 13:03, 18 September 2011 (UTC)

151.148.122.100 (talk) 15:44, 26 September 2008 (UTC)

Flight International

The EM drive is briefly mentioned in the news section of Flight International (26th May 2008). The news short said that the EM Drive woudl be presented as a thruster design for station keeping on satellites at an astronomy/space convention in (I think) London. News short makes no mention of technical feasibility or junk science. Haven't added it to the article yet because that's the extent of what I can remember from memmory. I'll add the details to the article after checking details today.ANTIcarrot (talk) 09:36, 27 May 2008 (UTC)

Presentation at Space '08

A presentation on the EmDrive were given at the Space '08 - slides available here: http://www.rocketeers.co.uk/?q=node/330

The wiki article here suggest that the EmDrive violates conservation of momentum or energy, which it's inventor says is not the case. If you want to keep the claims regarding violation of laws of physics in the article, you will have to show (with citations) that these violations actually exist in the theory of the EmDrive - anything else is intellectual dishonesty.

The claims made about the EmDrive's performance by its inventor sounds like science fiction - but so did rocket propulsion in space in its day. I'm no rocket scientist, but I see stuff going in (solar energy) and stuff going out (thrust) - I do not see how this system violates the laws of conservation. Present your proof that it does, or suffer my flaming sword of editorial justice. —Preceding unsigned comment added by AndersFeder (talk • contribs) 03:16, 13 September 2008 (UTC)

Energy and thrust are two very different things. If you saw someone put apples into an empty bag and then found that it was full of oranges, you wouldn't just say "well they're both stuff, so that explains it". Apples don't magically change into oranges. So you'd want a proper explanation. Likewise thrust is a very different thing from energy, so you don't expect to put energy into an item and magically get thrust. If it turns out that you do then you need a good explanation for that. As for conservation, there are two things that have to be conserved for devices operating according to our current understanding of physics. The first is energy and the second is momentum. While people can agree that a device like an ion drive conserves both, they find it difficult to see how a device like the Emdrive can conserve either. However proof is in the pudding. If the Emdrive works as advertised then it's up to the theoreticians to explain why, either by showing how it conserves the two quantities or by showing why there is an exception. Most theoreticians find it a lot easier to just claim that the device doesn't work. -- Derek Ross | Talk 06:10, 13 September 2008 (UTC)

I was not saying that Shawyer's claim are explained or even plausible, but merely that the article does not show the violations of physics that it claims the EmDrive exhibits. You will also note that putting apples into an empty bag and then subsequently finding oranges in it does not violate any laws of physics. The absence of evidence (that the bag's change of content is physically sound) is not evidence of absence (of physical soundness). I think the point where the article breaks down is when it, without citing any sources, asserts that the EmDrive is a reactionless drive. The only one who knows what the EmDrive is or isn't, namely Shawyer, specifically has said that the EmDrive is not reactionless. The unverifiable claim that the EmDrive is reactionless is idle speculation on the part of whoever authored that section and has no place in Wikipedia. I'm no physicist (though someone who were once told me that E=mc² and that p=mv, which naively(?) could be interpreted as p=(E/c²)v) - I'm just taking issue with the quality of this article. AndersFeder (talk) 22:52, 17 September 2008 (UTC)

The elements that go to make up an apple or an orange are not the same, so yeah, it would violate physics.- (User) Wolfkeeper (Talk) 23:18, 17 September 2008 (UTC)

It really wouldn't as I could have exchanged the apples with oranges without you noticing, which would be in perfect accordance with known laws of physics. --AndersFeder (talk) 03:40, 18 September 2008 (UTC)

Yes, fraud like that is in perfect agreement with the laws of physics ;-)- (User) Wolfkeeper (Talk) 22:30, 26 September 2008 (UTC)

The p=(E/c²)v) equation is great for showing how the momentum of a photon is related to its energy but unfortunately it doesn't tell us anything about thrust which is a force, ie a change in momentum per unit time. You need other equations for that which I will mention in a minute. In the meantime. I can agree with Shawyer's claim that the device doesn't violate conservation of energy. However his claim that it doesn't violate conservation of momentum is a bit more controversial. Shawyer's claim that that the device isn't reactionless is really another way of saying that it doesn't violate conservation of momentum. Now his claim is based on the fact that photons can change their mass but not their velocity. This is completely different from normal non-relativistic conservation of momentum where items can change their velocity but not their mass. Thrust is normally calculated as F = m * (v₁ - v₂) / t, whereas Shawyer is basically calculating it as F = (m₁ - m₂) * v / t. His opponents say that you can't do that. That's why they claim that his drive is reactionless and he doesn't. -- Derek Ross | Talk 00:23, 18 September 2008 (UTC)

That's interesting. But is his claim then not in fact contingent upon conservation of momentum? When the photons shed mass, something have to respond with an increase in velocity to conserve momentum? Or where does the mass in fact go when photons change mass?--AndersFeder (talk) 03:40, 18 September 2008 (UTC)

Well, I guess that he would say that the thing that responds with an increase in velocity is the drive and whatever it's attached to. In other words --

((m₁ - m₂) * v_photon) + (m_device * (v₁ - v₂)) = 0

-- and that's why the momentum of the overall system is conserved in his view. As far as I'm concerned the real difficulty is in the shedding of mass by photons. The only way that I know of doing that is to aim them straight up through a gravitational field. However he seems to think that he can do it via repeated reflection within the shaped cavity of his device. Maybe he can. We should know soon. If his superconducting version works as predicted it will demonstrate forces far too large to be ignored. As for where the photon mass goes, presumably it is converted into the kinetic energy of the device itself so that conservation of energy holds for the overall system too. -- Derek Ross | Talk 07:20, 18 September 2008 (UTC)

Look, when this first came out, it took me a few days to prove that, as described, this thing cannot possibly work. By work I mean, it cannot give you any *net* acceleration. So you can't switch it on, accelerate with it, then switch it off and maintain the velocity. For if it does that, it violates *both* momentum and energy conservation laws, and I was able to show you could build a perpetual motion machine. The reason is simple, if you can use it to change reference frames, in the initial reference frame it gains kinetic energy and (presumably) loses power from its power source. But in the final reference that it ends up in, since you switched it on, the kinetic energy has gone *down* as well as the loss of power in its power source. Where has this energy gone? Some has gone as heat, but only a proportion. Where's the rest of it? Because it has no external propellant emitted, there's nowhere for this missing energy to have gone (unlike rockets). It's just a mistake or a fraud, it can't work with any physics as we now know it. The same argument holds in relativity, and this thing is supposed to be relativistic.- (User) Wolfkeeper (Talk) 22:24, 26 September 2008 (UTC)

Biefield-Brown effect

Just read this guys blog, claims the device works on the principle of the Biefield brown effect. In short, the device does create some thrust, by the movement of charged ions throughout the device // ion wind //, but it would do precisely zero in a vacuum. Anyone familiar with the details of this concept?

http://www.rocketeers.co.uk/?q=node/349 —Preceding unsigned comment added by 217.34.37.92 (talk) 10:47, 26 September 2008 (UTC)

Could be. Vacuum testing on the EM drive would be essential to rule out causes of this type. Bit late to find out how much money you've been wasting if you have to wait until it's out in space. By the way, the blog link to the report on the NASA investigation of the Biefield-Brown effect was well worth reading. It gave a very solid (and not at all esoteric) explanation for that effect, whether or not it has anything to do with the EM drive. -- Derek Ross | Talk 14:57, 26 September 2008 (UTC)

Yeah I will be very interested to see what happens when you pop the EM drive in a near vacuum, im kind of surprised this hasnt been done already considering a) the drive is specified for space travel, and b) there is a well known effect which could potentially explain the function of the EM drive without destroying the laws of physics. Im actually considering emailing Shawyer, not that hed ever see it, just to get his opinion on the subject. —Preceding unsigned comment added by 217.34.37.92 (talk) 14:22, 3 October 2008 (UTC)

Unfortunately the Biefeld-Brown case was also fraud. Brown was the typical crackpot inventor and Biefeld was a highly respected academic and astronomer. However, by the time that Brown exploited him, Biefeld was clearly suffering from senile dementia (he was once found wandering around a strange city of no memory of how he got there). Nevertheless, 'electrogravitics' attracted a great deal of attention from 'high-tech' companies until a damning report from the Office of Naval Research outed Brown as a nutter. Among other things, he claimed that his instruments could detect changes in the Dow-Jones Index. It is very sad that Brown, Tesla, etc. are still referred to with awe, when they should be cited only as pseudoscientific fraudsters. — Preceding unsigned comment added by 81.147.128.77 (talk) 13:20, 18 September 2011 (UTC)

Northwestern Polytechnical University

Recently, Shawyer said researchers at Northwestern Polytechnical University (NPU) in Xi'an under the supervision of Professor Yang Juan independently created a mathematical simulation showing that a net force can be produced from a simple resonant tapered cavity. Shawyer said that NPU is currently manufacturing a drive based around this theoretical work. Yang Juan confirmed the results of the mathematical simulation, also saying that NPU is building a part of the drivee and that results had been submitted to a journal.

Moving this paragraph from the article, as I can find nothing more reliable than the cited Wired blogger's report on an interview with Shawyer. As Yang appears to be a legitimate published researcher, our biographies of living persons policy comes into play. The blogosphere certainly seems to have noticed this, though, so it would not surprise me to see better reporting in a few days if this is as it appears (and maybe even a mea culpa or two later on when conservation of momentum is upheld, demonstrating once again that the laws of physics apply everywhere). If there is nothing more than exaggeration, misunderstanding, and poor fact-checking to this story, though, it should remain excised. - Eldereft (cont.) 21:25, 26 September 2008 (UTC)

Yes, it is a blog, but seems fairly reliable. It includes quotes from Yang Juan (or it did, see below), so it can't just be an interview from Shawyer- else it would be much more suspect. I just now put back in the claim that it has be submitted to a journal, which is what the article says Juan said. However, I think the article has changed since I wrote the piece. It had that claim in it, and as I recall, it was sourced to Juan himself, not shawyer. It definitely said it was submitted to a journal and was under editorial review, as I remember (I'd never have manufactured that claim). So, this indicates the sources has something fishy about it. For some reason, it seems to have changed (and thus not everything I just said is true). Might be better just to wait for better sources. ——Martin^phi ☎ Ψ Φ—— 22:04, 26 September 2008 (UTC)

Anyone can submit anything to a journal. It's getting it published by a reputable, refereed, journal that is the trick ;-)- (User) Wolfkeeper (Talk) 22:13, 26 September 2008 (UTC)

The Reliable Sources Noticeboard] might disagree, but I would put this on the RS scale somewhat below a regular column in Wired, but well above a random WordPress account. By putting their imprimatur on the blog, the magazine is staking some reputation on the accuracy of the content and its relevant to their target audience. Two minutes of poking around did not yield a statement of editorial control or a vetting process, though. I only checked the English version of NPU's website, so we might be missing the obvious source. I am happy to wait for better coverage on this one, but if someone else actually is working on a prototype it is a pretty big deal and should be treated by this article. As a side point, to have manufactured that claim would have been drastically out of character for Martinphi. - Eldereft (cont.) 04:30, 27 September 2008 (UTC)

Yeah... but unless my mind is playing tricks it changed, so it isn't being very reliable at the moment. And thanks for the compliment (: I think there was more to this paragraph "The NPU have confirmed that they have reproduced the theoretical work, and are building a demosntration version of the Emdrive." I spent some time looking, and I doubt there are any better sources out there. ——Martin^phi ☎ Ψ Φ—— 07:15, 27 September 2008 (UTC)

Laymen should ignore such 'confirmations' and instead check out Langmuir's analysis of 'pathological science'. Initial confirmation from 'reputable people' is, in fact, the norm. It happened with cold fusion, for example. — Preceding unsigned comment added by 81.147.128.77 (talk) 13:29, 18 September 2011 (UTC)

Requested rename

The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section.

No consensus to move. Vegaswikian (talk) 01:16, 29 April 2010 (UTC)

EmDrive → The 8 September 2006 Issue of New Scientist — This article focuses much more heavily on the date and title of this publication than the EmDrive itself. 76.27.230.215 (talk) 07:22, 22 April 2010 (UTC)

• Oppose Horrible name, and that issue does not solely cover the EmDrive either, so that name is wrong. 70.29.208.247 (talk) 05:25, 23 April 2010 (UTC)

• Oppose The name is the subject of the article Racklever (talk) 06:40, 23 April 2010 (UTC)
• Oppose Horrible name.--Oneiros (talk) 13:55, 24 April 2010 (UTC)

The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Automate archiving?

Does anyone object to me setting up automatic archiving for this page using MiszaBot? Unless otherwise agreed, I would set it to archive threads that have been inactive for 30 days and keep ten threads.--Oneiros (talk) 14:03, 24 April 2010 (UTC)

Why? Typically you leave three discussion on the talk page, and there aren't that many discussions here at all, nor are they long. Setting up auto archiving when you don't need it just loads down various machines in processing things that don't need it, slowing Wikipedia, and the archival bots. 70.29.208.247 (talk) 02:27, 25 April 2010 (UTC)

Dr. John Costella

I read the citation that this article uses to assert that Dr. Costella is a credible critic and I do not believe he should be mentioned so much in this article. He is an irrelevant person, with no academic affiliation, and if not for his PhD he would have absolutely no basis to stand on. His attack on the EMDrive (which I also am skeptical of by the way) is ignorant and contains personal attacks. I am not a theoretical physicist, but I am a physics student at the University of Michigan and I believe that either a more qualified critic should be found or these challenges should be deleted. At the very least, the wording needs to be changed so the article doesn't sound like Dr. Costella is a resident expert on EmDrives.

You're probably right that he wouldn't be notable if it wasn't for his academic qualifications. On the other hand, he does actually have an academic qualification in the particular realm that the emdrive designers claim is the working principle behind it, and he does seem to be a notable critic of the drive.- Wolfkeeper 20:10, 26 April 2010 (UTC)

You can have a PhD and still make terrible and flawed arguments on a subject. Credentials should not excuse intellectual laziness. —Preceding unsigned comment added by 68.35.236.214 (talk) 17:09, 12 May 2011 (UTC)

Any 'intelligent schoolboy' could have made the Costella claim and have had a right to be believed without question. Scientific knowledge is not based upon the opinion of a few trendsetters (as pop culture is) but upon innumerable reproducible experiments which have led unavoidably to the consensus of opinion known as scientific laws. Any claim to have breached those laws, especially when it is put straight 'into production' without conducting any proof-of-principle experiments will always attract nothing but derision from professional physicists. — Preceding unsigned comment added by 81.147.128.77 (talk) 14:43, 18 September 2011 (UTC)

BUILD IT

Why, oh why is so little information given in the article about actual experiments both accomplished and underway with this technology? Over and over and over again we read excruciating detail about the theory behind the drive and analysis of the negative aspects of this.

Unfortunately, the article almost completely avoids any positive results or detailed analysis of actual experiments. Comments by skeptics are given more than adequate exposure. But there is virtually no countervailing commentary about the results of experiments or comments by those who witnessed them that call into question the skeptical arguments. Only ONE SENTENCE in the article deals with Chinese confirmation of the theory and NOTHING WHATSOEVER is said about THAT analysis.

Experiments make or break theories. This article and indeed this discussion page is NOT written from a Neutral Point of View (NPOV) but rather with a strong bias against the technology bordering on pseduoskepticism. There absolutely should be an examination of the weaknesses of skeptical comments given the stakes of the outcome in this matter. And experimental results ABSOLUTELY MUST be a cornerstone of challenges to any skeptical comments.

I can think of no better example of misplaced skepticism than that aimed against of another flight technology in the not-so-distant past. According to highly credible, learned people making the rounds on the rubber chicken circuit of the day, aerodynamic flight violated Newton's sine-squared law. We now know that this law only applies to hypersonic flight, not slow speed flight such as the one the Wright Brothers made. Their experiments proved beyond all doubt that heavier-than-air craft could fly. And not to put too fine a point on it, we also know today that hypersonic craft can fly. Theory and opinions by skeptical experts mean nothing when it comes to proving anything. It's the experiments that provide the proof of a new technology or disprove it.

Shawyer has outlined a theoretical construct that explains enough to construct his drive and it's not all that difficult to construct. The rest of the story is what happens when it's actually built. To the skeptics I say, BUILD IT! SHOW ME that it does or doesn't work but DON'T try to convince me with opinionated discussions that cherry-pick the facts. There are other experiments now underway and these should be reported in the article with some detail, complete with available information about the individuals involved.

The tags at the beginning of this article note that it was nominated for deletion. It's too bad it wasn't deleted because the article, as written, is clearly biased and not NPOV. Perhaps if it had been deleted, a better article would have been forthcoming.

USER I —Preceding unsigned comment added by 174.17.138.253 (talk) 19:29, 22 May 2011 (UTC)

Implications of EM-drive success or failure

It occurs to me that the EM-drive can be used to settle the Abraham–Minkowski controversy experimentally. Basically, if the EM-drive works, Minkowski is right; if it doesn't, Abraham is right. -- Derek Ross | Talk 19:11, 12 July 2011 (UTC)