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The result of the move request was: not moved. Jenks24 ( talk) 08:51, 12 August 2014 (UTC)
EmDrive →
Microwave thruster – "Microwave thruster" is NASA's terminology for this type of propulsion, which is in the news right now due to a claimed successful test. Moreover, the article currently covers more than just the "EmDrive" design. While I'm mindful that the controversy over the original proposed design ought to be covered, if the successful test is replicated then the original controversy will be a mere footnote. I don't claim to be able to predict the future; I only think we should have the article at the generic, recognizable title.
Miscellaneous user (
talk) 17:09, 4 August 2014 (UTC)
According to some recent news, it appears that a NASA test of a US-built prototype of this device seem to show that it actually does work. The original NASA publication is here, though I'm not sure how to integrate this into the article. Would someone be able to assist? Grandmartin11 ( talk) 21:43, 31 July 2014 (UTC)
I was already working on it! Alanf777 ( talk) 22:12, 31 July 2014 (UTC)
I can only get to the first page of the NASA paper. They say they tested the Cannae version (as reported by Wired) -- 40 micronewton at 28W , but ALSO a "tapered" version, which is an emDrive -- 91 micronewton at 17W. The latter wasn't reported by Wired. Maybe we should wait until the story's picked up elsewhere. Alanf777 ( talk) 22:51, 31 July 2014 (UTC)
We now have multiple REFS to the same paper(s), which need to be changed to a named REF. I'll do it tomorrow if nobody else does it. Alanf777 ( talk) 22:44, 1 August 2014 (UTC)
It is said here that the test was run at the atmospheric pressure. I was reading the paper and couldn't find any mention of this. This is from NASA's paper:
-- 188.2.82.243 ( talk) 11:06, 5 August 2014 (UTC)
I have removed the claim that the tests "were performed at about a hundred-millionth of normal atmospheric pressure" because the cited source ( http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive) got that wrong. While the NASA AIAA paper does go into quite a lot of details of the vacuum chamber setup (see comment above mine), the paper also clearly states at the end "VI. Summary and Forward Work" that tests were conducted at ambient pressure:
This is already stated clearly in the first paragraph of the section "RF resonant tapered cavity thruster (EmDrive)". PS: I'm totally new to editing Wikipedia, I hope I didn't break anything! ;) Mr. Zet ( talk) 14:41, 12 August 2014 (UTC)
I realize there's bound to be a bit of sloppy terminology surrounding a subject such as this, but I must ask, What is meant by the phrase "stationary relative to their thrust"? Does the new scientist article illuminate? I couldn't access it. I assume it means "stationary in the direction of the thrust", but then the question becomes "relative to what object?" The Earth? Spiel496 ( talk) 02:53, 19 February 2013 (UTC)
Quite like I misunderstand something, and maybe it's been answered already - but how can the device require an energy source but lose any energy? Where does the energy put into it go?-- Cyberman TM ( talk) 10:34, 11 August 2014 (UTC)
How the device works is presently considered pure speculation. In particular Shawyer's explanation concerning the mechanics involved, is thought to make no sense at all. The Chinese have proposed that this device produces an Electro-magnetic effect, whereby they provided a hypothesis and related equations. The Chinese explanation and equations somewhat match observed propulsion rates relative to the electrical input in Watts but not enough so that their explanation is preferred. If the NASA explanation has merit then additional explanations are needed since none of the above explanations address the perceived conservation of momentum problem. IMO few additional speculative explanations will be forthcoming if they also are contrary to modern physics theory, or classical mechanics such as the conservation of momentum. To have an idea of a possible explanation concerning what I am talking about, below is an example of such an explanation that would preserve the conservation of momentum but seemingly would be contrary to Quantum Mechanics and modern physics.
A hypothetical explanation of the mechanics of this engine: As the microwaves would build up inside the tapered chamber their intensity and density would build up within the chamber and their reflecting trajectories would "flatten out" and race around the internal periphery of the device. These high intensity microwaves would accordingly corkscrew toward the big end of the reflection chamber. If these microwaves are interacting with the Zero Point Field as NASA has speculated, then the Zero Point Field (ZPF) could, upon high intensity interaction with the microwaves, be spiraling out of the big end of the device creating a low ZPF pressure inside the device while being replenished by the ZPF flowing inward from the small end of the device. There could be a considerable flow of the ZPF through the device. If there would be such a ZPF flow-through then the conservation of momentum would be maintained and the device would also not be reactionless. The proof that this could be happening would require a test of the Casimir Effect at the big end of the device whereby the two plates or the Casimir test could be pushed together from a greater distance, meaning there would be a greater differential pressure in the ZPF outside the device, pushing the Casimir plates together if the explanation were valid.
From Shawyer's company's writings, and from "Wired" sources which was a witness to the testing of this device, the efficiency of this device was discussed. If valid this device and propulsion would be many factors better than present space craft technologies, potentially reducing costs by factors of 5 to 10, and reducing the time of travel for space flights from 1/2 to 1/5 present requirements for conventional propulsion. My explanation of this efficiency was deleted from my addendum to the main article. Of course it is speculation by "Wired" and by Sawyer himself but it is readily understood based upon an insight into the technology, as I have. I think this potentially great increase in efficiency relating to reduced costs and time of travel concerning space flight, may be the most important aspect of this technology if it is valid, so I think it should be at least mentioned. 11:47, 12 August 2014 (Fn) — Preceding unsigned comment added by Forrestnoble ( talk • contribs)
The electrical power losses Pe are assumed to be I2R losses, that means heat loss, so I don't see where anyone (inventor or critic) has claimed "no energy leaves the device". I'm going to take that bit out until someone points to a source somewhere that supports it. __ E L A Q U E A T E 21:40, 12 August 2014 (UTC)
"No energy leaves the device, but it requires an energy source. How does that work? Answering the above question:
The EM radiation being pumped into the system is turned into microwaves which are absorbed as heat by the resonance cavity of the device. At ambient external conditions this heat does not rise more than 30 degrees above ambient temperatures. There is a cooling system device and circulation for some internal components that draws off the heat. It is expected that it conducts and radiates its temperature away so that the temperature does not rise beyond desirable levels. In space I expect the cooling device and circulation system of the device would need to be larger. Also the device itself and a heat sink could be placed behind a shading sun-shield behind solar panels used to generate electricity for satellite propulsion and solar system missions once in space. For heavy-lift Emdrive devices on Earth or Mars, extensive cooling cryogenics are claimed to be needed for much larger superconductive high-voltage and Wattage heavy lift-to-orbit Emdrive devices, according to Shawyer. Once at orbital heights rocket power is thought to be preferable to get the cargo or passengers moving at orbit velocities more quickly than the Emdrive. Once above orbital velocities Emdrive would take over again to get to whatever desired speed is desired since Emdrive would accordingly apply a continuous force until the desired speed is reached. In the same way when approaching a desired destination, Emdrive could slowly decelerate the craft until orbital velocity was reached, then maneuver the craft and land it slowly with comparative ease. The device could take off at low speeds away from a planet without rocket assistance, but it would be less efficient since it could take weeks instead of just hours to reach the escape velocity of a rocket from Earth. Forrestnoble ( talk) 18:57, 24 August 2014 (UTC)
I cleaned up the addition to the article made recently by 208.113.47.50, about early proof-of-concept tests on the Q-drive (Cannae). It now better matches the description in the source. However, I'm not convinced the material belongs in the article. It was published on the company website at one time, but has since been removed. Does that still count as published? Spiel496 ( talk) 19:20, 26 August 2014 (UTC)
Currently there's an entire subsection on NASA test results on the Cannae drive which, while apparently similar to the EmDrive, seems to be something else. Thus that section seems rather off-topic. Dmatteng boldly split it off into a dedicated Cannae drive article (though the quality of the resulting article is debatable, as may be the notability of the Cannae drive itself), but Brian Everlasting reverted the split without giving an explanation for the reversal beyond "lack of consensus". Thoughts? Personally I don't think this article should conflate the EmDrive and the Cannae drive, the latter of which apparently is supposed to work according to a different set of highly speculative physics, and according to the NASA test results even "works" when it's set up not to. Huon ( talk) 16:40, 16 August 2014 (UTC)
It seems we might have a consensus re including inventor's claim that no physical laws are broken. Would someone go ahead and implement it? About this family of articles - I would propose to limit them to two articles then. The EmDrive will be just about the specific EmDrive implementation, and we will move Cannae Drive info to the general article. Dmatteng ( talk) 20:10, 23 August 2014 (UTC)
We cannot come to consensus that no physical laws of physics are broken since as the information states, there is no consensus as to how the device works. I think what we can come to consensus on is that it doesn't matter much what the inventors of these related devices say, or what the critics of them say, experimental testing of the devices have been confirmed by many different entities and witnesses a great many number of times. So whether the device works or not is not in question. These devices were not tested within a vacuum chamber because some internal components were vulnerable to damage based upon such a test. These components will be changed according to NASA and others. It was also noted that thrust was reported immediately upon the application of power, and ended immediately upon power disconnect. This did not leave any time for air currents to build up or subside as some criticisms have speculated. Shawyer claims no problems in vacuum testing were observed but independent vacuum testing needs to be conducted and confirmed before larger prototypes are built. The only questions after that, other than how does it work, seems to be how big these devices can be built and still work to produce higher, or very high thrust levels and lift capacity. It has already been noted that at present levels of thrust this device is better than any existing satellite propulsion system. 23 August 2014 (FN)
So IMO the only question is whether we can develop a functional Emdrive propulsion system without undue delays caused by naysayers that cannot understand how it works, and accordingly we need no flag at the beginning of the article concerning the validity of what is being said in this article Does anyone disagree? If not the flag should be dropped. The other flag for clarity seems appropriate, at least for a month of two longer. 23 August 2014 (FN)
That section has nothing about theory or development. It's more talk about the controversy. Kortoso ( talk) 16:28, 28 August 2014 (UTC)
I suggest people familiarize themselves with WP:FRIND, and WP:FRINGE generally. Article content can not be based on primary sources, particularly the vast volumes that were present in this article (also WP:OR). Second Quantization ( talk) 21:07, 2 August 2014 (UTC)
Reference 11 in the article provides a clear statement of the fundamental error that is at the heart of this problem: "For electromagnetic wave, energy of quantum is transferred at the group velocity vg, its momentum is p=mvg=hfvg/c2". The entire hypothesis of the EmDrive is built on this assumption, which is simply untrue. First, the assumption is made that radiation pressure is the result of the Lorentz Force acting on electrons in the surface of reflection. This is ably refuted by Rothman and Boughn ( http://arxiv.org/pdf/0807.1310v5.pdf ), and indeed the Wikipedia article on radiation pressure supports this. Second, quantum energy is transferred at the phase velocity, not the group velocity. These concepts are clearly explained in the linked Wikipedia articles Radiation pressure is unrelated to group velocity, which is really a rate of propagation of information rather than energy. The group velocity does vary but the phase velocity is constant throughout the frustum resonator, consequently there are no unbalanced forces. Danwoodard ( talk) 22:05, 8 September 2014 (UTC).
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)
-- 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)
I do not agree that the entry should be deleted, as it is widely noted in the lay press. Rather the flaws in the idea should be carefully identified to refute it. I've tried to do this isn the theory section. Danwoodard ( talk) 22:12, 9 September 2014 (UTC)
This talk page has over forty topics, is over 190,000 bytes, and contains discussions that are seven years old. Do other people agree it is time for some automated archiving, per H:ARC? Archiving is generally supposed to happen after about ten topics and the page being 75k.... __ E L A Q U E A T E 12:04, 10 September 2014 (UTC)
I have published a paper suggesting an explanation for the emdrive results. It agrees quite well with the data. I added it to this page and it was deleted. Please can we discuss this? http://www.ptep-online.com/index_files/2015/PP-40-15.PDF 81.156.122.132 ( talk) 21:13, 3 March 2015 (UTC)
An article appeared on IGN today, saying that NASA has found some of the beams of light they fired into this thing appear to have travelled faster than (the usual) speed of light. This seems like it should be incorporated into the WP article somehow? The IGN article is here. Xmoogle ( talk) 15:05, 28 April 2015 (UTC)
So, this article says the NASA experiment was repeated in a vacuum:
http://www.theverge.com/2015/4/30/8521691/nasa-seemingly-impossible-space-drive-test-succeeds — Preceding unsigned comment added by Special:Contributions/ ([[User talk:|talk]]) 19:11, 30 April 2015 (UTC)
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edit request to
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Change " with a greater area at the large end of the device" ( redundant ) to " with a greater area at the far end of the device"
99.35.153.179 ( talk) 00:16, 3 May 2015 (UTC)
I will to love reach consensus regarding my edits Quantanew ( talk) 22:38, 3 May 2015 (UTC)
I have heard this argument neither I or you are going to define this, let a consensus be reached Quantanew ( talk) 22:51, 3 May 2015 (UTC)
Your threat of report while a discussion is been made will constitute Wikipedia:TROLL. Quantanew ( talk) 23:08, 3 May 2015 (UTC)
There is no deadline and we need a third opinion all of this according to: Wikipedia:Edit_warring#The_three-revert_rule Quantanew ( talk) 23:08, 3 May 2015 (UTC)
Just to add the current sources on the whole article are not peer-reviewed sources. It was put on delete and the consensus was not to delete the article, obviously other editors considers this article important. This article is already in the category of fringe physics and hypothetical technology and with that in mind I just enumerate the potential applications of the technology, all of this cited by the current team a NASA JSC Eagleworks working on the device. Quantanew ( talk) 00:23, 4 May 2015 (UTC)
As will be seen below claims made for the EmDrive not requiring any reaction mass as fuel (Wikipedia article EmDrive) and any claims of generating motion without propellant ( Reactionless drive and Reactionless_drive#Modern_approaches) are at best suspect due to one of the main components in the drive, namely the magnetron ( EmDrive), requiring electric current to operate that will not be present until one thing occurs, this being the application of some form of energy on the input side of a transducer to cause the movement of electrons in sufficient quantity and with sufficient EMF on the transducer’s output side to power the magnetron.
First consider such substances as liquid hydrogen, oxygen or kerosene, regarded as reaction mass in rockets, sharing one characteristic with coal, natural gas and yes even uranium this having BTU content or the ability to release energy in the form of heat. See Energy Content in Common Energy Sources [2], Fuel Gases – Heating Values [3] and Heat Values of various fuels [4] as well as GJ to BTU conversion [5]
Second, Electricity_generation#Methods_of_generating_electricity and Electricity_generation#Turbines covers the process and the fuels (reaction mass) used to convert liquid phase water into gas phase water or steam to rotate a mechanism (turbine) turning a device utilizing electromagnetic induction to cause an electric current which ultimately powers the magnetron in the EmDrive at least here on the ground. The transducer in this case is the device driven by the turbine using electromagnetic induction to cause the electric current to flow to the magnetron.
Third, Since the use of fuels for the intermediate purpose of rotating mechanisms as above described is, it is hoped, obvious by its sheer bulk and weight unusable in space craft it falls to the form factor and internal design of the RTG on the Voyager spacecraft [6] from Voyager The Interstellar Mission and [7] from Radio Isotope Power Systems to provide a clue as to how furnish electrical power for the EmDrive’s magnetron in a space craft. As the total output of Voyager’s 3 RTGs [8] at the beginning of its mission might have been sufficient to drive the 300W magnetron sited in EmDrive#Second_device_and_New_Scientist_article the 800W magnetron in EmDrive#DTI_grant_and_first_device would have been out of the question. This raises the possibility of having to conduct studies into the feasibility of scaling up RTGs or whether an actual small uranium fueled reactor would be needed for a sufficient number of thermopiles (transducers converting heat into electricity) to even provide power for the 2,500 W input power magnetron sited in EmDrive#Chinese_Northwestern_Polytechnical_University_.28NWPU.29
History of rocket engines Rocket_engine#History_of_rocket_engines records a statement to the effect that the 13th century may have seen the first examples of rockets, albeit solid fuel, as we now know them. Liquid or solid fuel the operating principal is the same. The reaction mass (fuel) is directly converted into the force or high velocity exhaust that moves the vehicle.
With the EmDrive this 800-year-old direct model no longer applies. Instead there is an intermediate step, the transducer, that converts the thermal or heat energy of a fuel (reaction mass) into the electric current required for the magnetron to generate thrust in a resonant cavity.
VPR-80 ( talk) 13:09, 7 May 2015 (UTC)
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I cleaned this up a bit. Including an example of a discussion of resonant plasma thrusters from the 1990s, and more balanced coverage of EmDrive and other trademarked implementations of the idea. The title should probably be "RF resonant cavity thruster" to be inclusive. [If one or the other takes off, it may deserve its own article; for now they can all be sections here.] – SJ + 19:07, 9 July 2015 (UTC)
I'd like to modify the static thrust section to convey the notion that the specific thrust (in N/W) is not a constant, but really "rapidly decreases if the EmDrive is used to accelerate the vehicle along the thrust vector" [9]. Specifically, that decrease seems to negate the claim that the EmDrive could "lift a large car". In Earth's gravity, even hovering a car means the EmDrive would be providing an acceleration of 9.8 m/s^2. Or does "accelerate the vehicle along the thrust vector" really mean "there is velocity along the thrust vector"? Any other sources clearer about this? Or am I trying to decipher bullshit written about bullshit, so I should just give up? Spiel496 ( talk) 17:41, 9 July 2015 (UTC)
A "Criticism" section is missing from the article. Here is a first draft, feel free to contribute:
None of the tests were conducted inside Helmholtz coil to completely cancel Earth's magnetic field, thus all tests are susceptible to EMF (Electromotive Force) between currents running in the test setup and Earth's magnetic field. In the typical test setup, 10 Amps magnetron supply running on 1 meter wire under Earth's magnetic field exerts a force of more than 100 µN on the wire, which is in the same order of magnitude as the measured anomalous thrust. — Preceding unsigned comment added by 85.250.215.196 ( talk) 23:52, 28 July 2015 (UTC)
All this is WP:OR, or course, so we can't put it in the article, and you'd hope that experimenters would have both designed their experiment to eliminate the possibility of such a force being generated in their experiment, and also found a way to check that they had done so correctly, but it does show how difficult it is to do experiments involving these sorts of tiny forces.
Here's another example of how easy it is to think up mechanisms for experimental error: if I was an experimenter, I'd also want to investigate the possibility that unforseen parasitic RF rectification processes within the apparatus were not creating stray DC currents inside it, which would also interact with the Earth's magnetic field, possibly to generate forces of a similar magnitude. One way to check for this general class of effect would be to deliberately increase or decrease the magnetic field around the apparatus, and see if that caused the measured effect to change. Easy enough to arrange if the apparatus is already in a Helmholtz coil. -- The Anome ( talk) 11:04, 30 July 2015 (UTC)
I strongly support the existence of this article, but until the EM-drive is accepted by the general physics community as a valid effect, I believe the onus of providing "reliable source" is on the proponents of the technology, and not on the opponents of the technology.
Canceling earth's magnetic field using Helmholtz coils is a standard practice for measuring very low forces, search for "micro thruster" and "Helmholtz", for example [ [10]] and [ [11]]. Eletromagnetic forces are a significant source of errors in such tests, quote from second paper: "For example, a FEEP thruster has high voltage cables which may create electromagnetic forces disturbing the measurements".
Right now the article is all roses and promises, and missing any kind of "criticism" section, which is jarring. 85.250.62.87 ( talk) 12:10, 30 July 2015 (UTC)
This drive, em drive, is actually the old system began to study Soviet Russia, when its scientists received some documents from Tesla's Library in Belgrade. This plant shown here is only a pale copy of their operation, which was developed from the torsion theories scientists Akimov (theory of torsion fields) later thrown and lost. The theory was later developed by eng. elt. & Ph.D. phy. Milos Corlomanovic in his work "torsion fields and impacts on them," 2013 y. In this theory, he explains how the torsional field changes the density of the vacuum, creating thrust that comes from the environment. This is now implemented collapses in its program PAK-TA M (PAK-modified TA) aircraft, air cosmic forces, who will be able, with certain modifications to fly around the universe.
References: ^ "Torsion fields and impacts on them"; 17.5.2013 y. — Preceding Виктор Рубильов comment added by 93.86.146.205 ( talk) 03:26, 26 April 2015 (UTC)
I suggest that the part where it mentions the revolutionary possibilities of a propellant-less engine is removed. There are plenty of propellant-less drive concepts out there that have been proven to work under existing laws of physics, such as solar sails, laser propulsion, electromagnetic tether,etc. it seems like this might be possibly relevant to the idea behind a solar sail, where the "reaction" is provided by a change in momentum of photons, although this is just speculation on my part. All in all though, I think hailing this for using no propellant is just engaging in blatant sensationalism Ingebot ( talk) 14:08, 8 May 2016 (UTC)
I don't see what's specifically revolutionary about this. It uses a hell lot of energy for a very small force output, just like what happens if you fire a laser backwards to propell your craft forward. Both can work anywhere in the universe so long as you give it a huge source of power. In any case, the part where it talks about how great it is this uses no propellant doesn't make it come across as the way you put it, with no mention of "no outside force" in that part. Ingebot ( talk) 03:04, 9 May 2016 (UTC)
This, right here, is bullshit:
Shawyer's patent claims the thrust is generated in a closed cavity such that one end of the cavity receives a larger force than the opposite end. Electric heat turns liquid coolant into vapor, contributing to the force balance. Shawyer claims that a standing wave interference pattern is created by geometry, operating frequency and equal path lengths for all segments of the microwave. Shawyer claims that stress energy of space is altered inside the microwave cavity by addition of the interference pattern in which nearly all of the electric and magnetic components are canceled out by two microwaves approaching each other with equal intensity on the same path and most of the Poynting vectors are also canceled out. Puthoff's patent shows how a small but detectable curl free potential can be created from interference patterns passing through shielded barriers. Otherwise if all of the microwaves remain inside the cavity and there is no net interaction with the vacuum, then there is no established theory to give external thrust to the device.[citation needed]
I don't know the 1st thing about physics, but I know what bullshit smells like and this is bullshit. Smells like bullshit. All that's missing is the "trans-flux capacitor" and the "super-heterodyne geronomator". Also stop calling "it" a "drive" or an "engine". There's no "it", and engines make things GO. This idea hasn't made anything "go". The .02 newtons claimed were conveniently unverifiable because the magnetron "burned up". That's how bullshit starts. Someone claims something, then claims the proof is unavailable, then a bunch of people ignore the fact that it's bullshit, and all bullshit starts out like this, and pretty soon everyone is talking about bullshit like it's not bullshit.
But it's bullshit. This quoted passage here, is pure bullshit. The whole article is bullshit, actually, as it makes no attempt at conveying the simple facts and ideas in layman's terms; instead it goes straight to the big-words and high-minded concepts, which is how bullshit, and bullshitters, avoid scrutiny and condemnation. It's bullshit, and I'm condemning it as such. 66.25.171.16 ( talk) 22:36, 29 April 2016 (UTC)
The highly technical part of the article is fine, but there's a problem with the impression a novice might get. In the context you use, this can't work because it violates Newton - but Einstein violates Newton too! The article needs to be couched differently, exploring both sides of this topic. We could be looking at farce that violates basic principles, or we could be looking at something new and different. Scientists went to their deathbeds exclaiming that Einstein is wrong because it violates Newton, but depending on the problem, Newton or Einstein or BOTH may be applied. Pb8bije6a7b6a3w ( talk) 17:40, 25 April 2016 (UTC)
According to the MIT Technology Review, there is a new hypothesis that resolves most objections, although at the cost of introducting photonic inertial mass and changes to the speed of light in the cavity. See https://www.technologyreview.com/s/601299/the-curious-link-between-the-fly-by-anomaly-and-the-impossible-emdrive-thruster/#/set/id/601302/ . Do the SMEs think the hypothesis section will require a re-write? Tfdavisatsnetnet ( talk) 09:22, 20 April 2016 (UTC)
@ Rolf h nelson: Additional coverage seems to be flooding in.
http://www.theregister.co.uk/2016/04/21/em_drive_theory_why/
There is also an article at the examiner as well, but it won't let me link to that site due to "spam blacklist" (not sure about the reliability of that source but that seems weird). In any case the Forbes article seems reason enough to restore the removed material. Insert CleverPhrase Here 22:13, 23 April 2016 (UTC)
I restored the Unruh Theory section and MIT tech review ref, as well as adding the Forbes reference and the main conclusons contained within it. Insert CleverPhrase Here 22:36, 23 April 2016 (UTC)
![]() | This is an archive of past discussions. Do not edit the contents of this page. If you wish to start a new discussion or revive an old one, please do so on the current talk page. |
Archive 1 | Archive 2 | Archive 3 | Archive 4 | Archive 5 | → | Archive 9 |
The result of the move request was: not moved. Jenks24 ( talk) 08:51, 12 August 2014 (UTC)
EmDrive →
Microwave thruster – "Microwave thruster" is NASA's terminology for this type of propulsion, which is in the news right now due to a claimed successful test. Moreover, the article currently covers more than just the "EmDrive" design. While I'm mindful that the controversy over the original proposed design ought to be covered, if the successful test is replicated then the original controversy will be a mere footnote. I don't claim to be able to predict the future; I only think we should have the article at the generic, recognizable title.
Miscellaneous user (
talk) 17:09, 4 August 2014 (UTC)
According to some recent news, it appears that a NASA test of a US-built prototype of this device seem to show that it actually does work. The original NASA publication is here, though I'm not sure how to integrate this into the article. Would someone be able to assist? Grandmartin11 ( talk) 21:43, 31 July 2014 (UTC)
I was already working on it! Alanf777 ( talk) 22:12, 31 July 2014 (UTC)
I can only get to the first page of the NASA paper. They say they tested the Cannae version (as reported by Wired) -- 40 micronewton at 28W , but ALSO a "tapered" version, which is an emDrive -- 91 micronewton at 17W. The latter wasn't reported by Wired. Maybe we should wait until the story's picked up elsewhere. Alanf777 ( talk) 22:51, 31 July 2014 (UTC)
We now have multiple REFS to the same paper(s), which need to be changed to a named REF. I'll do it tomorrow if nobody else does it. Alanf777 ( talk) 22:44, 1 August 2014 (UTC)
It is said here that the test was run at the atmospheric pressure. I was reading the paper and couldn't find any mention of this. This is from NASA's paper:
-- 188.2.82.243 ( talk) 11:06, 5 August 2014 (UTC)
I have removed the claim that the tests "were performed at about a hundred-millionth of normal atmospheric pressure" because the cited source ( http://www.wired.co.uk/news/archive/2014-08/07/10-qs-about-nasa-impossible-drive) got that wrong. While the NASA AIAA paper does go into quite a lot of details of the vacuum chamber setup (see comment above mine), the paper also clearly states at the end "VI. Summary and Forward Work" that tests were conducted at ambient pressure:
This is already stated clearly in the first paragraph of the section "RF resonant tapered cavity thruster (EmDrive)". PS: I'm totally new to editing Wikipedia, I hope I didn't break anything! ;) Mr. Zet ( talk) 14:41, 12 August 2014 (UTC)
I realize there's bound to be a bit of sloppy terminology surrounding a subject such as this, but I must ask, What is meant by the phrase "stationary relative to their thrust"? Does the new scientist article illuminate? I couldn't access it. I assume it means "stationary in the direction of the thrust", but then the question becomes "relative to what object?" The Earth? Spiel496 ( talk) 02:53, 19 February 2013 (UTC)
Quite like I misunderstand something, and maybe it's been answered already - but how can the device require an energy source but lose any energy? Where does the energy put into it go?-- Cyberman TM ( talk) 10:34, 11 August 2014 (UTC)
How the device works is presently considered pure speculation. In particular Shawyer's explanation concerning the mechanics involved, is thought to make no sense at all. The Chinese have proposed that this device produces an Electro-magnetic effect, whereby they provided a hypothesis and related equations. The Chinese explanation and equations somewhat match observed propulsion rates relative to the electrical input in Watts but not enough so that their explanation is preferred. If the NASA explanation has merit then additional explanations are needed since none of the above explanations address the perceived conservation of momentum problem. IMO few additional speculative explanations will be forthcoming if they also are contrary to modern physics theory, or classical mechanics such as the conservation of momentum. To have an idea of a possible explanation concerning what I am talking about, below is an example of such an explanation that would preserve the conservation of momentum but seemingly would be contrary to Quantum Mechanics and modern physics.
A hypothetical explanation of the mechanics of this engine: As the microwaves would build up inside the tapered chamber their intensity and density would build up within the chamber and their reflecting trajectories would "flatten out" and race around the internal periphery of the device. These high intensity microwaves would accordingly corkscrew toward the big end of the reflection chamber. If these microwaves are interacting with the Zero Point Field as NASA has speculated, then the Zero Point Field (ZPF) could, upon high intensity interaction with the microwaves, be spiraling out of the big end of the device creating a low ZPF pressure inside the device while being replenished by the ZPF flowing inward from the small end of the device. There could be a considerable flow of the ZPF through the device. If there would be such a ZPF flow-through then the conservation of momentum would be maintained and the device would also not be reactionless. The proof that this could be happening would require a test of the Casimir Effect at the big end of the device whereby the two plates or the Casimir test could be pushed together from a greater distance, meaning there would be a greater differential pressure in the ZPF outside the device, pushing the Casimir plates together if the explanation were valid.
From Shawyer's company's writings, and from "Wired" sources which was a witness to the testing of this device, the efficiency of this device was discussed. If valid this device and propulsion would be many factors better than present space craft technologies, potentially reducing costs by factors of 5 to 10, and reducing the time of travel for space flights from 1/2 to 1/5 present requirements for conventional propulsion. My explanation of this efficiency was deleted from my addendum to the main article. Of course it is speculation by "Wired" and by Sawyer himself but it is readily understood based upon an insight into the technology, as I have. I think this potentially great increase in efficiency relating to reduced costs and time of travel concerning space flight, may be the most important aspect of this technology if it is valid, so I think it should be at least mentioned. 11:47, 12 August 2014 (Fn) — Preceding unsigned comment added by Forrestnoble ( talk • contribs)
The electrical power losses Pe are assumed to be I2R losses, that means heat loss, so I don't see where anyone (inventor or critic) has claimed "no energy leaves the device". I'm going to take that bit out until someone points to a source somewhere that supports it. __ E L A Q U E A T E 21:40, 12 August 2014 (UTC)
"No energy leaves the device, but it requires an energy source. How does that work? Answering the above question:
The EM radiation being pumped into the system is turned into microwaves which are absorbed as heat by the resonance cavity of the device. At ambient external conditions this heat does not rise more than 30 degrees above ambient temperatures. There is a cooling system device and circulation for some internal components that draws off the heat. It is expected that it conducts and radiates its temperature away so that the temperature does not rise beyond desirable levels. In space I expect the cooling device and circulation system of the device would need to be larger. Also the device itself and a heat sink could be placed behind a shading sun-shield behind solar panels used to generate electricity for satellite propulsion and solar system missions once in space. For heavy-lift Emdrive devices on Earth or Mars, extensive cooling cryogenics are claimed to be needed for much larger superconductive high-voltage and Wattage heavy lift-to-orbit Emdrive devices, according to Shawyer. Once at orbital heights rocket power is thought to be preferable to get the cargo or passengers moving at orbit velocities more quickly than the Emdrive. Once above orbital velocities Emdrive would take over again to get to whatever desired speed is desired since Emdrive would accordingly apply a continuous force until the desired speed is reached. In the same way when approaching a desired destination, Emdrive could slowly decelerate the craft until orbital velocity was reached, then maneuver the craft and land it slowly with comparative ease. The device could take off at low speeds away from a planet without rocket assistance, but it would be less efficient since it could take weeks instead of just hours to reach the escape velocity of a rocket from Earth. Forrestnoble ( talk) 18:57, 24 August 2014 (UTC)
I cleaned up the addition to the article made recently by 208.113.47.50, about early proof-of-concept tests on the Q-drive (Cannae). It now better matches the description in the source. However, I'm not convinced the material belongs in the article. It was published on the company website at one time, but has since been removed. Does that still count as published? Spiel496 ( talk) 19:20, 26 August 2014 (UTC)
Currently there's an entire subsection on NASA test results on the Cannae drive which, while apparently similar to the EmDrive, seems to be something else. Thus that section seems rather off-topic. Dmatteng boldly split it off into a dedicated Cannae drive article (though the quality of the resulting article is debatable, as may be the notability of the Cannae drive itself), but Brian Everlasting reverted the split without giving an explanation for the reversal beyond "lack of consensus". Thoughts? Personally I don't think this article should conflate the EmDrive and the Cannae drive, the latter of which apparently is supposed to work according to a different set of highly speculative physics, and according to the NASA test results even "works" when it's set up not to. Huon ( talk) 16:40, 16 August 2014 (UTC)
It seems we might have a consensus re including inventor's claim that no physical laws are broken. Would someone go ahead and implement it? About this family of articles - I would propose to limit them to two articles then. The EmDrive will be just about the specific EmDrive implementation, and we will move Cannae Drive info to the general article. Dmatteng ( talk) 20:10, 23 August 2014 (UTC)
We cannot come to consensus that no physical laws of physics are broken since as the information states, there is no consensus as to how the device works. I think what we can come to consensus on is that it doesn't matter much what the inventors of these related devices say, or what the critics of them say, experimental testing of the devices have been confirmed by many different entities and witnesses a great many number of times. So whether the device works or not is not in question. These devices were not tested within a vacuum chamber because some internal components were vulnerable to damage based upon such a test. These components will be changed according to NASA and others. It was also noted that thrust was reported immediately upon the application of power, and ended immediately upon power disconnect. This did not leave any time for air currents to build up or subside as some criticisms have speculated. Shawyer claims no problems in vacuum testing were observed but independent vacuum testing needs to be conducted and confirmed before larger prototypes are built. The only questions after that, other than how does it work, seems to be how big these devices can be built and still work to produce higher, or very high thrust levels and lift capacity. It has already been noted that at present levels of thrust this device is better than any existing satellite propulsion system. 23 August 2014 (FN)
So IMO the only question is whether we can develop a functional Emdrive propulsion system without undue delays caused by naysayers that cannot understand how it works, and accordingly we need no flag at the beginning of the article concerning the validity of what is being said in this article Does anyone disagree? If not the flag should be dropped. The other flag for clarity seems appropriate, at least for a month of two longer. 23 August 2014 (FN)
That section has nothing about theory or development. It's more talk about the controversy. Kortoso ( talk) 16:28, 28 August 2014 (UTC)
I suggest people familiarize themselves with WP:FRIND, and WP:FRINGE generally. Article content can not be based on primary sources, particularly the vast volumes that were present in this article (also WP:OR). Second Quantization ( talk) 21:07, 2 August 2014 (UTC)
Reference 11 in the article provides a clear statement of the fundamental error that is at the heart of this problem: "For electromagnetic wave, energy of quantum is transferred at the group velocity vg, its momentum is p=mvg=hfvg/c2". The entire hypothesis of the EmDrive is built on this assumption, which is simply untrue. First, the assumption is made that radiation pressure is the result of the Lorentz Force acting on electrons in the surface of reflection. This is ably refuted by Rothman and Boughn ( http://arxiv.org/pdf/0807.1310v5.pdf ), and indeed the Wikipedia article on radiation pressure supports this. Second, quantum energy is transferred at the phase velocity, not the group velocity. These concepts are clearly explained in the linked Wikipedia articles Radiation pressure is unrelated to group velocity, which is really a rate of propagation of information rather than energy. The group velocity does vary but the phase velocity is constant throughout the frustum resonator, consequently there are no unbalanced forces. Danwoodard ( talk) 22:05, 8 September 2014 (UTC).
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)
-- 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)
I do not agree that the entry should be deleted, as it is widely noted in the lay press. Rather the flaws in the idea should be carefully identified to refute it. I've tried to do this isn the theory section. Danwoodard ( talk) 22:12, 9 September 2014 (UTC)
This talk page has over forty topics, is over 190,000 bytes, and contains discussions that are seven years old. Do other people agree it is time for some automated archiving, per H:ARC? Archiving is generally supposed to happen after about ten topics and the page being 75k.... __ E L A Q U E A T E 12:04, 10 September 2014 (UTC)
I have published a paper suggesting an explanation for the emdrive results. It agrees quite well with the data. I added it to this page and it was deleted. Please can we discuss this? http://www.ptep-online.com/index_files/2015/PP-40-15.PDF 81.156.122.132 ( talk) 21:13, 3 March 2015 (UTC)
An article appeared on IGN today, saying that NASA has found some of the beams of light they fired into this thing appear to have travelled faster than (the usual) speed of light. This seems like it should be incorporated into the WP article somehow? The IGN article is here. Xmoogle ( talk) 15:05, 28 April 2015 (UTC)
So, this article says the NASA experiment was repeated in a vacuum:
http://www.theverge.com/2015/4/30/8521691/nasa-seemingly-impossible-space-drive-test-succeeds — Preceding unsigned comment added by Special:Contributions/ ([[User talk:|talk]]) 19:11, 30 April 2015 (UTC)
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Change " with a greater area at the large end of the device" ( redundant ) to " with a greater area at the far end of the device"
99.35.153.179 ( talk) 00:16, 3 May 2015 (UTC)
I will to love reach consensus regarding my edits Quantanew ( talk) 22:38, 3 May 2015 (UTC)
I have heard this argument neither I or you are going to define this, let a consensus be reached Quantanew ( talk) 22:51, 3 May 2015 (UTC)
Your threat of report while a discussion is been made will constitute Wikipedia:TROLL. Quantanew ( talk) 23:08, 3 May 2015 (UTC)
There is no deadline and we need a third opinion all of this according to: Wikipedia:Edit_warring#The_three-revert_rule Quantanew ( talk) 23:08, 3 May 2015 (UTC)
Just to add the current sources on the whole article are not peer-reviewed sources. It was put on delete and the consensus was not to delete the article, obviously other editors considers this article important. This article is already in the category of fringe physics and hypothetical technology and with that in mind I just enumerate the potential applications of the technology, all of this cited by the current team a NASA JSC Eagleworks working on the device. Quantanew ( talk) 00:23, 4 May 2015 (UTC)
As will be seen below claims made for the EmDrive not requiring any reaction mass as fuel (Wikipedia article EmDrive) and any claims of generating motion without propellant ( Reactionless drive and Reactionless_drive#Modern_approaches) are at best suspect due to one of the main components in the drive, namely the magnetron ( EmDrive), requiring electric current to operate that will not be present until one thing occurs, this being the application of some form of energy on the input side of a transducer to cause the movement of electrons in sufficient quantity and with sufficient EMF on the transducer’s output side to power the magnetron.
First consider such substances as liquid hydrogen, oxygen or kerosene, regarded as reaction mass in rockets, sharing one characteristic with coal, natural gas and yes even uranium this having BTU content or the ability to release energy in the form of heat. See Energy Content in Common Energy Sources [2], Fuel Gases – Heating Values [3] and Heat Values of various fuels [4] as well as GJ to BTU conversion [5]
Second, Electricity_generation#Methods_of_generating_electricity and Electricity_generation#Turbines covers the process and the fuels (reaction mass) used to convert liquid phase water into gas phase water or steam to rotate a mechanism (turbine) turning a device utilizing electromagnetic induction to cause an electric current which ultimately powers the magnetron in the EmDrive at least here on the ground. The transducer in this case is the device driven by the turbine using electromagnetic induction to cause the electric current to flow to the magnetron.
Third, Since the use of fuels for the intermediate purpose of rotating mechanisms as above described is, it is hoped, obvious by its sheer bulk and weight unusable in space craft it falls to the form factor and internal design of the RTG on the Voyager spacecraft [6] from Voyager The Interstellar Mission and [7] from Radio Isotope Power Systems to provide a clue as to how furnish electrical power for the EmDrive’s magnetron in a space craft. As the total output of Voyager’s 3 RTGs [8] at the beginning of its mission might have been sufficient to drive the 300W magnetron sited in EmDrive#Second_device_and_New_Scientist_article the 800W magnetron in EmDrive#DTI_grant_and_first_device would have been out of the question. This raises the possibility of having to conduct studies into the feasibility of scaling up RTGs or whether an actual small uranium fueled reactor would be needed for a sufficient number of thermopiles (transducers converting heat into electricity) to even provide power for the 2,500 W input power magnetron sited in EmDrive#Chinese_Northwestern_Polytechnical_University_.28NWPU.29
History of rocket engines Rocket_engine#History_of_rocket_engines records a statement to the effect that the 13th century may have seen the first examples of rockets, albeit solid fuel, as we now know them. Liquid or solid fuel the operating principal is the same. The reaction mass (fuel) is directly converted into the force or high velocity exhaust that moves the vehicle.
With the EmDrive this 800-year-old direct model no longer applies. Instead there is an intermediate step, the transducer, that converts the thermal or heat energy of a fuel (reaction mass) into the electric current required for the magnetron to generate thrust in a resonant cavity.
VPR-80 ( talk) 13:09, 7 May 2015 (UTC)
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I cleaned this up a bit. Including an example of a discussion of resonant plasma thrusters from the 1990s, and more balanced coverage of EmDrive and other trademarked implementations of the idea. The title should probably be "RF resonant cavity thruster" to be inclusive. [If one or the other takes off, it may deserve its own article; for now they can all be sections here.] – SJ + 19:07, 9 July 2015 (UTC)
I'd like to modify the static thrust section to convey the notion that the specific thrust (in N/W) is not a constant, but really "rapidly decreases if the EmDrive is used to accelerate the vehicle along the thrust vector" [9]. Specifically, that decrease seems to negate the claim that the EmDrive could "lift a large car". In Earth's gravity, even hovering a car means the EmDrive would be providing an acceleration of 9.8 m/s^2. Or does "accelerate the vehicle along the thrust vector" really mean "there is velocity along the thrust vector"? Any other sources clearer about this? Or am I trying to decipher bullshit written about bullshit, so I should just give up? Spiel496 ( talk) 17:41, 9 July 2015 (UTC)
A "Criticism" section is missing from the article. Here is a first draft, feel free to contribute:
None of the tests were conducted inside Helmholtz coil to completely cancel Earth's magnetic field, thus all tests are susceptible to EMF (Electromotive Force) between currents running in the test setup and Earth's magnetic field. In the typical test setup, 10 Amps magnetron supply running on 1 meter wire under Earth's magnetic field exerts a force of more than 100 µN on the wire, which is in the same order of magnitude as the measured anomalous thrust. — Preceding unsigned comment added by 85.250.215.196 ( talk) 23:52, 28 July 2015 (UTC)
All this is WP:OR, or course, so we can't put it in the article, and you'd hope that experimenters would have both designed their experiment to eliminate the possibility of such a force being generated in their experiment, and also found a way to check that they had done so correctly, but it does show how difficult it is to do experiments involving these sorts of tiny forces.
Here's another example of how easy it is to think up mechanisms for experimental error: if I was an experimenter, I'd also want to investigate the possibility that unforseen parasitic RF rectification processes within the apparatus were not creating stray DC currents inside it, which would also interact with the Earth's magnetic field, possibly to generate forces of a similar magnitude. One way to check for this general class of effect would be to deliberately increase or decrease the magnetic field around the apparatus, and see if that caused the measured effect to change. Easy enough to arrange if the apparatus is already in a Helmholtz coil. -- The Anome ( talk) 11:04, 30 July 2015 (UTC)
I strongly support the existence of this article, but until the EM-drive is accepted by the general physics community as a valid effect, I believe the onus of providing "reliable source" is on the proponents of the technology, and not on the opponents of the technology.
Canceling earth's magnetic field using Helmholtz coils is a standard practice for measuring very low forces, search for "micro thruster" and "Helmholtz", for example [ [10]] and [ [11]]. Eletromagnetic forces are a significant source of errors in such tests, quote from second paper: "For example, a FEEP thruster has high voltage cables which may create electromagnetic forces disturbing the measurements".
Right now the article is all roses and promises, and missing any kind of "criticism" section, which is jarring. 85.250.62.87 ( talk) 12:10, 30 July 2015 (UTC)
This drive, em drive, is actually the old system began to study Soviet Russia, when its scientists received some documents from Tesla's Library in Belgrade. This plant shown here is only a pale copy of their operation, which was developed from the torsion theories scientists Akimov (theory of torsion fields) later thrown and lost. The theory was later developed by eng. elt. & Ph.D. phy. Milos Corlomanovic in his work "torsion fields and impacts on them," 2013 y. In this theory, he explains how the torsional field changes the density of the vacuum, creating thrust that comes from the environment. This is now implemented collapses in its program PAK-TA M (PAK-modified TA) aircraft, air cosmic forces, who will be able, with certain modifications to fly around the universe.
References: ^ "Torsion fields and impacts on them"; 17.5.2013 y. — Preceding Виктор Рубильов comment added by 93.86.146.205 ( talk) 03:26, 26 April 2015 (UTC)
I suggest that the part where it mentions the revolutionary possibilities of a propellant-less engine is removed. There are plenty of propellant-less drive concepts out there that have been proven to work under existing laws of physics, such as solar sails, laser propulsion, electromagnetic tether,etc. it seems like this might be possibly relevant to the idea behind a solar sail, where the "reaction" is provided by a change in momentum of photons, although this is just speculation on my part. All in all though, I think hailing this for using no propellant is just engaging in blatant sensationalism Ingebot ( talk) 14:08, 8 May 2016 (UTC)
I don't see what's specifically revolutionary about this. It uses a hell lot of energy for a very small force output, just like what happens if you fire a laser backwards to propell your craft forward. Both can work anywhere in the universe so long as you give it a huge source of power. In any case, the part where it talks about how great it is this uses no propellant doesn't make it come across as the way you put it, with no mention of "no outside force" in that part. Ingebot ( talk) 03:04, 9 May 2016 (UTC)
This, right here, is bullshit:
Shawyer's patent claims the thrust is generated in a closed cavity such that one end of the cavity receives a larger force than the opposite end. Electric heat turns liquid coolant into vapor, contributing to the force balance. Shawyer claims that a standing wave interference pattern is created by geometry, operating frequency and equal path lengths for all segments of the microwave. Shawyer claims that stress energy of space is altered inside the microwave cavity by addition of the interference pattern in which nearly all of the electric and magnetic components are canceled out by two microwaves approaching each other with equal intensity on the same path and most of the Poynting vectors are also canceled out. Puthoff's patent shows how a small but detectable curl free potential can be created from interference patterns passing through shielded barriers. Otherwise if all of the microwaves remain inside the cavity and there is no net interaction with the vacuum, then there is no established theory to give external thrust to the device.[citation needed]
I don't know the 1st thing about physics, but I know what bullshit smells like and this is bullshit. Smells like bullshit. All that's missing is the "trans-flux capacitor" and the "super-heterodyne geronomator". Also stop calling "it" a "drive" or an "engine". There's no "it", and engines make things GO. This idea hasn't made anything "go". The .02 newtons claimed were conveniently unverifiable because the magnetron "burned up". That's how bullshit starts. Someone claims something, then claims the proof is unavailable, then a bunch of people ignore the fact that it's bullshit, and all bullshit starts out like this, and pretty soon everyone is talking about bullshit like it's not bullshit.
But it's bullshit. This quoted passage here, is pure bullshit. The whole article is bullshit, actually, as it makes no attempt at conveying the simple facts and ideas in layman's terms; instead it goes straight to the big-words and high-minded concepts, which is how bullshit, and bullshitters, avoid scrutiny and condemnation. It's bullshit, and I'm condemning it as such. 66.25.171.16 ( talk) 22:36, 29 April 2016 (UTC)
The highly technical part of the article is fine, but there's a problem with the impression a novice might get. In the context you use, this can't work because it violates Newton - but Einstein violates Newton too! The article needs to be couched differently, exploring both sides of this topic. We could be looking at farce that violates basic principles, or we could be looking at something new and different. Scientists went to their deathbeds exclaiming that Einstein is wrong because it violates Newton, but depending on the problem, Newton or Einstein or BOTH may be applied. Pb8bije6a7b6a3w ( talk) 17:40, 25 April 2016 (UTC)
According to the MIT Technology Review, there is a new hypothesis that resolves most objections, although at the cost of introducting photonic inertial mass and changes to the speed of light in the cavity. See https://www.technologyreview.com/s/601299/the-curious-link-between-the-fly-by-anomaly-and-the-impossible-emdrive-thruster/#/set/id/601302/ . Do the SMEs think the hypothesis section will require a re-write? Tfdavisatsnetnet ( talk) 09:22, 20 April 2016 (UTC)
@ Rolf h nelson: Additional coverage seems to be flooding in.
http://www.theregister.co.uk/2016/04/21/em_drive_theory_why/
There is also an article at the examiner as well, but it won't let me link to that site due to "spam blacklist" (not sure about the reliability of that source but that seems weird). In any case the Forbes article seems reason enough to restore the removed material. Insert CleverPhrase Here 22:13, 23 April 2016 (UTC)
I restored the Unruh Theory section and MIT tech review ref, as well as adding the Forbes reference and the main conclusons contained within it. Insert CleverPhrase Here 22:36, 23 April 2016 (UTC)