Talk:Dean drive

message: It might be nice to add a few words saying that most alleged reactionless drives employing rotating unbalanced weights seem to work when placed on a surface, or hung on a rope, because they can scoot themselves along by "slip and stick friction," employing the fact that the coefficient of stationary friction is greater than the coefficient of sliding friction.  When you hang such devices from a ballistic pendulum, where they can't get any traction, they show no net acceleration in any particular direction.
There is newfound interest in reactionless drives based on observations that either Mach's Principle or rotating superconductors may permit shielding of inertial mass, but I think everyone agrees that mechanical reactionless drives are a dead end, and as was observed in the article, if you build the device described in Dean's patent, it doesn't work. Hermitian 22:15, 9 January 2006 (UTC)
replies: text: Well, assuming the patent was based on what Dean considered to be a working drive, then it logically follows that at least ONE device, based on the patent, should be something that Dean, at least, would consider to be a working drive.  The problem, of course, is, "How much of the working drive did Dean leave out of his patent?" V (talk) 04:13, 10 February 2009 (UTC)
replies: text: Absolutely have people not yet given up.  Here's a site where it is claimed that a Dean Drive has been succussfully reconstructed and tested.  http://www.inertialpropulsion.com/  Very likely the reconstruction differs from the original, but they are calling it a reconstruction because the Dean Drive patent was the starting point for their efforts.  And, yes, patents have been filed for this device. V (talk) 22:10, 4 November 2009 (UTC)
replies: text: Nevertheless, professor Provatidis has co-authored a paper on Dean drive in cooperation with one of the biggest aerospace industries (C. Provatidis and M. Gamble, Support forces in a synchronized rotating spring-mass system and its electromagnetic equivalent, International Journal of Applied Electromagnetics and Mechanics Vol. 41, No. 3, pp. 313–334, 2013). I found the Conclusion of this paper very interesting, but I am not allowed to continue this talk unless I violate the copyright (I fear because the paper includes two pages referring to company's IP rights; I have never met such an event). Thanks!  CProvat (talk) 19:45, 5 January 2014 (UTC)
thread_title:  Testing 

message: I was just rereading some of the debate that was generated by the disputed editing made by Gwernol and reverted article information on the "history" page.  It occurs to me that the debate produced some good information about the Dean drive and the controversial subject of whether or not it really works.  Maybe we ought to summarize the "best of" material on this page.
That would include a summary of quotes where applicable by Gwernol, juxtaposed with material taken directly from Wikipedia policy documents.  It may be that we can get a reconsideration of certain changes in the article with regard to a more neutral presentation.  There are clearly differences of opinion regarding  what Wikipedia policy IS.  I think a convincing case can be made that some of the material presented in the article that was subsequently reverted ought not to have been removed.
IF the case can be made convincing enough, we COULD take the next step in the dispute resolution process for a more formal review of the dispute.  This isn't going to be easy though and we will have to stick to the facts.  (i.e., no personal attacks or emotional arguments. 71.35.28.231 (talk) 02:12, 5 July 2008 (UTC)
replies: text: To some extent, dealing with the issue can be a matter of starting off with remarks to the effect that the Dean drive is controversial, as demonstrated by the various claims and counterclaims that have been made over the years.  Some of the claims are factual --e.g., a device actually existed which Dean demonstrated to various people, some of whom were quite technically competent, and who became convinced that the device exhibited anomalous behavior-- and some counterclaims are certainly factual --e.g., devices that Dean described in patents cannot exhibit anomalous behavior-- and some counterclaims may be flawed --e.g. of those who flatly state the demonstrated device did not or could not work to exhibit anomalous behavior, none present any evidence they ever saw Dean demonstrate it, so how could they know?.  How is it "original research" to simply read the counterclaims and the articles they reference (when possible), and state such an obvious thing about the authors of those counterclaims?  Meanwhile, here's a [slightly edited] quote from William O. Davis' article in the May, 1962 Analog:  "Actually, the situation [with respect to theory and the Dean drive] is no worse than it once was in the field of electricity.  It was sincerely believed a century or so ago that it would be impossible to do work with alternating current without violating Conservation of Momentum, since the average current was zero.  Although the current in one direction is balanced by an equal flow in the opposite direction, the flows are not equal and opposite simultaneously and thus work can be done.  Furthermore, when all else failed, radiation was invoked to preserve the Conservation of Momentum.  We are going to try the same approach. ..."  That's how Davis starts leading up to the notion of "gravitational inertial radiation" as a means of Conserving Momentum and thus explaining how the demonstrated Dean drive could exhibit the anomalous behavior that he witnessed.  They actually published in the article a fairly complicated equation (with integrals) way "over the heads" of most readers of a science fiction magazine in 1962, and Davis basically wrote that the equation indicates that if a "changing acceleration" and the necessarily associated "critical action time" are added to Newtonian Mechanics, then some of the energy associated with an applied force does not become kinetic energy of the object to which that force was applied, and (since Energy must also be Conserved) could be expected so appear in some other form (such as a radiant form).  So far as I know, NOBODY making counterclaims about the Dean drive has ever challenged Davis' equations.  In G. Harry Stine's June 1976 article, he indicates that Davis' team "... wrote a scientific paper.  Entitled "Some Aspects of Certain Transient Mechanical Systems," Davis delivered it on April 23, 1962 at the Washington, DC meeting of the American Physical Society.  There were no comments."  Regarding Davis' 1962 Analog article ("The Fourth Law of Motion"), Stine wrote: "... the article didn't draw the sort of comment we had expected ..."  It's almost as if a lot of people found Davis' ideas too alien to be worth discussing or even remembering.  Even today people who say certain things (as on this very discussion page, see the first sentence in the "Dean Drive Impossible" section) are at the very least demonstrating considerable ignorance of the WHOLE story.  I really wish there was an easy way, besides waiting decades for copyrights to expire, to get that whole story onto the Web (the "rexresearch" links near the start of this page can't be expected to stay valid, but currently they do seem to lead to accurate copies of certain articles).  I know of only one other place on the Web, "halexandria.org" that contains a fair amount of analysis of Davis' work (and others); it MAY qualify as a suitable Wikipedia reference, if one can get past the mysticism while hunting down the hard-science "inertial propulsion" links, such as this one:  http://www.halexandria.org/dward133.htm  —Preceding unsigned comment added by 216.9.73.3 (talk) 08:45, 5 July 2008 (UTC)
replies: text: Two other pages at the "halexandria" site that may be useful are dward137.htm and dward138.htm  —Preceding unsigned comment added by 216.54.28.10 (talk) 13:35, 8 July 2008 (UTC)
thread_title:  Summary of Debate Needed 

message: In the first section, "there is no known theoretical mechanism for a mass to be moved one way while nothing moves the other way, at least in a flat spacetime." is untrue.  Objects move relative to one another all the time.  Consider the planets in their orbits.  Consider the expanding universe.  Consider an object falling into a gravitational well.  Consider Newton's First Law.
Needs someone smarter than you to comment! There is no known exception to Newton's third law. Some textbooks still say that electrical charges do not obey it. That is untrue. Even over astronomical distances (with an obvious time-delay) it applies. Even at the quantum level, it applies. Please do not try to 'make your little education do the work of some', as De Morgan used to say.  — Preceding unsigned comment added by 86.185.251.10 (talk) 16:40, 18 April 2013 (UTC)
thread_title:  needs someone smarter than I to edit 

message: SED has been disproven? I've read about some null experiments but not actual disproof. Why isn't this mentioned in the main article and why aren't any sources cited? 98.154.22.134 (talk) 14:22, 22 November 2012 (UTC)
thread_title:  Stochastic Electrodynamics 

message: It is a disgrace to Wikipedia, an insult to physicists as a profession, and a disservice to students, even to mention this ludicrous device. There is no doubt that it could never produce nett motion in outer space. There is no room for waffle. The fact that some 'academics' (such as Provatidis) defend it should serve as evidence that those academics are incompetent, and not as valid support for an untenable thesis. No reputable print encyclopedia would ever have included it, and Wikipedia's somewhat laissez-faire attitude smacks more of intellectual laziness than open-mindedness.  — Preceding unsigned comment added by 86.185.251.10 (talk) 16:30, 18 April 2013 (UTC)
replies: text: There are several good reasons to include this article even though the device itself has been effectively dismissed as an actual working device. First, the Dean drive was a frequent science fiction narrative vehicle and featured in popular science and science fiction magazine articles in the 1960s and so some interest in it still exists. Second, the history of the promotion and eventual discounting of this device now serves as a cautionary tale when considering similar claims for other reactionless drives. Third, proposals to NASA and modern reactionless drive research papers now include statements as to how spurious thrust effects due to friction and other ordinary environmental interactions (collectively referred to as "Dean drive" effects) are excluded from the experimental results.  Aldebaran66 (talk) 18:51, 31 May 2013 (UTC)
thread_title:  Call for Deletion of Entire Article 

message: Why is the tone so positive, and pretending that it might still work? It's been +50 year, and:
* Dean didn't leave any working model
* No independent test has ever been made by third parties
* He refused independent tests while still alive
* No one has made a working model from the patents
* At least one physics textbook gives it as an example of drive that was not able of breaking Newton's motion laws
* All positive coverage is decades old, except one theoretical paper by a mechanical engineer
* It's given as an example of the dubious stuff that Campbell promoted in the 1950s-1960s, by three different books from reputable authors (and I found more mentions of this fact in other books, like , written by the guy who gives his name to the sci-fi award Thomas D. Clareson Award for Distinguished Service)
Dean's grandson has edited the article to defend his grandfather. I am sorry for him, but wikipedia can't give the impression that the principles behind the Dean Drive are considered anything other than completely wrong by today's physicists. --Enric Naval (talk) 19:18, 28 May 2013 (UTC)
replies: text: I added the pseudoscience banner as Dean never provided any theoretical basis for operation and was evasive about demonstrating a working prototype, the usual tip-offs of a pseudo-scientific (and nonfunctional) device. I also increased the class to B as the article is fairly complete and pretty well-referenced now. Aldebaran66 (talk) 20:52, 28 May 2013 (UTC)
thread_title:  tone of the article 

message: A great many recent edits have been made by an editor whose WP username would appear to indicate that he is one of the authors of the papers he's citing. This appears to me to be a WP:COI violation. The same editor has made edits to several other articles, adding material (with refs to what may be his own paper) that seems to try to give credence to pseudoscience-y ideas. It is my opinion that all of this editor's work (or at least that which references what appears to be his own paper) is suspect. Jeh (talk) 21:42, 2 January 2014 (UTC)
thread_title:  Conflict of interest in recent edits 

message: The Sept. 1976 issue of Analog SF, p. 171, published a letter from Joseph P. Martino regarding the evaluation of the Dean Drive by the AFOSR. In 1960. In 1960, Joseph P. Martino contacted Dean and was allowed to perform a series of experiments which are described in the letter. At first, the drive appeared to work as stated, and this was supported by the initial analysis. A check of the analysis by Martino showed it was in error, and after correction, showed no net thrust. An independent contractor examined the bathroom scale used and found that it worked as a "negative peak reading" device, in that "it gave a constant reading equal to the negative peaks of the vibration." Another independent contractor, Jacob Rabinow, was then asked to evaluate the drive. Rabinow performed a pendulum test, where the drive suspended on a pendulum pulled a load attached with a rigid rod. Rabinow found that Dean drive moved the load through sharp jerks, pushing back on the static friction of the floor. When the load it was pulling was on a lubricated sheet, it merely oscillated back and forth. The conclusion of these tests were that the drive did not work. Although the device did not work, Martino felt that "Dean was sincere in his belief . . . and was not a Con artist."--RKihara (talk) 16:28, 7 February 2017 (UTC)
thread_title:  Summary of a Letter regarding the Dean Drive Evaluation by the Air Force Office of Scientific Research 

message: Just like the website describes, it does work. The motors are being driven by electricity at a constant speed. If you have a firm grasp of the "fundamental anomaly" as described on the website,, then it's easy to see why the "rectifier" works. 
The weights are moving at a constant speed, so the parent body does not oscillate when they "swing next to eachother", because they are not accelerating. instead, as the weight is forced to turn because it is attached to the rotor shaft, the weight pulls on the rotor shaft to result in this change in direction. The motor is not stressed at this time, and drives constantly. 
when the cam freezes in place, it prevents the rotor mount from moving back in the other direction (of its oscillation). So, as the weights move along the opposite side of the rotation, they pull on the entire machine instead. When this happens, the motor will be stressed, and consume more energy than normal. The motor is moving at a constant speed (or trying to), but during this push will require more energy to do so. (so although the rotor is not accelerating, although it actually is because it slowed down at one part of the rotation, the motor is at a higher load). 
basically the tuning of the system allows for more energy to be consumed during specific points of the rotation of the rotors. 
if you placed the mechanism on a more frictionless surface, and the original builders managed to make it work on a surface with a certain amount of friction, you may need to increase the weight of the enclosure to result in an increased load on the motors. So, the way the air force tester simply placed the machine tuned for a frictioned surface on a frictionless surface, it's imaginable that the enclosure moved too easily, and the motors were not able to be loaded as much as they were using the small wheels, so the motors would not consume extra energy at the time that it would on the wheels. YOu can observe the loading in one of his videos, when he actually pushes the machine resulting in a change in motor speed. the motors are loaded so much they slow down. additionally, if the tester placed the machine in an oil, the oil viscosity would result in a "pocket" that would trap the machine if it were unable to overcome the pocket. So if the machine "barely worked" under the designers original conditions, it wouldn't take very much to throw the delicate tuning off. If the rotor were specifically accelerated more dramatically during the right moments of the rotation, this might allow for a broadening operating conditions, although it would result in other problems the engineers would need to overcome, to prevent saturating the rotor for example.  2603:800C:706:2000:2C73:9F54:C698:8F91 (talk) 04:28, 2 May 2021 (UTC)
replies: text: I get the impression that this is not about improving the article (the purpose of this page). See WP:NOTFORUM. --Hob Gadling (talk) 05:41, 2 May 2021 (UTC)
thread_title:  It works because of the cam