Talk:Woodward effect

Woodward Effect

Dear Meawopp

Thank you for spending the time and energy to incorporate the Woodward Effect into wikipedia. A couple of suggestions...

Please mention that Jim Woodward prefers to call this effect a "Mach Effect"

The Mach Effect does not violate the laws of conservation since it is relativistically invariant

Jim is doing this work at the California State University at Fullerton (CSUF)

There are some spelling typos

Best,

Peter Vandeventer"

---

I actually performed the above edits and added the car on the freeway analogy. Duncan Cumming

---

Text amended to refer to Mach effects. Woodward effect is slang for Mach effects. Other notable researchers are also involved in Mach effects. Dr. White at NASA Houston for example. Nembo Buldrini in Europe.

An attempt to explain Conservation of Momentum at major points in the process of producing Mach effects has been made today. Scie8 (talk) 06:05, 26 February 2013 (UTC)

---

This is a good attempt, but I think general explanation about what is momentum and momentum conservation should not be written in the article, since they already have their own wikipedia entry. Now the "Debate" section is dangerously inflating with no reason, with some claims that should only appear in a "Talk" page. There are some weird comments that one founds on forums or blogs, written below references published in peer-reviewed journals. And it stays there, with no correct sources, no citations. Not even correct assumptions, being thought with rudimental newtonian mechanics whereas all the effect is relativistic and should be accounted with general relativity tools. Momentum conservation is not a problem because the Mach Effect derivation is relativistically invariant so the conservation laws are satisfied. Period. The only word important above all this is "Lorentz invariance". Citations from Woodward and other about the validity of Sciama's equation within general relativity were added. Maybe some physics specialist editor on wikipedia should come and see why all these weird unsourced claims are still present. Tokamac (talk) 18:25, 3 March 2013 (UTC)

Nature of effect

This entire article is dedicated to defending this effect from claims of not conserving momentum, without ever explaining what the effect is, or how its local appearance doesn't conserve momentum, how the process is built or initiated or operates, or anything. Actual content would be nice. 134.53.26.228 23:39, 13 June 2007 (UTC)

Idea

I must say on first thoughts I don't understand how the mass variations can be brought about by using a capacitor/inductor etc. system. Sure, the mass may change from one to the other (front to back say in the system under supposed propulsion) but it then has to return from back to front...which can only be achieved via pushing on the mass, which will lead to a backward push on the system. Maybe I'm missing something here though using an electric circuit in the way described in one of the Woodward papers. Could we just use instead two big tanks filled with water, one in front and back, and then pump the water between the two to create the desired mass change? This later system would surely have the problem described above, so would not lead to a net forward force.

It seems to me we need to induce a mass change without mass motion forward and back. Could this be achieved by what special rel tells us? Say we have 2 large discs in front and 2 in back on our ship. We spin up the back discs (in opposite directions) to relativistic speed. We then expand the ship (via pizoelectrics like Woodward, or just a simple string). This'll push the nose forward while the rear stays put ... at least that's what an outside observer would see. We then stop the rear discs and start the front discs...then contract the ship, which will pull the rear forward etc. Over and over. I don't see how spinning up and slowing the discs would create a counter force in the backward direction. Excess heat generated in the process could be ejected out the back to give us a little extra push. I'm guessing there's something wrong with this idea also, though I can't see what it is myself for the moment! ScottRShannon 05:30, 20 June 2007 (UTC)

- I believe, that the moment we transfer energy from one end of the device to another, we also transfer mass (thanks to E=mc^2 principle)... — Preceding unsigned comment added by 89.68.164.90 (talk) 00:19, 12 February 2013 (UTC)

Cleanup Tag

General cleanup suggested including sectioning and inline citations. It is on my watchlist and I will eventually get to it myself, if nobody else does. Zab (talk) 05:04, 14 February 2008 (UTC)

- I've done the suggested cleanup, please review and approve. 75.67.80.68 (talk) 15:31, 10 June 2009 (UTC)

I cleaned up the references from bare urls and added more inline citations. I believe that the major concerns of cleanup have been addressed and I have removed the banner. I also removed the unresolved banner from this section. We still need the review of a physicist though. Aldebaran66 (talk) 22:04, 6 February 2013 (UTC)

Some problems I see with the article

There is no rigorous description of whatever the phenomenon is supposed to be. There is only one reference to a paper. No context in the form of related work is given. Of the external links at the bottom, I was not able to access the last three; the patent application is unhelpful (patent applications are, by nature, not scientific works). The self-doubt expressed in the paragraph with the Sagan quote is… just weird. Lacking a mathematical formulation, a lucid explanation, experimental evidence, opposing viewpoints and alternative explanations ([1] in particular) and a sound set of references, this article (about a phenomenon that appears to violate conservation of momentum, no less!) is not really useful.

By the way, this topic is referenced in [2], hopefully it’ll attract somebody with the knowledge it takes to clean up the article. —xyzzy_n 10:24, 15 February 2008 (UTC)

- It doesn't violate conservation of momentum because as a physicist would know, the 'system' in this case encompasses the whole universe, so the mass fluctuations in the device allow it to take momentum from the rest of the universe preferentially, and momentum is conserved. The reaction mass is the mass of the universe. 75.67.80.68 (talk) 15:02, 10 June 2009 (UTC)

I have removed the "expert" banner as I believe the criticism (from 2008), that no theoretical treatment is presented, has been addressed. I have added a Theory section that summarizes the idea and, of course, it can be expanded. I also added illustrations to show how the effect is supposed to work. The theory is not complex, but does it work? Aldebaran66 (talk) 03:34, 20 February 2013 (UTC)

From where does reference to 'ions' come?

This article begins with...

"The Woodward effect is a hypothesis proposed by James F. Woodward, a physicist at California State University, Fullerton, that energy-storing ions experience transient mass fluctuations when accelerated."

Is this a leap of the author into ion-wind devices? or is Woodward publishing on this, also?

Please help me understand where Woodward mentioned ions (perhaps a later citation than his patent work).

Woodward's patents I've found (so far) are about piezoelectric transducers vibrating. And his earlier work with vibrating capacitors was suggested (by NASA BPP) to be duplicated on a rotating toroid to eliminate false effects from vibration harmonics.

Woodward is not referring to ionized atoms of gas, but rather to the solid ions in the crystal lattice of barium titanate. Movement of these ions is responsible for energy storage in ceramic capacitors. Not to be confused with the many "ion engines" out there, some of which work in air and some in a vacuum. ~~Duncan —Preceding unsigned comment added by 69.234.49.239 (talk) 17:19, 4 October 2010 (UTC)

I am hoping there is an available citation to Woodward doing ion experiments. Thanks for the article!

—DonEMitchell (Wikimedia.org newbie) —Preceding unsigned comment added by DonEMitchell (talk • contribs) 16:38, 26 March 2010 (UTC)

"Rocket propellants will eventually run out"

The above sentence is unfounded in the article and should be removed or modified. Plasma motor propellants, for example, have no reason to "run out". One could say "Chemical rocket propellants will become more difficult to produce in large enough quantities for interstellar space travel". Ga2re2t (talk) 15:32, 14 June 2010 (UTC)

I disagree. plasma motor propellants are still propellants and a spaceship that relies on them is either limited to the propellant it has when it starts out, or it must garner more propellant enroute. ϢereSpielChequers 16:31, 14 June 2010 (UTC)

I think the OP thought the article was talking about peak oil or somesuch which is obviously not the case. By "run out", it's meant that you expell mass, and therefore at somepoint will have nothing left to expell. Think of it like a hot air balloon jettisonning ballast. 193.191.138.242 (talk) 14:36, 26 July 2010 (UTC)

"Hypothesis Without Merit?"

I have not been able to find any "respected theoreticians" prepared to say in print that this hypothesis is without merit. In fact, very few gravitaional physicists are prepared to say anything at all about this topic. Therefore I editied the sentence about this hypothesis being "without merit", since it gave no citation. Also, this article refers to the controversial works of a living person, so such uncited statements are against Wikipedia policy.~~Duncan

> You may also note that you'll be unable to find any "respected theoreticians" prepared to say in print that this hypothesis is *with* merit. In fact, very few physicists of any sort are prepared to say anything at all about this topic. The conclusion should not be that therefore it has merit. The conclusion should be that this topic is outside mainstream physics. Indeed, as a physicist, my strong personal opinion is that virtually every physicist who encounters this topic realises immediately that the effect is fictional. When they look at the (lacking) experimental evidence, and finally at the basic mathematical error that the adherents have been accused of, they will consider that confirmed. From wikipedia's point of view, the strong signal that should come across is that this topic is not part of mainstream physics: The effect is not *probably real* until physicists prove it wrong.H123b wiki (talk) 14:40, 17 June 2018 (UTC)

There certainly is propellant in this device.

However, it has no rest mass. The thrust comes from electromagnetic waves being emitted by the device in a preferred direction. Each photon constituting this wave has a defined inertial mass equal to ${\frac {h}{c\lambda }}$ and a momentum equal to ${\frac {h}{\lambda }}$. The device does provide a force, but it is not based on "action at a distance". The principle of locality is not violated.siNkarma86—Expert Sectioneer of Wikipedia
^{86 = 19+9+14 + karma = 19+9+14 + talk} 14:08, 27 March 2011 (UTC)

Please read Woodward's work (and before, Sciama's or Barbour's work about Mach principle if you can). What you are talking about has nothing to do with Woodward effect / Mach effect propulsion. Tokamac (talk) 17:55, 3 March 2013 (UTC)

Wormholes

After listening to the show where Woodward talked about wormholes, i corrected and tried to clarify the section on Wormholes. It could even be removed entirely, since it's not directly related to the subject. — Preceding unsigned comment added by 82.232.149.24 (talk) 21:37, 11 September 2012 (UTC)

I have removed the Wormholes section as it is not relevant to this article in any way that I can see. Perhaps it should be included in the Wormhole article or an article about Woodward himself if one is ever created. Please add this section back if you feel it adds anything. Aldebaran66 (talk) 01:22, 1 February 2013 (UTC)

It has a lot to do with the article. I added some explanation and correct sources. If you're interested in collaborating to this article as you seem to be, you should really read some articles cited in the "References" section (may I suggest you simply Woodward's book? I've personally ordered my copy). You would be aware that all Woodward's work for twenty-three years is not only about experiments of Mach effect thrusters (for future spacecraft engines) but also about how to theoretically create wormholes. They are not two different ideas followed separately by the author; their possible existence lay in the same formula generated by the derivation of Mach Effect equations, where creation of exotic mass is shown to be theoretically feasible, as you can see in the new entry I added to the article. Even the word "Stargates" appears in titles of Woodward articles published in peer-reviewed journals. Tokamac (talk) 18:06, 3 March 2013 (UTC)

James F. Woodward - Making Starships and Stargates

James F. Woodward: "Making Starships and Stargates - The Science of Interstellar Transport and Absurdly Benign Wormholes" [3] — Preceding unsigned comment added by 95.88.236.187 (talk) 01:06, 11 January 2013 (UTC)

I added a reference to this book in the James F. Woodward article as it expounds on his theories on wormholes among other things but I haven't included a reference in this article as I don't yet see how it is directly relevant. Aldebaran66 (talk) 22:00, 6 February 2013 (UTC)

Some references added (see my previous comment above). Tokamac (talk) 18:08, 3 March 2013 (UTC)

Addressing Issues of Neutrality, Some former issues, gaps of clarity

A number of corrections and changes have been made to provide clarity, continuity and insight into Mach effects aka Woodward effect. Where needed, additions have been made to text and references. To the extent possible, every issue cited above has been addressed although the ion issue needs further work since Mach effects (Woodward) is a relativistic mesoscopic effect.

In order to maintain a neutral viewpoint, the subtopic Criticisms has been retitled History. Further Reading has been added with 2 entries. Consideration has been given to the fact this is not an expert topic and as a result, without the expert mathematics. Scie8 (talk) 05:28, 26 February 2013 (UTC)

Adding references

There are a lot of references lacking in this article, especially results from experiments reported in peer-reviewed papers wrote by other researchers. I'm adding some. Tokamac (talk) 17:54, 2 March 2013 (UTC)

Neutrality & sources

I see the following issue (emphasized by me here in bold) in "Experiments" section:

• On January 20, 2006 Paul March reported experimental results at an American Institute of Physics conference. Test results were nullified due to electromagnetic interference sources.

Where does this claim originates from? Nowhere I found it on the Internet nor in the original paper, where the results were rather claimed positive. In the paper (available to anyone through download), an hypothesis is however made about the thrust being one to two orders of magnitude higher than theoretical predictions, due to the fact that the authors computed the equations with a constant rest mass density value, whereas the entire idea is about mass fluctuation. I add a temporary [citation needed] flag on this one before reverting the sentence. I just wait a bit for the one behind 69.181.36.250, who initially wrote the original claim on 1^st December 2012 at 22:31 ("Palfreyman does not consider the results conclusive since high levels of electromagnetic radiation (EMI) were present, due to the high value (8:1) of the voltage standing wave ratio (VSWR) in the matching network, and the fact that the balance used was electronic, and thus prone to spurious readings"), to let him add the correct sourced citation, if such one exists. Especially as small EMI effects are indeed cited as detected in the original publication, but that they do not overcome or null out the other results.

Tokamac (talk) 18:42, 2 March 2013 (UTC)

Some references have absolutely no connection to Mach effects and Woodward's transient mass fluctuation whatsoever, like the link to Fran De Aquino paper, or the one from Benoit T. Guay. Do contributors even read the references they're adding? Tokamac (talk) 14:48, 3 March 2013 (UTC)

"Acceleration" effect is wrongly explained throughout the article

In its current form, the Woodward effect article explains that transient mass fluctuation arises in an object (a capacitor) by injecting energy into it, through "relativistic effects E = mc²". And then that this "charge mass", made heavier, is accelerated to transfer increased momentum forward, resulting in an effective thrust. It is not the case. This results from an incomprehension of the fundamental role played by the acceleration of the object during transient mass fluctuation. Without acceleration, a charged capacitor does not experience mass fluctuation at all. Mach effects are all about inertia, which involves acceleration. If internal energy is modified inside the object (say by charging a capacitor) no resulting mass fluctuation will arise if the object is not accelerating at the same time. This is not explained as it should be. I'll try to add some clarification. Tokamac (talk) 14:52, 3 March 2013 (UTC)

Mach effects" section vs "Impulse engine" and "Warp drives and wormholes" sections

Scie8, I don't see the benefit of the newer "Mach effects" section since it duplicates what have already been detailed further in "Impulse engine" then "warp drives and wormholes" sections. Now there are several sections, each talking about the impulse drive, the Alcubierre metric and the absurdly benign traversable wormhole (Kip Thorne). No need to duplicate IMHO, which lacks clarity. I propose that the only new elements (the references to "open and closed curved space" and naming Kip Thorne) should be separated and inserted in the already existing sections, and not under this "Mach effects" section. All three (impulse engine/warp drive/wormhole) are proposals from Woodward, hence pertain to the Woodward effect. Sure they have already been investigated by other physicists, but the derivation of Sciama's equations shows the possibility of expressing negative mass. This is proposed by Woodward, and is for now called the Woodward effect. When the different effects explained by the equations are proven to be true, replicable, scalable and doable, they will perhaps be more generally renamed as "Mach effects" in the future, but it is for now only Woodward's proposal. Thus the Woodward effect. Tokamac (talk) 12:26, 17 March 2013 (UTC)

Terminology section

The section labelled "Terminology" is not a section usually found in an article. It just list a bunch of terms, and claims some of them are related to the topic. The normal practice is to wikilink terms such as these when they are first used in the article, and perhaps again when they are used in a section farther down. If they are wikilinked that way, they do not need to be set out in a terminology section. if they are not used in the article at all, then it seems pointless to list them. Related articles cn also be listed in a "See also" section even if they are not mentioned in the article. Accordingly, I will remove the "Terminology section to make this article more like other science articles. Edison (talk) 01:17, 17 September 2013 (UTC)

Doesn't the transfer of energy from rear to front cancel the trust?

Doesn't the transfer of energy (which has, of course, a very small mass itself) from the rear mass after the actuators have expanded, to the front mass cancel out the trust generated? IMHO the device neglects the effects of transferring energy (e.g. by wires) between both energy storing/mass changing devices in the front and back. Example: Rear energy tank is charged up, gains mass, front device discharged, actuators expand and pushes the small mass in the front farther forward than the larger mass in the back. Now the energy has somehow transfered from the rear to the front so that the actuator can contract again and the device can generate trust. So far, this effect has neglected, because the same energy/mass now has to be moved forward again and thereby should, at least in my opinion, cause a momentum opposite to the trust that was generated in the first cycle. This is however neglected in the theory of operation. — Preceding unsigned comment added by 188.155.186.23 (talk) 08:26, 2 September 2014 (UTC)

You're missing the entire point of the theory. You're pushing forward when the mass is lighter, and pushing backward when the mass is heavier. So, even though the force in each direction is the same, the thrust is higher in the forward direction. Obviously this is assuming that Woodward's equation is correct—which is a pretty big assumption, and without it the whole idea falls apart. But if it is, the idea makes sense. Your argument is akin to saying that AC can't work because the voltage difference between 0 and 2pi is 0, neglecting the fact that the voltage difference between pi/2 and 3pi/2 is 1. --70.36.140.225 (talk) 04:05, 30 September 2014 (UTC)

I looked into it, basically the idea is that inertial mass [Kg] of a region of space is also function of the power derivative [W/s] of the internal energy [J], with the imbalance being carried away by gravitational waves and other even minor effect rising due to this. The effect is quite small but still macroscopic enough to be measurabile by realistic apparatus (about a few microgram of mass imbalance in realistic small scale apparatus). While the math of this is sound, it seems to me that this effect is an artifact due the lack of a complete understanding of the phenomenon. Until there is some solid experimental confrmation i would be a lot more skeptic about this topic in this page IMHO. Anon, 13 November 2014

I request one of the regular editors of the article please delete this section. The entire section is in violation of the principle that a talk page is designed to discuss the HOW TO IMPROVE THE ARTICLE and not general discussion of the topic itself. Trilobitealive (talk) 04:14, 15 November 2014 (UTC)

I agree with 188.155.186.23. To simplify, pretend it's not capacitors, wires, and electricity but water, pipes, and tanks. You can definitely get net motion by moving water tanks together or apart when one has more mass than another -- but moving water back to the 2nd tank one will reverse that motion. Energy-mass equivalence doesn't stop being true for moving electricity :P Fry-kun (talk) 00:31, 25 November 2014 (UTC)

You all miss the point that the "closed system" (from a thermodynamical point of view) of a device expressing a Mach effect (here, a Mach effect thruster) is not limited to the couple thruster + electrical generator, but the device coupled with all the matter in the universe. The conservation of momentum is thus assured by the interaction of all matter in the universe through an ambient "gravinertial" field that is of Wheeler-Feynman "action at a distance" type (see Wheeler–Feynman absorber theory). Inertial forces are instantaneous (as opposed to gravity waves, which propagate at the speed of light) because the interaction is carried by retarded (forward-in-time) and advanced (backward-in-time) waves.

The Mach effect thrusters are not transducers, i.e. they do not convert electricity into kinetic energy. They rather are gravinertial transistors, controlling the flow of inertial flux into and out of the active mass, instantly exchanging momentum with the chiefly distant matter in the universe, through this ambient gravinertial field.

May you read Woodward's book Making Starships and Stargates: The Science of Interstellar Transport and Absurdly Benign Wormholes in which all this is clearly explained.

Tokamac (talk) 16:03, 30 November 2014 (UTC)

Neutrality

The language of this article refers to this hypothesis as a theory. It makes huge leaps and has not been proven. This may not be notable enough for Wikipedia and may be original research.198.2.4.2 (talk) 17:13, 25 November 2014 (UTC)

Thank you for your concern. I have three question for you that will hopefully allow us to fix the issue you've highlighted:

• (1) Can you clarify the difference between a hypothesis and a theory, as it relates to this article?
• (2) Given that this subject appears to be referred to by a number of notable sources, including new publications and peer-reviewed journals, can you share more of why you feel the topic is not notable enough for Wikipedia?
• (3) Can you point to the original research that you are referring to?

Rustandbone (talk) 22:36, 8 December 2014 (UTC)

After review, I do not believe there is a problem with the neutrality of this article and am removing the tag. In reference to your stated concern, can anyone provide support as to whether the Woodward effect is a hypothesis or a theory? Rustandbone (talk) 17:36, 11 December 2014 (UTC)

EM Drive

So this:

"Based on the White conjecture, the proposed theoretical device is called a quantum vacuum plasma thruster (QVPT) or Q-thruster. No experiments have been performed to date. Unlike a Mach effect thruster instantaneously exchanging momentum with the distant cosmic matter through the advanced/retarded waves (Wheeler–Feynman absorber theory) of the radiative gravinertial field, Sonny's "Q-thruster" would appear to violate momentum conservation, for the thrust would be produced by pushing off virtual "Q" particle/antiparticle pairs that would annihilate after they have been pushed on. However, it would not necessarily violate the law of conservation of energy, as it requires an electric current to function, much like any "standard" MHD thruster, and cannot produce more kinetic energy than its equivalent net energy input.[citation needed]"

seems like the [EM Drive] [NASA] just tested and confirmed. Should there be an added note about that in the section on Quantum Mechanics?

External links modified

Hello fellow Wikipedians,

I have just modified one external link on Woodward effect. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

• Added archive https://web.archive.org/web/20070613073754/http://relativity.livingreviews.org/Articles/lrr-2006-3/ to http://relativity.livingreviews.org/Articles/lrr-2006-3/

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 10:46, 11 November 2017 (UTC)

External links modified (January 2018)

Hello fellow Wikipedians,

I have just modified one external link on Woodward effect. Please take a moment to review my edit. If you have any questions, or need the bot to ignore the links, or the page altogether, please visit this simple FaQ for additional information. I made the following changes:

• Added {{dead link}} tag to http://ralph.open-aerospace.org/deep/repository/zampino2.pdf
• Added archive https://web.archive.org/web/20120219112838/http://www.thespaceshow.com/detail.asp?q=689 to http://www.thespaceshow.com/detail.asp?q=689

When you have finished reviewing my changes, you may follow the instructions on the template below to fix any issues with the URLs.

This message was posted before February 2018. After February 2018, "External links modified" talk page sections are no longer generated or monitored by InternetArchiveBot. No special action is required regarding these talk page notices, other than regular verification using the archive tool instructions below. Editors have permission to delete these "External links modified" talk page sections if they want to de-clutter talk pages, but see the RfC before doing mass systematic removals. This message is updated dynamically through the template {{source check}} (last update: 5 June 2024).

• If you have discovered URLs which were erroneously considered dead by the bot, you can report them with this tool.
• If you found an error with any archives or the URLs themselves, you can fix them with this tool.

Cheers.—InternetArchiveBot (Report bug) 21:50, 25 January 2018 (UTC)

This article gives the erroneous impression that the woodward effect is mainstream

This article gives the impression that the woodward effect is mainstream and has found acceptance within the physics community subject to future experimental confirmation. This is not the case: The woodward effect is almost completely ignored by physics, outside of an extremely small number of people researching it and, so far, failing to demonstrate it experimentally. The reason for this is that the vast majority of physicists feel certain that the effect is not real. In turn, the reason for that is that effects that violate the conservation of momentum, which this does, violate energy conservation. Let's be absolutely clear: This would enable a perpetual motion machine to be built. Furthermore, as the article suggests, deep in the undergrowth, the original reason to think the effect might be real was based on a mathematical error in basically undergraduate level maths. I think that this article should be reframed slightly to make it much more clear that this "theory" is highly speculative, bordering on pseudoscience. H123b wiki (talk) 14:16, 17 June 2018 (UTC)

I'm not so sure that the article fails to note that the proposed effect is not accepted among mainstream, in fact the sentence which begins The effect is controversial within mainstream physics... seems to do a fairly good job of noting that the proposed effect has no experimental evidence and appears to me to underscore the fact that the proposed effect is considered fringe. Yes, it approaches the realm of pseudoscience however it fails to achieve pseudoscience since there is solid math which suggests that there could be such an effect albeit an effect so minute as to be swamped in to utter unmeasureability, ergo an effect that can not even in principle be confirmed or refuted experimentally. SoftwareThing (talk) 00:06, 26 June 2018 (UTC)

The debate section leaves out what critics say is the likely cause of the signal

The debate section leaves out what many critics claim is the most likely cause of the "thrust" signal, shifts in the center of mass caused by the movement of asymmetric device components. The idea is that due to the asymmetric motion inside the Faraday cage, the center of mass of the cage and its contents shifts relative to the cage. But the center of mass must still remain where it was before (relative to the laboratory). So the faraday cage moves aside, while its center of mass stays put. Woodward has attempted to address this in some of his experiments, but recent simulation work presented at the Advanced Propulsion Workshop at Estes Park 2018 has shown how it is possible to create the same thrust signals as Woodward's device using only moving parts and classical mechanics.

Resonant cavity thruster

The reference for this section does not support the claim. I cannot find anywhere in the article where it says the emdrive may work because of mach effects. I have read this on some forums, but never from a reliable source. Recommend removing this section until a source can be found to support claims.— Preceding unsigned comment added by Monomorphic (talk • contribs) 15:55, 13 April 2021 (UTC)