EmDrive — A Challenge to Scientific Orthodoxy (Roger Shawer)

A reader forwarded to me a presentation by Roger Shawyer, the British inventor of the EmDrive, who reports he has been given permission by the UK Department of Defense to put this in the public domain. Mr Shawyer would like to have this presentation circulated as widely as possible.


Shrivenham presentation V.3
  • Chapman

    I guess it falls on me to be the party pooper here, but while I was initially intrigued by the concept, I can not place this in my “hopeful science developments” folder.

    Shawer’s theory of operation, to describe the REPORTED thrust obtained is based on some really bad science. While that does not disqualify the EM Drive itself, I can as yet see no physics loopholes that might allow it to perform as reported.

    The Group Velocity theory presented here is nonsense, and ignores the reality of how photons interact with space, matter, and each other.

    To explain the EM Drive thrust you must explain a mechanism whereby the vector of a photon’s momentum can be changed without interacting with the mass of the thruster itself. This would require some form of force and control to be applied to the photon relative only to absolute space, of which the thruster is only a co-occupant. A photon effected in this way could then impart force to the thruster directly, and the photon would be functioning strictly as a moderator of force between space and the thruster mass. This would maintain the overall conservation of momentum, because it shifts half the force directly to space, resulting in an asymmetrical force being applied to the thruster body.

    In order to “push off” you gotta have something you are pushing off OF, and that “OF” receives the exact same force that you do.

    Note: I am NOT ruling this out. The thruster MAY BE REAL, and doing exactly as described above. I am merely saying that whatever theory one presents to justify the EM Drive has to answer, realistically, how this is done.

    (I am currently looking to see if there is some way that a twit might be the key, and I would welcome any communications engineers to weigh in on the idea, but I am just grasping at straws WISHING the EM Drive were true, and desperately seeking something to pin my hopes on)

    OK. Let the “Hate on CHAPMAN” commence…

    • Chapman

      I should also note that I could build you an EM Drive over the weekend, if any of you happen to have a compact singularity in your garage that you are not using right now.

      A perfectly straight waveguide, with a length properly tuned to resonate at the frequency of the generated microwaves, will happily reflect those photons end to end with great efficiency. This is what happens when you sing in the shower, and you hit those “sweet notes” that reverberate.

      Anyway, if you placed that “straight” waveguide very close to a compact black hole, the warping of space by the black hole, just above the event horizon, will cause the waveguide to be wrapped part way around the circumference. If the length of the waveguide is sufficient that the opposite ends are exactly 180 degrees around the circumference from each other, the “straight path” from one end to the other will result in both ends pointing in the same direction. All momentum transfers resulting from the reflected photons will be of uniform direction, and you will get 100% conversion of microwave energy to directional thrust. It would basically be using gravitational lensing to fool mother nature, and overcome the troublesome demands of COM.

      Easy peasy!

      So, who wants to come over this weekend, with their singularity, and get their hands dirty with me in my workshop?

      • LION

        Hi Chapman, do you really have a workshop?????? and if so are you doing active LENR research, do you for instance have a LFH setup or are you doing electrolytic research and N.H. or Deuterium???? Had any success???
        Every serious researcher counts, good for you.

    • Engineer48

      Hi Chapman,

      It is standard microwave engineering to calc the lower group velocity and longer guide wavelength as a bunch of microwave length photons are injected into a waveguide, with the guide wavelength increasing as the diameter decreases as the group velocity decreases. This is existing physics.

      In 1951, the UK research scientist Cullen showed, experimentally, that the radiation pressure exerted by the microwave photon energy in a waveguide is reduced by a factor of the ratio of the external wavelength / internal guide wavelength. So Roger’s equations are correct.


      You might be interested in watching his explanation of why the EmDrive works:

      • Chapman

        The problem is in the extrapolations of force per square inch vs total force in either direction.

        With extreme energy levels you may be able to deform the smaller end plate, but you will not move forward in free space.

        VG does not alter the momentum of individual photons, and the unit does not alter the NUMBER of photons. Everything seen is just local effect, with localized concentrations of energy, but no violation of COM. And, of course, without violating COM, or anchoring to some external substrate, you are not generating thrust.

        Standing waves and Traveling waves are produced as a gross effects of the aggregate phases of individual photons, and do not alter the total energy of the existing photon population, nor alter the absolute spatial direction of their momentum. This is exactly why the whole concept falls apart. It looks like it SHOULD work, I grant you that. I spent long hours chasing rabbits down holes, pursuing every possible anomalous factor that could save the idea, but to no avail.

        As I have stated, I am not declaring that the EM Drive is bogus, only that Shawer’s explanation of the physics that MAKES it work is bad.

        There may be an answer out there, I do not know for sure. But there is one thing I am sure of:
        Neither I, nor Shawer, have discovered it…

        • Ged

          The NASA scientists and associated DIYs on the NASA spaceflight forums have been hard at work to develop the theories and find the mechanisms, and then working to test them. A lot is know now, much more than shown here, but much much more remains to discover.

          You are completely right that Shawyer’s ideas on their own don’t work out. Radiation pressure can’t be the source of the effect, though red shifting from unequal dissipation rates at the two ends could be, as WarpTech has shown by math. Then there is the Machian gravity equations which would explain both it and the Mach Effect Thruster, and there is Dr. Harold White’s proposed mechanism of quantum vacuum degredation. Actually, there are a number of forming theories backed by general relativity that would work at the levels seen in experiments. Question is which of any (if it all really works once all error is ferretted out) or in combination is the real culprit. As it is, experiments are being done to try to differentiate between the theories.

          From the data, I kinda favor WarpTech’s dissipation red shifting theory as it matches well with how the direction of thrust in EmDrive experiments are affected by resonance mode shape, dialectrics at one end or not, and other configurations. That ability to predict force direction gives his theory a lot of weight to me, but it is still unknown as the other theories may be able to explain the same too once fully applied. And in fact, all three theories could be describing the same thing from simply three different views. We shall see as more data comes in.

          But as Dr. Paul March has said about all his testing of the EmDrive and attempts to remove all possible sources of error, “[a]nd yet, the signal remains.”

          • Chapman

            Darn it, GED!

            I had finally resolved myself to the fact that I had exhausted all avenues of investigation, and was ready to move on to other projects, and you have to go and get my hind brain all worked up again with a new set of leads…

            Now I will NEVER finish getting caught up on “Orange is the new Black” on netflix!

            Nice going… 🙂

          • Ged

            Gotta keep you endlessly entertained somehow 😉

          • Chapman


            Like a child, I tend to get into trouble when not being distracted and amused.

            But you have already ruined my day with your statements to RicalWikis above. I have lived a long life, happily confident in the fact that size does NOT matter! Thanks A LOT!!!

            Are you intentionally trying to undermine my worldview? What did I ever do to you??? 🙂

          • radvar

            If as Engineer48 says the basic physics holds up, then the explanatory problem seems to this: because we cannot translate the concept of group velocity into the metaphor of throwing rocks out of the back of a row boat, Shawyer’s theory cannot be valid.

            Maybe the problem is requiring that solution fit the metaphor of throwing rocks out of the back of a row boat.

            Maybe there is a metaphor like “pushing against the speed of light, which doesn’t move” that could be more effectively explanatory, even though it is (as yet, and may always be) incomprehensible in billiard ball / row boat / Newtonian / Cartesian modeling.

            Light bends. Can mental models?

          • Engineer48

            Hi Radvar,

            Photons are NOT ROCKS. They DO NOT change velocity when their momentum changes. What happens is their wavelength increases as they lose momentum.

          • radvar

            Hi Engineer48,

            I’ve been clear on the “not rocks”. My apparently less clear post was saying that:

            an obstacle to understanding was that people tried to make Shawyer’s thesis fit the “throwing rocks” model, so perhaps another model might be needed.

            It appears from your comments that the necessary model is not that exotic, requiring mostly Maxwell with some special relativity.

            I VERY MUCH APPRECIATE the comments that you have added to this thread.

            I have been discontented since EM first “made the news” (here and elsewhere), because I had not seen any attempts to take on Shawyer thesis directly and either explain it or or defeat it in his terms. The discussions always seemed to get stuck at “no rocks being thrown, so it cannot work”.

            Your comments in my view have definitively knocked the walls down around that cognitive blind alley, so THANK YOU!

          • Engineer48

            Hi Radvar,

            Thanks for the kind comments.

            All I have done is look at the claims and check out the physics without doing a Knee Jerk reaction and saying “It Can’t Work”, which involves almost no mental effort.

            The physics seems to check out and there are several replications.

            Why others, with a lot more qualifications than I, have not gone down the pathway to check before reject is something I don’t understand.

            I can understand Shawyer’s feelings and statements about how he was treated, even called a Fraud in the UK parliament, when it was experts appointed by the UK MOD (Minister Of Defence) that reviewed his work and gave it the thumbs up.

        • radvar

          And, of course
          It looks like it SHOULD work
          every possible anomalous factor
          There may be an answer out there
          one thing I am sure of

          Open right brain, cease left brain dogmatism, admit alternative views

        • Engineer48

          Hi Chapman,

          Then again you may not be aware of all the proven and relevant microwave physics.

    • radvar

      “nonsense, and ignores the reality”
      A meta-discussion about “closed systems”…

  • Engineer48

    Should add that Roger Shawyer was INVITED to give this presentation to the UK Defence Academy. It is not just something he created and posted to the net:


    “About the Defence Academy of the United Kingdom
    The Defence Academy is responsible for post-graduate education and the majority of command, staff, leadership, defence management, business skills and technology training for members of the UK Armed Forces and Civil Servants.

    It is also responsible for the provision of non-technical research and assessment in support of the Department, and for establishing and maintaining itself as the MOD’s primary link with UK universities and with international military educational institutions. By operating under unified direction and with a single budget, it capitalises on the combined strengths of its Colleges, enables the flexible and cost-effective use of staff, facilities and money and maximises influence nationally and internationally.

    The Academy is comprised of the Royal College of Defence Studies (RCDS), the Joint Services Command and Staff College (JSCSC), the Shrivenham Leadership Centre (SLC), the Armed Forces Chaplaincy Centre (AFCC), Nuclear Department, Defence Centre of Training Support (DCTS), the Technology School, Business Skills College (BSC), the Defence 6th Form College (DSFC), Defence Technical Undergraduate Scheme (DTUS), Defence Technical Officer and Engineer Entry Scheme (DTOEES) and Defence Engagement. The Academy has three strategic partners – King’s College London, Serco UK and Europe, and Cranfield University – who provide our academic and facilities support and who are vital to our success.


    The Defence Academy has a number of sites. The Headquarters, JSCSC, Technology School, Business Skills College and Shrivenham Leadership Centre are based at Shrivenham, the RCDS is in Belgravia, London and the Armed Forces Chaplaincy Centre has its home in Andover. Other important sites include the Nuclear Department based at HMS Sultan, DCTS based at RAF Halton, DSFC, Welbeck and the 5 Universities (Aston, Loughborough, Newcastle, Northumbria and Southampton).”

  • Leonard Weinstein

    The analysis by Roger Shawyer is wrong. The simple fact is that the force equation using the momentum equation (F=d(mv)/dt), where v=c here, and combining this with E=mc2, results in F=(dE/dt)/c. This results in a required power of 3E8 W/N at 100% efficiency (and real cases are <100%). This EM drive is a simple photon drive using microwaves. There are no gains over the maximum possible shown. Thus for a few kW input, the maximum thrust would be microN , not mN. If in fact the thrust is much higher than stated here, the system is doing something other than known physics.

    • Ged

      Check out Machian theory (and gravity assists) and Dr. White’s theories on a degradable quantum vacuum for more data and competing physical mechamisms for this subject, and on how the EmDrive could be orders of magnitude higher in force per power than a photon rocket (as experiments continue to demonstrate so far).

      Shawyer doesn’t present much that is useful as he doesn’t seem to try to find how to balance his energy equation in a wider context and so gets stuck trying to get it to work with only half the picture.

    • Engineer48

      Hi Leonard,

      Inside a resonant cavity, the total photon harvested momentum gain is increased via each end plate absorb & emit event. As each event occurs the emitted photon is red shift to reflect their lost momentum and energy.

      So on the mass side we have dV = dp/m and on the photon side we have dwavelength = Planck’s constant / dp. So CofM is conserved. {lease think on the fact that the photons are massless.

      I did include this graphic on my earlier post but have included it here so you can get a better understanding of how the mass vs photon momentum exchange works.


      There is nothing outside physics here.

  • Leonard Weinstein

    Rogers analysis did result in F=Pv/c2, and since v=c, was the same as F=P/c. It is the rest of his analysis that is bogus. Note that P=dE/dt to compare the analysis. For Rogers analysis to be valid, conservation of Energy has to be violated.

    • Ged

      A gravity assist maneuver increases momentum and thus the energy of a space probe passing by a gravity well without the probe expending any power what so ever–apparently violating conservation of energy if one looks only at the probe’s side. However, energy is conserved through the gravitational interactions of the probe and the planet or star being used to sling shot it to higher momentum and energy, when both parties are considered together.

      Machian theory for instance solves the issue by presenting the universe itself via gravity as the other party to the enter equation for the Mach Effect Thruster and also by extension the EmDrive. There are other like theories where the equation is balanced by stealing energy from another source like NASA’s Dr. Harold White’s theory of the degradable quantum vacuum as the power source of EmDrive propulsion.

      In the end, if something works–like a gravity sling shot of a space probe–but appears to violate conservation of energy, it just means the other side of the picture has been missed.

      I can’t speak to Roger Sawyer’s theory, as to my understanding he unsuccessfully tortures the math to try to make it work with only one side of the equation. But our understanding of the EmDrive anomaly is growing greatly as we find more evidence of possible pathways and interacting partners with the drive which balance the energy equation.

      Dr. Rodal, who has done much theoretical work and analysis around the Match Effect Thruster and EmDrive, has some great treaties on this subject involving gravity, energy conservation and the math of the EmDrive over at the NASA space flight forums, which may be of help to any curious mind wondering about the energy conservation question.

      • Chapman


        I knew GED would get it! It is not an unsolvable problem, it just can’t be solved via VG.

        The solution, if it exists, lies in some physics that goes far deeper than we are playing with right now.

      • Leonard Weinstein

        A gravity assist does not increase the system energy for free, it changes orbit direction and takes some of the energy from planet orbital velocity to speed up. The planet loses this amount of energy and slows down, but the planet is so big it does not notice it. Quantum energy and other hypothesis as source of energy are unproven, so calling in these is not supporting evidence. Shawyer gave an analysis with no supporting logic for any extra energy, just hand waving. I ran into the problem of measuring very small thrust or drag force variations in my work at NASA, and am very aware of the difficulty of measuring such. I studied both electrodynamic forces, and small changes in aerodynamic drag in flow, with variations in forces in the range of mN in the presence of total forces of N.

        • Leonard Weinstein

          Some references on my work on low force difference measurements can be found in the following. These were not all of my work at the low force difference measurements, but give an idea. I designed and made several special force measuring systems to do the measurements:

          Weinstein, L.M.; and Balasubramanian, R.: An Electrostatically Driven Surface for Flexible Wall Drag-Reduction Studies. Presented at the Second International Conference on Drag Reduction, Cambridge, England, August 31-September 2, 1977.

          Walsh, M. J.; and Weinstein, L.M.: Drag and Heat Transfer Characteristics of Small Longitudinally Ribbed Surfaces. AIAA Journal, Vol. 17, No. 7, July 1979, pp. 770-771

          Weinstein, L.M.: Effect of Driven-Wall Motion on a Turbulent Boundary Layer. IUTAM Symposium on Unsteady Turbulent Shear Flows, Toulouse, France, May 5-8, 1981. Springer-Verlag, 1981.

          Malik, M.R.; Weinstein, L.M.; and Hussaini, M.Y.: Ion Wind Drag Reduction. AIAA 21st Aerospace Sciences Meeting, Reno, Nevada, January 1983.

    • Engineer48

      Hi Leonard,

      CofE is only valid in the same inertial reference frame.

      Please refer to my latest post on how a photon vs mass momentum exchange is very different to a mass vs mass momentum exchange: http://www.e-catworld.com/2017/06/17/emdrive-a-challenge-to-scientific-orthodoxy-roger-shawer/#comment-3367286599

      • Leonard Weinstein

        We are talking about a force(thrust) due to use of energy of electromagnetic source. You need to keep in mind that E=mc2 implies that m=E/c2. i.e., energy HAS equivalent mass. In addition, the speed of light does not change in a different frame (unlike physical mass speed). My simple analysis and the conservation of energy are valid as stated unless new physics is present!

  • Ged

    Actually, so far evidence and some theories suggest that the larger the thruster the bigger the effect. This has to do with the longer the wavelength the better the effect, so to resonate a longer wavelength you need a larger cavity. I am sure there is some sweet spot where increasing size is no longer as effective as increasing drive numbers, but that crossover point is not yet known. Could be with smaller drives in arrays like you suggest, or larger than even what has been tested so far. We shall find out!

    • Engineer48

      Hi Ged,

      Basically the higher the Q the larger the thrust vs the longer the cavity, the greater the transit time, the lower the number of reflections and the lower the thrust.

      Then add in the effect of frequency. The higher the freq, the lower the skin depth and the lower the per cycle losses vs higher freq needs a smaller cavity, which causes Q to drop.

  • Andreas Moraitis

    A naive question: If you have a chamber that is open on one end (similar to the combustion chamber of a rocket) with a photon source inside, shouldn’t the radiation pressure at the closed end generate thrust as well?

    • Andreas Moraitis

      That should also work with a parabolic aerial or (at much higher frequencies) a flashlight. The force F could anyway be calculated as P/c (see Leonard’s comment below). So why is the EMDrive so special?

      • Andreas Moraitis

        Answer: Higher efficiency, due to the ‚recycling’ of the photons (see above). Here is a calculation for a ‘flashlight drive’ of 1 kW power in a 100 kg space probe:

        F = 1 kW / c = 3.336 * 10^-6 N
        a = F / 100 kg = 3.336 * 10^-8 m / s^2

        That means within 1 year the probe could be moved by (a / 2)*(1 y)^2 or 16589 km. For 10 years one gets 1.659 million kilometres, which seems a lot, but is still very little on an astronomical scale.

        The efficiency of the EmDrive is claimed to be three orders of magnitude higher, compared to an ‘open’ drive. That would make it indeed useful for space travel. Anyway, its special quality is not propellant-less propulsion: the latter can be generated by any electric torch from the shelf.

    • Engineer48

      Hi AM,

      With an open end, there is no resonance, no photons transiting from end to end, no multiple photon absorb and emit events, each causing a momentum xfer event, occurring at each end plate.

      The way the single photon momentum xfer event is increased is via resonance, the higher the better as then more photon transits and more photon end plate absord, emit events.

      EACH photon vs end plate events is based on p = (2*E*lambda ext)/c*lambda guide with lambda guide increasing as the cavity diameter decreases. In a well designed EmDrive there are millions of photon vs end plate events, so the resultant momentum transfer is increased millions of times over that of a single photon vs end plate event.

      This was experimentally proven by Cullen in 1950, so take it as existing microwave physics. Just not a lot of folks know of this effect.


      Then in 1955, Bailey experimentally proven the radiation pressure on an plate inside a resonant cavity is increased by the cavity Q, which implies there are more photon vs plate events as the cavity Q increases. So again a known and proven fact of physics that not a lot of folks are aware of.


      • Andreas Moraitis

        I see. The photons are ‘recycled’, which makes the system more efficient. However, the open box would also produce propellant-less thrust, in the sense that no (rest-) mass has to be ejected. Therefore, all the excitement about the “propellant-less-ness” seems a little exaggerated.

        • Engineer48

          Hi AM,

          You miss the point.

          Nothing is exhausted to carry away the momentum.

          The trapped photon wavelets red shift to “carry away” the momentum without actually being exhausted from the EmDrive.

          • Andreas Moraitis

            That’s clear. But the ejected photons (in the open box) are as well ‘nothing’, if you consider rest mass as the decisive parameter.

  • Bob Greenyer

    My comment

    “EMDRIVE – How to increase thrust based on alternative hypothesis of its operation”


    • Engineer48

      Hi Bob,

      Shawyer’s theory works and is totally inside existing physics.

    • Chapman

      Well done, Mr. Greenyer.

  • Engineer48

    In 1950 Cullen experimentally proved the radiation pressure on an end plate of a waveguide is lower than the radiation pressure expected outside the wave guide. The reduction follows wave length external / wavelength internal.


    Then in 1955, Bailey experimentally proved the radiation pressure on a vane inside a resonant microwave cavity was increased by the cavity Q.


    Modern field simulators, based on Maxwell’s equations, show that inside a resonant cavity the 1/2 wavelength increase as the cavity diameter decreases, as microwave physics predicts.


    Then we need to understand a photon vs mass momentum exchange event is not the same as a mass vs mass momentum exchange event.

    Mass represents a momentum loss or gain via a change in velocity. However photons always travel at c, so if the lose or gain momentum, their velocity doesn’t change. What changes for photons is their wavelength alters, going longer for a momentum loss and shorter for a momentum gain.


    No new physics are needed to understand how a EmDrive works. Just try to fully understand the above.

    If you don’t understand how guide wavelength and group velocity varies inside a waveguide to that external to the waveguide, try this page:


    To understand radiation pressure go here:


  • Axil Axil


    The Bussard ramjet is a theoretical method of interstellar spacecraft propulsion proposed in 1960 by the physicist Robert W. Bussard. Bussard proposed a ramjet variant of a fusion rocket capable of reasonable interstellar travel, using enormous electromagnetic fields (ranging from kilometers to many thousands of kilometers in diameter) as a ram scoop to collect and compress hydrogen from the interstellar medium.

    In a LENR based variant of this concept, once the hydrogen is collected, it is isotopically purified and the deuterium is discarded. The purified hydrogen then enters storage to even out the collection of interstellar gas. From storage the hydrogen gas is metered into a Holmlid reaction chamber where the hydrogen is ignited into a high energy plasma via the catalyzed LENR reaction.

    I would now like to draw your attention to applicable new research undertaken by Professor Leif Holmlid involving ultra-dense hydrogen and its decay into near light speed charged particles and neutral fragments.

    Holmlid uses a catalyst to produce ultra-dense hydrogen that can be excited into nuclear disassociation through the application of a EMF stimulus.

    I like LENR as a basis to support a light speed capable interstellar motor. As discovered by Holmlid, LENR produces sub atomic particles and nuclear fragments moving at ¾ light speeds. And even better, LENR produces its own energy from muon based catalyzed fusion. This fusion energy would be used to sustain the electromagnetic hydrogen collection fields. If we want to fly between the stars, LENR is the way to go… think LENR.

    • Engineer48

      Hi Axil,

      At 1g, with a mid way flip and burn to slow down, Alpha Centauri is a 3.6 ship years and 6 Earth years journey.

      A LENR reactor would be perfect to supply the electrical power to the EmDrive.

      • Axil Axil

        As a general system’s design principle, it is usually more efficient to keep the usage of energy close to its point of creation. The process of multiple energy conversion steps adds layers of inefficiencies to energy utilization.

        A stream of charged high mass mesons/muons/electrons whose reaction mass is further increased through the application of additional relativistic energy via EMF charged particle acceleration methods is more effective and efficient at reaction force projection then pushing against virtual particles in the vacuum as per the EM drive, IMHO.

        • Engineer48

          Hi Axil,

          The EmDrive does not push against virtual particles in the vacuum. Far from it. It is about harvesting momentum from trapped photon wavelets.

          • Axil Axil

            Well what is more efficient at projecting momentum, thrust produced by relativistic atomic fragments moving at near light speed or harvesting momentum from trapped photon wavelets? If you can analyze that I will be impressed.

          • Engineer48

            Hi Axil,

            Photon wavelets are created inside a resonant cavity from Rf energy. As long as there is electrical energy, say produced by a LENR reactor, there will be thrust.

            Atomic fragments are fuel that must be carried and which will one day be gone.

            BIG DIFFERENCE.

          • Axil Axil

            Not True… the Ramjet harvests the fuel it uses from the space that it travels through. The EM drive has a finite amount of fuel stored on board where the Ramjet has an unlimited fuel supply harvested from its flight path.

          • Engineer48

            Hi Axil,

            Another difference is the LENR reactor and the EmDrive are real world working devices. Your RamJet is just theory and still needs the electrical energy from the LENR system.

            Both are limited by the LENR reactor fuel life and amount of extra reactor fuel carried on the space craft.

            It is believed a non cryo, non superconducting EmDrive can achieve a specific force around 1kN/kW (100kgf/kW).

            What is the best specific force for the RamJet?

          • Axil Axil

            Since the continued propulsion of a nuclear fusion ramjet spaceship is dependent on interstellar hydrogen, the nature of interstellar hydrogen is the main issue of concern when designing such a spaceship. Two aspects of particular interest are the overall density and the isotopic composition of the interstellar hydrogen. The overall density controls the rate at which fusion reactions can take place relative to the craft’s speed and the size of the scoop’s area. The isotopic composition determines which fusion reaction pathway can be used.

            The interstellar density of hydrogen is 0.86 atoms/cm3. The energy gain relationship determined by Holmlid were found to be 390 MeV per each diproton reaction (two hydrogen atoms). The remainder of the proton mass and associated electrons are used as reaction mass. From this info, the scoop volume might be calculated as of function of spacecraft speed. The faster you go the more hydrogen that you can harvest.
            There is a minimum takeoff speed before the energy sustain relation is met and the scoop volume may be reduced as the Ramjet accelerates.

            There is more mass/energy content in deuterium which is about 1 atom out of 5000 captured.

          • Engineer48

            Hi Axil,

            One advantage of a 1g EmDrive is the ship can land on and leave a planet or moon with an 1g or less gravity well, plus of course there is a continual thrust gravity of 1g for the comfort of the ships human occupants.

          • Axil Axil

            The nature of the vacuum may preclude the possibility of an acceleration as high as 1G. Don’t count your chickens before they’re hatched.

          • Engineer48

            Hi Axil,

            Dr White’s QV theory was proven incorrect via his peer reviewed paper. QV thrust was predicted to scale as ^2 of the power. It was measured to scaled as the power scaled, ie linear relationship as the SPR theory predicts.

            So maybe move on past thoughts of the EmDrive thrust mechanism involving quantum vacuum interactions.

            It is just mass gaining momentum and from that a velocity change (dv = dp*m) and associated acceleration from photon wavelets as their wavelength red shifts due to the lost momentum and energy.

            So CofM is conserved but as the EmDrive is an open system, under special relativity, KE CofE is not conserved as there are different inertial reference frames involved and CofE is not conserved across different inertial reference frames.

            Here Dr. White did get it right as attached.


  • Engineer48

    Here is an interesting paper from Dr. Harold White, the director of NASA Eagleworks. In Appendix A he discusses the apparent KE CofE violation and shows it is based on the chosen inertial reference frame and that across different internal reference frames KE CofE does not apply:


    The full paper, direct from the NASA server, can be found here:

  • Engineer48

    Hi Chapman,


    Really all I have done is to properly check out the SPR theory, do the maths and check the references. At the end of the day, the SPR theory stacks up. Which is not to say it is correct. But it does say the theory can be used to design and build EmDrives as the theory matches the built results, which as an engineer is all you can ask for.

  • Engineer48

    Should add that I do not know if the SPR theory of the EmDrive is really how it works.

    What I do know, from doing the math and doing the reference searches is the SPR theory is based on existing physics and that it was developed by a team of UK experts appointed by the UK gov. Should add this expert theory development group had a working EmDrive to base their theory development work from. Fairly hard to doubt the device works, when it is generating thrust in front of your face.

    Just a few of the physics effects used in the SPR EmDrive theory are not very well known as they were established in the 50s and thus most members here might not know of them.

  • Engineer48

    Many folks rightly ask where and how is the momentum carried away from the EmDrive? They ask there must be a exhaust to carry away the momentum? Right?

    Well YES there is a momentum exhaust with the EmDrive, just not the kind we normally think of. This image should help to understand what is happening.


    It also helps to understand the photon wavelets are massless and due to Special Relativity the mass of the EmDrive cavity and the photon wavelets are in different inertial reference frames and thus the EmDrive is an open system. As such it is possible to transfer momentum from photon wavelet to EmDrive mass without breaking any rules.


    • Bob Greenyer

      Help me E48, in one part you say (and I paraphrase) that the photon wavelets are massless, and in the next sentence you say “it is possible to transfer momentum from photon wavelet to EmDrive mass”.

      So my question is, how do you have momentum in the photon wavelets if they are massless.

      • Leonard Weinstein

        The photons have no mass in the conventional sense, but do have mass equivalent as energy. E=mc2 implies m=E/c2. The momentum transfer force: F= vdm/dt which for this case yields F=cE/c2 per sec or F=E/c per sec or F=power/c (Watts divided by the speed of light). That is all there is to this issue unless there is new unknown physics involved, and I seriously doubt that.

        • Andreas Moraitis

          Yes. Most of the confusion about the EmDrive seems to result from the attempt to explain its function by means of Newtonian mechanics, even though this concept has been overruled by Einstein’s theory a Century ago.

          • Engineer48

            Hi AM,

            Actually both Newton and Einstein would be very happy with the EmDrive as all their laws are seen to apply.

            What is difficult for some folks is to understand is

            1) the resonant cavity increases the number of end plate momentum transfer events,
            2) the reducing cavity diameter drops the momentum transfer at the small end vs the big end,

            3) the increasing photon wavelet wavelength is what balances (carries away) the lost energy and momentum of the photon wavelet.

        • Bob Greenyer

          Yes, of course, the relationship between mass and energy.

          I’ll need that held in mind as I lay out some of my more radical thinking in the coming weeks.

          • Chapman

            That is the issue at the very heart of the question regarding the drives function. The photons in question have only relativistic mass, and that mass produces momentum that can be transferred – but there must be some rational effect that changes that mass disproportionately with respect to direction, or you altering the photon’s direction without any local interaction.

            Obviously, simply focusing, or concentrating, the photons does nothing to alter their individual mass, therefore it also does nothing to alter the sum of the total. I am trying to understand the influence that the formation of engineer’s “wavelets” has on individual vs group relativistic mass. I must admit that it is beyond my current physics knowledge, and I am desperately hoping that Engineer will come through and enlighten me.

            Such a mechanism, if it exists, has ramifications that extend far beyond a mere EM Drive. It implies a mechanism allowing for the direct manipulation of the effects, and fundamental strength, of the Electromagnetic Force itself.

          • Engineer48

            Hi Chapman,

            A photon wavelet’s Energy, Momentum and Wavelength are tied together by 2 simple equations which show that if the photon wavelet loses momentum and energy to causing mass to alter it’s velocity, the photon wavelet’s wavelength DECREASES to indicate the lose energy and momentum.

            It should be made clear that the shorter the wavelength of the photon wavelet, the higher is the energy and momentum.

            So in the EmDrive, as the photon wavelet transfers energy and momentum, causing a velocity change of the mass, the photon wavelet red shifts to a lower frequency or longer wavelength.

            This is what breaks conventional billiard ball momentum transfer as in that case BOTH masses alter their velocity to represent the momentum change. In the case of mass vs photon wavelet, when the mass accelerates and changes velocity, the needed momentum and energy came from the photon wavelets, which can no alter velocity, as does conventional mass, but instead alters the photon wavelet wavelength to a longer wavelength to represent the lost energy and momentum.

            This is not hard. It is not even rocket science.

          • Chapman

            I get all that, and expounded at great length on the matter when I was considering the EM Drive recently. In fact, it was YOU that reminded me of the sequential red-shift over the life of the photon as it slowly degrades.

            But I am not referring to the relative energy states of photons before and after reflections, I am talking about the change in photon energy and momentum as an instantaneous value based upon wavelet formations.

            If a formed wavelet has more or less energy/momentum than the sum of that of the photons who are congregated to FORM the wavelet, then where does that extra energy come from or go to? NOT over a period of time, but at one instant, relative to the photons traveling either left to right, or right to left?

          • Engineer48

            Hi Chapman,

            Each photon is a wavelet. It’s emitted freq determines it’s E and p.

            For a 2.45GHz cavity with 1,000W of Rf energy applied at resonance, there will be 6.16^26 photon wavelets emitted, by the impedance matched internal antenna coupler, every second.

            As the 6.16^26 2.45GHz photon wavelets do the 1st end plate adsorb & emit cycle, the emitted photon wavelets are at a very slightly lower freq from both eddy current losses and energy & momentum used to alter the EmDrive’s mass to a different velocity. If there is no velocity change then there is no momentum & energy transfer from the photon wavelets.

          • Chapman

            With the Lord God Almighty as my witness Engineer, you are one of my favorite personalities on this site, so know without any doubt that I am not badgering, harassing, mocking, or deriding you in any way, nor trying to get your goat over some technicality. Every word I speak to you is with earnest respect, and comes from a desire to better understand the issues.

            I am re-reading all these posts, and I think there may be a small bit of miscommunication going on. I do not think I, or many others, are tracking when you use the term “photon wavelet” in various instances, whether you are referring to the wave function of single photons, or the group effect of a congregation of photons. I see instances where you are using the term when referring to what I think is two separate things. And it looks to me like that is the same thing tripping up a few others who are equally respective of your input, and seeking your clarification.

            You are thinking you have a bunch of folks here who can’t seem to understand something you have described plain as day, but if you look closely you will see that many of those same guys are well educated and intelligent individuals who would not have any problem properly interpreting a clear explanation. This is no knock on YOU!!! I am simply asking if you can review the comments, and try to see where the wires are getting crossed.

            Everybody here loves you, and is hanging on your every word. There is no opposition here to your engineering authority. You are The Big Dog! If we did not trust you, we would just tune you out, or make BEC jokes at your expense! But we would not be asking follow-up questions like this.

            Our badgering in this regard is a sign of our deepest respect. PLEASE take it in that light, and do not get frustrated with us. 🙂

          • Engineer48

            Hi Chapman,

            I see a photon as the 2 dimensional circle as in this gif. It has height and width but no depth as the depth is time past and time future. That is why I call it a wavelet as it is the smallest fraction of what we think about as an em wave, which really doesn’t exist as a wave, like in the ocean, but is instead multiple photon wavelets stacked against each other.


            Each of those grey circles is what has the energy and momentum of the emitted wavelet. As it moves forward in time and space, the varying E and H fields trace out the conventional wave shape.

          • Chapman

            I thought so!

            See, I keep seeing the term wavelet and taking it to mean the gross effects of a small number of photons being seen as a group, which is the way the term is used in imaging circles. I was just looking at articles about improved resolution via interpretation of wavelets, and THAT is the definition I had stuck in my brain, which is why I kept asking about the INDIVIDUAL photons.

            But you WERE talking about the individual photon evolution/track as it travels. Your comments make more sense now. Forgive us for being dense, OK? And I am positive that YOURS was the proper use of the phrase, I simply point out what others, without your engineering background, may have taken the term to mean.

            So… let me see… You are saying that the actual lateral “resonation” of each photon is being constricted by the narrowing waveguide, and that this constriction forces the photon to a higher frequency/smaller wavelength, and as it gains frequency, it also gains mass and momentum (a mathematical necessity), until it strikes the small end plate, imparting a double dose of that artificially high momentum, then descends the waveguide, whose walls are now expanding, which allows the photon to relax to a lower frequency/longer wavelength, which exhibits less mass, and therefore less momentum when eventually colliding with the large end plate, transferring a double tap of this lower momentum in the backward direction, then reflecting back up the waveguide to do it all again, and each time the photon reflects it gives up a little of it’s energy, so that the photon slowly lowers in actual “raw” frequency, and experiences a slow decline to the red until after potentially hundreds of thousands of reflections the photon is finally tapped out, and just gets absorbed as a small amount of residual heat.

            This is not a compression of a group of photons into a smaller square inch area, but rather a compression of the physical envelope that defines the physical characteristics of each individual photon, resulting in a change in the momentum manifested BY that photon when traveling right versus left.

            And basically, the wavelet of which you speak is kind of the 4 dimensional track of a single photon, integrating the states of its electromagnetic and electrostatic fields over time as it travels. The wavelet of which you speak is what we muggles would call a time lapse image of the photon in motion! Your insistence on referring TO the effects on the wavelet being that it is the deformation of the photons frequency/wavelength/mass/momentum over time and travel that explains the effect, and focussing on the photon at ANY given point in time will never reveal the function being discussed…

            Am I now getting it straight? Forgive the run on sentences, but I am just trying to puke out the simple step by step link of events, and not really worried about the quality of the composition

          • Chapman

            If all this is correct, then we can now address the other issue being disputed, which is the force equations. The momentum of the photon is NOT a simple matter of e=MC2, right? It is derived from wavelength and Planck’s Constant, and means that each reflection only imparts a fraction of the E=MC2 potential as momentum and force, thus the slow degrading of the photon into the red. BUT, the high Q factor means keeping the photon confined to the Thruster Bell, and just letting it wear itself out bouncing back and forth, and eventually you ARE getting nearly all the energy wrung out of the photon according to E=MC2, only over hundreds of thousands of reflection events. Nonetheless, you still do not get a measurable “thrust” equal to the foot pound conversion of mass/energy, because the productive “thrust” is only the difference between all the momentum transferred to the small end (which is being increased by the waveguide shape), minus all the momentum transferred to the large end. Increasing the efficiency of energy conversion to working thrust will mean tuning the waveguide to the maximum distortion of the photon wavelet (I have no idea how to calculate how far you could push it, but experimentation and innovation should surely increase it over the simple models now being demonstrated), and increasing the instantaneous thrust level would require the shortest possible waveguide length, as well as maximizing the population of working photons within the structure, which is probably limited by thermal considerations.

            Am I at least CLOSE to being right???

            If I AM right, Engineer, then please take it to heart that your efforts were not in vain, and eventually, if you persevere, you can enlighten even a lunkhead like me!

            And know that I greatly appreciate your seeing the painful process through. You are a trooper, and a Gentleman of the first order. Next time I’m in Sydney I owe you a Foster’s…

        • Mats002

          Hi, if photons don’t have mass in the conventional sense – then I don’t understand how a solar sail can can work at all. Is there no ‘solar wind pressure’?

          • Andreas Moraitis

            Yes, there is. Particles have a rest mass and a relativistic mass. The first one is fixed, whereas the latter increases with their velocity. The theoretical rest mass of photons is null, therefore they must move all the time (otherwise they would produce a division by zero 😉

          • Engineer48

            Hi AM,

            The photon wavelet’s mass is always zero as otherwise it could not travel at c.

          • Andreas Moraitis

            No exactly a relativistic mass in the usual sense, but a relativistic mass equivalent (E/c^2), which allows them to generate radiation pressure.

          • Andreas Moraitis

            The momentum of a photon of the energy E can therefore be calculated as follows:

            |p| = m * v = (E/c^2) * c = E/c

        • Engineer48

          Hi Leonard,

          You need to add that when the photon wavelets are trapped inside a resonant cavity, they do 100,000s to 100 of millions of end plate absorb and emit cycles as the dual travelling waves that are created make end plate to end plate transits.

          This may help to illustrate how the Maxwell modelled standing waves are created from superposition of the dual travelling waves that actually do the end plate absorb and emit events.


        • Zephir

          This mass is low and it cannot explain the EMDrive effects.

          From these data it’s evident, that the EMDrive cannot work as a photon rocket, because it’s thrust is way higher. The formula for the differential radiation pressure emitted is roughly F(N)=sigmaflatarea/c(Temp narrowend4 -Temp wideend4 ) (assuming
          emissivity is ~1). Sigma=5.67×10-8 Wm-2 K-4, c=3×108 ms-1, flatarea~0.12 m2. Assuming a reasonable temperature differential of 30K gives thrust F=6×10-9 Newtons, which is nearly million times smaller than the
          thrust 1mNewton/kWatt observed by NASA.

      • Engineer48

        Hi Bob,

        Photon wavelets have Energy, Momentum, Wavelength, E & H fields.

        Their Energy gives them a mass like effect due to E = m * c^2.

        The photon wavelet Energy equation is E = (h * c) / wavelength.

        The photon wavelet Momentum equation is p = h / wavelength.

        Where h = Planck’s Constant.

        The H field induces eddy current flow in the walls of a metallic waveguide, in which the walls form boundary conditions that restrict the photon wavelets free movement.

        In a resonant cavity, the metallic walls and the eddy currents cause the guide wavelength to increase and the group velocity to decrease relative to what happens outside the waveguide.

        This GIF may to help to visualise a photon wavelet, which is just the 2 dimensional moving circle as it moves through space time.


        This simulation of a resonant cavity (left side) shows that Maxwell agrees that inside a tapered waveguide, the guide wavelength of the 1/2 wave at the small diameter end is much longer than the 1/2 guide wavelength (length between the null zones). This effect is at the heart of what makes the EmDrive generate asymmetric forces at the 2 end plates.

        So you can see that Maxwell and Shawyer agree on what happens to photon wavelet guide wavelengths inside a tapered resonant cavity. The photon wavelet’s guide wavelength INCREASES as the cavity diameter decreases.


      • Chapman

        Did anyone else get a “Princess Leia” vibe from the opening salutation in Mr. Greenyer’s post???

        And here I took Bob as a devoted Trekkie!

        (Hi Bubbles… Don’t mind me, just havin a little fun!)

        • Bob Greenyer

          I have something to reveal that will stun you all and I want it to help this journey.

          • Chapman

            Lay it on me, big guy!

            God knows I need all the help I can get. 🙂

          • Bob Greenyer

            those BEC, they get everywhere.

            I am trying to get something out of the door so I can resume normal programming ASAP.

          • Chapman

            I will be patiently waiting!

            Take your time…

          • Bob Greenyer

            Thanks, this week I have had to learn to get old code into 64bit and work with an advertising framework and go through a 100 hoops to get some app variations published. Might have done it – we’ll see.

      • Engineer48

        Hi Bob,

        Not only are photons massless, can photons transfer momentum and energy to mass, they are also an elementary point particle and the carrier of the electromagnetic force.

        To make the point, hehe, photons do not have a depth, width or length. They are a 3 dimensionless point in space, with oscillating E and H fields that are 90 deg away from each other. The period of oscillation determines their frequency, which is set by their energy being the max E or H field or the instantaneous average of each added together.

      • Zephir

        Waves also have momentum, despite they’re massless. But photons aren’t waves, but solitons of light waves. Solitons propagate slower than their carrier wave.

    • Leonard Weinstein

      Think of the tapered box filled with a gas. the pressure is equal on the walls. The large base area is larger than the small base area, so the pressure times the areas produces a larger force on the large end than the small end. Why is there no thrust? The answer is the tapered walls, with components of force in the other direction that balance the forces. I think you are missing the same issue.

      • Engineer48

        Hi Leonard,

        Your analogy is not correct. The radiation pressure is not the same at all point of a tapered cavity.

        At the small diameter end, the photon wavelet’s guide wavelength is much longer than at the big end. Maxwell’s equations agrees with this. Left image is produced via resonant cavity simulator that is based on Maxwell’s equations. See how the 1/2 wave guide waves are longer at the small end vs the big end? This causes the radiation pressure to be asymmetric in a tapered resonant cavity.


        As Cullen in 1950 experimentally discovered, the radiation pressure on an end plate in a microwave waveguide decreases as the waveguide diameter decreases.


        There is nothing here that is outside physics. Just that there may be a few physics effect that occur to microwave photon wavelets inside a waveguide that you may not be aware of.

    • Chapman

      Sir, I am intrigued by the direction of your explanation, and I am trying to follow it and grasp the force mechanics involved.

      To that end, can you take a moment to expand on the “photon wavelets” and how the formation of such effects the total relativistic mass, and thereby the momentum, of the photons involved? Is there an induced change in each individual photon, or is there a separate additional mass generated as a result of their organization? And if so, where is the energy drawn from that creates the greater mass for the wavelet, over the sum of the mass of the individual photons?

      I think this is the specific mechanical principle some of us are missing. I know you have done a full review of the theory, and have done the math, but my math is missing that part. Where am I going wrong? My math keeps telling me that the energy and relativistic mass of a wavelet is still restricted to the sum of the energy and relativistic mass of its constituent photons. Obviously I am suffering from a blindspot in my understanding of the issue, but I really want to understand.

      • Engineer48

        Hi Chapman,

        Photons don’t have relativistic mass. They are just pure energy. Their Energy, Momentum and Wavelength can be explained with 2 simple equations:

        1) E = (h * c) / wavelength

        2) p = h / wavelength

        E = J, p = kg m/s, h = Planck’s Constant

        Higher freq photons have higher energy and momentum, lower freq photons have lower energy and momentum.

        Here you can calculate the energy of a photon of any wavelength or freq.


        Select J in the output energy box and for our EmDrive example select M then enter the value of c / freq which is 0.12230 for 2.45GHz and using c as in air. Please note how the photon energy drops as the freq decreases or wavelength increases.

        How you have proof that as a photon loses energy and momentum, it’s wavelength increases and it’s freq decreases.

        • Zephir

          Photons don’t have relativistic mass. They are just pure energy./**/

          • Engineer48

            Hi Zephir,

            Photons have a mass like effect due to E = mc^2 which implies m = E / c^2 and p = E / c.

            Photons are an elementary point particle, they have no width, length nor depth and are the carrier of the electromagnetic force.

            They have oscillating E and H fields, with the H field oscillation shifted 90 deg to the E field oscillation. When the E field is peak the H field is zero and when the H field is peak then the E field is zero. While the gif does show the E and H field oscillation it is incorrect as it shows there is no 90 deg shift between peak E and peak H field events.


            Photon energy is the peak E or peak H field or the sum of the two and is related to it’s freq or wavelength as higher energy = higher frequency or shorter wavelength.

            The period of oscillation of the photon’s E and H fields determines the photon frequency and wavelength with wavelength = hc / E.

            If the photon loses some of it’s energy, it red shifts, decreasing it’s frequency and increasing it’s wavelength.

          • Zephir

            Photons are an elementary point particle, they have no width, length nor depth and are the carrier of the electromagnetic force.

            In scintillators or spark chambers the photons behave like the pin-point particles of characteristic size given by wavelength of deBroglie wave.

  • Bob Greenyer
    • Zephir

      Bob you’re acting like AxilAxil – just because one theory is currently in hype in some area, it doesn’t mean, it could be applied to another area of research.

      • Bob Greenyer

        Whoever you are Zephir, I don’t know why you have such an issue with everything I have done, not done, do, or say – perhaps if you revealed who you actually are, it might bring some clarity as to your motives.

        In my missives I clearly state it is a hypothesis and/or speculation – this is a clear differentiator from persons that state things as fact, I think you are aware that this is so, as you strike me as intelligent.

        Now, specifically regarding AxilAxil, your phrasing suggests that attributing his approach to another, is a put down, it does seam to be what you are good at having observed your contributions here and on other fora – however, whilst there are some that seem to have a beef with his approach, there are many others, including myself, who have learned a lot by following his various thought streams – I appreciate his contributions and I think that the community would be much denuded without them.

        Given that LENR (or the EmDrive) has not been categorically and unequivocally proven, then all bets are off – I recognise this – so what makes you think you can stand in judgement over myself, the MFMP, AxilAxil or anyone else for that matter.

        Personally, I just want the truth, I am quite comfortable with considering many parallel theorems at the same time – since all may be equally invalid. When I publish my Asti presentation, you will see that it represents work which I have devised or done attempting to test not one, but MANY theories or potential angles…

        and another

        The implications of some of the data from experiments conducted or ash analysed may support or discount theories including those above but also Storms.

        Your missives about the MFMP seam to real you neither understand the motivation or what has been done and what it means. What I can say is, we have no theory we are trying to defend or support and we are all free to say what we feel at any given time. The MFMP is not science by committee, it was set up precisely to address that exact thing which happened to P&F.

  • Warthog

    Pardon my irateness, but who gives a flying **** about all the theorizing. What do experimental tests and replications show?? THAT should be the first thing that gets discussed, not theoretical maunderings about “why it works”. The first order of business is “does it work at all”, which can be neither proved nor disproved by math modelling. The comments indicate that experimental testing has shown devices of this sort to work.

    I admit to not having followed the EMdrive other than in passing as it is well outside my area of expertise, but surely there exists a summary of experimental results “somewhere”.

    • Brent Buckner

      You might save yourself some time on another occasion by googling rather than taking the time to post. See “Tests and experiments” on the top hit on google: https://en.wikipedia.org/wiki/RF_resonant_cavity_thruster

      • Warthog

        I don’t particularly see Wikipedia as a reliable source. See their coverage for LENR as an example of why.

        • tchernik

          What, Hive-mind-pedia isn’t reliable?

    • Engineer48
      • Warthog

        Thanks E48. I will work my way through those (slowly).

        But as soon as you mentioned a photon wavelength change as happening, the light pretty immediately dawned as to how it works. My original graduate training was in spectroscopy, so “delta E = Plancks constant* C/wavelength” is part of my academic genes.

        I still think Jerry Pournelle gave the simplest experimental recipe for testing any “reactionless drive”. Build the drive on a platform. Hang the platform from the ceiling. Turn on the drive and measure the deflection of the suspending cable. With a mirror on the cable, and a laser bounced from same, very tiny deflections should be measurable.

        • Chapman

          Bonus points awarded for invoking the name of one of the greatest writers in human history! Especially the books he co-authored with Niven.

          2,680 more points and you can trade them in for a genuine Frank Acland BobbleHead, which no dashboard should be without!

          • Warthog

            Glad you used the qualifier “one of the”. Pournelle and Niven are great, but IMO THE “Grand Master” of science fiction is Robert A Heinlein.

          • Chapman

            Without any doubt! The guy who defined the “Shipstone”. From Friday, door into summer, farnham’s freehold, Puppet Masters, and Job: a comedy of Justice just to name a few. His writings helped form my worldview, my interest in science, and my political beliefs which are based upon human nature being what it is.

            I simply could not agree with you more than I do. I am delighted to see him receive public recognition. 🙂

  • Leonard Weinstein

    The effect of the interaction on the tapered walls has not been considered, and unless the present laws of conservation of energy are not valid here, are where the error lies. The maximum force possible for any electromagnetic drive is power divided by the speed of light (Watts/c).

  • Chapman

    I am signing off for the night. It has been a fun Sunday discussion, and I thank you all for taking the time to keep me entertained! 🙂

    But I do want to take just a moment to step up on this soap box and publicly thank ENGINEER for his patient instruction on key issues regarding the EM Drive.

    I apologize for using the term “relativistic mass” too loosely. I, and many others, tend to use the term to denote mass that is the product of motion, versus the mass that is physical. In the case of photons, the momentum/mass is not actually derived from E=MC2, and I get that. The actual momentum of a photon, as Engineer has pointed out, is much lower, and is derived via Planck’s constant and wavelength. That is why photons do not disappear entirely when they reflect. If the momentum was equal to the entire energy OF the photon, all that would be transferred in one collision, and the photon would cease to exist. But only a small portion of the photon’s energy is given up as momentum when it reflects, which is why a photon CAN reflect off of surfaces hundreds of thousands of times.

    Engineer has suffered a great deal of frustration today as he tried to get us all to see that, and to stop saying relativistic mass. To many of us it was a general term, but the difference is critical to the bigger picture he has been trying to clarify, so it was of great annoyance to him for us to be using the term in the wrong context.

    I am sorry Engineer. You were right, and it was not nit-picking for you to be insisting on the proper term, and underlying formulae.

    Engineer ALSO worked overtime to clarify the idea of the wavelet, and how the wave guide distorts the physical attributes of photons. Here I have been demanding that someone explain how the drive works with ONE photon, rather than throwing out exotic theories about groups of photons interacting, and Engineer was doing EXACTLY as I requested, but I did not recognize it. His wavelet explanation IS how a single photon is distorted by the drive shape. Multiplying the effect by the number of photons simply gives you a final thrust value, but the mechanism that creates that thrust, as he has patiently explained, is derived from a pure mathematical analysis of a single photon within the geometry of the Drive.

    For the record, I am satisfied. That is to say, I understand exactly why Engineer says that he sees no problem with Shawer’s theory. As he stated, he does not know if it is correct. He has simply been trying to explain what is right, and what is NOT wrong, with the theory.

    I still have my suspicions that there is something wrong with the VG vs VC aspect of the theory, but I think Engineer has pretty well cleared up that the drive could work on the published principle even if VG is not a wholly appropriate analysis. I also believe that VG will actually cause a braking action, and significantly reduce thrust due to a forward redshift effect within the drive, but that is a discussion for another day.

    As for today, My hat goes off to Engineer.
    Well done Sir!
    I am in your debt.
    You gave me everything I asked for.

    • Engineer48

      Hi Chapman,

      My bad.

      Should have stated the photon is a dimensionless elementary point particle.

      Did suspect that may blow a few minds.

  • Engineer48

    In Fed 2017 Roger Shawyer does an INVITED presentaion at the UK MOD Defence Academy about EmDrive in space & militarisation.

    Then in June 2017 the USAF does this:

    Dots connecting?

  • Observer

    Why hasn’t anyone made an EmDrive with a tapered single mode optical fiber?
    Since photon momentum is inversely proportional to wavelength you should get more thrust per photon. Make it an erbium doped fiber laser with mirrored ends.

    • Engineer48

      Hi Observer,

      Cavity Q drops faster than shorter wavelength increases energy and momentum.

  • Engineer48

    Interesting news from Gilo’s FaceBook feed, as attached.


    Links with the other slide from Roger where he states Gilo Industries Research is officially involved with SPR in solving the EmDrive’s high Q acceleration issue.


    • Chapman

      Can you say X-37?

      • US_Citizen71

        It sure would be a good candidate for testing an emdrive.

        • Chapman

          It can’t come soon enough. We need a mobile space platform with “payload” capacity that can sit on station for extended periods, then respond on demand when needed. I see in the news that Herr Bartels, of the fourth reich, is now plotting to build a new military. It seems folks will never learn…

    • TOUSSAINT francois

      Sorry slightly off topic , micro wave burn ?


  • Engineer48

    Hi Hiram,

    NASA Eagleworks, SPR and Prof Yang have published EmDrive peer review papers.

    Following the physics is not that difficult and when you do that, the claims stack up.

    It shows there are no new physics involved and the EmDrive works from microwave waveguide effects known since 1955.

    Shall we ask for peer review of radiation pressure or that microwave guide wavelength and end plate radiation pressure are reduced inside a wave guide and the reduction follows the diameter reduction?

    Or should we ask for peer review that photons red shift as they lose energy and momentum?

    • Chapman

      I question the validity of the concept that peer review alters reality. At last count, the academic community agreed with a 98% consensus that I should shut up, yet here I am, still making noise!

      They keep using the word “requires”. I do not think they know what that means…

      [MIC DROP]

      • Warthog

        Peer review isn’t reliable proof. Replicated experiments are.

        • Chapman

          I fully agree. I want to see it in action. But that is just ME, wanting to see it to remove all doubt in my mind, before I would invest in stock in the company. But I am not so egotistical as to believe that the level of my conviction on the matter has any influence on what physically occurs on the other side of the world in someone ELSE’S secret laboratory.

          I simply do not understand, or have any patience with, the insistence that something is not real until it has been officially endorsed by some self-appointed priesthood. These guys are a joke, and an offense to logic and reason. The GOD of PHYSICS does not wait upon the learned opinion of a bunch of lab coats to decide whether or not they approve before he acts.

          Every educated person knows full well of the failure of the peer review system. The gross number of “approved” papers that are proven later to be flat out wrong, taken with the number of papers that FAIL, and yet are proven ultimately to be correct and widely recognized and embraced, shows that peer review has nothing to do with scientific validity.

          On the other hand, if you want to prove an idea you have concerning uranium, and critical mass, well all you gotta do is show me the boom!

  • Chapman

    I do not think a peer reviewed paper is going to have any direct effect on the validity of the drive. Peer review is an issue of opinion (as is it’s usefulness), but I do not know of any “Consensus Constant” being utilized in any of the equations we have gone over so far.

    Hold on a minute…

    Nope. I just double checked. Sure enough, we have Speed-of-Light, Planck’s Constant, heck – there’s even a little Ohm’s law implied in the eddy currents in the inner skin of the waveguide, but no matter how hard I look, I just don’t see any “Consensus Constant” upon which the physics involved is dependant.

    Are you using the same formulas Engineer just took the time to pass out? I mean here he went to all that trouble, but you seem to have a set of formulas all your own. Can you share them with the class? With your formulas, does the drive EFFICIENCY increase proportionally with academic consensus? Does it effect total thrust? Thermal breakdown? I mean, if consensus has some direct property of proportionality to ANY of the device parameters, it would be nice to know that relationship when they go to optimize performance!

    If we hand out grants, and gets LOTS of “physicists” to sign on, can we maybe get a working FTL drive? I am pretty sure that the track record shows that handing out research grants like trick-or-treat candy to a bunch of unscrupulous grad students can get us up to 97%. Is that enough, you think, to get us to Betelgeuse in a single life span???

  • Engineer48

    AIM is the American Institute of Mathematics. It is funded by the National Science Foundation and is used by a number of US government agencies.

    Interesting it has detailed knowledge of EmDrive theory and a solution to the high Q acceleration problem.


  • Engineer48

    One thing I have discovered is a photon vs mass absord event works almost the same as 2 billiard balls impacting each other.

    For both the mass and photon, momentum is conserved as is E. Interesting thing about the photon, as it always moves at c, is the photon’s virtual mass, m = E/c^2 drops (due to photon E drop from doing work to alter mass velocity) instead of velocity changing as it does with mass. Thus the photon’s lost E and momentum is represented by the photon red shifting.

    Ie the KE and momentum gained by mass, from a photon impact is reflected in lower photon E and momentum and thus lower freq and longer wavelength, even though the massless photon continues to travel at c.

    As Shawyer has said many times, the EmDrive is a classic machine that obeys both the laws of Newton & Einstein.

    How and why the EmDrive works is really very simple once you understand the above and how the photons reaction to E & momentum change is very different to how we are accustomed to think about how mass reacts to E & momentum change.

    • Chapman

      Rest assured, that you have explained it all very well. Seriously. I think everybody gets it now. Anyone who is still in the dark needs more help than you can give. You have done all you can here…

      Thanks for not giving up on us.

      You know, I had completely forgotten that the waveguide is an active part of an electrical circuit, rather than just a passive light channel. As soon as you mentioned the eddy currents my brain went ZING, and I had a bit of an AH-HA moment. That clarification alone eliminates all the discussions regarding sidewall collisions, and I imagine that is what you were trying to get at when you kept telling us it was not like billiards. The photon doesn’t bounce its way down the waveguide, it is centered and focused by the skin effect currents on the inside walls, which is why a waveguide can bend and weave from point A to point B.

      What I honestly did NOT know was the fact that a constricting waveguide forces a blueshift on photons trapped inside. I know that photons are rejected by an orifice that is too small, but I had never seen any reference to what happens when a photon is “slowly” squeezed. That is interesting, and a bit of knowledge well worth learnin’. And finding out from you that it has been well known since the 50’s just kinda makes me turn blue. How had I never heard that? My background is Semiconductor Physics for God’s sake! Well, better late than never, right? Now I know. Thanks to you…

      As for the EM Drive, The whole thing reeks of special relativity! Red shifting, blue shifting, frame of reference, and the fact that a blue shifted photon will exhibit the exact same energy profile and behavior as a photon “native born” to that higher frequency.

      I am dead serious here Engineer – the whole thing makes perfect sense now. Not just something I can “accept” on the basis of your expert testimony, I mean it makes perfectly good sense according to everything I have ever learned, and if I had remembered the active role of the waveguide, and been aware of the constriction/blueshift thing, I would have seen the whole thing properly in minutes. You were right, it really isn’t rocket science. But I contend you can not call me a doofus, because the redshift bit IS a bit of specialty knowledge that is kind of limited to the radio communications and radar disciplines.

    • Chapman

      So, do you think you have enough goodwill and patience left to survive one more question? I promise it is not a boneheaded question, but I will wait until invited to ask it…

      • Engineer48

        Hi Chapman,

        Ask away.

        • Chapman

          Looking at the Prototype EM Drive, I notice it is a pretty big unit, compared to microwave wavelength.

          Can you speak briefly on the relationship between wavelength and waveguide cross section? I think we would find that helpful in terms of us daydreaming about modifications. ( we are all tinkerers at heart! )

          • Engineer48

            Hi Chapman,

            At 2.45GHz, the wavelength is 122.33mm. Of course inside the cavity the guide wavelength is longer and it changes as the diameter changes.

            Basically a TE013, 2.45GHz, cavity is around 0.25m long, with a small end of 0.15m and a big end diameter of 0.3m.

            Watch this interview:

          • Chapman

            Perfect. Thanks. 🙂

  • Chapman

    So, would somebody please take a bite of this apple and tell me if it is poisoned? I have been modelling the EM Drive based upon our new insights, but I see a strange phenomena that must exist, if all we are saying is true.

    Consider the EM Drive. An artificial blueshift is imposed upon a forward traveling photon, and that causes it to reflect with more momentum off of the small plate. When traveling back down the waveguide, the photon is able to relax to its natural frequency governed by energy alone, and reflects off the large plate with less force due to the lower frequency. Right? We all agree?

    Now, consider a straight waveguide with NO taper, but the same reflective ends. Photons bounce off each end with the same force, so there is no thrust. Agreed?

    Now push the waveguide from the outside to start it moving forward. Photons traveling up the waveguide are now redshifted due to the fact that the front plate is receding from the rear plate, which was the point of origin. Do you see that? The front plate is always moving away from where the rear plate WAS, so the photon has a redshift, as the frequency is drawn out relative to the front plate, which makes it longer. It is the same effect as we see with distant stars, and is the heart of the logic behind the Big Bang Theory, because the universal redshift tells us everything is moving away from us. Right?

    SO… The motion of the drive in the forward direction creates a decrease in the force of forward photons. This effect means the photons impart less force the faster you go. Not a problem. This logic matches classical physics, as well as SR. The speed of light acts as an analog to the expulsion velocity and force of a propellent, and the more forward velocity you have, the less effective a given amount of expelled propellent becomes. In this case, the closer you get to the speed of light, the less thrust you get from a given photon. Still with me?

    That works fine for a light sail, but the EM Drive is not a light sail. We are not satisfied with bouncing a photon off the front plate and kissing it goodbye out the back. We recycle. WE bounce the photon off the back plate, and reuse it, in order to wring every erg of energy out of the thing we can. So what happens to the photon moving backwards from the front to the rear?

    Blueshift. And that means NOT just a relativistic drop in forward thrust, but an actual REVERSE THRUST! The harder you push the waveguide forward, the harder the photons push back to slow you back down to a stop.

    It is a breaking action. And the faster you move forward, the higher the actual foot pounds of breaking force that will be generated. Do the math. Think it through. It involves the exact same formulas that the EM Drive analysis is using.

    So now combine this braking action with the tapered waveguide functions. What do you get?

    In forward motion, there is an increase in reverse thrust that is proportional to velocity. And there is a forward thrust which is constant, being generated by the precise angle of the taper, and the frequency of photon being used. The combined effects will balance out at a precise velocity, when equilibrium is achieved between the constant forward thrust, and the increasing reverse thrust.

    This drive will never get to high percentages of light speed, no matter how many centuries it runs. It will accelerate to a precise max speed and lock on to that speed for the duration of its flight.

    If the EM Drive generated 1 newton of thrust, it would accelerate to the point that the reverse thrust equaled 1 newton also, and your velocity would stay absolutely the same forever after, which means you might as well turn it off and coast until it is time to flip over and start decelerating. All the equations that predict how long it would take to reach high relativistic speeds at a given G of thrust, and how long a trip takes BASED on all that math is gone.

    This engine has a throttle governor.
    It obeys a posted speed limit.

    And you know what ELSE all this tells us?
    That you can build a thruster with NO taper, and it will act as an anchor, keeping you dead still in space. Any velocity will automatically generate a counter thrust to bring you back to a dead stop.

    TADA… Your Star Cruiser now has a parking brake also.

    • Engineer48

      Hi Chapman,

      The input Rf energy exits as IR photons of a higher freq and energy but a lower quantity.

      IE, the cavity gets warm.

      • Chapman

        That’s what I am thinking. In this respect, as far as SR is concerned the drive is a closed system. Dont worry, I get the aspect of the force working against the speed of light limit, which means it is interacting with “space” and that makes it an open system, but in terms of purely SR effects causing redshift or blueshift between the plates, the velocity is common to both, so no effect is seen WITHIN the drive.

        I am just trying to think a few things through. I am not proposing there are problems. I am just establishing some fundamentals to sharpen my mental model of the whole system, and catalog all the contributing factors…

        • Engineer48

          Hi Chapman,

          SR has nothing to do with photon Red or Blue shift.

          The EmDrive is an open system because the velocity or velocity change of the EmDrive does not change the photon velocity.

          IE there can be an energy and momentum transfer between photon and EmDrive.


          • Chapman

            Don’t fret. I did not go off the rails. You simply misunderstood the point I was making.

            I was expressing the observation that there is no redshift or blueshift OBSERVED within the drive as a result of forward velocity OF the drive because all surfaces share the same velocity. If the drive walls were transparent, then an observer outside at a stationary position would observe a blueshift of photons traveling from back to front, and vice versa, but the small plate is moving away from the advancing photon at the same velocity, which will cause it to experience a proportional redshift. A 1Ghz photon leaving the large plate will hit the front plate as a 1Ghz photon, except for the exact frequency shift imposed by the taper.

            It is a matter of eliminating other factors, and establishing what must be considered when considering design variations.

            It is a closed system in so far as at no point within the drive is there any way to reference what the external velocity IS. Everything internally looks the same, whether the drive is standing still, or moving at half light speed. It is a question of frame of reference.

            And my point was specifically that there IS no SR effect on the photons contributing or affecting the thrust effect.

          • Engineer48

            Hi Chapman,

            Actually Red shift from acceleration is what limits thrust in high Q EmDrives.

            Roger actually lengthens the cavity to keep it resonant during acceleration.


            Notice the piezo length extenders, item 13, that track the photon red shift to longer wavelengths:


          • Chapman

            Yes, but Redshift is still dominant under there, right?

          • Chapman

            [go ahead, I double-dog dare you]

          • Chapman

            I just made you say “Under Where?” !

          • Engineer48

            Hi Chapman,

            Photons undergo permanent red shift via energy loss to wall eddy current heating and if the cavity is being accelerated, via energy loss to do work on mass, to accelerate it, to change its velocity. This red shift is continual and permanent.

            Doppler induced red and blue shifts are not related to energy gain or loss but relative end plate observer Doppler shifts due to cavity acceleration.

            Two very different effects.

  • Chapman

    I will agree with YOU, and that makes it a consensus.
    Therefore WE are right, by way of their logic.
    Thank GOD. The Polar Bears are now safe.

    I feel so… validated!

  • Engineer48

    For anyone wishing to learn more about microwave guides and how they alter guide wavelength and group velocity as diameter varies, I suggest they go here.


    Everything there 100% supports the claims of SPR as those claims are based on existing physics.

    EmDrives normally excite the cavity in TE013 mode. Take away is TE01 mode for the above reference and the 3 means 3 x 1/2 guide waves from end plate to end plate. You can see the 3 x 1/2 waves in this simulation that is based on Maxwell equations. Please note how the 1/2 guide wave at the small end is much longer than the 1/2 guide wave at the big end. So again SPR and microwave physics are correct that guide wavelength increases as cavity diameter reduces. Here you can see the effect of all the above equation with your eyes.


  • Chapman

    Hey Libby (mind if I call you Libby?). Here’s something to ponder:

    If they believe that consensus and peer review function on physical reality in the same manner that the copenhagen interpretation of Quantum Mechanics theorizes that events are only a POTENTIAL until actively observed, and that probability only resolves itself into REALITY due to the effect of conscious observation forcing it to take on a physical state (schrodinger’s cat concept), then WE NEED TO GET A LAWYER!!!

    Because, that means Global Warming was only a POTENTIAL problem, until AlGor, Bill Nye, and the 97% dumbass scientists who signed on to the theory agreed to that peer reviewed paper, and thus forced the mere probability of Runaway Global Warming to manifest as an actual climatological threat!

    According to HaHaHiram NOTHING is real until it is subjected to peer review and accepted by the priesthood. But that means those guys had the option of saying NO, and AGW would never have been a problem.

    CO2 does NOT cause global warming. Moron Scientists do.

    This PROVES that AlGor INVENTED, AND CAUSED AGW… probably right after he got done inventing the internet.

    So let’s get lawyered up, take our case to the International Criminal Court, and see if we can get these scoundrels put behind bars where they belong! Just look at what they have done to our lovely planet…

  • Chapman

    “Reductio Ad Absurdum”

    Let me be clear. Peer-Review is a perfectly wonderful mechanism of great value to Academia, the Professional Physics community, and Government.

    It allows researchers to openly share ideas, and submit them to the challenge of being disproven. This greatly diminishes the wasted efforts of others who may be pursuing parallel research to the same dead end. That alone helps accelerate the rate of scientific advancement. In addition, even a failed theory includes unique insights that still have great merit, and are worthy of being shared.

    Within Academia, it is important that the offered curriculum reflect the current state of scientific knowledge, and that the instruction being provided results in an an Education that has VALUE in the marketplace. As such, any university needs to know that the physics they are teaching is in line with common consensus within the Professional Physics community. Peer review offers just such a benchmark standard. All well and good.

    When it comes to Government distribution of public funds, it seems reasonable to use peer review as a basis for establishing the worthiness of individual research to be funded based upon how closely that research tracks the current drift of physics evolution. We do not WANT public monies being wasted on fringe science and nonsense. This TOO is all well and good.

    The problem comes when mentally ill individuals develop an academic psychosis, and begin to believe that peer review actively CONTROLS and EFFECTS physics and reality.

    It is at this point that peer review turns from being an intellectual fraternity into a despotic priesthood. It is at that point that a simple mechanism intended to advance science becomes a tool of some to attempt to CONTROL the direction of scientific research and discovery. It is at THAT point that peer review is elevated beyond its actual utility, and becomes an active hindrance to discovery, and a serious threat to the evolution of human knowledge.

    I have responded to your ridiculous claims that “nothing is real until it has passed peer review” by expanding the ramifications of such nonsense to the absurd maximum, thereby exposing the underlying fault in your hypothesis. As is quite often the case, the real threat that exists from your distorted worldview is hidden beneath layers of seemingly reasonable logic. Your smug academic certitude blinds you to the real damage being done to the scientific community by your unjustified insistence on the over inflated importance you place upon the peer review process in general.

    In this case, there was a perfectly reasonable discussion going on analyzing the details of the operating principles behind the EM Drive, and that discussion was focusing SPECIFICALLY on well established scientific principles used in everyday communications equipment, but your personal conceit and territorialism drove you to step in and remind us that such thoughts are subject ultimately to the approval of the peer review process. How egotistical and Narcissistic must you be that you need to “mount” everyone here and establish the bounds of academic authority???

    Folks are having a pleasant conversation. We did not call the thought police, or invite a referee to make a judgement on the validity of our discussions.

  • Engineer48

    Hi Apple,

    Dielectrics are not involved.

    Shawyer has stated they reduce thrust as they introduce additional loss and reduce Q.

    Just focus on the point photon being absorbed and then emitted by an electron of the metallic atoms on the end plates or what is called Radiation Pressure.

  • Engineer48

    Hi Hiram,

    What Sagan said is rubbish. It takes the same amount of experimental evidence to prove any effect, no matter how major.

    What I suspect is embarrassing to mainstream physics is the lack of knowledge of Cullens work in the early 50s that experimentally proven radiation pressure on a reflecting end plate in a waveguide reduces as the waveguude diameter reduces. Had that been widely known, Shawyer’s results would have at most resulted in a forehead to palm impact event, followed by the thought, “Clever Boy”. Instead many physicist made a knee jerk reaction and without thinking it through nor checking on Cullen’s work, embarrassed themselves by declaring the claim to be RUBBISH.

    I spent many months going through Shawyer’s equations, test results and links to supportative claims. What I found stacked up, as you have seen here.

    Would suggest anybody with the necessary physics and math skills can repeat that process, so why the need for a peer review, of which there are around half a dozen.

    Shawyer has his peer review paper on his web site plus 4 very detailed enginerring reports and reviews by UK gov appointed experts.

    Have you read all that is on http://www.emdrive.com ?

  • Engineer48

    Wonder how much funding the new US Space Corp (USSC) will get?
    Bet it is a LOT more than NASA.


    • Chapman


      Guess who’s getting Space Marines for Christmas!!!



      • Engineer48

        Hi Chapman,

        USSC is part of the USAF, not part of the US Navy as are the Marines. However do admit that Space Marines sounds the part.

        • Chapman


          Guess who’s getting Space FLYBOYS https://uploads.disquscdn.com/images/4713b52ca5f8ff6110f8ae6008cfa3d1b4225674bf435102561269fff43e084f.jpg for Christmas!!!


          • Engineer48
          • Chapman

            That is probably what’s wrong with me. I was brought up on Monty Python, Benny Hill, The Goodies, and Paul Hogan (the Aussie show, before Crocodile Dundee).

          • Engineer48

            Hi Chapman,


            Plus Dr. Who, ThunderBirds, Space 1999 (Eagle Transporter was a really good design), Men Into Space. . . .

            Also helped that the Kennedy Lunar Mission shaped a lot of young engineers ideas and goals. Mine included.

          • Chapman

            Space 1999 was ahead of it’s time! Production quality fell off pretty quick, and they had to resort to some Sid and Marty Krofft level makeup, but they really tried to present a workable situation.

            I mean, except for the whole nuclear waste explosion that blew the moon out of orbit in the first episode that is. I think they would have all been squished, but hey, they moonbase and all the equipment was believable. It was sure a huge step forward from Flash Gordon stuff.

            And of course there was Barbara Bain. BADABOOM! I loved her and Landau from the old Mission Impossible series. Glad they kept working together.

            And the Thunderbirds? OH GOD, The Thunderbirds!!! HA! I had almost forgotten them!

            What was that other show with a moon base with female staff and an albino agent on Earth? You remember that? Guy looked like spock dipped in a vat of bleach. Same haircut, but white as snow…

            Oh geez… you got me trippin down memory lane now. I will be remembering old tv all night. Mind you, I go back to the Red Skelton and Jackie Gleason days, so there is a lot to reflect upon!

          • Engineer48

            Hi Chapman,

            We finally have the engine tech to make all those and more happen. Like who needs Epstein Drives to make The Expanse happen?


            Shawyer Effect Drives will work just as well.

          • Chapman

            You are either making fun of me, or tracking my cable box…

            The Expanse is one of my favorite current TV shows. It ALSO tries to present the entire reality of space travel, colonies, and interplanetary politics in an imaginative, yet realistic way. Stuff worthy of Asimov or Clarke.

            (I like my Sci-Fi to have a little intellect behind the makeup and Death Rays)

          • Chapman


            “UFO” was the other show from the 70’s, with the luscious Lunar Girls, and the Albino.

          • Bob Greenyer

            Nothing wrong with that.

  • Engineer48

    These 2 slides should help to understand why the EmDrive works and that is DOES NOT violate any of the laws of physics.



    Please listen to Roger Shawyer explaining why and how the EmDrive works. Probably listen to him several times as there are many statements to properly stack together to under the overall effect.


    • Zephir

      /* It’s all about consensus! */

      Which consensus? 60% of American still don’t believe in evolution?

    • TOUSSAINT francois
      • Engineer48

        How to get to Mars, 100mkm away, in 33 days at 0.005g or 0.049m/s^2 acceleration and a mid way flip and burn to slow down.


        With at 100t ship (50% ISS) and an EmDrive at 5N/kW or 0.5kgf/kW, that needs 0.98MW of Rf.
        Very doable with a LENR electricity generator.

        • Gerard McEk

          5N/kW seems quite high, compared to the existing test results. Any proof that this is feasible?

        • Leonard Weinstein

          The NASA Eagleworks paper stated 1.2 mN/kW. I do not see where 5, or .5, or .4 N/kW is shown as likely. Tests on less accurate measurement rigs would be suspect. A number of 5 mN/kW may be plausible, but no more without good data. this is 0.005 N/kW. A 100,000 kg spacecraft would have an acceleration of 0.00000005 m/s2 for this thrust per kW power. To get 0.005 g’s acceleration (0.049 m/s2), you would need 980 mW, not 1mW.

          • Engineer48

            Hi Leonard,

            From my analysis, the Eaglework device used a dielectric and was apparently built as a test of Dr. White’s QV thruster theory. As such it was not an attempt to replicate Shawyer’s work. In fact no where in any of Dr. White’s various papers is Shawyer, SPR or EmDrive mentioned. Prof Yang’s Chinese work is mentioned.

            In one of the IBT interview videos, Shawyer did mention he had supplied data to NASA but I have never seen it mentioned.

            Bad form that.

            Shawyer’s 2009 Flight Thruster achieved a measured 0.326N/kW with a cavity Q of 50k.

            Both Dr. White & Shawyer have stated higher cavity Q increases the specific force. Shawyer states it is linear. Dr. White believes ^2.

            Shawyer’s latest patent uses a YBCO coated cavity that is LN2 cooled and from calculation has a Q in the 100 of millions.

          • Engineer48

            Hi Leonard,

            At 5N/kW & 980kW = 4,900N

            4,900N / 100,000kg = 0.049m/s or 0.005g

            Then 100mkm with midway flip & burn = 33 days.

      • Engineer48

        Hi Toussaint,

        From my research Paul March seems to not be a supporter of Shawyer’s theory or built methods as Shawyer has rejected the use of dielectrics.

        The published EW results suggest Dr White and Paul March may have found another way to achieve Propellant Less Propulsion.

    • Chapman

      Hey Engineer!

      You know, just in case anyone doubts the fact that a waveguide taper shifts frequency, couldn’t they just go here:
      buy one and test it out? This one shown is for 12.4GHz to 18GHz, right? Over the counter, standard issue, been around for 50 years, lab equipment. As you said, not such a mystery after all.

      • Engineer48

        Hi Chapman,

        Tapered waveguide doesn’t alter photon frequence.

        What alters as the diameter reduces is the guide wavelength increases while the group velocity drops.

        To cause the photon’s frequency to drop, the photon’s energy needs to drop.

        • Chapman

          just to be clear I am following you: you are now back to talking about the effect of the group velocity of the photons travelling towards the small plate dropping to zero due to the waveguide impedance increase via the taper – and this taper creates a low end cutoff frequency that climbs with the reducing cross section until it is higher than the actual working frequency. This causes a “stall” in the photon advancement, and actually reflects the photons back just from the EM field then, rather than ever having a physical small end plate reflection, right? So group velocity is brought to zero toward the small end, and returned to VC (ok, not VC but rather the unaltered VG of the tuned waveguide at its operating frequency) as they advance back to the large end. Am I understanding this right?

          So, if the taper creates a virtual “EM Mucus Plug” that acts to reverse the photons back down the guide, is the field not anchored to the cavity walls which HAVE the taper, and wouldn’t the same momentum be transferred against the field, and hence the body of the drive? While I fully understand the cutoff frequency and the VG thing, I do not see clearly how the ultimate transfer of momentum is altered. In fact, we have now effectively eliminated all the work establishing the frequency dependence of the momentum of the photon, so you are kind of throwing a wrench in the whole logical sequence.

          Either photons must have higher frequency, and thus higher momentum, when colliding internally with the front plate (in order to transfer higher rebound momentum to the drive body in the forward direction) or some action must REDUCE the momentum transferred to the large end. Group velocity only affects wave propagation as a classic high pass filter. In this respect there is little difference between the microwave system and classic RLC circuits I can build for a shortwave system. I get the math! What I don’t get is how the actual photon momentum is altered. Even if the photons are reflected by a force field internally spanning the narrow end, so that no interaction with the conductive end plate takes place, that forcefield is still anchored to the drive, and momentum will be passed through to the supporting framework. AND if we DID uses taper to allow us to cause VG reduction to independently reverse the photons without any cavity force transfer, then low-and-behold, the drive WOULD move in the direction of the LARGE end, just as the wiki page shows.

          So at this point we are just talking in circles! For the umpteenth time, I understand VG. I understand waveguide impedance. I understand momentum. THAT is my problem! None of that works to create thrust. The one thing that surprised me because I had NEVER heard of it was the frequency shift! That is was news to me, and I was utterly gobsmacked by it and left in utter wonder as to how I had never heard of it, but I was willing to accept that it was a blind spot in my physics because even with years as a homebrew shortwave hobbyist I could see it as a specialty effect limited to the Microwave communications and Radar field. I said this over and over! “Gee, how is it I never heard of this frequency shift thing” yada yada yada! And now you say never mind, it doesn’t happen after all??? You KILLING me with this!!!

          So, tell me… Forget theory, let’s just see if we can nail down the physical:

          What direction do YOU believe the drive moves in, relative to the direction of the chamber’s taper?

          • Engineer48

            Hi Chapman,

            The Demonstrator EmDrive, on an air bearing, simulating thrusting against a 100kg satellite in orbit moves small end forward:


            I agree with Roger’s slides as attached:



            Remember Newton 3: For every Action / Thrust there is an equal but opposite Reaction / Acceleration.

            Look at it this way. Inside the cavity there is a momentum gradient created, with photon momentum moving toward the Big End and thus the EmDrive reacts and moves toward the Small End

          • Engineer48

            Interesting paper from Dr James Woodward, developer of the Mach Effect Thruster:


            His conclusion match those of Dr. White:


            Which also match those of Shawyer:


            Being these is no CofE violation with propellant less propulsion (P-P) drives as KE or velocity gain is based on a reference frame and that reference frame may be any of an infinite number of reference frames. In the reference frame of the EmDrive, there is no KE gain and thus no CofE violation.

            Is it fun how a simple device like the EmDrive causes us to rethink and relearn stuff that we thought was cast in stone.

          • Chapman

            I follow you exactly, through everything up to the last paragraph… THAT is where my brain loses track with your logic.

            If the photon momentum gradient increases towards the large end, then the reflection of the photons OFF the large end will result in a greater momentum transfer TO the large end plate, and result in motion of the the large end plate away from the reflected photons. Equal and opposite reactions. Photons bounce back down the waveguide, end plate gains momentum away from center mass of drive cavity. But the force transferred must not be equal at the two plates, resulting in a coherent physical thrust relative to absolute space. The photons must be experiencing a DROP of momentum as they approach the large end, in order for a net force to be moving the drive in the direction of the small end.

            Photons MUST be “banging” on the inside of the small end HARDER than on the inside of the large end! They must have more individual momentum at the time of the reflection off the small plate. So what effect, other than photon energy or photon frequency, alters the momentum of individual photons??? That is really the simple question I keep asking!

            I get that there are slides that say it happens.
            I get that there are formulas that result in an output that quantifies the effect.
            I am asking about the ACTUAL MECHANICAL CAUSE. Not the mathematical proof, or even a trustworthy source that assures me that it DOES happen. I am simply begging for someone to explain HOW it happens. What is the actual, physical, “cause and effect”, put a wrench on it and give it a turn, mechanism.

            Now, if it is still unknown, then I get that.
            No harm.
            Planck had no explanation as to WHAT the constant he defined is actually linked to, he just knew it fixed the math so that it matches observation.
            The ancient Chinese had no chemistry knowledge as to WHY sulphur, charcoal, and saltpeter go bang, but they sure did make fine rockets.
            I am not complaining if no one really knows WHY the EM Drive works, when we can see it works in videos and has been tested in reputable labs.
            IT WORKS!
            Praise God!

            I only keep asking HOW it works because folks keep saying they KNOW how it works. And I keep saying “please, have pity on my curious mind, and share that insight” but then I only get a slide that says
            “drive moves that way —>”
            … But it is not the “RESULT” that I am asking for. I accept the result. I do not question the outcome. I am asking HOW is the momentum of individual photons altered in the course of their travels up and down the waveguide.

            If there are 100 photons in the chamber, then there are 100 photons that bounce off the small plate, and then, after a trip down the waveguide, that same 100 photons then bounce off the large plate. If there is a net surplus of force transferred by reflection at one end that causes forward acceleration of the drive chamber, when the total photon COUNT does not change, then the momentum of the individuals must change. And if not by a change of FREQUENCY, or ENERGY, then how does that individual photon momentum change???

            We can explain how Uranium goes supercritical, down to the neutron. We can explain how plants convert sunshine to energy, and how I can convert the sugars to Vodka. We can even explain how the sun evolves over billions of years, from happy little yellow fusion ball to eventual nova! So why can’t anyone tell me how a photon’s momentum is altered in an EM Drive???

            Look. If you were given the opportunity to ask for a research grant from President Trump, and the sky was the limit! And the only caveat was that you have to explain to him HOW it works and convince him, then what would you say? Once you had channeled your inner Neil DeGrasse-Tyson and summoned all your science communication skills, what would you say? Would you just say “it all has to do with Group Velocity, and Radiation Pressure. Here, I have this formula that gives a result that confirms it should work”?

            Please! I am at my wits end on this matter. Nowhere have I found anyone who can answer my simple question.

            And I will say this just one last time:
            Not knowing is perfectly fine.
            We are all in the same boat then, and it is no biggie.
            And I would not keep asking someone the same question over and over EXCEPT for the fact that they say they know, and seem so happy to share the information.

          • Chapman

            And Engineer, please do not take ANY of my comments out of context, or read into them anything but absolute respect and gratitude!

            I am a big fan.

            A REALLY big fan.

            In fact, I would go so far as to say that I am “Your Number 1 FAN”, and as such, I am prepared to do what is required by that status:

            Should you EVER be driving through the Arkansa woods on a stormy night, and run off the road, I will drag you back to my cabin, lovingly nurse you back to health, then HOBBLE you with a sledgehammer and keep you captive until you agree to re-write this accursed last chapter on the workings of the EM DRIVE!!!


            [the joke should be self evident, and any overall appearance of a threat must be considered relative to the literary context…]

          • Engineer48

            Hi Chapman

            The answer is Newton 3. For every force there is an equal and opposite force.

            Engineers say the sum of the force vectors must equal zero.

            Assuming 1kg force on the inside of the big end plate, 0.3kg opposing force on the inside of the small end plate. According to Newton 3 this is not possible as the force vectors on the inside of the cavity are not balanced.

            However if we add another force vector on the entire cavity of 0.7kg toward the small end, Newton 3 is happy as the overall force vectors are balanced, plus the whole cavity moves small end forward because of the 0.7kg reaction force generated to balance the unbalanced internal forces.

            Could say this all happens because of the unbalanced forces inside the cavity.

          • Chapman

            Well, this looks promising! It sure feels like an answer is hidden in there! I am processing it…


            Why only .3 on the small end, when the photon count is the same as those at the large end generating 1 full kg, and neither the energy nor the frequency of the photons has changed?

            Where are we getting the additional .7 we are then seeing applied to the small end, and why would that additional .7 generate a thrust when it perfectly balances overall enplate radiation pressure?

          • Engineer48

            Hi Chapman,

            Cullen, in 1951 experimentally showed the radiation pressure on a totally reflecting end plate in a waveguide was reduced from that expected external to the waveguide and that the drop in radiation pressure followed the increasing guide wavelength caused by the reduction in waveguide diameter.

            His equation (#15) was p = ((2 * E) / c ) * (external wavelength / guide wavelength):


            This effect, discovered by Cullen, is at the heart of the Shawyer Effect drive.

          • Engineer48

            Shawyer’s thrust equation is

            Accelerative small end leading force = (2 * Qu * Pwr * Df) / c
            where Df is the Design factor that defines the force relationship between the end plates:


          • Chapman

            Yeah… see, I am not at peace with these equations simply because they are using total applied power.

            I am not looking for a formula that dependably predicts produced thrust for a given power input. I am chasing down the details of the actual mechanics. I am trying to “think like the photon”, and to “be the photon”.

            This formula just tells me the amount of thrust to expect. NOT how that thrust is generated.

            Again, useful bit of math if I was building one in my secret lab, but I am not. I am just trying to nail down the excruciatingly fine details of its theory of operation. Once I understand the function intuitively, I can derive the formula from simple analysis when needed. I have never bothered memorizing formulas. If you get it, you will be able to construct the formula. If you don’t, the formula does you no good anyway!

            That is why I keep getting pissy. Forgive me. At least take SOME comfort in knowing that “that annoying chapman guy” is hanging on your every word, and genuinely convinced you have the answers I seek. If I did not have faith in your superior Kung-Fu I would just walk away and leave you alone. But I am convinced you have knowledge ( that is KNOWLEDGE, not just FACTS ) that I desperately seek, so I am beating on you mercilessly to shake it loose. If you ever want to pursue the secret of achieving the perfect Pilsner, then you are welcome to beat on me the same way! And I will, in turn, take it as an honor that someone appreciates my brewing skills enough to badger me for my award winning recipes and secrets!!!

          • Engineer48

            Hi Chapman,

            There are many things in the SM that are not known.

            What I know as an engineer, is if I follow Shawyer’s information, build an EmDrive following his recipe, adding NOTHING new, it will work.

            Why it works will probably win someone a Nobel.

          • Chapman

            AH HA!!! So, regardless of how much I appreciate and respect your knowledge on the topic, there are limits, yes? And it is not some selfish refusal to share that prohibits you from endowing upon me some state of EM DRIVE Enlightenment! 🙂

            I hear you saying you get it, and you know it works, and you have played with it, and cuddled it, and damn well know it’s real, but there is a limit to what I can squeeze out of you, cause you ain’t God, and only he really knows why a photon even does the crazy crap they do!

            Dude, there ain’t nothing I respect MORE on this great green Earth than that simple truth of life!!! Know that I appreciate every minute you have taken to pass on what you got, and that I apologize for any stress I have caused probing for what you ain’t got. You have given me plenty!!!

            Now you only have to deal with one last thing. Now that I respect you even MORE, you gotta deal with the fact that you are now gonna be my go-to guy to bounce what I think I figured out off of. Because we all need someone well rooted who can tell us an idea is drifting off the mark!

          • Chapman

            Is this dependant on a resonant state? That is, are we looking at the effects of a standing wave when the cavity is tuned to perfect resonance? If so, I think I get what you are implying. It is similar to standing wave PROBLEMS in a transmission line, like we used to have to chase down in improperly terminated 10base2 networking cables. A resonating transmission line creating a standing wave creates “HOT LOBES” and “DEAD LOBES”. The dead lobes were bad, because even though the line is passing max current, there is zero voltage potential to actual drive the local transceiver, so you get a workstation that can not “see” the network… Differential inputs mean no voltage = no signal.

            SO… following that logic, are you saying that the small end deforms the wavelength by stretching it, rather than compressing the frequency? And the lengthened wavelength then imparts lower momentum because the end plate is also a zero point in the standing wave? I see that the electric field is reduced to zero, while the magnetic field is doubled. Is that due to the taper explicitly, or does that apply to any straight waveguide as well?

            And, please forgive my curiosity and secondary observations, does the “lobe” occupy the same volume no matter the waveguide diameter? Is that the reason for the increased wavelength proportionality to cross section? I find it fascinating that orbital dynamics reduces to the need to maintain the simple geometry that any orbiting mass must cover the same two dimensional volume of space per radian travelled per time constant, regardless of distance from the focus, and that all orbits, and all the advanced math is a simple derivative from that relationship. Is each LOBE of the wave maintaining a constant volume? THAT would be a fundamental principle my brain could easily incorporate. Narrowing the waveguide would force a lengthening of wavelength.

            I think I am getting there now, but could you clarify – is it necessary for the waveguide to be in resonance? I think that is the next key to me actually achieving an intuitive understanding here…

            Oh, and you are batting a thousand right now on clarity, so thanks…

          • Engineer48

            Hi Chapman,

            Microwave physics says the photon’s guide wavelength increases as the waveguide diameter drops. Likewise the group velocity drops as the guide wavelength increases.

            Energy in a waveguide propogates at the group velocity and not at c.


            Resonance is needed to achieve coupler impedance match, so to xfer max Rf energy to the coupler inside the cavity and then to emit the max number of photons.

            1kW of Rf applied for 1 sec will result in 6.16^26 photons being emitted from the coupler’s surface metallic atoms.

            In a TE013 resonant cavity, there are 3 x 1/2 guide wave long lobes, with null points at each end plate and 2 in the space between the end plates.


            However the standing wave is not real and is only the superposition of the dual travelling waves that continually travel from end plate to end plate and “reflect” off each end plate.


            The standing wave generates the wall and end plate eddy currents, due to time variant Photon H fields, but not the end plate radiation pressure, which is generated by the dual travelling waves generated radiation pressure.

          • Chapman

            Is the TE013 config key to the thrust? I see the “small end” maintains its zero reference, while the large end undergoes a full cycle. I know, that is because of the fractional wave count, and I get that the standing wave is a superposition of the two independent waves, do not worry… But is the thrust gradient relative to the average endplate composite wave amplitude?

          • Engineer48

            Hi Chapman,

            The gif is something I found on the net. Good to explain relationship between standing and travelling waves. The ends are not representative of a TE013 cavity as the standing wave nulls stay put at each end plate.

            TE013 is a cavity resonance mode that Shawyer suggested experimenters use to design cavities.

            I produced and publicly distributed an Excel based EmDrive design tool that made the design process fairly simple.

          • Chapman

            No problems. I understand.

            Just to let you know, I do this with semiconductors, and I build amplifiers and transmitters and all sorts of villainous fun stuff, all because in electronics I DO think like an electron. Each class of component is really just a question of its effect on the life and happiness of electrons. I construct vast circuits, in which I can sit back and just FEEL the current seek its own happiness within the little world I create for them. This is how I was taught electronics from the old HeathKit days, and it is how I approach everything in my life. Auto mechanics, Brewing, Programming, you name it. Heck, the only thing that has ever interested me that I never mastered was marital relationships. Unlike my auto collection, or my brewing, or some pretty foolhardy high power electronics, I have had several of my marriage experiments just blow up in my face with NO understanding of what I did wrong!!! Finally had to give up on building from scratch, and just resolve myself to sticking to rentals…

  • Zephir

    Many commercial technologies work without any peer-reviewed replications, because their details were never presented at public. Roger Shawyer himself stated, he has been given permission by the UK Department of Defense to put this in the public domain. Mr Shawyer would like to have this presentation circulated as widely as possible. This info shouldn’t come as a surprise, because [UK keeps three times as many patents secret as the US](https://www.newscientist.com/article/dn18691-uk-keeps-three-times-as-many-patents-secret-as-the-us/).

    What you can read in peer-reviewed journals is just a tip of iceberg of observable reality – just face it…

  • Zephir

    This is principle of photon rocket, not EMDrive thruster.
    It’s not based on radiation pressure by [reflection or absorbtion](http://i.imgur.com/M23eT4i.png),
    but by redshifting due to polarization.

  • Chapman

    For anyone else out there scratching their heads, feeling that the whole EM Drive thing seems like it should not be that difficult, and yet struggles with an uncomfortable feeling that comes on when just when you think you have it down, some bit of info comes along and makes you question if you missed something… I just want to assure you that you are not wrong. There are absolutely 100% contradictory info, diagrams, and statistics out there that start by saying the same thing, but then show something totally opposite of what you thought you understood.

    At first, you blame yourself, thinking “how could I have misunderstood everything so far? Where did I get THAT crazy idea?”

    Again – It ain’t YOU!

    Engineer got to the bottom of it by reducing everything down to the one simple fact, and that is “artificial Blueshift imposed upon a photon by a constricting waveguide”. Everything else is just a mathematical consequence of that simple action. No mystery physics. No obscure techno-babble required.

    There is no need to go on about Group Velocity, Radiation Pressure, Special Relativity, or even VG vs VC.

    So why was it so hard to reduce the nonsense, clear the deadwood, and just focus from the start with the relevant facts? And why is there ANY controversy at all?

    Let me show you something:
    This is from Wiki…

    And THIS:
    is from Engineer…

    Notice anything?

    And this is not by any means the only example I could provide. Everywhere you look, everywhere you go to seek enlightenment you find contradictory garbage that confuses the senses. There is a obsessive need out there to use arcane verbiage and obscure terminologies, as well as just flat out misrepresentations of actual core physics principles.

    You can even check out videos from seemingly learned sources like PBS SpaceTime and get your brain scrambled with utter nonsense and false facts.

    In the end, we all need to accept the ONE TRUE REALITY that seems indisputable:
    Most folks are full of Bovine Excrement.

    You just gotta screen out the crap, identify the sources and avoid them in the future, elevate your respect for those sources you have identified as dependable, and think everything through three times with a conviction that you are being lied to.

    Then, and only then, can you find peace, and maybe enjoy the camaraderie of a few other guys who have waded through the swamp of misinformation.

    So crack a beer, and take a deep breath.
    IT AIN’T YOU!!!

    • radvar

      Once again attempting to put BS above reason, and to position yourself as the master of BS, a now all too familiar power tactic. Let’s let the biggest loudmouth fly the plane.

      Reality is complicated. Over-simplifications lead to bridge failures.

      If you can’t handle it, admit that and at least get out of the way of people who are trying to work on it.

      So in fact it is “you”.

      • Chapman

        Sphincter still a little sore?

        Just get over it friend.

        • radvar

          Reported as offensive.
          Perfectly demonstrates the true level of your mind.

          • Chapman

            My friend, do you not see that it is you absolutely losing your mind?

            Don’t worry about the splinter in the eyes of others till you deal with the LOG stuck in your own! That is just good advice, regardless of your religion.

            It is YOU that is attempting to troll and annoy and insult ME, so get over yourself. Do not smack the fence if you don’t want to get bit!

            Do not go crying victimhood and get all weepy when you decide to go looking for a confrontation. If you are going to instigate a fight you have to man up and take your licks.

            I am willing to play with you, but you have to be a man about it.
            Stop whining…

          • radvar

            More reality distortion, since I have exhibited none of those characteristics.

            You don’t seem to be able to deal with reality very well. Your initial post was basically excusing yourself from not understanding the math. Your follow on post was an evocation of potty humor. Your third post is diversion from the first two posts.

            Further, encouraging people to drink beer instead of trying to think harder is exactly a corruption of truth-seeking, which needs to be opposed. You were not here in 2012 when there were many trolls every day. YOU should oppose corruption of truth-seeking.

            Another attribute of people who are obsessed with their personal sense power is that they refuse to be accountable for their own behavior.

            There can be peace here, however, it starts with your demonstrating some accountability, and first and foremost, apologizing for the incivility.

          • Chapman

            If you take a deep breath and count to 50, then re-read your own posts it will be evident, even to you, that you are being a monumental jackwad.

            The good news is that you can choose to stop at any time. Nobody is compelling you to get on the forum and flame people. It’s all you. You are shopping for your own straight jacket.

          • radvar

            Your behavior still stands, and you’re still being potty-mouth.

            Ok,so you apparently don’t know how to do this, so I’ll go first. If have flamed you, I apologize for any stress that has caused you.

            However, my interpretation of your initial post and your general behavior in followup still stands. If you would like to defend your initial post more rationally, that’s your choice.

          • Chapman

            And I, in kind, beg forgiveness for any offense.

            But I too must stand by my original post, which was an assurance to all others trying to follow the EM Drive Physics that they really are seeing totally conflicting diagrams and force descriptions dependant upon the site or reference they are viewing.

            I merely pointed out THAT fact, and the need to qualify the validity of each source and then just concentrate on the insights you can glean from those that prove valid.

            And for this you come on and throw bucketloads of crap upon my head, accusing me of all sorts of things, and generally denigrating me? For what?

            I apologize for upsetting you,
            but you, Sir are utterly, completely, and TOTALLY insane.
            Mad as a March Hare.
            Nutty as a Payday candybar.
            Bonkers as a LooneyToons Character.
            Your mind is as twisted and distorted as Engineers Avatar!!!

            But please, DO accept my humble apologies…

          • radvar

            I accept your interpretation of your initial post. My response was wrong. I repeat my apology for having caused you any distress.

            Since your last comment is laden with insults, not in the least humble, and again attempting to create a distorted view of reality to satisfy your agenda, I don’t recognize it as a sincere attempt to leave this in peace.

          • radvar

            Another diversion. Nothing to do with climate change. Everything to do with your distortion of reality.

    • Chapman

      If I may, please allow me to make a clarification regarding my post, lest I should be misunderstood…

      We are, in my humble opinion, blessed to have had Engineer with us to bring to light the simple underlying science behind this phenomena.

      My warning was in regards to the fact that even the Wiki page on the topic discusses the Casimir effect, quantum foam, and every other bit of advanced physics theory they could throw in, but never mentions the well documented waveguide function Engineer describes… AND, they show a diagram that totally inverts the momentum and force factors involved. Who ever edited the WIKI page on the subject knows less about it than YOU DO. And 90 percent of the articles and analysis I have tracked down are no better.

      That is what I was trying to get across. Once you “get it”, and see what is happening in the Drive, then just rest easy with that knowledge and tune out the nonsense published on the topic. Just because someone else writes that it is all about the quantum vacuum and virtual particles does not mean it is right, or that they know what they are talking about. Experience tells me to trust Engineer.

      I do not claim to have all the answers, but I am happy to celebrate the fact that we have, on this topic at least, one guy who DOES! And we are all better informed now thanks to him.

      If all we had to fall back on was Wiki, we would all still be confused about which direction the darn thing is even supposed to fly…

      • Martin Lund

        Hallelujah preacher Chapman! Amen!

  • Gerard McEk

    TheNewFire tweeted: https://www.digitaltrends.com/cool-tech/emdrive-news-rumors/
    Has NASA leaked details about their tests on the EM drive?

  • Engineer48

    About my 5N/kW reference:

    That is based on my experimental data of 50gf at 100W.
    Have been in communication with Roger Shawyer for 4 years.
    Was of some assistance to NASA Eagleworks resolving some of their issues.
    Roger sent me the latest presentation to distribute.
    Frank was one of the recipients, which started this thread.

    Now doing EmDrive research on a commercial basis.
    Several patents and papers are in process, so disclosure is low.
    Goal is a non superconducting, non cryo Floater, based on a 100N/kW design.

    As some have pointed out 5N/kW is good enough to change space exploration.
    Could eliminate fuel on all satellites and enable 30 day trips to Mars.
    Getting to TRL 9 is NOT an easy, fast nor low cost process.


    Currently at TRL 3 or 4:


    • Engineer48
    • Martin Lund

      At this point, to fully convince me of the EmDrive effect, I would love to see NASA report a successful EmDrive replication attempt with 1+ N/kW to fully and indisputably eliminate any possible measurement errors or magnetic field / heat effects etc. causing movement.

      • Engineer48

        Hi Martin,

        As far as I know, Dr. White has moved on to other duties, Eagleworks is no longer funded and NASA has no interests in EmDrive.

        Would really like to be proved wrong but that is the feedback I get.

        • Martin Lund

          Hi Engineer,

          Why would NASA not be interested in the EmDrive effect? Isn’t it one of the goals of NASA to explore new propulsion technologies to advance space travel?

          If NASA was turned off by Eagleworks replication attempt then that is not a good sign that the EmDrive effect is real.

          • Engineer48

            Hi Martin,

            NASA is not one person but many, with many varied interests.
            NASA has a large investment in Ion Drives and other exotic propulsion tech.

            Would suggest the very low 1.2mN/kW specific force that Dr. White achieved was not enough to generate any serious interest. Ion drives are around 60mN/kW or 50 times more thrust / kW than what Dr. White achieved.

            Please do note the thruster Dr. White built was not a Shawyer EmDrive. He advised them to remove the dielectric but Dr. White needed it for his QV theory.


            Plus the thruster’s small end diameter was below cutoff, below the min diameter that Shawyer recommends.

            To me this says Dr. White was very lucky to measure any thrusts as he violated 3 of Shawyer’s design rules.

            1) Used a dielectric
            2) Small end diameter too small and below cutoff.
            3) Did not use convex small end and concave big end spherical end plates.

            Below is an early thruster design that meets all the Shawyer design rules.


          • Martin Lund

            Hi Engineer,

            I understand. As with any big organization there there are lots of politics involved that affects which projects get priority. Also, considering the current American anti-scientific administration, I bet funding is also troublesome.

            I wished they wouldn’t have violated Shawyer’s design rules. Imagine if they had reached a thrust effect of 100mN/kW or more then things might have been different. Especially, considering that the EmDrive effect is exhaust less as compared to e.g. the ion drive.

            You mentioned that you are doing commercial EmDrive research… I’m curious as to know what is the maximum thrust you have observed in your experiments at this point? Have you ventured into the 1+ N/kW range already or are you still in design stage?

          • Engineer48

            Hi Martin,

            Dr. White’s goal seemed to be to prove his QV theory, which needed a design that was non Shawyer. He predicted thrust should increase 4x power. The tests showed 1x or thrust scaled with power as Shawyer’s theory predicts and his tests support.

            So Eaglework’s tests were not designed to verify Shawyer’s test data and did not use a Shawyer design rules compliant thruster.

            As for my work, Shawyer is my Yoda & by following his breadcrumbs. My 1st successful thruster achieved 8mN at 95W or 85mN/kW, which was a long way below his 2009 Flight Thruster at 326mN/kW.

            My recent work has achieved 50gf at 100W or 5N/kW. I believe Shawyer and Gilo are into the 100s of N/kW with 1,000N/kW their goal. They, as are other teams I know of, are developing cryo LN2 and LH2 cooled superconducting cavities.

            I believe the Shawyer/Gilo thruster is a 900MHz design, which with a bigger cavity increases Q, which increases thrust.

            My focus is on low cost, 2.45GHz, simple copper thrusters that do not need cryo cooling as the cooling vastly increases design complexity, weight, cost & reduces overall system reliability.

            Goal is bolt on space rated P-P 5N/kW thrusters, with complete electronics, Rf amp, etc that can be switched on by the simple application of DC power and are TRL 9 rated. At around TRL 3 to 4 at present.

          • Martin Lund

            Hi Engineer,

            Those performance figures sound mighty impressive. If what you are saying is true then this thruster technology holds great potential for the future.

            I assume an ideal cavity design based on high temperature superconductivity combined with a high density energy source (eg. LENR device) could potentially bring some amazing new modes of transportation (eg. flying cars).

            Either way, I’m always a skeptic so I will be looking forward to the day when some of the work you mentioned becomes available for public scrutiny in the form of independent test reports etc..

            I’m curious. Would it be possible to scale down this thruster technology so that it could be integrated in a cubesat (10cm x 10cm x 10cm). It could be a great way to demonstrate the technology in a real world scenario and the cubesat program is relatively cheap way for testing things in space.

          • Chapman

            In regards to the QV theory, am I understanding things correctly that he is basically harvesting naturally occurring electron/positron pairs popping out of the ether and using them as propellent? Please, do not flame me, I know that is a simplified statement, but isn’t that the effect? And isn’t this basically a form of Hawking radiation? In the case of a black hole, the escaping member of the pair accounts for a loss of singularity mass, without the escape of any information, which was an astonishing revelation, while the drive unit uses the same particle resource as a pool from which to draw viable propulsion mass. Yes? Just wondering…

          • Engineer48

            Hi Chapman,

            All of Dr. White’s papers can be found and studied on the NASA paper server here:


          • Chapman

            oops… dead link.

    • Toussaint françois

      Hi engineer48,

      What is your opinion on the work of Thomas Townsend Brown ?

      Have you heard of the work of Jean-pierre PETIT on MHD ?


  • Chapman

    Today, that is on 6/26/2017, I simply do not believe Monkeys can talk.

    Mind you, it is not that I am philosophically or religiously AGAINST the concept, it is simply that my life experience, and my limited understanding of things zoological leave me with a conviction that “taking monkeys” is an eventuality that simply has not come to pass.

    On the other hand, if on the morrow I was to visit the local zoo and find myself bemused and entertained at the Ape exhibit, and if I were amusing myself by offering a banana to a particularly interesting female, and if I were to become perplexed at her refusal to accept my proffered tropical treat to such an extent that I was driven to ask myself outloud “now, why won’t she take this fine Banana?” only to be shocked by hearing a reply in perfect diction “BECAUSE I LOATHE BANANAS!!!”, well, rest assured dear friends that I would then become an instant believer!

    And yet… It is a strange quirk of mine – some unexplainable sense of curiosity – that my next logical thought would be to ask “How did this Ape acquire speech?” Not “did that just happen?” because I trust my eyes, and I just witnessed it. And I would not be hesitant to accept the fact, because a long life has led me to understand that there are stranger things in this world than my imagination could ever dream up! I am at peace with the unexpected, and accept such changes in easy stride. No, what happens is that I am then compelled to seek the cause OF the change.

    I do not demand proof, I seek answers.

    If my learned betters then tell me “it is a function of her vocal cords”, I would ask, “yes, but how did she GET vocal Cords?” I understand biology. I know what vocal cords are, and what they do. You do not need to explain sound as a waveform propagating through the atmosphere. I get all that. It is not the question, you see? I would be asking HOW the ape GOT vocal cords in the first place. There must have been some surgical intervention, or diabolical, and likely illegal, DNA Hanky-Panky going on. And even WITH the vocal cords, who took the time to attempt to teach an ape the King’s English, when they had no reason to suspect she may actually have a unique gift of speech in the first place?

    So again, I would implore my fellows “How did this Ape come to be capable of speech?” And someone might respond, “The speech center lies in the parietal lobe of the left hemisphere of the brain for right-handed persons and most left-handed. The area of the brain responsible for motor control of the anatomic structures is called Broca’s motor speech area”. To which I would become slightly aggravated and say, “Dammit man, how did the bleedin’ monkey ever GET a functioning “Broca’s motor speech area???”.

    I would be well on my way to a nervous breakdown at that point, and fighting to maintain my composure, when someone very well might then say, “well, lookit, maybe, just maybe, she simply doesn’t LIKE bananas! You ever think of THAT, smart guy?”

    At which time my skull would implode out of utter frustration over the fact that I was sure I was asking a perfectly reasonable question, and that there must surely be an answer, and yet not only was no one able to provide the answer I sought, but it was perfectly clear that no one was even understanding the relatively simple question I was asking. And it would infuriate me to have to recognize, at that moment, the undeniable fact that this MONKEY seemed to have better communications skills than I do!!!!!

    Does ANYONE OUT THERE understand my point???
    Am I alone in this frustration???

    • Chapman

      For the record, acceptable answers might include any of the following:

      Well, the ape underwent extensive stem cell transplants to the brain and throat, while also being subjected to direct electrical stimulation of the nervous system in an effort to force the development of the relative physical organ structures. From there it was just a matter of intense training and patience.


      We do not really know! She was acquired from a rescue shelter, and we have no knowledge of her early life and development. But one day she said NO, and we all took an interest and started reading to her, and, well, what can we say? Neat, huh?


      Actually, one of our female attendants is a Cultural Anthropology Graduate Student working on her Doctoral Thesis. She wanted to study the apes more closely, but did not have time to slowly become accepted by the troop alla Jane Goodall, so she just got an Ape suit from a local costume shop and hangs out in the cage on her lunch break. Sorry mate, but Sue was just having a little fun with you. Relax.

    • Martin Lund

      You have clearly gone off the rails. Please stay on topic. This thread is for the topic of EmDrive and not the evolution of talking monkeys nor bananas.

    • georgehants

      Morning Chapman, you simply have to be prepared that your question is being answered without the use of the crude, ambiguous use of a human language.
      The apes communicate perfectly well with each-other or humans.
      Because we are so dumb that we cannot talk ape, whale or dolphin makes us the fools.
      When we learn some kind of positive, progressive, honest, peaceful communication with each-other we may begin to overtake the animal, insect, species.

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