New EmDrive Replication Reported

Stepping away from LENR for a moment, here’s a topic that has been of interest to a number of people on this site recently.

In the best spirit of open science, there is another very interesting experiment that is being reported by a Romanian experimenter named Berta Iulian, who has attempted to replicate the EmDrive, a propulsion device invented by British engineer Roger Shawyer, and which has reportedly been recently replicated by a NASA team. Last month, the website reported that a group at NASA’s Johnson Space Center had

“successfully tested an electromagnetic (EM) propulsion drive in a vacuum – a major breakthrough for a multi-year international effort comprising several competing research teams. Thrust measurements of the EM Drive defy classical physics’ expectations that such a closed (microwave) cavity should be unusable for space propulsion because of the law of conservation of momentum.”

Berta Iulian has release a video of his own replication efforts in which he measures thrust:

More information about this experiment can be found here on his website:

  • Gerard McEk

    It may be right but the proof is poor. There may be little Lorenz forces between the feeding wires, or the scale is being influenced by the high frequencies. The latter can be excluded by putting the ‘thruster’ on a stand and switching it on (it should indicate no weight change).

    • Ged

      The scale diesn’t seem to be anywhere near the wires (in fact, hidden from them by the wall and a solid copper plate it seems) since the force is being transfered through a spring dampened lever arm. This is some classical physics measuring methods, can’t see anything wrong with it at first brush at least. Should be easy enough to turn the device around and measure the opposite direction.

      • Gerard McEk

        Indeed that would be a good test. The very small forces and the equivalent sensitive instrument should make you very aware that things mabe measured faulty and that the test is not very convincing for others.

        • Ged

          Yeah, measuring in the opposite direction with the same setup is the best way to rule out measurement error or some other unknown event occurring that causes the scale to decrease–I agree with your caution about the small signal size versus the imprecise nature of the scale at such low values seen earlier in the vid. If we see the same magnitude in the positive direction, that would be much stronger evidence.

  • tobalt

    I dont see the fuss..

    Any directional emitter of electromagnetic radiation produces photon recoil thrust. This has been known and established in physics for 100 years since it became clear through deBroglie that photons have momentum.

    If they hang a laser or even a lamp with a half-sperical mirror in their chamber, it is going to convert energy into “reactionless thrust”. Just that it is not reactionless but uses the photon recoil to preserve momentum…

    • Ged

      The fuss is this is a closed container. Imagine you are in an enclosed container, say a ship (Stargate Atlantis had a great episode demonstrating this), and you want to move it in some dirction. What would happen if you threw your weight against the wall on one side? Would the vessel move? No, because the opposite force you generated to push yourself forward to hit the wall nullifies the force hitting the wall, and thus the net thrust is 0.

      The same is true for photons classically. Emitting photons generates thrust in the opposite direction of the wall, and hitting the wall would put thrust in the direction of the wall equal to the thrust of the emission (like the person’s body example above), causing a net 0 thrust. Put another way, every action has an opposite and equal reaction (conservation of momentum). This is why rockets have to throw mass out a nozzel to make net thrust in the opposite direction.

      Now, the thrust of emitting photons alone is so vanishingly small, it’s useless. What is happening in an EmDrive is you bounce the photons off a wall, which should be net 0 thrust, and then you have them bounce off the smaller, opposite wall and then back and forth till they finally absorb–this is a resonance chamber–and somehow this vastly multiplies the force by orders of magnitude (maybe kinda like electron resonance building up to a laser emission) and also, due to the difference size in the walls, makes the thrust lopsided and no longer net 0 (I have no idea how).

      In fact, the thrust in the direction of the small wall of the chamber is so big, it’s similar to an ion engine of like size, and completely applicable to space travel.

      If it scales well enough to make rocket levels of thrust while not using impossible amounts if energy, it could get you to orbit, but likely like ion engines it’ll only be useful for high speed over long distances in vacuum.

      • tobalt

        I understand that the fuss would be justified if this thing indeed generated thrust while emitting no photons. i think the objection about the closed contained is only valid if there is either zero or fully isotropic emission to the environment of radio waves. and I think that this is not the case.

        1) the magnetron is attached to one side which will already radiate substantially.

        2) for the GHz frequencies the copper plate is like a capacitor, ie. the skin charge on the inside will induce an opposite skin charge on the outer skin of the copper plate, which will again radiate substantially.

        If they could just meter the rf radiation “in front” and “behind” the device along the direction of thrust with an rf antenna, would immediately rule this out. if this is either both zero or isotropic, the photon recoil cannot explain the thrust.

        Still my point was, I dont understand why the results that the thing produces thrust, are doubted. It is very natural to expect thrust due to photon recoil. New physics only come when thrust is observed while photon recoil is ruled out experimentally.

        • Oystein Lande

          Weell, NASA claims it violates the law of conservation of momentum.

          I assume our excellent NASA scientists have thought of your possible explanation, and excluded it from the “equation”…. 😉

          And I have a feeling that the measured thrust is far beyond any possible photon recoil thrust…?

        • Omega Z

          I’ve always considered nuclear fission to power a spacecraft a desperate last resort. LENR on the other hand has no radiation issue’s were aware of & what little may exist is easily shielded & dealt with.

          Artistic concepts of nuclear fission ships have always included shielding “only” between the crew & the reactor, because the weight & cost for complete shielding of the reactor is considered prohibitive. Ultimately, the crew would be exposed to some degree of radiation.

          Interestingly, LENR needing little or no shielding may be capable of generating a Magnetic bubble extending beyond a spacecraft protecting the crew from the natural radiation in space similar to the protection provided by planet earth. Thus a minimum of shielding of the spacecraft for that purpose.

          Possibly, LENR could produce a magnetic field drive where the field produced is so adverse to ones surroundings that it propels you through space trying to find an equilibrium. Somewhat like an Ion thruster, but with faster acceleration/deceleration. Caution is needed. Liquids don’t clean up so well in space.

        • Ged

          Well, photon recoil by itself is pretty dang small, which is why we don’t put magnetrons on spacecraft as propulsion. Let’s ignore that skin charges or thermal gradients would conduct across the surface of the copper, and lack meaningful directionality and thus thrust, and instead just look at photon recoil.

          Given the equation that photon momentum, p, is equal to total energy divided by the speed of light, we get: p=E/c.

          Here, it is reported that due to the lever ratio, we have about 0.5 grams of true upwards thrust. This is equivilant to about 5 milliNewtons.

          Using our equation above, this gives us about 1.9 megajoules of energy in pure photons to produce that level of recoil. Given the speed of the device to get to full thrust is around one second, that would put us at 1.9 megawatts of photon power. Suffice to say, there would be no experimentor video of this event if this was so.

          You can also see why photon recoil by itself is not practical. Even 50 microNewtons recoil would need upwards of 19 kilojoules of pure photon energy. This isn’t including efficiencies of converting an energy source to photon energy, so you can see why sticking magnetrons to things is horridly impractical, and why photon recoil can’t explain these results.

  • ecatworld

    In a comment on the YouTube video, experimenter Berta Iulian says he will next try the experiment with the cone upside down.

    • Ged

      Excellent. That’ll better test if this is real.

      • Rolls Canhardly

        Someone in his comments section mentioned that if it was hot air inside the frustrum expanding which caused the effect, the weight wouldn’t go back to zero the second he turns off the device, which is what it seems to do.

        • Ged

          That isn’t possible anyways, as the volume of the copper container doesn’t change enough and is enclosed, so hot air can’t cause expansion and air displacement (and thus “lift” via change in density) like it would a balloon. So, no surprise weight immediately returns to normal on shut down each time (other than the surprise it changes at all!).

  • Roger Bird

    Unfortunately, the EM drive is not worth much if LENR or something similar to LENR is not true.

  • GreenWin

    If one was to wire two Em drives in parallel, would it be fair to call it an “Emnem drive?”