Forbes Article on the EmDrive and its Implications for Physics

Ethan Siegel is a name familiar to people following the LENR story, as he has been quite a strong critic of the E-Cat and other LENR devices since he doesn’t think they can work, based on his understanding of physics.

Now he has turned his attention to another controversial technology that has been making news: the EmDrive. Recently a paper published by a team from NASA has concluded that the EmDrive does produce thrust, without the use of propellant. Siegel has written an article for Forbes, titled “How Physics Falls Apart If The EMdrive Works” (, in which he examines the implications for physics, if the EmDrive does actually work as the NASA paper reports.

He states that if the EmDrive really does produce thrust without any kind of propellant, then we must throw away Newton, Einstein and any other physics built on the principle of conservation of momentum. He says this would be a very radical thing to do, since so many experiments over the centuries have verified Newton’s laws. He thinks the most likely thing is that there really is some kind of thrust being produced by the EmDrive, probably electromagnetic in nature; or, that the NASA researchers were simply mistaken in what they reported.

Roger Shawyer, the inventor of the EmDrive, also doesn’t think that Newton’s laws are violated by his machine. He has stated:

“What I would say is that the idea that EmDrive violates the laws of conservation of momentum is itself nonsense. Of course it doesn’t. It wouldn’t work if it did. All that EmDrive is a device for exchanging the momentum of the electromagnetic waves going up and down inside it, with the momentum of the thruster as it accelerates. It’s all actually elementary physics.”

Regardless of whether physics is broken or intact, there’s a lot of new interest in the EmDrive, and it does seem that the race is on to see if practical technology can be derived from it. There’s quite a lot of coverage about it in the news these days; see the current spate of articles that is gathered by Google News here+.

  • Gerard McEk

    Roger Shawyer: So exchanging the thruster’s and the (mass-less) EM waves momentums you can cause a force? Interesting, but I can’t understand how that would work if there is no mass to pull or push.

  • Dods

    Don’t like the bloke I think he’s right up himself. What has the last paragraph got anything to do with the EM Drive working or not. He goes off naming loads of examples in the negative where the experiment was wrong and science was right. What about a list of examples where science was wrong and some new discoveries were made to balance out your pointless end point Ethan. He is just a gate keeper protecting the tower from being rocked to much imho.

  • Bob Greenyer

    It may appear black for all history, until someone changes the exposure or sensitivity.

    Some like to cast out that which they cannot conceive or do not have the will or wherewithal to create, for they like to think their world is explained and yet the reality is we know so little. Arrogance begets stupidity.

    More inconvenient truths will be realised in the coming years since science gives birth to the truth and all the celebrity/notoriety in the world cannot stop it.

  • Bob Greenyer

    He contradicts himself before he reaches the end of his second sentence – quite an achievement!

    “Imagine a rocket that works without fuel. You pump energy into it and away you go…”

    I think he needs to replace the word “fuel” with “propellant”

    Energy is needed as he says to create the microwaves which will likely radiate into space, there will be extremely small mass loss in the overall system. In part this will be why you would want to test this horizontally to remove the doubt surrounding convection related movement. The point is that you could have a nuclear battery or LENR power source driving this consistently

  • Bob Greenyer

    “they all have no evidence except this one engine to show for it.”

    This might be all the evidence NASA has personally, but presumably they didn’t start working on it before considering the evidence from the devices that Shawyer built and the EMDrive the Chinese built in 2013

    This produced 720 mN (about 72 grams) of thrust – not to be sniffed at!

    and the Chinese worked on the theory “They started with a new analysis in terms of quantum theory in 2008 which indicated that the theoretical basis was sound and net thrust is possible.”

  • Pekka Janhunen

    At least the quotation above of Roger Shawyer (“What I would say…”) is total BS. Either the device doesn’t work or one must postulate new physics. There is no third way, and this is a mathematical fact which is independent of any experimental results. The relevant calculations can be found for example in .
    His argument sounds similar to the classical perpetuum mobile claims: if one makes this push that and so on, the wheel will rotate forever… The only difference is that it’s electromagnetic rather than mechanical device and that the conceptual focus is on momentum rather than energy. But a free momentum-producing device would also be a free energy producing device: for example accelerate it to 0.5c and ram against a planet. In relativity theory, energy and momentum together form a 4-vector so that it depends on the observer’s state of motion whether something looks more like momentum or energy.

  • NCY

    Have you seen Ethan Siegel’s new article on Forbes though? The one about is theory that the Emdrive=dark matter interactions?

    • sam
      • NCY

        Indeed. It is interesting that Siegel has done an about face when it comes to the device, now he is looking for ways that it can work without breaking conservation (his dark matter theory is actually rather interesting). He strikes me as the sort of fellow that resolutely believes in the scientific consensus, and as soon as some peer reviewed work came out that actually indicated pretty clearly that the thing probably does actually work he accepted it and moved on to trying to explain it (this raises my respect for him considerably).

  • Billy Jackson

    My only problem with the article is the implication that we know everything their is to know about physics. That arrogance astounds me.

    • Warthog

      LOL…true, but nothing new.

  • radvar

    Once again, a complete failure to even ADDRESS Shawyer’s statements that the thrust occurs because the constancy of the speed of light creates a reference frame that extends outside of the reaction chamber.

    Is there some kind of worldwide total failure of ability to think outside of the Newtonian/Cartesian box?

    Yes, special relativity is unsettling. But ignoring it is exactly like looking under the streetlight when the wallet was dropped back in that space-time-warped alley.

  • Zephir
  • sam
  • Albert D. Kallal

    The information on the EM drive is rather sketchy right now.

    NASA also noticed that thrust was lingering even after the power was off. The same was noticed by the German engineers. This suggests that thermal energy is producing that thrust. (why the thrust continues after power is cut?)

    Experimenters also noticed that thrust is generated slowly, not instant when the power is turned on.

    These issues are VERY bad – and this suggests something rather simple is going on here. Measurement of thrust should be instant when power is tuned on – not “after” a while when the device get VERY hot. Why does the device have to “warm up” and get hot?

    There is nothing at this point in time suggest that some momentum violating the basic laws of physics is occurring here?

    As I stated here previously, an EM drive based on heat is zero surprise. And heat = electromagnetic energy.

    Also they placed the device on a VERY sensitive “scale” and thus even some thermal expansion of the device could “offset” the balance of the device.

    We are talking VERY small forces here – the thrust is equal to that of a grain of sand. So any thermal expansion or change in the center of balance point of the device would cause such a force. And then there is the issue of electro-static forces that would act against the walls of the chamber housing the whole test device.

    And again same goes for forces against the earth’s magnetic field. Or magnetic forces against the walls of the housing that holds the device.

    There is perhaps some force being generated here, but what that force is acting against remains to be seen.

    And why have testers noted the device while hot with the power cut off still produces thrust? And it’s not clear why some time has to pass for the thrust to increase – it should be instant when power is turned on.

    I all ears and hope they found something new and interesting here – but so far my skeptic meter is VERY high.

    This so far sounds like a funding scam.

    Albert D. Kallal
    Edmonton, Alberta Canada

  • sam
    • sam

      Comment from Lenr forum

      User Avatar
      Is China stealing a march on the West in space?
      13 minutes ago
      Hi all

      Is China stealing a march on the West in space?

      If China can move its space craft around without reaction mass it will gain a significant increase in capability and will be able to use smaller less detectable platforms.

      If China’s capabilities with LENR are at the same level, ie they have been working on em drives since 2008 and are already testing in orbit while the west dithers, that would explain the swagger we see in Chinese foreign relations.

      If their LENR research is as far in advance of Western LENR research as their EM drive is then we may have a problem.

      Kind Regards walker

  • sam

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