A Possible Explanation for the EM Drive’s Newtonian Paradox

An Explanation?

An Explanation?

Its not warp drives or jump gates, but a form of in-space propulsion many regard as just as improbable, the EM Drive, is managing to remain in the news. Billed as possibly reducing travel times to Mars in half, the EM Drive holds the potential to change how we view access to the rest of the solar system. If only it is real.

In short, the EM Drive uses electromagnetic waves, introduced into a sealed, specially shaped metal cavity to generate thrust. Although seemingly impossible due to the clear violation of Newton’s Third Law which demands for every action there be an equal and opposite reaction, a new, peer reviewed paper published in AIP Advances, argues that the apparent violation of Newton’s Third Law, is just that, only apparent.


“Recent reports about propulsion without reaction mass have been met on one hand with enthusiasm and on the other hand with some doubts. Namely, closed metal cavities, when fueled with microwaves, have delivered thrust that could eventually maintain satellites on orbits using solar power. However, the measured thrust appears to be without any apparent exhaust. Thus the Law of Action-Reaction seems to have been violated. We consider the possibility that the exhaust is in a form that has so far escaped both experimental detection and theoretical attention. In the thruster’s cavity microwaves interfere with each other and invariably some photons will also end up co-propagating with opposite phases. At the destructive interference electromagnetic fields cancel. However, the photons themselves do not vanish for nothing but continue in propagation. These photon pairs without net electromagnetic field do not reflect back from the metal walls but escape from the resonator. By this action momentum is lost from the cavity which, according to the conservation of momentum, gives rise to an equal and opposite reaction. We examine theoretical corollaries and practical concerns that follow from the paired-photon conclusion.”

With various versions of the EM Drive having been demonstrated, including by NASA, albeit with rather enigmatic results, the introduction of a plausible explanation for its seeming paradox might open the door a bit wider for further study without the background soundtrack of giggles and guffaws, accompanied by the wet blanket suffocation of professional scorn.

A long shot, sure, but we are regularly asked to asked to believe far less plausible things.

Posted in: Advanced propulsion

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2 Comments on "A Possible Explanation for the EM Drive’s Newtonian Paradox"

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  1. Keith Pickering says:

    This explanation for emdrive thrust is extremely unlikely to be true, for two reasons.

    First, the thrust reported from these devices is hundreds to thousands of times greater than a photon rocket. Thus even if all the input energy were reduced to photons and expelled, that thrust would not be as great as the thrust observed.

    And second, there is no a priori reason to expect the putative photon pairs to exit the device in any preferred direction.

    A better explanation is provided by quantized inertia, Mike McCulloch’s theory that also does away with Dark Matter and Dark Energy in the universe. An elegant exposition of quantized inertia in a thermodynamic framework has recently been published by Giné & McCulloch in Modern Physics Letters A:


    … and predictions of emdrive thrust from quantized inertia theory, which match reasonably well with observations, can be found here:


  2. tyy says:

    Best explanation is provided by sloppy measurements.

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