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.
The researchers began by asking: Is there any other phenomenon, besides that demonstrated with the EM drive, where photons, as carriers of the electromagnetic force, are ‘fed in’ but nothing seems to be ‘coming out’? Yes, when coherent rays of light interfere, a diffraction pattern emerges with bright and dark bands – and at a dark band we see nothing (Fig. 1). We see no light when two photons combine with opposite phases. Their electromagnetic fields cancel perfectly, but that does not mean that the photons themselves would have vanished for nothing
Researcher propose the EM drive expels photons in pairs where the two co-propagate with 180 degree phase difference. These composite bosons have no net electromagnetic field, and hence they do not reflect back from the resonator’s metal walls, but escape to surroundings. The paired-photon efflux carries momentum, and hence the cavity experiences an equal but opposite reaction. Thus, they claim that the thrust of an EM drive is the action due to the paired-photon efflux.
FIG. 1. Two parallel waves, shown with crests (red) and troughs (blue), propagate coherently from left to right through two slits and interfere with each other. Along those directions where the crest of one wave is exactly at the trough of the other wave, the interference is completely destructive (blank). Our reasoning is that when light waves combined with opposite phases, the photons do not vanish for nothing but continue propagating and carrying momentum
The explanation is that the EM drive expels photons in pairs where the two co-propagate with 180 degree phase difference. These composite bosons have no net electromagnetic field, and hence they do not reflect back from the resonator’s metal walls, but escape to surroundings. The paired-photon efflux carries momentum, and hence the cavity experiences an equal but opposite reaction. Thus, they claim that the thrust of an EM drive is the action due to the paired-photon efflux.
Roger Shawyer invented the Emdrive. NASA Eagleworks is testing the EMdrive and the Cannae drive and getting interesting results Shawyer presented in October, 2014.
EMDrive results have not been conclusively proven yet.
There are interesting results in the 50-900 micronewton ranges. There does seem to be scaling with increased power levels.
SOURCES – AIP Advances
Brian Wang is a Futurist Thought Leader and a popular Science blogger with 1 million readers per month. His blog Nextbigfuture.com is ranked #1 Science News Blog. It covers many disruptive technology and trends including Space, Robotics, Artificial Intelligence, Medicine, Anti-aging Biotechnology, and Nanotechnology.
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