[Boogieman]

I think the novel part here is what they are converting to achieve the effect. They set the photons oscillating in a chamber which forces the wavelengths to change as the photon goes from one end to the other. This alters the group velocity of the photons, which changes the radiation pressure as the photons strike each end of the cavity.

So the conversion seems to be between the forward group velocity and the lateral oscillation, which is immaterial as it pertains to the desired effect of the drive. The photons don’t lose any energy before hitting the other side, they are just reconfigured so that they will impart energy less efficiently before they hit that side.

[FredZarguna]

The "novel part" of the theory, that a closed waveguide [of any shape] can produce a net momentum is almost certainly wrong.

It's pretty clear that most of the Wiki article was actually written by the inventor of the drive, who does not really address his critics, and who did not originate the theory himself [whihc may or may not be applicable to his drive.]

[InterceptPoint]

They set the photons oscillating in a chamber which forces the wavelengths to change as the photon goes from one end to the other. This alters the group velocity of the photons, which changes the radiation pressure as the photons strike each end of the cavity.
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Someone needs to explain how you change the wavelength of a photon without some non-linear mechanism. Are we really talking about somehow filtering the AVERAGE wavelength of a broadband energy source as a function of the direction of travel in the cavity?