Nature published a paper where people claim to measure superluminal speed for photon propagation.
https://www.nature.com/articles/s41467-019-08735-8.pdf
That looks pretty much like what I discussed with other people. Since Holmids last paper I did suspect that the photon wave trajectory in spin matter is a trajectory on a halve way scissored SO(4) surface. This explains the extra circle the photon may take and these guys do interpret it as super luminal speed - what of course is halve way wrong. What they see is a second (4D) phase dimension - nothing more.
SO(4) is the correct mathematical space to describe dense matter. (see alsohttps://www.researchgate.net/p…r-and-particle-physics-20)
If you correct the measured speed of light 1.34c (given in paper at measurement axis 53 degrees)) with the ratio of sin(53)/sin( 45) then you get 1.51c this is exactly the ratio (to be measured in 3D,t space) we expect, if the wave occupies 3 out of 5 possible spin dimensions of SO( 4).
The 3 waves (2 phases) structure should be the maximum in free space as the scissoring cuts two axes of the Clifford torus homomorphous SO(4) charge carrying surface.
Key for LENR is that matter can go into a SO(4) spin (1FC - weak spin force) conform intermediate state (H(0) -Holmlid) that does/"is able" to directly interfere with a photon wave (e.g. laser wave packet).
The SO(4) spin photon trajectory has been predicted, but I didn't expect to get this answer from an experiment that quick. The experiment has ben done with skyrmions that represent spin matter.