Photons travel slower than neutrinos by 25 ppm!
I find it interesting that photons travel about 25 ppm slower in a vacuum than neutrinos do through hard rock! It comes as no surprise to me that something that cuts through matter like a hot knife through butter should outrun a wimpy photon that is buffeted around by weak electric fields. Why the big surprise? What surprises me is that the speed difference is so small. I would guess that what is really in error is the speed of light in a true field free vacuum. I would bet that photons travel at the same velocity as neutrinos. What is in error is our assumption that we actually have a pure vacuum measurement of the speed of light.

