A couple afterthoughts on the speed of light: The interaction of the electric field of the light with the matter (glass or whatever) can be (for nonobvious reasons) well modeled by the electric field exerting a force on an outer electron in an atom as though the electron were bound to the atom by a spring-like force, with damping. The details of the spring stiffness and damping depend on the material and on the frequency of the electric field. In some materials this works out in such a way that in the downstream electric field (the sum of the field contributed by the accelerated source charges and the re-radiation by the accelerated electrons in the material) the peaks can actually be earlier than in the absence of the intervening material, in which case it looks as though the speed of transmission is actually faster than 3e8 m/s. But it is of course still the case that the first detection downstream occurs at 3e8 m/s.
As to whether the (apparent) speed of propagation of neutrinos would differ in different materials, I think not. The change in phase speed for light is due to the rather strong interaction of light with matter, leading to re-radiation. Neutrinos have an amazingly small probability of interacting with matter, which is why one can detect them after they've traveled hundreds of kilometers through solid rock. So I wouldn't expect matter to have any effect on the speed of neutrinos. Bruce ============================================================ FRIAM Applied Complexity Group listserv Meets Fridays 9a-11:30 at cafe at St. John's College lectures, archives, unsubscribe, maps at http://www.friam.org
