Faster Than the Speed of Light?

{revised 10/14/10}
This post has nothing really to do with creationism/evolution but is an interesting scientific tidbit I recently found.  I'm close to finishing a "podclass" (Nuclear Engineering 101, U.C. Berkeley, Fall 2009, Prof. Eric Norman; see iTunes U).   It's been a real interesting class and the professor seems quite good in his teaching abilities.

In one of the latest lectures, the professor notes how it is often heard that nothing can go faster than the speed of light.  To be specific, Einstein said that nothing can move faster than the speed of light in a vacuum (it's always important to be specific about what is said).  The mathematical notation "c" (from the Latin, celeritas, meaning speed or swiftness) is often used to denote the speed of light in a vacuum.  However, when light travels through other media, it often travels at a speeds less than "c". An example of this is when light travels through water, it only travels at approximately 0.75c, that is, 3/4 the speed of light in a vacuum (as a sidelight, you can calculate this speed by using the refractive index of the material).  

What is interesting is that, in the same medium in which light travels less than "c" (in this example of a water medium, the velocity is 0.75c), very small charged particles (e.g. electrons or muons) can travel faster than 0.75c without violating the laws of relativity.  When these particles travel faster than the speed of light, radiation/photons are emitted as something analogous to a sonic boom is produced (sort of like a photonic or electromagnetic shock wave).  This radiation is called "Cherenkov Radiation" and has the characteristic blue glow that one sometimes sees in movies when nuclear reactors are depicted (see picture; obtained from Wikimedia Commons and is in the public domain).