Science Struck
Science Struck: How Does Light Travel Through Space and Other Media?
A detailed discussion of the nature of light, how it can travel through a vacuum, and how the speed of light is affected when light travels through a medium.
Symmetry Magazine
Symmetry Magazine: Explain It in 60 Seconds: Cherenkov Light
Cherenkov light is explained here as the light emitted when a charged particle travels through matter faster than light would be able to. This would be slower, however, than the maximum speed of light, which occurs in a vacuum. "Explain...
Society for Science and the Public
Science News for Students: Breaking the Universal Speed Limit
Describes research into whether neutrinos travel faster than the speed of light.