Impressive New Tricks of Light, All Within the Laws of Physics

"Instead, in the latest example of logic-defying tricks that physicists can now perform with light, Dr. Boyd and his colleagues demonstrated an optical fiber - a glass strand that transmits pulses of light - with a couple of odd characteristics:

A pulse of light shot into the fiber departs before it enters.

Within the fiber, the pulse travels backward - and faster than the speed of light."