On this episode of Cut to the Chase:, Dr. Adam Liebovich, physics professor from the University of Pittsburgh, explains what is light. The speed of light, a light year, rainbows, color and all other goodies that derive from and are effected by light. So yes-let there be light, come to the light, light as a feather and so many other references to light in the Bible and in our folklore, it's a wonder that we should all understand what is light.