A simple explanation why light slows down in glass
Everyone has heard the claim that light always move at light-speed in vacuum relative to a reference point.
However everyone also heard that light slows down in the atmosphere or glass.
So how is that possible without violating the laws of physics?
http://www.youtube.com/watch?v=FAivtXJOsiI&noredirect=1
Something related explains why glass is transparent
http://www.youtube.com/watch?v=Omr0JNyDBI0
I hope people get more interested in real science. :-)