The Speed of Light in Glass

How does light speed up after leaving glass or water? What do light and the President of the United States have in common? Tweet it - http://bit.ly/pK7A3A Facebook it - http://on.fb.me/q7BQbz minutephysics is now on Google+ - http://bit.ly/qzEwc6 And facebook - http://facebook.com/minutephysics Minute Physics provides an energetic and entertaining view of old and new problems in physics -- all in a minute! Music by Nathaniel Schroeder youtube: http://bit.ly/pakJLE myspace: http://mysp.ac/qtmZQj and from http://musopen.org Created by Henry Reich