The first site offered by What Why Web is entitled Everyday Physics: What is the Speed of Light? (1) The one page site describes the definition of the speed of light, how it changes passing through various medium, its historical significance, and what symbol is used for the speed of light in a vacuum. The next site from the NOVA online Einstein Revealed Web site is called The Light Stuff (2). Visitors can compare the time it would take to travel at the speed of light to various places, find objects in "Joe's Room" that slow down light, and try the Time Traveler Game which shows how time changes if you could travel very quickly. The third Web site, Speed of Light (3) offers a historical timeline of measuring the speed of light and various quizzes geared to students. Next, from the University of California at Riverside Department of Mathematics comes the Usenet Physics FAQ (4) Web site. Under the Relativity and Cosmology heading are several speed of light topics including: is the speed of light constant, why is it so high, is there an equivalent of the sonic boom for light, and more. The fifth site, which is maintained by the University of Colorado at Boulder is entitled Speed of Light (5), and has a unique interactive feature. Users can vary an electromagnetic wavelength, which travels at the speed of light, to calculate the distance it travels and time it takes to return to its original location. The 1728 Software Systems Web site, Relativity Calculator (6), offers a similar conversion applet which shows the changes that occur when objects approach the speed of light. After reading the theory behind it, follow the directions and play around with the calculator to see some of the surprising results. Offered by CNN.fyi.com, the Speed of Light Lesson Plan (7) site teaches students how the NEC Research Institute was able to "bend" Albert Einstein's theory of relativity. Students are asked to read the "Breaking the Speed Limit?" article (which is provided) and then discuss several questions about the piece. The last site, part of Berkeley's Center for Science Education, is called Light Tour: Discover Light's Mysteries (8). The interactive tour lets students discover basic information about light in the Universe and how astronomers make use of light wavelengths.