This page concludes your light tour. On the previous 34 pages you learned the basic but
the most important properties of light. We have sorted our information into three categories. Below are the key
points from this light tour
 Light from the classical point of view
 Maxwell was The Man. He unified electromagnetic phenomena with his equations
 Light is an electromagnetic wave
 We describe EM waves by their frequencies
 Visible light is just a tiny fraction of the whole EM spectrum
 Speed of light depends on the medium the light propagates in.
 In matter particles can travel faster then the speed of light
 Light and the theory of relativity
 Einstein was The Man. He wrote the theory of relativity
 In a vacuum, light propagates with the highest possible speed in the universe
 In the theory of relativity, two speeds do not simply add up; therefore it is not true that 1+1 is 2!
 Any moving object gains mass
 Any moving object ages more slowly than a stationary one
 It is possible that a red light was emitted but a green light was received
 Simultaneity of events depends on the frame of reference
 Any moving object is contracted in the forward direction
 If you found an object moving at a speed greater than 299,792,458 m/s check your instruments, something is wrong
 Light in the quantum world
 Planck was The Man. He solved the blackbody radiation problem
 Light consists of a bunch of particles called photons
 Our world is dual; everything behaves as both a particle and a wave.
 We have plenty of photons at Fermilab :))
Please send us your comments for future improvements.
The author of these pages of light Arnold Pompos thanks Sharon Butler for her great help.
