An Illustrated Guide to Relativity

This class is based on the book, An Illustrated Guide to Relativity,
by Tatsu Takeuchi, of Virginia Polytechnic Institute and State
University, a delightful book that uses simple space-time diagrams to
visualize and teach the basic features of special relativity. This is
done so well that the material can, in principle, be learned directly
from the figures and annotations without referring to the main text
at all.

Relevant Sections of the textbook:

Online Resources

If you will remember in 1905 Albert Einstein, based on two 
principles, the principle of relativity and the finite constant
speed of light, developed the special theory of relativity.

Wikipedia Page for Special Relativity

Twin Paradox

The Mechanical Universe - 43 - Velocity and Time
29:07 minute Video

Unlike Lorentz, Albert Einstein was motivated to perfect the central
ideas of physics rather than to explain the Michelson-Morley
experiment. The result was a wholly new understanding of the meaning
of space and time, including such matters as the transformation of
velocities, time dilation, and the twin paradox.