My friend Professor Bill Harter, Physics Department, University of Arkansas, is a sort of experimental theorist in that he has built a number of heavy duty research grade computer simulations to better understand relativity and quantum mechanics. He is now constructing his own website to make his results accessible to folks with less powerful computers. His approach is heavily influenced by an undergraduate course he has developed in which he shows his students how to use ruler and compass, which he calls the "weapons of math instruction," to graphically represent complex (literally) and sophisticated concepts. This is an approach I greatly admire and has influenced my understanding of relativity.

A stronger influence on my own thinking, however, has been years of conversation with my close friend Lew Epstein with whom I shared an office at City College. His widely read book, Relativity Visualized¹, was first published over twenty years ago and is still in print. It is written to be accessible to the non-scientist and, while filled with drawings and diagrams, contains hardly any equations at all. Even so, this has not prevented serious physicists from gaining from his presentation. Professor Harter, who has never met Lew, read his book years ago and credits him with helping him develop his own approach.

Lew's influence can be seen in my own textbook, Introductory Physics, A Problem Solving Approach² ,particularly in my section on The Structure of Time, starting on p. 557

Many of the diagrams on this website are borrowed with permission from Lew Epstein's book, and many of the animations are animated versions of his drawings. The central story, Meet Molly, however, has evolved out of my thirty years of teaching college physics.

¹Relativity Visualized, Lewis Carroll Epstein, 1981, Insight Press, 614 Vermont Street, San Francisco, CA 94107

²Introductory Physics, A Problem Solving Approach, Jesse David Wall & Elender Wall, 1997, Analog Press, 225 Edna Street, San Francisco, CA 94112