Edwin F. Taylor

Recommended by Brian Greene in his book Fabric of the Cosmos.

This is a 1992 textbook suitable for students/readers with an algebra background. It focuses on the main equation of invariance (aka relativity), i^2 = t^2 - x^2, which says the square of the invariant "distance" (formally known as the spacetime "interval") between events (and "events" are the basis for relativistic physics) is always equal to the *difference* between the square of the apparent time between the events and the square of the apparent space between events (with a little hand-waving regarding units and the speed of light). Always. As in, no matter what frame of reference you're in, no matter how fast it's going or not going. It's the "difference" part of that fundamental equation that leads to hyperbolas, the twin paradox and all the confusion.

There are good examples and plenty of diagrams in the book, but unfortunately the best examples seem to be left as problems to be solved (and thus I take off 1/2 a star).… (meer)