This model permits manipulation of variables in order to observe the effects of time dilation on twin objects, one moving and one not, as shown in a spacetime diagram.

College-level electrical physics course highlighting Einstein's Special Theory of Relativity. Course introduces the physics of Lorentz contraction, time dilation, the "twin paradox", and E=mc2. Course features suggested readings,...

This site from the Georgia State University provides an interesting chart form of the ideas of relativity. Column 1 - Idea, Column 2 - Experiment. Each item is linked to its own page of explanation, which is well done. A nice type of...

This site, in German, offers numerous apps that illustrate common physics principles. Apps are organized into categories: mechanics, oscillations and waves, electrodynamics, optics, thermodynamics, the theory of relativity, physics of...

This page provides an incredibly detailed description of Albert Einstein's Special Theory of Relativity. Definitely an excellent website with great pictures and examples!