Part I - Space-time Geometry
Part II - Optics and Signals
All animations are referenced in the main text, where their context is fully explained.
The animations are clearest when you use them as a supplement to the main text, not when you simply view them
by themselves, out of context.
Warning: sometimes screens can subtly distort images.
For example, the author has seen small but measurable distortions in some angles, when a screen is
not using its default resolution.
Animations - Part I:
Animations - Part II:
The author is John O'Hanley.
He is a retired computer programmer, and he earned a B.Sc. in Physics from the University of Prince Edward Island (Canada).
If you have any corrections, criticisms, or questions about the site, he would be pleased to hear from you.