You can understand Einstein's
Theory of Special Relativity

{ within 5 minutes ! }

iou – I began writing this page recently, and so far it has no content, but...
the ideas are developed elsewhere, and soon there will be links to those places.
But now you can understand why we should call it Einstein's Theory of Constancy.

a clarification:  In 5 minutes you can understand WHY time must be relative,
if two other things (speed of light, laws of physics) are not-relative, i.e. are invariant,
although you won't understand everything about Special Relativity, and certainly not
the General Relativity that is much more complex and more difficult to understand.