Addendum: If L was imaginary, that means motion of the light clock, and consequently its observer, in an imaginary direction. What could that mean? Perhaps a fourth spatial dimension? Of course, you'd have to go forth and back between the fourth dimension and our third otherwise I suppose you'd be trapped forever in some higher dimensional plane and that doesn't sound pleasant. How would that work? It's quite convoluted. I'll try to draw it, beginning with a four-dimensional space-time graph (or at least my best attempt at it). The real issue with people when they try to make things 4-dimensionally is that they concern over continuity. At integer-time intervals like what I'm making, it becomes simple, I guess. The spacetime diagram gives the relevant details for 3-dimensional space plus a time dimension. For simplicity, assume that each progressing XYZ-axis to the right signifies an advance in the time dimension by one tick (or whatever they...