Is special relativity finished? It seems to me that there is more to special relativity. If we define C as equal to 1. (time = nanoseconds and length = feet) then we do a special relativity experiment an interval is defined. This interval is given by the square root of X squared minus T squared. The interval is the same regardless of the motion of a observer. That same result is obtained if we use the Pythagorean rule and precede the time with a “i” making time a imaginary number This fact hints that there is something more going on. Also in the physical world there are 3 spacial dimensions and one time dimension. In the mathematical world there are many dimensions that seem to be analogous to spacial dimensions but only one imaginary dimension. It seems to me that the equations of special relativity should include a “i”.