So would it be fair to say that S it is not measured as a distance but as an interval in order to account for the temporal distance between the two points as well as the spatial? and because its measured as an interval that's why there is subtraction instead of addition?
So I'm new to the forum and to relativity as well and I am confused as to how the equation for an invariant distance between two points in spacetime is derived, specifically where subtraction comes from
s^2=srqrt[((ct)^2)-x^2)]
i understand most of that but just not why its subtraction...