Quote by nitsuj
Maybe I need to ask it differently,
Why does c have to be squared (why are the terms squared in the first place)?
I'm pretty sure I've heard it has to do with the units (physical units I assume). Im just trying to piece that together.

Nope, it's just the pythagorean theorem. The distance between any two events in a twodimensional world is √(x
^{2} + y
^{2}). In a three dimensional world with an "imaginary" time dimension being measured in seconds, it's √(x
^{2} + y
^{2} + z
^{2}  (ct)
^{2})