1. The problem statement, all variables and given/known data For an event occurring at (x,t), consider the quantity I = x^2 - (ct)^2 Find a simple expression for this in the S' frame: I' = x'^2 - (ct')^2 How are I and I' related, and why is this noteworthy? 3. The attempt at a solution So the question is under "Lorentz Transformation" and I must simplify I' = x'^2 - (ct')^2. I am not sure if this is the way to go about it, but should I find the equation in the form of "c =" ?