Question: The equation for the spherical wave front of a light pulse that begins at the origin at time t=0 is (x^2)+(y^2)+(z^2)-((ct)^2)=0. Using Lorentz transformation, show that such a light pulse also has a spherical wave front in S' by showing that (x'^2)+(y'^2)+(z'^2)-((ct')^2)=0 in S'.