I'm not quite following. The light in each "shell" continues to dissipate in an inversely quadratic method from the shells distance from earth, no? It would help if I had this drawn out.
No, the total light in each spherical "shell" is the same as every other shell.
Stars that are 20 light-years away are 4x dimmer than stars 10 light-years away. But there are 4x more stars 20 light-years away than 10 light-years away. As you go outward from Earth, the stars get dimmer and more numerous, but these balance each other, and the infinite sum is 1 + 1 + 1 + ...
(This is no chance happening; regardless of the # of spatial dimensions the universe has, this relationship holds true.)
