And just to add a little more-- Laser beams at short distances don't fall off inverse square and may even increase in intensity (decrease in spot size) with di

And just to add a little more-- Laser beams at short distances don't fall off inverse square and may even increase in intensity (decrease in spot size) with distance. But in the end, beam dispersion/the diffraction limit wins and the power density is inverse square. (I can focus a big light down to a smaller spot; but ultimately the light is going to be spreading out. This can be true for radio, too, with weird things happening close).