On Friday, May 22, 2015 at 10:17:14 AM UTC-4, Scott Lurndal wrote:
Visible light decreases with the square
"inverse square law". Wonder why magnetism
would be different?


Because it doesn't.

Visible light does not decrease with the inverse square rule.

Visible light from a point source decreases with the inverse square rule.

Visible light from a line source like a fluorescent tube decreases with a simple inverse, no square involved, rule. Until you get far enough away that a line source appears to be a point.

Visible light from a plane source doesn't decrease at all, until you get far enough away that it appears to be a point.