Yes that is an explanation of a variation of my paradox:if you remove everything from the plane except for some "small piece". However I asked what happens when that small piece is just a single point, hence coloumb's law applies everywhere in that case (and that paradox has a different solution...
Well in both cases the repulsion force is vertically upwards. (can be justified by symmetry in the initial case). Since all the points are below the ball, the vertical component of the repulsion force contributed by each individual point is upwards. Less such points means less force.
Ok so yeah the explanations of the previous posters is pretty much what I wrote in my initial post.
As for the word "indeed", a good way to use it that I like is: "[Insert statement of Theorem here]. Indeed [Insert proof here]". Indeed it is good :P
Ok for the record I havn't studied physics in a year, I'm a math student. But I was reminded of a paradox I came up with once in physics:
Suppose we place a positively charged ball above an infinite plane with positive charge. We know by Gauss law that the electric force on the ball ends up...