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Re: Bar magnets

Jack Uretsky wrote:

What makes you believe that the pole strengths of interacting
bar magnets is independent of distance?

My high school textbook, I suppose. Thanks for a good hint.
Let me follow it? As one end of the bar magnet comes closer
to another it induces "poles of the opposite kind at the surface.
It is similar to what happens in many dielectric materials. The
net pole becomes stronger at each bar magnet and the attractive
force between them changes more rapidly with the distance
than the 1/r^2 law would suggest. That is why magnets come
toward each other suddenly.

How come that Coulomb was able to determine the 1/r^2
dependence using a torsion spring balance? I suppose he
was dealing with repulsive forces only. Can a history of
science expert comment on this? Was he aware that the
dependence of F on r is more complicated? I will try
what Hugh suggested later today.
Ludwik Kowalski