# Infinite Coulomb force when charges contact

The Coulomb force between charged particles is inversely proportional to the square of the distance. Yet, why don't we observe the infinite force when the distance approaches zero? Say we can bring two positively charged glass rods and make them touch each other. We don't observe a very large amount of repelling force.

Consider two spherical planets with mass $$M$$ and $$m$$, with radius $$R$$ and $$r$$, respectively. The attractive force between them is $$\frac{GMm}{d^2}$$, where $$d$$ is the distance between their centers.
Now suppose the planets touch. What is the force? $$\frac{GMm}{(r + R)^2}$$, because $$d = r+R$$ when they touch. Is it infinite? No.