By Coulomb's law, say if we have 2 point particles each having a charge of +1C then by the formula, $$F = k/d^2$$
if we need to make the distance $d$ between them zero, clearly the formula, we need to have an infinite amount of force.
However, in a real life scenario, we see that if we rub two balloons with our head, they acquire the same charge. However, it is still possible to make them touch.
Is this because the two balloons are not point objects? OR is the definition $d=0$ actually mean "to occupy the same space".
for $d$ to be 0, do the objects only need to touch or do their centers need to be together?