In electrostatics, why is it that identical spheres that are touched for a brief moment or connected by a conducting wire (wire not gaining any charge) should have an equal charge? Why is that they come in an equilibrium of charge? For example - If we take 2 identical spheres one bearing a charge q and the other neutral. The spheres are touched for a brief moment after which they are separated. Then it is stated that they both bear a charge of q/2 because they are identical ? But why so ?