# Why is the electric field inside a conductor zero?

This is actually a tricky question that is best answered not by showing how it works but by showing how it DOESN'T work. Here's my sort of round-about approach: I'll start with a definition, then use a counter argument to show a contradiction, thus proving the definition. Got it?

Definition:

When there is no net motion of charge within a conducting sphere, the conductor is in electrostatic equilibrium.

If a conductor is in electrostatic equilibrium, the free electrons on the surface of the conductor are not accelerating away from each other.