This is a theoretical question about completing a circuit and trying to understand what a main panel ground rod does. The question is: Could you run just one hot wire (not in a conduit, but in free air) without an accompanying neutral to the lug of the bus bar in a main panel. The neutral bar in the panel is connected to the ground bar which in turn is connected to a ground rod in the earth. That way the breaker gets electricity to feed the branch circuit and the neutral from the branch circuit is connected to the neutral bar which is connected to the ground bar and then to the ground rod. Would this complete the circuit in order for a light bulb to burn?