Jacob's Ladder
Is air an insulator or a conductor?
Switch on the electric circuit with a high voltage. Although the copper wires are disconnected, the electric charge will break through the air and in the form of an arch rise up creating an impression of the rungs of a ladder. The exhibit can therefore be figuratively called a biblical Jacob's Ladder to the Sky. Under normal circumstances air is a good insulator. But if the voltage is high enough, it may cause so-called electrical breakdown. During this process the strong magnetic field speeds up the charged ions which are then able to tear off electrons from the molecules in the air creating more ions. The process spreads like an avalanche, the air is ionised and conducts electricity.
