Lightening Conductor

Lightning

Lightning is caused by friction between ice crystals in clouds.  Charges are induced when the ice crystals move through the cloud. 

A negative charge forms at the base of the cloud where the ice crystals collects, while the lighter ice crystals remain near the top of the cloud and create a positive charge.

The negative charge is attracted to the Earth's surface and other clouds and objects. When the attraction becomes too strong, the positive and negative charges discharge, to balance the difference in a flash of lightning.  The rapid expansion and heating of air caused by lightning produces the accompanying loud clap of thunder.

Thunderstorms are common occurrences on Earth. It is estimated that a lightning strike hits somewhere on the Earth's surface approximately 44 times every second, a total of nearly 1.4 billion lightning strikes every year.

Lightening conductors

A lightning rod or conductor is a very simple device. It is a pointed metal rod attached to the roof of a building. The rod is usually quite thin but must be taller than the building it is protecting. It connects to a huge piece of copper or aluminum wire. The wire is connected to a conductive grid buried in the ground nearby.

The purpose of lightning rods is to provide a low-resistance path to ground that can be used to conduct the enormous electrical currents when lightning strikes occur. If lightning strikes, the rod will carry the harmful electrical current away from the structure and safely to ground. 

The lightning-rod system is an excellent conductor and thus allows the current to flow to ground without causing any heat damage.

Lightning can "jump around" when it strikes. When lightning strikes it will seek a path of least resistance by jumping around to nearby objects that provide the easiest path to ground. If the strike occurs near the lightning rod, the rod can divert the strike current to ground because it has a low-resistance path it. 

The purpose of the lightning rod is not to attract lightning, it provides a safe option for the lightning strike to choose.