A lightning rod or lightning conductor is a metal rod mounted on a structure with the intended purpose to protect the structure from a lightning strike and thus avoid damage. In 1749, Benjamin Franklin invented the lightening rod. They were also calles a ‘Lightning Attractor’ or even a ‘Franklin Rod‘. This invention was a result of investigations of electricity. At that time his observations proved that a sharp iron needle can conduct electricity away from a charged metal sphere.
The purpose of lightning rods is often quite misunderstood. There is a popular believe that lightning rods “attract” lightning which is not really the case at all. It is better explained by saying that lightning rods provide a low-resistance path to a ground that can be used to conduct the very powerful electrical currents caused when lightning strikes.
What does a lightning rod look like? In most cases the are quite seamlessly integrated with their surroundings, unless you are looking for the lightning rods you can’t really notice them. Lightning rods are just a few cm tall and in diameter. Placed on a roof that is quite high up from the ground, the rods are barely visible from ground.
At the least, the spike current may damage the lightning conductor and can then find another conductive path, such as building wires or plumbing, and cause fires or other disasters. Grounding systems without low resistivity to the earth can still be quite effective in protecting a building or structure from lightning damage.
Lightning rods intercepts this voltage caused by a lightning strike, providing a safer path for lightning current to the earth. They do not necessarily decrease the likelihood your building to be struck by lightning, but rather provide a direct path to earth, preventing damage to your home from fire, explosion and electrical surges that can be as a result of a lightning strikes.
Contrary to a popular held belief, a lightning rod does not serve to prevent a lightning strike. The presence of the rod on the building can only serve to divert the charge in the bolt to the ground through a low resistance pathway and thus protect the building from the damage which would otherwise result.