Many people think that it is the rubber tires that protect them when their car is struck by lightning. In reality, their car is becoming a Faraday cage. What is that and how does it work?
Michael Faraday was a British scientist born in 1791. Although not formally educated, he had a strong interest in electromagnetism. He also credited with discovering Benzene and popularizing terms such as anode, cathode and electrode. As an apprentice for a bookbinder, he read many books which encouraged his interest in science. He soon became a well known experimental scientist leading to his name becoming a unit of electrical charge. He is also known for inventing the Faraday rotator and Faraday cage.
A Faraday cage is a conductive metal container that blocks electric fields. When electricity is applied to the cage, it distributes the charge and therefore protects anything inside. There are many applications that have benefited from this observation. For instance, a microwave is a type of Faraday cage. It, however, traps the waves inside to cook your food and protect those outside of it. If you have ever had an MRI done, then you have been inside a Faraday cage, also known as an RF Shield. In this case, the room is shielded so that outside radio frequencies don’t interfere with the images being taken and so that the ones being produced don’t interfere with outside machinery.
Another type of a Faraday cage is an airplane. Planes get struck by lightning more often than you think. When they are hit, the lightning spreads over the aluminum hull and protects the passengers inside.
Your car also essentially becomes a Faraday cage. The electrical charge will travel over the metal of your vehicle and protect you inside. Just make sure you have the windows closed or you will leave an opening for that charge to enter! You also don’t want to be touching any metal connected to the outside of the car while inside. If you check out the graphic below, you will notice how the current exits to the ground through the tires. So, the rubber tires on your car do not protect you from lightning, they simply ground your vehicle so that the electricity has a place to exit.