Electrostatic Lightning Rod

By Jenny Pao

A Little Bit About Lightning

Lightning happens when the air is warm, where humid air masses mix with cooler air masses. (June, July, August) Lightning usually targets an object that is the highest in the area. This is why people tell you to not stand under a tree, tall building, or in an open space. Lightning has a very large electric current, which can cause severe damage to any unprotected building, tree, person, or anything else.

Discovery of the Lightning Rod

Benjamin Franklin decided that lightning was discharge from the electricity in the clouds. With his son, they did an experiment in 1752. Through this experiment, he discovered lightning, and followed up his discovery by inventing the lightning rod to protect buildings from lightning bolts.

How It Works

Lightning rods provide a low resistance path to the ground so the big amounts of electrical current can be conducted into the ground. It is a metal sphere or point that is put on the highest point of a building that connects to the ground. A thick, insulated copper wire attaches the lightning rod to a plate of metal or metal cable in the ground. If lightning does strike, it will be attracted to the rod, and be conducted safely to the ground, and cause no harm to the building. Lucky, lightning rods are good conductors, if something that wasn’t a good conductor got hit by lightning, it would have massive heat damage.
Lightning Rods Part 1

How Is Electrostatics Used?

When lightning strikes a solid object, the current creates an enormous amount of heat, resulting in fires, high discharge of static electricity. This is like the spark you get when you touch your finger to the doorknob. It's the electrons going out of your body into the doorknob. The lightning rod is positively charged by induction, and the clouds are negative. The cloud is experiencing induce charge separation, the electrons in the cloud are attracted to the protons in the lightning rod. The charges between the cloud and the lightning rod neutralize each other, lessening the chances of lightning to strike. The cable attached to the lightning rod is insulated, but below the ground it is not, allowing the charge to be conducted into it.

Lightning Diversion Theory: Lightning rod protects building by providing a conductive pathway for the lightning towards the ground


Lightning Dissipation Theory: Lightning Rod protects building by preventing lightning. This is based on the the fact that the pointed objects surroundings has a greater electric strength. They ionize the surrounding air, enhancing its conductivity.

https://www.youtube.com/watch?v=yW1Dj_F8-UM

Why Is It Important?

Lightning is a very interesting thing, but can be very dangerous. Many forest fires, and destruction of buildings and other disastrous things are caused by lightning. Benjamin Franklin's discovery of lightning rod gives us protection from lightning. Lightning rods have two purposes; to reduce the chances of lightning to hit, if it does, to safely divert it to the ground. This protects many buildings from massive heat damage. You probably have a lightning rod on your own house, or in your work office, and are found on the tops of many buildings. There are many uses of electrostatics out there, things that you use in everyday life and may not know of, or take for granted.

Citations

Prints:

Zavisa, John. "Lightning Rods." howstuffworks. Discovery. Web. 9 Feb 2013. <http://science.howstuffworks.com/nature/natural-disasters/lightning7.htm>.

Henderson, Tom. "Static Electricity - Lesson 4." the Physics Classroom. comPADRE , n.d. Web. 11 Feb 2013. <http://www.physicsclassroom.com/class/estatics/u8l4e.cfm>.

. "Static Electricity and Lightning." Science NetLinks. AAAS. Web. 12 Feb 2013. <http://sciencenetlinks.com/lessons/static-electricity-4/>.


Databases:
"Franklin, Benjamin." Compton's by Britannica, v 6.0. 2009. eLibrary. Web. 12 Feb. 2013.

Textbook:
Blake, Leesa . "10.3 Charges at Work." Trans. Array How Does a Lightning Rod Work?. Mc Graw-Hill Ryerson. 9th ed. Canada: Diane Wyman, Print.