Lightning is an electrical discharge in the atmosphere. It usually occurs during thunderstorms, but can also occur during volcanic eruptions and dust storms. This article will discuss a few of the myths and facts about lightning.
“Lightning always strikes the tallest object.” Lightning does not always strike the tallest object. Lightning strikes occur in paths of ionized air that are formed by the electrical fields in the storm. Because of the way they are formed, these paths will not always touch the tallest objects.
“You are safe from lightning in a car because of the rubber in the tires.” You actually are safe in a car, but not because of the tires. The metal of the car allows the lighting to move over the surface and reach the ground. The safest place to be is as close to the center of the car as possible, away from all metal objects.
“A lightning rod will attract lightning.” A lightning rod only provides a low-resistance path to the ground in order to prevent damage to buildings. The lightning might not strike the lightning rod for the same reason it will not always strike the tallest object, but if the lightning strikes near the rod, it offers a path of lower resistance that the lightning can “jump” to in order to reach the ground.
“Victims of lightning strikes are electrified.” Victims of lightning strikes are not electrified because the human body does not store electricity.
The heat from the electric current in a lightning bolt causes the flash we see. The temperature of a lightning bolt (around 30,000 degrees Celsius) is hotter than the surface of the sun.
The heat of a lightning bolt also causes thunder. When the air heats up, it expands rapidly, creating a shockwave that we hear as thunder.
The Cassini spacecraft orbiting Saturn has detected lightning in that planet’s atmosphere. It originally detected only the radio emissions caused by lightning, but later was able to detect the flashes of light themselves.
Lightning produces nitrogen oxide because it ionizes the air and helps dissolve it into water. Once there, it is absorbed by the roots of plants, which need nitrogen in order to grow.
Most lightning is negative lightning, which is the transfer of a negative charge. However, lightning strikes can also transfer a positive charge; this kind is called positive lightning. Positive lightning accounts for less than five percent of all lightning strikes, but is still as dangerous as negative lightning. It originates near the top of a thunderstorm, and is thought to be responsible for a large amount of forest fires.
This collection of facts and myths has only covered a few of them. The sources below contain more information about each of these, as well as information about things not presented in this article.
How Lightning Works
Lightning Facts and Myths
Flash: NASA’s Cassini Spacecraft Sees Lightning On Saturn
Lightning Frequently Asked Questions
The Positive and Negative Side of Lightning
Lightning Safety Myths and Truths