In ancient times people believed that when God became angry they threw lightning bolts from the heaven. It was not until the 1700s that scientists offered an explanation for lightning. Lightning is electrically released from the earth’s atmosphere during thunderstorms.
How Lightning Develops?
Water droplets and ice particles inside a cloud carry electrical charges. Some of these charges are positive and the others are negative. Lightning occurs usually when too many negative charges built up in the cloud. To balance these negative charges, positive charges form under the cloud on the ground. As opposite charges attract each other, the negative charges in the cloud are attracted to the positive charges on the ground.
It is difficult for the charges to unite because charges do not move easily through the air. As the cloud grows, however, so does the strength of the charges. Eventually the charges overpower the air and the cloud releases a strong, negatively charged electrical current. As the negative current heads towards the ground, a positively charged current appears from the ground to meet it. When the currents join, a bright flash is created that heads back up towards the cloud. This is called lightning flash. This process repeats until all the negative charges in the cloud have been used.
In addition to the cloud-to-ground lighting that most people are familiar with, lightning can occur within a cloud, between clouds, or between a cloud and the air. Similar building up and releasing of electrical charges produces all the different types of lightning.
The loud boom that follows lightning is called thunder. The electricity from the lightning heats the gases in the air. As the gases expand violently, they make loud noise.
Effects of lightning
Lightning can damage builds, ships and airplanes when it strikes. It can also kill or seriously injure a person. People are safer inside a building or a car during a thunderstorm. They should stay away from electrical appliances, doors and windows. People who are outside during a thunderstorm should stay away from trees.
Lightning can also be useful. The heat from lightning joins the nitrogen and oxygen in the air to form nitrates and other compounds. These nutrients fall to the earth when it rains. The earth’s soil requires these nutrients to grow plants.