Lightning occurs when the attraction between the negative charges at the bottom of the cloud and the positive charges on the ground is strong enough. The lightning we see is actually the return stroke; when the positive charges move up to the cloud.
From Benjamin Franklin’s dangerous experiment involving lightning, a kite and a metal key (and this man was a genius?), we know that lightning is a form of electricity. In fact, it’s a giant electrical spark. The spark is caused by the ice and water in a cloud, rubbing together and causing static electricity.
Lightning is dangerous because it strikes objects—including people—directly. It can start fires or kill someone. Believe me, you’ll either be dead or not feeling too hot (sorry) after getting whacked by lightning—each spark can reach more than eight kilometers, hit temperatures of 28,000 degrees Celsius, and contain 100 million electrical volts. Pretty dangerous stuff!
Lightning kills more people than hurricanes or tornadoes. It’s unpredictable and does strange things—it can even destroy a tree. Lightning can heat up the sap in the tree’s trunk. The sap becomes steam, which expands and, wham! Kablooey! The tree blows apart.
Lightning does strike twice, and sometimes more. Park ranger Roy Sullivan holds the record for surviving lightning strikes. Between 1942 and his death in 1983, he was struck seven times. The first lightning strike shot through Sullivan’s leg and knocked off his big toenail. That’s gotta hurt.