A Amanda Gumber, research assistant, Space Science and Engineering Center at the University of Wisconsin-Madison: Thunder is formed by the intense heating produced by lightning. The thunder you hear ...

When lightning occurs, a large discharge of electricity causes the surrounding air to vibrate as it passes through the atmosphere to the surface. Q How does thunder form? — Hazel Foster, Madison, Wis.

A: Thunder is formed by the intense heating produced by lightning. The thunder you hear is made up of vibrations that travel as sound waves through the air until they reach your ear. When lightning ...