Dear Tom,
Why is lightning zigzagged instead of being straight?
—Millie Lichter
Dear Millie,
It is a vexing question and lightning experts cannot give a definitive answer. Lightning comes to the ground in “steps” approximately 50 yards in length. A precise explanation for this is not known, but it seems to be the result of the composition of the Earth’s atmosphere. As a cloud-to- ground flash comes down, it usually reaches toward the ground within 18 degrees of the vertical. Its lower tip branches out, unsuccessfully spreading in different directions without reaching the ground. The best path— the path that ultimately reaches the ground—is probably connecting to slightly more favorable pockets of electric charges attached to water and ice particles in the air.