I love storms. My son used to be afaid of them, but he's gaining knowledge about them, and that helps. Besides, he's 13 and it's not cool to admit you're afraid of much at that age.
Thunder is the sound of rapidly heated air expanding and vibrating, and shock
waves. Light travels faster than sound, so we see the lightning
before we hear the resulting thunder. Using the speeds of light and sound as
well as the atmospheric conditions, you could calculate
exactly how far away the storm is.
Chances are you're not going to have a
calculator handy during a storm. However you can approximate the storm's
distance in miles by counting the seconds between the lightning and thunder and
dividing by five. It takes about five seconds for the sonic boom to travel one
mile, so if you see the sky illuminated by a streak of lightning and count 10
seconds until you hear the low rumble of the thunder, the storm is about two
Of course, lightning is dangerous, so
it's always a good idea to seek shelter before
you stop to count seconds. Otherwise, it might be your final countdown.