Thunder and Lightning
Thunderstorm in Germany
You can find out for yourself how far away the lightning is, and also see that light waves really do travel a lot faster than sound waves do. Go outside or look out the window during a thunderstorm. When you see a big flash of lightning, count the seconds until you hear the thunder that goes with it. That thunder happened at the same time as the lightning, but it traveled more slowly and took more time to reach you. If the thunder and lightening seem to you to happen at the same time, then the lightning is very close to you, and dangerous. If there's five seconds in between, then the lightning is a mile away from you - nothing to worry about. You see the lightning essentially right away, but the sound of the thunder travels at the speed of sound, about five miles a second.
For a second activity, to show how storms build up electric charges and then make lightning to even out the pressure, you'll need a styrofoam cup and a metal pie pan. Cut off a strip of the styrofoam and use it to make a handle on the piepan with tape. Then rub the styrofoam cup against your hair for about a minute, pretty fast. Electrons will jump from your hair to the styrofoam, so that the styrofoam has too many electrons, and your hair has too few. Your hair has a positive charge, and the styrofoam has a negative charge. Now put the styrofoam cup on the table with the rubbed side facing up. Carefully pick up the pie pan by the handle and drop it onto the styrofoam. Slowly touch your finger to the pie pan (don't touch anything else). Do you feel a shock? That's electrons moving around, evening out the negative and positive charges.
Now use your other hand to hold the styrofoam handle and ask somebody to turn out the lights. Lift up the pie pan and touch it with your finger. Do you see a spark? That's a little tiny piece of lightning - electrons, moving around, again to even out the charges.
Main page about Thunder and Lightning
More about Electricity
More about Weather
Learn by doing - Seasons
To find out more about weather, check out these books from Amazon.com or from your library:
