Fun & Science

By Edith Hope Fine

On a windy day, the moving air can push hard enough to bend a tree. And air has “push” even when it’s not moving.

Try this activity to experience the pressure of the air around you. You need a flat piece of paper (typewriting paper works well), a thin rubber band, and tape.

Tape one side of the rubber band to the center of the paper. Lay the paper on a smooth, clean surface, such as a table. Then hold the loose end of the rubber band and pull up with a quick, firm tug.

At first, when you pull up, you have to stretch the rubber band to get the paper moving. Once the paper is pulled away from the table, it doesn’t take much pull to lift it farther.

How It Works

Air is always pressing in on us and on everything around us.

If the paper is flat against the table, there is no air underneath it, and the air presses only one way—downward.

When you pull up on the rubber band, the paper seems to stick at first because you are pulling against this downward push of air. Once the paper bends, a little air goes underneath it, making the air pressure the same on both sides of the paper. Then you can lift it easily.