2. Twenty-six hundred years ago, a Greek named Thales noticed something peculiar about the yellow beads many people wore. He noticed that when someone rubbed the beads with a piece of cloth, nearby bits of straw would jump to the beads and cling to them for a while before dropping off. (Later we’ll tell you how to make this happen.) Unit 4 Static Electricity

3. The beads were made of hardened yellow pine sap that the Greeks called elektron. Today we call the material “amber.” Why, wondered Thales, did elektron attract straw when it was rubbed? No one could give the answer.

4. Many centuries later, around the year 1600, an English scientist named William Gilbert found that many pairs of substances behave like amber and cloth when rubbed together. This effect, which Gilbert called “electric,” is known today as static electricity.

5. You may have observed static electricity if you have ever tried to separate clothes when they come out of a hot dryer. The clothes cling together and crackle when peeled apart.

6. You can see static electricity another way. The next time you are combing your hair in front of the bathroom mirror, try this: run a tiny stream of water from the faucet; comb your hair (which must be dry) several times; then bring the comb near the water. You should see the stream of water bend.

7. Or, if you have a comb handy right now, you can try another experiment. Place a small pile of paper bits on a table, then run the comb through your hair ten times really fast. Bring the comb near the pieces of paper and watch them fly up and stick to the comb.

8. Here is another experiment you can do with static electricity. To begin with, you will need a long piece of string and two blown-up balloons. Attach each end of the string to a balloon.

9. “Electrify” the balloons by rubbing them with a clean, dry cloth or on your clothes, and pick up the string in the middle. What happens to the balloons? Now place a piece of paper in between the balloons and see what happens. What happens when you pull the paper out?

10. Explanation: The “electrified” balloons both have a negative charge, which is what forces them apart. When a piece of paper is put between them, the electric fields around the balloons give the paper a positive charge, which attracts the balloons. Removing the paper takes away the positive charge, so the balloons move apart again.

11. As many scientists have said, science is everywhere around us — even in those things that we don’t pay much attention to, such as combing your hair or taking off your sweater. William Blake, a British poet, once invited his readers “to see a world in a grain of sand.” To better understand the world around us, we should open our eyes to the things that don’t usually receive much attention from us.