Adhesion and Gravity Science Experiment

Spoons Revisited

On Thanksgiving, while the adults were sitting and talking, I spent the afternoon doing science tricks with the kids. We took over the kitchen and had a blast with a few sheets of paper, some string, some coins, and anything else we could find. One of the biggest hits was spoon hanging, an experiment that I wrote about several years ago. At the time, I did not know why it works. I have had quite a bit of time to think about it, and I think that I have a better grasp of what is going on.

To try this, you will need:

• a metal spoon
• your nose
• a coin

Hold the spoon in your hand, with the bowl up and the handle down. Place the bowl of the spoon onto the end of your nose, letting the handle rest against your chin. Press it firmly against your nose and then gently release it. The spoon should stick, hanging from your nose. It may take a little practice, but if you are patient, you will get the hang of it.

How does it do that? In researching, I found several answers, from "I don't know" to thoughts that the pores on your nose act like tiny suction cups. After playing for a while, the main factor seems to be something called adhesion. When two different substances stick to each other, we call it adhesion, as in adhesive tape. The metal of the spoon is sticking to your skin. Really? You can see it in action by pressing a small coin firmly against your forehead. When you release it, it will stick.

Adhesion by itself it not enough to stick a heavy spoon to your nose. It is also helped by the shape of the spoon. Your nose fits into the curve of the bowl. Gravity is pulling the spoon downward, pressing it against your nose. That adds to the adhesion. The heavier the spoon, the more it presses against your nose. That means more adhesion to help keep the spoon from sliding down your nose and falling off.

The handle of the spoon is important too. When you hang the spoon from your nose, you will feel the handle pressing against your chin. This gives more metal skin contact for adhesion, to keep the spoon from slipping. My beard keeps the handle from touching my skin, making this experiment more difficult for me. It still keeps the spoon in a position where the curve of the bowl presses down on your nose. Without the handle, the bottom of the spoon would tilt inwards, pulling the top of the spoon away from your nose.

Adhesion, gravity, and the shape of the spoon work together to hold it on your nose. If you actually tried the experiment instead of just reading it, you deserve a bowl of ice cream. Just be sure you get a clean spoon first.

Have a wonder filled week.

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