1. Hold a drink in your hands. Technically, hold a cup or a glass that has a beverage in it. Water and milk aren't good choices. It's better to have something like hot chocolate, coffee, or soda, as these drinks are more heterovisual, a word I made up just now whose meaning will hopefully become clear.

2. Sit in a well-oiled swiveling desk chair.

3. Spin around in it.

4. Note how the contents of your cup or glass don't spin around with you -- if there are bubbles on the top, for example, they do not rotate as you do.

5. Repeat steps 1-4, but spin the other way.

6. Repeat steps 1-4, but spinning in the original direction.

7. Repeat steps 1-4, but spinning the other way again.

8. Repeat some more.