(This idea was contributed by a visitor)

1. Stuff the paper towel tightly into the bottom of the tumbler. It should stay there even when you hold the tumbler upside down.

2. Fill a sink with water.

3. Turn the tumbler upside down. Hold the tumbler very straight and plunge it into the water.

4. Slowly count to 10. Lift the tumbler out of the water without tipping it.

5. Pull the paper towel out of the tumbler. Is the paper still dry? Why?