Experiment 77. Magic lift.
Fill a tumbler with water, press your palm down on the top with your fingers pointing downward (Fig. 101), straighten your fingers without admitting air to the tumbler, and then lift your hand. Do you lift the tumbler of water also?
There is a partial vacuum between your hand and the water, and the atmospheric pressure upward and downward holds your hand and the tumbler together.
FIG. 102
TUMBLER PENDULUM