Step-by-step tutorial
Step 1
Place the glass over the ball and start moving the glass in a circle. Keep the glass flat on the table as you do this.
Step 2
When you find the right rhythm, the ball will start to roll up the wall! If you get it spinning fast enough, you should be able to lift the glass off the table with the ball still rolling along inside. Just make sure to keep the ball spinning!
Final result!
This trick uses centrifugal force. Spinning the ball in the glass will cause the ball to press against the wall of the glass, allowing it to lift up off the ground.