A small, fantastic interlude that will drive your audience crazy. Just as suitable for a bar bet as it is for the mental magician who controls objects with the mind.
They show a small metal vial with a hole in the side. You rotate the hole so it is facing up and insert a steel ball into it. Logically, if you turn the vial with the hole facing down, the ball will fall out. They show it two or three times: gravity remains gravity, the ball falls.
Then the magical moment follows: the viewer himself puts the ball in the hole, they turn the small bottle over, the ball remains in the recess as if by magic. The viewer immediately wants to do it, but you guessed it: the ball falls out. No magnets, no threads, no glue, no exchange, no add or take away. Super easy to repeat as often as you want. With you the ball stays in, with the audience it rolls over and over again on the table.