My name is Ben Nemzer and I'm a magician. One of my specialties is close-up magic, which is magic with ordinary objects, decks of cards, ropes, rubber bands. And I do that all over New York City.
I'm going to teach you some of the basics of magic that you guys can start performing right away. This is how you make a cup float. And this is the secret. Before this trick starts, you need to have a Styrofoam cup.
And what you do is you poke a little hole in the back with your finger. Then you hold it with two hands, and when nobody's looking, you sneak your thumb into that little hole. That way if you were to let go of all your hands and fingers, it should stay right on your thumb. But that's not the whole illusion.
You have to hold it with both hands and slowly remove your fingers. Then you can push your thumb forward just for a moment and it will create the illusion that the cup is floating. Remember this trick won't look good from the side or the back, only straight on. And that's how you make a cup float.