A mathematician and a physicist agree to take part in an experiment.

Both enter the experiment in a state of hunger, and the mathematician is chosen to go first.

He is put in a chair in a large empty room.

His favorite meal, perfectly prepared, is placed at the other end of the room.

The psychologist explains, "You are to remain in your chair. Every minute, I will move your chair to a position halfway between its current location and the meal."

The mathematician looks at the psychologist in disgust. "What?! I'm not going through this! You know I'll never reach the food!"

And he gets up and storms out.

The psychologist then ushers the physicist in.

He explains the situation, and the physicist's eyes light up and he starts to drool.

The psychologist is a bit confused. "You DO realize that you'll never reach the food... don't you?"

The physicist smiles and replies: "Of course! But I'll get close enough for all practical purposes!"