Bod's Apple

Here is Bod holding an apple. "I'm going to throw this apple up in the air and catch it," he says. "Watch me!" He throws the apple up in the air - and waits for it to come down. But it doesn't come down. "That's funny," says Bod. When Bod's friends see him waiting for the apple to come down, they wonder what he is doing and they decide to wait with him. What has happened to Bod's apple? Do you know?