Stuff You'll Need

• index cards
• scissors
• several pieces of paper of different sizes

How to do it

1. Make two cuts in the index card that go almost to the top of the card.
2. Try to pull on both of the ends of the index card at the same time, ripping it so that the middle part falls to the ground. Impossible, huh?

3. There are two reasons why it's impossible to do this: First, it's almost impossible to make two cuts that are exactly even. So, when you pull both sides, one side will almost always break first.
4. Second, it's almost impossible to pull equally on both sides. So, the side you pull on with more force, or pull on first, will rip first.
5. Try this with a different sized piece of paper and see what happens.