How black holes form!
What you need:
1) peace of paper
2) 1lb of like change
3) 1lb needle -not sure if anyone actually makes this
Put coins on pice of paper and see how each one pushes the paper down a bit. See how if you stack them it pushes down more. Now take a pin that has the same weight and it will go right through. Even though you had the same amount of mass or in this case weight on the paper once you concentrated it in a very small point there was too much and it just fell though.