Okay, what we've got here is the bed of nails. Alright, what we've got here is the bed of nails. This is a demonstration of pressure. I have a weight force and even if I'm lying horizontally, there's still quite a bit of force downwards. The amount of force per unit area is pressure. If I'm lying on the floor, the pressure per square centimeter of me isn't too great, quite comfortable. But think about lying on these nails. Now if you put your whole weight on one nail, if you stood on one nail, it would stick into your foot because all your weight would be on that one nail. But I'm going to spread it over these. So in theory, I should be quite safe as long as I don't fall and put extra force onto it. So here we go. So force per unit area. Still got the same amount of force down. Small area means we've got larger pressure. But luckily, the force is spread over quite a lot of nails, so the pressure isn't great enough for them to go through my skin.