Equal Air Pressure

 Do you want to do a practical joke on your brother or sister? Well, all you need is a bottle with a pinky size hole in it. Believe it or not, the drink won't leak, until you ether squeeze the bottle or unscrew the lid. This is because the air pressure in the bottle is equal to the pressure outside the bottle. But when you remove the lid, the weight of the water has a greater pressure than the outside of the bottle resulting in it leaking.

Georgia