Get the full course at: http://www.MathTutorDVD.com In this Physics Experiment, we will discuss what air pressure is and how it works. Our experiment will be the famous egg in a bottle demo. By heating the air inside of a bottle with a match, an egg can be forced into the bottle due to air pressure. What happens is that as the air cools off inside of the bottle, the pressure becomes lower inside of the bottle compared to outside. Because of this, the outside air pressure pushes on the egg and forces it inside of the bottle.