Magdeburg Hemispheres- amazing alternate method- no pump // Homemade Science with Bruce Yeany
This Magdeburg Hemisphere is a popular demonstration of atmospheric pressure that usually requires a vacuum pump to remove the air from inside the sphere. A more impressive method that is simpler and less expensive can be to use a long plastic tube and a bucket of water. The weight of water inside a long narrow tube attached to the hemispheres will decrease the pressure inside as it is lifted higher and higher. As the pressure decreases inside, the atmospheric pressure outside will require a sizable amount of force to pull the hemispheres apart.