"A vacuum is a hell of a lot better than some of the stuff that nature replaces it with."
Tennessee Williams, Cat on a Hot Tin Roof (1955)
A vacuum is an empty space containing nothing, not even air. Anything containing a vacuum has a much lower pressure on its inside than its outside, and this creates a tremendous force. Otto von Guericke (1602- 1686), a German scientist, was the first to experiment with the power of the vacuum. In his experiments, he filled containers with water and then used a suction pump to remove the water while trying to avoid letting in any air. Wood was useless for this as it leaked air, so he used glass or metal containers. To minimize air intake, Guericke put his container in another layer of water as it was easier to stop water leakage than air leakage. The inward pressure on the containers was often so great that they would collapse. Further trials led Guericke to the conclusion that spherical containers were optimal because their smooth shape avoided weak points in the structure. To prove the power of his discovery, Guericke demonstrated to Emperor Ferdinand III that neither fifty men nor teams of horses could pull apart two copper hemispheres that contained a vacuum.
In science vacuums are most commonly used for their ability to create a truly empty space, enabling the study of particles without the confusion of air. They are essential in many machines used in industry for pumping liquids and other materials, moving objects, and powering heavy machinery.
