Archimedes (287-212 BC) was a brilliant mathematician who established the principles of plain and solid geometry. He is said to have invented the hydraulic screw for moving water from one level to another. He also proved that the volume of a sphere is equal to two-thirds of the volume of the smallest cylinder in which that sphere will fit. Archimedes is said to have been so proud of his work on the volume of a sphere that he asked that a figure of the sphere and cylinder be marked on his headstone.
But Archimedes was interested in more than math. Fluids at rest were also of interest to him. Perhaps the most famous story about Archimedes is of his Eureka moment. The moment when he realized that his body displaced an amount of water equal to his own weight. He also noticed the feeling of being pushed up by a force while in the water – known as buoyancy. His observations of the behavior of the fluid led to what is known as Archimedes’ Principle, stated as: When an object is immersed in a fluid it is buoyed upward by a force equal to the weight of the fluid displaced. Archimedes was able to use this observation to prove that a crown made for King Heiro II did not contain all the gold it was supposed to contain.
Archimedes published a work entitled “On Floating Bodies” as a result of his work with fluids at rest. In this work, he lays out several assertions that include definitions of displacement and buoyancy.
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