Week 21 History Essay

            This week I learned about Johannes Kepler, Galileo Galilei, the slide rule, and John Napier. First is Johannes Kepler. He was an astronomer and mathematician, and he came up with the theory that the sun was the center of the universe. This changed a lot, because everybody thought that the Earth was the center of the universe. Second is Galileo Galilei. He was an Italian astronomer, physicist, engineer, philosopher, and mathematician. He is most famous for the telescope, but he didn’t invent it. With his telescope Galileo figured out that the moon is not flat and that Jupiter has moons. Next I learned about the slide rule. It is a mechanical analog computer that is made out of wood or plastic. It was invented by Wlliam Oughtred, and it was used for division and multiplication. Without the slide rule people could not do math quickly. Last I learned about John Napier. He was a Scottish mathematician. He went to University at 13, but didn’t get his degree. He invented logarithms. Math would not be the same if we did not have logarithms.