
Blaise Pascal was born June 19, 1623 in Clermont, Auvergne, France. Blaise's mother died when he was three years old. Blaise's father, Etienne, oversaw Blaise's education at home. Etienne decided that Blaise was not to study mathematics until age 15. At age 12, Blaise's curiosity in geometry grew as he rediscovered many of Euclid's elements on his own. When his father realized this he relented and gave Blaise a copy of Euclid's book. In 1639 the family moved to Rouen where Etienne had been appointed as a tax collector. Blaise had his first paper, Essay on Conic Sections published in February 1640. In an effort to make his father's work easier, Pascal invented a calculator, which used the movement of gears to add or subtract. The device was called the Pascaline and it resembled the mechanic calculator of the 1940's. Only about 50 calculators were manufactured, because not many could afford the price. In 1647 Pascal wrote New Experiments Concerning Vacuums, however many scientists disagreed on whether a vacuum exists. Descartes visited Pascal for two days and they argued about the vacuum. In a letter that Descartes wrote to Huygens he stated, "Pascal has too much vacuum in his head." Pascal continued to work on mathematics and physics writing Treatise on the Equilibrium of Liquids (1653) and The generation of Conic Sections (1654). Pascal wrote Treatise on the Arithmetical Triangle, which is a triangular array of numbers that had been handed down by Chinese mathematicians several centuries earlier. Pascal discovered new properties of the triangle and solved problems using it, therefore the triangle became known as "Pascal's Triangle." Pascal became interested in probability when given a gambling question. The dice problem asks how many times one must throw a pair of dice before one expects a double six while the problem of points asks how to divide the stakes if a game of dice is incomplete. In correspondence with Fermat, they solved the problem of points for a twoplayer game. Pascal with Fermat laid the foundation for the theory of probability. Pascal nearly lost his life in an accident in 1654. The horses pulling his carriage bolted and the carriage was left hanging over a bridge above the Seine River. Although he was not physically hurt, this accident affected him psychologically. He soon pledged his life to Christianity. Much of his work was then centered on theology. In his work Pensees, Pascal claims to prove that belief in God is rational with the following argument. "If God does not exist, one will lose nothing by believing in him, while if he does exist, one will lose everything by not believing. We are compelled to gamble." Pascal suffered a toothache, which kept him awake at night. In an effort to take his mind off the pain he focused on the cycloid, the curve traced by a point on the circumference of a rolling circle. Pascal solved the problem of the area of any segment of the cycloid and the center of gravity of any segment. He also solved the problems of the volume and surface area of the solid of revolution formed by rotating the cycloid about the xaxis. Pascal died at the age of 39 from a malignant stomach ulcer. Pascal never married and he will be remembered by his work in mathematics, physics, philosophy, and religion.

Contributed by Audrey Smalley 
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