Born on this date in 1623 -- Scientist / Philosopher Blaise Pascal

from Writer's Almanac (American Public Media: Garrison Keillor) June 19 is the birthday of mathematician, physicist, and theologian Blaise Pascal, born in Clermont-Ferrand, France (1623). A child prodigy, by the time he was 19 he had already perfected the first mechanical calculator for sale to the public. In the field of physics, he discovered that air has weight, and he conducted experiments to prove that vacuums could exist, which led him to formulate the hydraulic principle that "pressure exerted on a fluid in a closed vessel is transmitted unchanged throughout the fluid." This principle is used today in devices such as syringes, hydraulic presses, automobile brakes, and aircraft controls. In mathematics, he founded the theory of probabilities and developed an early form of integral calculus. He spent much of his life in conflict between science and religion, and was one of the first philosophers to seriously question the existence of God. But in 1654, he experienced a revelation, the account of which he carried sewn into his coat lining until his death. He came to the conclusion that there was no science to prove God exists; instead, humans must rely on their faith. He produced two great works of religious philosophy, Les Provinciales (Provincial Letters, 1657) and Pensées (Thoughts, 1658). Blaise Pascal, who said, "The heart has its reasons which reason knows nothing of."