Pascal's Accomplishments

Pascal made important contributions in the natural and applied sciences, studying fluids, and clarified the concepts of pressure and vacuum.
Following Galileo and Torricelli, he disproved Aristotle's followers who considered the creation of a vacuum impossible and insisted that “nothing could not be something.” Pascal experimented on atmospheric pressure, proving that a vacuum existed. His results caused many disputes before being accepted. When Descartes visited Pascal in 1647, they argued about the vacuum which Descartes did not believe in. After his visit Descartes wrote about Pascal: “He has too much vacuum in his head.” When a year later Pascal observed that the pressure of the atmosphere decreases with height and assumed that a vacuum existed above the atmosphere, Descartes wrote about Pascal's experiments saying: “It was I who two years ago advised him to do it, for although I have not performed it myself, I did not doubt of its success...”
Pascal's other important scientific contributions include the derivation of the law or principle, which states that fluids transmit pressures equally in all directions, and his investigations in the geometry of infinitesimal. He insisted on empirical experimentation as opposed to analytical methods, and he believed that human progress was achieved by the increase of scientific discoveries resulting from such experimentation.