ABSTRACT
The seventeenth century witnessed the development of new ways of making knowledge about the natural behaviours of material bodies. Galileo taught about the motion of heavy bodies in the vicinity of the Earth's surface, arguing that freely falling bodies accelerate from rest with their speed of fall increasing in proportion to the time elapsed. He asserted that the truth of this claim could be known from experimental tests using balls rolling down inclined planes and the careful measurement of the times elapsed during their traversal of particular distances. Such experimental demonstrations depended on ways of converting assertions of experimental results into universally applicable knowledge-claims. Similar practical questions of knowledge-making were soon afterwards confronted by the French mathematician Blaise Pascal when he tried to establish doctrines concerning air pressure and water pressure, and by the English natural philosopher Robert Boyle with his experiments using an air-pump.
