terrella. From these experiments, he concluded that the Earth was itself magnetic and that this was the reason compasses point north. De Magnete was influential because of the inherent interest of its subject matter as well as for the rigorous way in which Gilbert describes his experiments and his rejection of ancient theories of magnetism. According to Thomas Thomson, "Gilbert['s]... book on magnetism published in 1600, is one of the finest examples of inductive philosophy that has ever been presented to the world. It is the more remarkable, because it preceded the Novum Organum of Bacon, in which the inductive method of philosophizing was first explained." Galileo Galilei has been called the "father of modern observational astronomy," the "father of modern physics," the "father of science," and "the Father of Modern Science." His original contributions to the science of motion were made through an innovative combination of experiment and mathematics. Galileo was one of the first modern thinkers to clearly state that the laws of nature are mathematical. In The Assayer he wrote "Philosophy is written in this grand book, the universe ... It is written in the language of mathematics, and its characters are triangles, circles, and other geometric figures;...." His mathematical analyses are a further development of a tradition employed by late scholastic natural philosophers, which Galileo learned when he studied philosophy. He ignored Aristotelianism. In broader terms, his work marked another step towards the eventual separation of science from both philosophy and religion; a major development in human thought. He was often willing to change his views in accordance with observation. In order to perform his experiments, Galileo had to set up standards of length and time, so that measurements made on different days and in different laboratories could be compared in a reproducible fashion. This provided a reliable foundation on which to confirm mathematical laws using inductive reasoning. Galileo showed an appreciation for the relationship between mathematics, theoretical physics, and experimental physics. He understood the parabola, both in terms of conic sections and in terms of the ordinate (y) varying as the square of the abscissa (x). Galilei further asserted that the parabola was the theoretically ideal trajectory of a uniformly accelerated projectile in the absence of friction and other disturbances. He conceded that there are limits to the validity of this theory, noting on theoretical grounds that a projectile trajectory of a size comparable to