the beginning of the Scientific Revolution. Heliocentrism was resisted by the Catholic Church because it contradicted the Bible; the Catholic Inquisition imprisoned Galileo Galilei (sometimes called the "father of modern science" for his many empirical discoveries) for promoting this theory. Armed with detailed observations from Tycho Brahe, Johannes Kepler found the idea that the planets moved in ellipses rather than on perfect celestial spheres, publishing Kepler's laws of planetary motion. The commonly held idea that the fixed stars are mounted on a large sphere was replaced by the idea that they are distant suns. Astrology and astronomy began to separate into different disciplines, with only astronomy using scientific methods. Telescope technology improved tremendously as did the study of optics. Aristotle's laws of motion were demonstrated to be incorrect, and were replaced by Newton's laws of motion and Newton's law of universal gravitation. The 1687 publication of Isaac Newton's 1687 Principia is often used to mark the end of the Scientific Revolution. A revival of atomism (denied by Aristotle) and corpuscularianism began to undermine the classical elements. Both 8th century Islamic experimenter Jabir ibn Hayyan and 17th century Christian experimenter Robert Boyle have been described as the founders of modern chemistry, both worked as alchemists before the fields were clearly separated. Boyle argued for corpuscularism in the 1661 book The Sceptical Chymist, and discovered Boyle's Law of gases. Phlogiston theory was refuted by empirical discovery of conservation of mass, among other discoveries bring the chemical revolution. The discovery of modern chemical elements would not begin until the 19th century in the late modern period, followed by experimental confirmation of atoms. Finally overcoming the difficulties human corpses to perform dissections, the anatomical descriptions of the 2nd century Galen were updated by the 1543 publication of De humani corporis fabrica by Andreas Vesalius, considered a foundational text of modern medicine and early modern anatomy. The 1628 work De Motu Cordis by William Harvey was a major advance in the understanding of the circulatory system. The field of microbiology began with the invention of the microscope and the first observations of microorganisms, famously by Anton van Leeuwenhoek in the 1670s and probably also by Athanasius Kircher in the 1640s. Though microorganisms were (correctly) proposed as the cause of infectious diseases as soon as they were discovered, this theory was generally dismissed. Though scientific investigation undermined humorism in medicine, miasma theory remained dominant throughout the