Robert Hooke

Robert Hooke (; 18 July 1635 – 3 March 1703) was an English polymath who was active as a physicist ('natural philosopher'), astronomer, geologist, meteorologist, and architect. He is credited as one of the first scientists to investigate living things at microscopic scale in 1665, using a compound microscope that he designed. Hooke was an impoverished scientific inquirer in young adulthood who went on to become one of the most important scientists of his time. After the Great Fire of London in 1666, Hooke (as a surveyor and architect) attained wealth and esteem by performing more than half of the property line surveys and assisting with the city's rapid reconstruction. Often vilified by writers in the centuries after his death, his reputation was restored at the end of the twentieth century and he has been called "England's Leonardo [da Vinci]". Hooke was a Fellow of the Royal Society and from 1662, he was its first Curator of Experiments. From 1665 to 1703, he was also Professor of Geometry at Gresham College. Hooke began his scientific career as an assistant to the physical scientist Robert Boyle. Hooke built the vacuum pumps that were used in Boyle's experiments on gas law and also conducted experiments. In 1664, Hooke identified the rotations of Mars and Jupiter. Hooke's 1665 book Micrographia, in which he coined the term cell, encouraged microscopic investigations. Investigating optics – specifically light refraction – Hooke inferred a wave theory of light. His is the first-recorded hypothesis of the cause of the expansion of matter by heat, of air's composition by small particles in constant motion that thus generate its pressure, and of heat as energy. In physics, Hooke inferred that gravity obeys an inverse square law and arguably was the first to hypothesise such a relation in planetary motion, a principle Isaac Newton furthered and formalised in Newton's law of universal gravitation. Priority over this insight contributed to the rivalry between Hooke and Newton. In geology and palaeontology, Hooke identified the organic origin and significance of fossils embedded in sedimentary rocks, thus questioning the Biblical view of the Earth's creation. His explanations for the origin of such fossils, some of which he identified as being of extinct species, presaged 19th-century arguments for biological evolution. He also argued that hills and mountains had become elevated by geological processes (rather than having been created exactly as they are today).