<b>Robert Hooke Renaisance Man of 17th Century England Life One of the most interesting early founders of the British Royal Society was Robert Hooke (1635-1703). No reliable likeness of him exists so no one knows what he looked like. Hooke was known for his competitive nature, for the quickness of his ingenuity, and for his quarrels with other scientist about the priority of discoveries and inventions. He was a kind of Renaissance man of the 17th century and was considered one of the most accomplished experimentalists of his time in that he designed and built various scientific devices including microscopes, telescopes, pendulum clocks (balance-spring watches), and vacuum devices. His response to any scientific problem was to invent a piece of equipment to resolve it. In this way, he considered himself a kind of “scientific craftsman.” He also helped redesign St Paul’s Cathedral in London together with Christopher Wren and provided surveying assistance to the team rebuilding London after the “Great London Fire” of 1666. Royal Society Hooke was appointed Curator of Experiments for the Royal Society. His duties involved the demonstration of various experiments for the members often using devices of his own making in order to test the experiments of others. He was appointed by his boss at that time, Robert Boyle, who was then one of the most well-known scientists of his time. Boyle employed Hooke to design customized experimental equipment and to investigate any topic that Boyle was currently interested in. These experiments included creating vacuums using air pumps, an experiment on respiration on a live dog whose thorax was cut open to show the beating of its heart and whose lungs were inflated by Hooke using a bellows (he never repeated this experiment because of “the torture of the poor creature”). Inventions and patents He was one of the first to devise a regulator for a marine clock that worked using springs instead of gravity. It functioned by causing a balance wheel that was attached to a spring to oscillate back and forth around its own center of gravity thereby facilitating a regular periodic interval for the stopping and starting of the clock. This allowed the measurement of units of time. Hooke never patented this invention and had a dispute with Christian Huygens over who had priority. He did manage to build a watch and presented to the King. Hooke asserted in the inscription on the clock that it had been invented as far back as 1658. Although Hooke lacked mathematics he sought to persuade through practical experimentation and formalized recording of data. Hooke invented or improved barometers, thermometers, and wind gauges. He recorded London’s weather regularly. This and other discoveries made by Hooke were quite often written in code in order to protect the priority of his claims. This was common practice in Hooke’s time to write up observations in code and file them as patents until deciding when to make these public. Often additional work had to be done on these entries before these discoveries could be revealed to the public. The first portable clock that could be used at sea to measure longitude was not invented until 1714 by John Harrison who won a prize of 10,000 pound from the English government. Discoveries Hooke’s law A physical law is named after Hooke which states that “a spring when stretched resists with a force proportional to the extension of the spring” (see The Discoverers, by Daniel Boorstin, pg 52). Redspot of the planet Jupiter Hooke’s discoveries in astronomy include the massive “redspot of the planet Jupiter” which today is known to be a massive storm area “40,000 kilometers long and 10,000 kilometers wide” (see Cosmos by Carl Sagan pg 136). He also observed the rings of Saturn as did his contemporary Christian Huygens and Galileo before them both. The Micorgraphia Hooke had made many observations of microscopic life using his microscope which had a higher magnification than the one originally designed by Antoine Leuwenhoek. He observed for instance thin layers of cork and was able to see regular square-like honeycomb structures that he called “cells.” This was the first time this term was used to describe these regular structures that make up all living animal and plant tissue. Robert Hooke’s most famous work was the “Micorgraphia” published in 1665. In this book Hooke states that “The Science of Nature has been already too long made only a work of the Brain and the Fancy. It is now high time that it should return to the plainness and soundness of Observations on material and obvious things.”(see Isaac Newton by James Gleick pg 62). In this book Hooke provided a description of the microscope and its uses. He presented 57 handrawn and engraving illustrations of what he saw under his compound microscope including the eye of a fly, the shape of a bee’s stinger, the anatomy of a flee and a louse, structure of feathers and the structure of plantlike molds (there were also engravings that included a thyme seeds). The book also presented Hooke’s theories of light and color as well as his theories about respiration and combustion. Hooke in order to improve the quality of the images he saw under the microscope invented a device that he called a “scotoscope (or a condenser in modern terminology).” This consisted of a glass globe filled with brine that he positioned between the light source and the lens of the microscope. He also placed a convex lens between the light source and the globe to focus the light source. He found that he could improve the quality of the images by adjusting the relative positions of the lamp, globe, and lens. Hooke also speculated on the nature of light and color. “Light is born of motion” he claimed. He stated that all luminous bodies are in motion and that we see two main colors red and blue that are caused by their impression on the retina of the eye by an “oblique and confused pulse of light.” At this point red and blue “met and crossed each other” to produce “different kinds of greens.” Hooke and Newton According to Gleick, Hooke was an inspiration to Newton who was actually 7 years younger than Hooke. Newton never admitted this and throughout their lives Newton was goaded by Hooke. Newton saw Hooke as his nemesis and tormentor. Hooke also became Newton’s victim. One famous dispute Hooke had with Isaac Newton was after the publication of Newton’s landmark work the “Principia” (Mathematical Principles of Natural Philosophy). Hooke claimed that many of the ideas presented by Newton were plagiarized from communication he had had with Hooke a dozen years before. (An interesting aside involved a dispute between Hooke, Christopher Wren, and Edmond Halley that they addressed to Newton. The asked Newton what he thought would be the best curve or path of the planets that would describe their motion around the Sun assuming that their force of attraction to the Sun would decrease with the reciprocal of the square of their distance from the Sun. According to this story, Newton immediately answered that the path would be best described by an ellipse. Halley asked him how he knew that and Newton claimed that he had calculated it. However after some searching he could not find the proof but said that he would derive it again and send it to Halley. This turned out to take 3 years (1684 to 1687) and resulted in the “Principia” Newton’s most famous work). (See the Ascent of Man by Jacob Bronowski pg 233) Newton was so upset by Hooke’s claims of plagiarism that he deleted all reference to Hooke’s work and even threatened to give up publishing the “Principia.” Newton so resented Hooke that he refused to assume the presidency of the Royal Society until after Hooke’s death. It is not entirely clear whether Hooke’s claims were true or not. However, Newton did not merely speculate on the ideas he discussed (as Hooke apparently did), but he also presented mathematical proofs for his ideas. Hooke may have had early insights into the ideas presented by Newton but he had not done the experiments to prove his hypotheses. Hooke also argued against Newton’s theory of the physical nature of white light. Newton described that white light is not modified by passing through a prism but instead it is physically separated when passing through a prism and this brings forth the characteristic spectrum. Hooke did not agree with this and the dispute must have been so vehement that Newton refused to publish his book on optics until after Hooke died