Robert Hooke
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Robert Hooke, FRS (July 18, 1635 – March 3, 1703) was an English polymath who played an important role in the scientific revolution, through both experimental and theoretical work. His father was John Hooke, curate of the Church of All Saints, Freshwater.
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[edit] Early life
Robert Hooke was interested in the sciences, particularly biology, from his early childhood. Like his three other brothers (all ministers), Robert was expected to succeed in his education and join his father's church. However, Hooke continually suffered from headaches whilst studying. His parents, fearing he would not reach adulthood, decided to give up on his education and leave him to his own devices.
Born in Freshwater on the Isle of Wight, Hooke received his early education on the Isle of Wight and, from about the age of 13, at Westminster School under Dr. Busby. In 1653, Hooke secured a chorister's place at Christ Church, Oxford. There he met the chemist (and physicist) Robert Boyle, and gained employment as his assistant. It is possible that Hooke formally stated Boyle's Law, as Boyle was not a mathematician.
[edit] Career
In 1660, he discovered Hooke's Law of elasticity, which describes the linear variation of tension with extension in an elastic spring. In 1662, Hooke gained appointment as Curator of Experiments to the newly founded Royal Society, and took responsibility for experiments performed at its meetings.
In 1665 he published a book entitled Micrographia which contained a number of microscopic and telescopic observations, and some original observations in biology. Hooke coined the biological term cell, so called because his observations of plant cells reminded him of monks' cells which were called "cellula." He is often credited with the discovery of the cell, and although his microscope was very basic, research by British scientist Brian J. Ford has now shown that Hooke could have observed cork cells with it. Ford furthermore shows that Hooke used more high power single lenses to make many of his studies. He also has identified a section in the Preface that contains a description of how to make a microscope, and Hooke's design was utilized by the Dutchman Anton van Leeuwenhoek, described as the father of microbiology.
The hand-crafted, leather and gold-tooled microscope that Hooke used to make the observations for "Micrographia," originally made by Christopher Cock in London, is on display at the National Museum of Health and Medicine in Washington, DC. Also in 1665 he gained appointment as Professor of Geometry at Gresham College. Hooke also achieved fame as Surveyor to the City of London and chief assistant of Christopher Wren, helping to rebuild London after the Great Fire in 1666. He worked on designing the Monument, Royal Greenwich Observatory and the infamous Bethlem Royal Hospital (which became known as 'Bedlam').
[edit] Death
He died in London on 3 March 1703 (ns). He amassed a sizeable sum of money during his career in London, which was found in his room at Gresham College after his death. He never married.
[edit] No portrait
It seems that no authenticated portrait of him survives (Newton instigated the removal of Hooke's portrait in the Royal Society). In 2003 the historian Lisa Jardine claimed a recently discovered portrait represents Robert Hooke. However, Prof. Jardine's hypothesis was soon disproved by Prof. William Jensen (University of Cincinnati) and independently by the German researcher Andreas Pechtl (Johannes Gutenberg University, Mainz). Actually, the portrait represents Jan Baptist van Helmont. A seal used by Hooke displays an unusual profile portrait of a man's head, that some have argued portrays Hooke. Both these claims remain in dispute, however. Moreover, the engraved frontispiece to the 1728 edition of Chambers' Cyclopedia shows as an interesting detail the bust of Robert Hooke.
[edit] Achievements
In addition to the book Micrographia and Hooke's Law, Hooke invented the anchor escapement and may also have invented the balance spring before Christiaan Huygens. Devices known as escapements regulate the rate of a watch or clock, and the anchor escapement represented a major step in the development of accurate watches. The balance spring also regulates the flow of energy from the mainspring of a timepiece. It coils and uncoils with a natural periodicity, allowing for fine adjustment of the period of ticks. Modern spring watches still use balance springs, and derivative designs of Hooke's anchor escapement remain in common use. In February 2006, a long-lost copy of Hooke's handwritten notes from several decades' Royal Society meetings was discovered in a cupboard in Hampshire, and the balance-spring controversy appears by evidence contained in those notes to be settled in favor of Hooke's claim.
Historians sometimes credit Hooke with inventing the compound light microscope, a design consisting of multiple lenses (usually three — an eyepiece, a field lens and an objective). While he did give much advice on new microscope designs to the instrument-maker Christopher Cock, this attribution appears incorrect, since Zacharias Janssen had already assembled compound microscopes in 1590. Hooke's microscopes achieved no more than 30x magnification, which is insufficient to resolve the fine structural details in the insects, etc., that he engraved. Research by Brian J. Ford has shown that Hooke used a single-lensed 'simple' microscope to observe such things.
Leeuwenhoek took Hooke's inspiration and used similar microscopes to those Hooke described to discover his world of animalcules. Robert Hooke was later asked to confirm Leeuwenhoek's findings. He found simple microscopes tiresome to use, and once called his compound microscopes "offensive to my eye" and "much strained and weakened the sight".
Hooke's other significant achievements include the construction of the first Gregorian reflecting telescope, the law of elasticity, and the discovery of the first binary star. He also receives credit with inventing the first practical universal joint, sometimes called the Hooke joint, although the Italian mathematician Girolamo Cardano had proposed the idea about a century earlier and may or may not have built one.
Hooke also experimentally demonstrated the inverse-square law of gravity, but did not prove it mathematically.
Hooke has been described as London's Leonardo (Bennett 2003) because of the breadth of his interests and the volume of his output which included not only science but architecture, surveying, town planning and invention.
[edit] Some of Hooke's significant achievements in science
- First to refer to cells in living matter. 1665: Robert Hooke discovers cells in cork, then in living plant tissue using an early compound microscope.
- First to study fossils and hypothesize that they were extinct species.
- First to report Jupiter's Red Spot and by observing it deduce that the planet rotated.
- First to report the rotation of Mars.
- Worked out the number of vibrations of each musical note.
- Observed Lunar craters.
- Published the first book on microscopy, Micrographia.
- First to explain the shape of crystal in terms of the packing of their component parts.
- One of the first to observe a binary star.
- Postulated a wave theory of light, rejected by Newton and not re-established until about 1820 by Fresnel.
- Advocated the medicinal use of Indian Hemp.
- Proposed the inverse square relationship for gravity.
- Proposed to Newton the idea that planetary motion was a combination of linear and circular motion. It is this that is far more important for Newton's work than the inverse square law.
- Devised Hooke's law of springs and stretching.
- His investigations into combustion that came close to discovering oxygen 100 years before Lavoisier.
[edit] Inventions
Like many scientists of the Early Modern era Hooke was also a prolific inventor. Some of Hooke's inventions that are still in use:
- The first anemometer.
- The first recording weather station.
- A thermometer.
- The universal joint.
- The spirit level.
- The use of rhumb lines to navigate a great circle route.
- The first Gregorian telescope.
- Developed the air pump for Boyle.
- The spring driven clock and spring balance wheel.
- The anchor escapement for clocks.
- The iris diaphragm used in cameras.
- Telescope crosshair sight.
- The sash window.
[edit] Hooke and Newton
Robert Hooke and Isaac Newton entertained a considerable mutual dislike for each other. They fell out in 1672 when Hooke criticized Newton's presentation showing that prisms split white light rather than modifying it. (Hooke, unlike many others, had been able to reproduce Newton's prism experiments and so spoke with some authority.) Newton expressed fury that Hooke seemed unable to grasp his ground-breaking discovery, and threatened to leave the Royal Society.
Relations between the men grew worse as time progressed. In 1679, Hooke wrote to Newton advocating an inverse square law of gravitation. He had probably discovered the relationship before 1660 but lacked the mathematical ability to formally prove it. In his Elements of the Philosophy of the Human Mind, Ch. 4, Sect. 4, Dugald Stewart quoted Hooke as follows: "I will explain (says Hooke, in a communication to the Royal Society in 1666) a system of the world very different from any yet received. It is founded on the three following positions. 1. That all the heavenly bodies have not only a gravitation of their parts to their own proper centre, but that they also mutually attract each other within their spheres of action. 2. That all bodies having a simple motion, will continue to move in a straight line, unless continually deflected from it by some extraneous force, causing them to describe a circle, an ellipse, or some other curve. 3. That this attraction is so much the greater as the bodies are nearer. As to the proportion in which those forces diminish by an increase of distance, I own I have not discovered it, although I have made some experiments to this purpose. I leave this to others, who have time and knowledge sufficient for the task." When Newton published his Philosophiae Naturalis Principia Mathematica in 1687, including a proof of an inverse square law, he failed to credit Hooke at all despite initially having included acknowledgement of Hooke in the manuscript.
It is possible that this dispute may be overplayed: Gunther suggests that the two men held each other in some regard until quite late, citing as evidence their correspondence over matters such as the inverse-square law of gravitation, which Hooke (an undoubtedly gifted experimenter) had demonstrated. On the other hand Newton appears to have delayed publication of his Opticks until after Hooke's death for fear of Hooke's reaction to its contents.
The famous Newton quote, "If I have seen further, it is by standing on the shoulders of giants," appeared originally in a letter to Hooke, and this has been interpreted as a sarcastic remark directed against Hooke. This is somewhat speculative: Hooke and Newton had exchanged many letters in tones of mutual regard, and Hooke was not of particularly short stature, although he was of slight build and had been afflicted from his youth with a severe stoop.
At a time when science was progressing by leaps and bounds it was inevitable that two men with such similar interests would come up with similar ideas. Whether Hooke or Newton first invented the reflecting telescope is a matter of conjecture, but it is the case that Hooke did demonstrate what is now known as the Newtonian telescope some time before Newton is credited with inventing it, as well as documenting "Newton's rings" before Newton did.
Newton's animosity towards Hooke extended to the removal of Hooke's portrait in the Royal Society and an unsuccessful attempt to have Hooke's Society papers burned. Some have argued that Hooke's own unsympathetic character was also a factor: his diary shows that he did have uncomplimentary words for a number of the men he worked with, and had a long dispute with Huygens. Inwood (2002) points out that Hooke enjoyed a very active social life in the coffee houses of London and was known to have many close friends, such as Christopher Wren. On this basis, he appears to have been far more sociable and gregarious than Newton, who spent much of his life as an academic recluse in Cambridge.
[edit] Hooke the architect
Robert Hooke was an important architect. He was the official London Surveyor after the Great Fire of 1666, surveying about half the plots in the city. As well as the Bethlem Royal Hospital, other buildings designed by Hooke include: The Royal College of Physicians (1679); Ragley Hall in Warwickshire; and the parish church at Willen, Milton Keynes (historical Buckinghamshire).
Hooke's collaboration with Christopher Wren was particularly fruitful and yielded The Royal Observatory at Greenwich, The Monument (to the Great Fire) and St Paul's Cathedral, whose dome uses a method of construction conceived by Hooke.
In the reconstruction after the Great Fire, Hooke proposed redesigning London's streets on a grid pattern with wide boulevards and arteries along the lines of the Champs-Élysées, (this pattern was subsequently used for Liverpool and many American cities), but was prevented by problems over property rights. Many property owners were surreptitiously shifting their boundaries and disputes were rife. (Hooke was in demand to use his competence as a surveyor and tact as an arbitrator to settle many of these disputes.) So London was rebuilt along the original mediaeval streets. It is interesting to note that much of the modern-day curse of congestion in London has its origin in these petty disputes of the 17th century.
[edit] Mass media
Robert Hooke is one of many real-life personages featured in the historical adventure novels The Baroque Cycle by American author Neal Stephenson; Hooke's skill in the sciences and surgical arts are used to great (and often darkly comedic) effect throughout the cycle.
[edit] Books
- The Man Who Knew Too Much, Stephen Inwood, Pan Books, 2002. ISBN 0-330-48829-5. (Published in the USA as The Forgotten Genius)
- Early Science in Oxford vol vii, Dr. R. T. Gunther, ed., privately printed, 1923-67.
- Robert Hooke, Margaret 'Espinasse. William Heinemann Ltd, 1956.
- The Curious Life of Robert Hooke: The Man who Measured London, Lisa Jardine. Harper Collins Publishers, 2003. ISBN 0-00-714944-1.
- London's Leonardo: The Life and Work of Robert Hooke, Jim Bennett, Michael Cooper, Michael Hunter and Lisa Jardine. Oxford University Press, 2003. ISBN 0-19-852579-6.
- England's Leonardo: Robert Hooke and the Seventeenth-century Scientific Revolution, Allan Chapman. Institute of Physics Publishing, 2004. ISBN 0-7503-0987-3.
- Robert Hooke and the English Renaissance, Allan Chapman and Paul Kent (editors). Gracewing, 2005. ISBN 0-85244-587-3.
- Hooke, Robert (1635-1703). Micrographia: or some physiological descriptions of minute bodies made by magnifying glasses with observations and inquiries thereupon...
[edit] See also
[edit] External links
- Website dedicated to Hooke, hosted by Westminster School
- Works by Robert Hooke at Project Gutenberg
- Hooke Timeline
- England's Leonardo lecture on Robert Hooke
- Engraved bust of Robert Hooke
- Robert Boyle and Robert Hooke
- Lost manuscript of Robert Hooke discovered — from The Guardian
- Exploring our archives, a blog by researchers at the Royal Society exploring Hooke's lost manuscript
