Robert Hooke, an incredible polymath, the British da Vinci

Wikipedia entry

When I was in junior high, I learned that Robert Hooke was famous for coining the word cell in biology. He had looked through early microscopes and examined thin slices of cork, noting that they were made of a network of interconnected holes. These reminded him of empty rooms in monasteries; the rooms were known as cells, so the name fit. Hooke had actually seen and drawn cell walls, which are tough thick plant frameworks.

Hooke and his drawing of cork cells

Hooke published his findings and observations in a book Micrographia in 1665. The microscope had not been around very long, and he made his own modifications to create one with two lenses that provided combined magnification power over just one lens. Moreover, this design required adjusting the lens for better focus, instead of moving the specimen. A container of water focused light from a lamp tightly on the specimen. His observations on insects, sponges, bird feathers, and more caused the book to be an instant success. 

From micro.magnet.fsu.edu

But that is not the end of the story. Hooke was a polymath -- a person who has a great deal of knowledge and expertise in many fields. Compare him to another famous polymath, Leonardo da Vinci. Hooke was born on the Isle of Wight, England on July 18, 1635. His father noticed how adept he was at drawing and at building small mechanical objects and thought he'd be either an artist or clockmaker. But, Robert enrolled at the University of Oxford’s Christ Church College in 1653 and took up experimental science. He became an assistant to the famous chemist Robert Boyle, who himself belonged to an informal group called the "Philosophical College" or "Invisible College" that discussed a variety of scientific topics. Hooke designed most of Boyle's equipment and was later rewarded by being named Curator of Experiments for the Royal Society. The Society's motto was Nullus In Verba (Take Nobody’s Word For It), and this responsibility paved the way to Hooke's success in many areas of science.

He also studied physics and developed Hooke's Law of elasticity in 1660. This stated that the force required to extend or compress a spring (or many types of material) is proportional to the distance it is stretched or compressed. This had widespread applications for pressure gauges, scales, balance wheels of clocks, seismology, acoustics, and even simple things today like a ball pen spring, balloons, and toy guns. Hooke applied it to create the balance spring for pocket watches and improve the pendulum.

In 1665, he became professor of geometry at Gresham College in London. One year later, the "Great Fire of London" destroyed much of the city, and Hooke worked as a city surveyor with architect Christopher Wren to design streets and buildings to restore the city. 

Unknown painter (1675)

Hooke's polymath talents reached into paleontology and geology, too. During his time, nobody knew exactly how animal fossils arose. Some said there was a force in the Earth that simply shaped materials there to look like bones. He studied petrified wood and shell fossils under the microscope (a first for his time), and compared them to living samples. His conclusion was what we now know happens as minerals deposit into organic matter and replace it:

"this petrify'd Wood having lain in some place where it was well soak'd with petrifying water (that is, such water as is well impregnated with stony and earthy particles) did by degrees separate abundance of stony particles from the permeating water, which stony particles, being by means of the fluid vehicle convey'd, not onely into the Microscopical pores. . . but also into the pores or Interstitia. . . of that part of the Wood, which through the Microscope, appears most solid. . ." (reference here for more)

Pores of petrified wood (roberthooke.org.uk)

He spoke in 1670 about how gravity applied to all bodies in space and that the force of gravity between bodies decreases with the distance between them. That was 17 years before Isaac Newton published his Philosophiae Naturalis Principia Mathematica. 

In the book Discourse of Earthquakes, published after his death, Hooke recounted how the presence of seashells on mountains might have been due to them being underwater as a result of "some very great Earthquake." In studying coiled shells of three living cephalopods, Nautilus, Argonauta, and Spirula, compared with a fossil ammonite, he reached the conclusion that many fossils are simply organisms that no longer existed on Earth. This was a surprising thought of the day, that animals could go extinct, and wasn't solidified until the 1800s.

Hooke's ammonite fossils (Discourse of Earthquakes)

Hooke's passion for tinkering with the mechanical brought about many inventions at his hands:

• odometer to measure distance traveled on wheels
• universal joint used in cars today
• weather instruments like the anemometer (wind speed), hygrometer (humidity), & barometer
• a telescope
• an "otocousticon" hearing aid

Hooke's hygrometer (left) and drawings for a universal joint (right)

His various scientific discoveries also included the following:

• the Great Red Spot on the planet Jupiter
• the phenomenon of light diffraction and interference on thin films
• an attempt to prove the elliptical orbit of the Earth
• one of the first double star systems
• an early view of the wave function of light

Hooke died March 3, 1703 in London. There are no known portraits of him, just many disputed ones. It is rumored that Newton discarded all of the ones that were to be hung in the Royal Society as a result of disagreements they had had. He never mentioned Hooke in his book on gravity despite Hooke's earlier lecture. Hooke feuded a lot in his later years with other scientists, often over whether he'd arrived at some discovery first, but he was also known as a wonderful conversationalist on many topics in bars and coffeehouses. Some think that because of his outspoken nature, often failing to curb a sharp tongue, the lack of paintings was more over not caring to preserve them, instead of to destroy them.

The preface to his Micrografia perhaps sums up Hooke's view on science. Keep in mind this was written 300 years ago:

"By the means of telescopes, there is nothing so far distant but may be represented to our view; and by the help of microscopes, there is nothing so small, as to escape our inquiry; hence there is a new visible world discovered to the understanding."

This article in JSTOR is a brief but nicely detailed account of Robert Hooke.