Hook Robert (1635- 1703) is one of the most outstanding British scientists in17th century. He has made great achievements in mechanics, optics, astronomy and many other aspects. The scientific instrument he designed and invented was unparalleled at that time. He himself is called the "eyes and hands" of the Royal Society.

Hook's life

Hook 1635 July 18 was born in Frey Schwart, Isle of Wight in the south of England. Father is a local parish priest. Hook was sickly and eccentric since childhood, so he couldn't go to school on time. But he is ingenious and likes to make mechanical toys. Such as wooden clocks and watches, airplane models that can move in water, etc. At the age of ten, Hooke became interested in mechanics, which laid a good foundation for the development of experimental physics in the future. 1648, Hooke's family declined after his father died. Thirteen-year-old Hook was sent to an oil painter's home in London as an apprentice. Later, he was the lead singer of the church choir, and he was also a servant of the rich.

With the enthusiastic help of the headmaster of Westminster School, Hook completed the middle school course. In almost a week, he greedily read the first six volumes of Euclid's Elements of Geometry, and immediately applied mathematical knowledge to mechanical design. Hook designed twelve mechanical structures and thirty flight methods. 1653, Hook entered Leo College of Oxford University. Here, he met some talented scientists. Most of these people later became the backbone of the Royal Society. At this time, Hooke was keen to participate in the activities of doctors and scholars, and showed his unique experimental talent. 1655, Hook was recommended to Boyle to work as an assistant in Boyle's laboratory.

1663, Hook received a master's degree in literature and was elected as a member of the Royal Society. From 65438 to 0665, Hooke was a professor of geometry and geology at Siam College in Gleiter, and engaged in astronomical observation. 1666 after the London fire, he worked as a surveyor and city inspector in London and participated in the reconstruction of London.

1676, Hooke published the famous law of elasticity. From 1677 to 1683, he became the secretary of the royal society and was responsible for the publication. As early as 1663, Hooke drafted the Draft Constitution of the Royal Society, stipulating that the purpose of the Society is to "improve the knowledge about natural things through experiments, as well as all related arts, manufacturing, practical machinery, engines and new inventions (not involving theology, metaphysics, morality, politics, grammar, rhetoric or logic)". As the administrator of the experimental work and daily affairs of the Society, Hooke has been in contact with and deepened the active frontier fields of natural science at that time and made his own contribution in the activities of the Society for more than 20 years. 1703 On March 3rd, Hook died in London at the age of 68.

Exploration and discovery in mechanics

Hooke's contribution to mechanics is particularly outstanding. From 166 1, he actively participated in the activities of the special committee of the Royal Society to study the nature of gravity. In order to determine the relationship between the gravity of an object and the distance from the center of the earth, he put a precise balance on the spire of Westminster Abbey, weighed a piece of iron and a long rope, then hung the iron at the end of the rope and weighed it again to see if the weight changed because the iron was close to the ground. As a result, no obvious change was detected. Later, he repeated the experiment in the old St. Paul's church. 1674, Hook published a paper "An Attempt to Prove the Annual Movement of the Earth from the Angle of Observation". According to the revised inertia principle, from the viewpoint of planetary force balance, three hypotheses of planetary motion are put forward:

1. All celestial bodies have gravitation or gravitation towards their center, attracting not only their own parts, but also other celestial bodies within their range of action;

2. Every object keeps a simple motion in a straight line and continues to move in a straight line until it is subjected to other forces, thus changing into a circle, an ellipse or other curved motion;

3. The closer an object is to the center of gravity, the greater the gravity.

In his letter to Newton in 1679, Hooke formally put forward the view that gravity is inversely proportional to the square of distance, but he did not use mathematical formulas to express his gravity thought like Newton, but used examples of the movement of the sun, the earth, the moon, planets and objects on the earth to verify it. Therefore, Newton was awarded the honor of discovering the law of gravitation, but some ideas of Hooke played a positive role in Newton's study of gravitation.

The law of elasticity is one of Hooke's most important discoveries and one of the most important basic laws of mechanics. In modern times, it is still an important basic theory of physics. Hooke's law of elasticity points out that within the elastic limit, the elastic force f of the spring is proportional to the length x of the spring, that is, f= -kx. K is the elastic coefficient of a substance, which is determined by its properties. A negative sign indicates that the spring produces an elastic force opposite to its stretching (or compression) direction. In order to prove this law, Hooke also did a lot of experiments and made various shapes of elastomers with various materials. He further applied flexibility to practical problems. At the same time, the law of elasticity is revealed, and simple harmonic motion's early analysis proves that the spring vibration is isochronous. As a result, he applied the spring to the manufacture of clocks and watches and achieved great success.

Optical and other contributions

Hooke also studied optical problems and achieved outstanding results. Hooke is a loyal supporter of the wave theory of light. He thinks that the propagation of light is similar to water waves, and further puts forward the concept that light waves are shear waves. He also studied the interference of light He observed and studied the colors of films and mica sheets formed by soapy water, and found that their colors were related to the thickness of films and mica. He said, "When the light falls on the transparent film, both sides of the film will be reflected, which will produce the effect of film color."

1665, Hooke published "Micro-body Theory", which is the most important work among all his achievements and one of the most important scientific documents in Europe in17th century. He began to apply the microscope to biological research. He carefully examined and compared the stings of bees, feet of flies, feathers of birds, fish scales, fleas, spiders, grass and marijuana with a microscope. He observed the connective tissue of cork and other objects, and explained it with "hole" and "cell". The word "cell" was directly adopted by biology. Hooke's discovery aroused people's research on cytology. Now we know that all living things are made up of countless cells. Hooke has made great contributions to the development of cytology.

Hook also conducted many studies on chemical combustion theory, respiration, geology, earthquakes and oceans through the Royal Society. He thinks that burning is similar to human breathing. Without air, the lights will go out; Using bellows to regularly inject fresh air into the lungs of dogs with small holes can also keep the puppy's heart beating for more than an hour, indicating that the role of breathing is to supply fresh air to animals. Hook strongly opposed biblical creationism in his lecture on earthquakes and why shells and other marine animal remains are often found on the ground. He put forward the viewpoint of landform change, and thought that landform change caused biological change, and fossils were the remains of ancient animals and a "monument" in the history of earth evolution. People can learn about the history of the earth from these fossils. Hook put forward these views before the evolution theory appeared, which is valuable.

Outstanding instrument manufacturer

Hook's expertise in making and improving instruments was revealed as early as his assistant Boyle. He helped Boyle improve the vacuum pump three times. The third improved air extractor has the prototype of modern vacuum pump, and its power is provided by the pump operator using pedals on the pistons on both sides of the pedal pulley. Using this equipment, Boyle and Hooke completed the experiment of Boyle's gas law. Hooke's improved instruments include a compound microscope and a wheel barometer reading with a pointer. He also suggested that the freezing point of liquid and the degree of expansion or contraction should be used as the basis for temperature calibration. Hooke once designed a large-scale "climate clock" to measure and record wind, direction, temperature, pressure, humidity and rainfall. On the telescope, he added the fork wire of the eyepiece, the adjusting screw and the diaphragm. His creative ability in experiments has made great contributions to the experiment-based research carried out by the Royal Society in the early days, and he is called "the pillar of the Royal Society". Because Hooke and Boyle played an active role in the Royal Society, people praised them: "If Boyle is the soul behind the Royal Society, Hooke provided eyes and hands for the Society."

Shortcomings in scientific research

Hook loved science and devoted his life to it. His research covers a wide range, such as architecture, fossils, meteorology and so on. And he also dabbled and made contributions. However, as a scientist, Hooke still lacks skillful mathematical and logical reasoning ability as a weapon for research and thinking, so it is not easy to thoroughly analyze and solve problems from the combination of theory and practice. This is also Hooke's inferiority compared with Newton and Huygens.