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. 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 and 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, which not only attracts their own parts, but also attracts other celestial bodies within their sphere of action. 2. Every object keeps a simple motion in a straight line and continues to move along the straight line until it is influenced by other forces, thus becoming a circle, 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. So the privilege of discovering the law of universal gravitation was given to Newton, but Hooke's thought played a positive role in inspiring Newton to complete the study of universal gravitation.
The law of elasticity is one of Hooke's most important discoveries and one of the most important basic laws of mechanics. Even in modern times, the law of elasticity is still an important basic theory of physics. 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.
2. Optical and other contributions
Hooke also studied optical problems and achieved outstanding results. Hooke supported the wave theory of light and further put forward the concept that light wave is shear wave. In 1672, he further pointed out that the vibration of light can be perpendicular to the propagation direction of light. He also studied the interference phenomenon of light and the color of the mother film, and confirmed that the light phenomenon varies with the thickness of mica films everywhere.
1665, Hooke published The Theory of Micro-body, 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, using "holes" and "cells" to explain the tiny objects observed. The word "cell" has been directly adopted by biology since then. Hooke's discovery aroused people's research on cytology. Now we know that all living things are made up of countless cells. In addition, he also found the cell wall. Hooke has made great contributions to the development of cytology.
3. In addition, Hooke has done a lot of research on chemical combustion theory, respiration, geology, earthquake and ocean 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.
4. Excellent instrument manufacturers
Hook's expertise in making and improving instruments was revealed when he was Boyle's assistant. He helped Boyle improve the air extractor and made a compound microscope, wheel barometer, pendulum clock, ocean sounder, seawater sampler and so on. 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. Hook once designed a large-scale "climate clock", which can measure and record wind, direction, temperature, pressure, humidity, rainfall and so on. 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."