Lu zengjian
jiaozuo university
Newton I was a great physicist, mathematician and astronomer. he
It occupies a unique position in the history of natural science. The publication of his scientific masterpiece Mathematical Principles of Natural Philosophy,
It marks the establishment of the classical mechanical system. The scientific achievements of classical mechanics theory system and scientific methodology enlighten us.
The infinite wisdom of human conquering nature has had a far-reaching impact on the development of modern science and technology and social progress.
The ring.
Keywords Newton's contribution to classical mechanics
Newton was a great physicist. In his time, Copernicus put forward the observations of Heliocentrism and Kepler from Tycho.
The data summarized the three laws of planets, Galileo gave the concepts of force and acceleration, and discovered inertia and self-laws.
According to the law of falling body. However, these physical concepts and physical laws are isolated and logically independent. newton
It is "standing on the shoulders of these giants" that has made an overall investigation and study on the motions of planets and ground objects, making physics a complete system that can express causality by mathematical methods. As Newton said, "natural philosophy should be called"
The purpose of "physics" is to discover the structure and function of nature, and reduce them to some universal laws and general laws as much as possible-establish these laws through observation and experiment, and then deduce the cause and effect of things. "Newton's research results on mechanics are embodied in his scientific masterpiece" Mathematical Principles of Natural Philosophy ",hereinafter referred to as" Principles ".
This book is an extremely important and great work in the history of science. Newton put forward three laws of mechanics in his book Principles.
And summed up his own physical discoveries and philosophical views.
Point. It can be said that in the whole history of science, no book can be compared with this book in innovation or thinking, and has made great achievements.
The same is true of grades. It not only marks the climax of scientific revolution in 16 and 17 centuries, but also marks the progress of human civilization.
The symbol of the times, it not only summarizes and develops almost all the important achievements of physics before Newton, but also summarizes and develops all the later disciplines.
A model of learning works and scientific methods. The publication of this book marks the establishment of the classical mechanical system and immediately becomes a new science lesson.
Canon's works are highly respected and have established an immortal monument in the history of scientific development.
1. 1 the epoch-making masterpiece principle
The book Principles is divided into two parts. In the first part, Newton first clarified several things that people often confused at that time.
Important concepts, such as mass, inertia, external force, centripetal force, time and space. , and then put forward the basic theorem and definition of motion.
Laws, namely, the three laws of Newtonian mechanics, the synthesis and decomposition of forces, the law of conservation of momentum, the law of motion of the center of mass, the principle of relativity and
Equivalent principle of force, etc. Although this part is not long, it is the basis of the whole book and its content is extremely important. The second part is
The application of these laws is divided into three parts. The first two parts deduce the law of universal gravitation through deductive reasoning, which is certain.
The concrete form of this law discusses damping motion, fluid dynamics and hydrostatics. In the third part, we use the published wording,
In the first issue, Lu Zengjian supplemented Newton's law and the establishment of classical mechanics to explain the cosmic system, and studied the observation data of celestial bodies, including the motion of planets around the sun, the motion of satellites around the planets, the falling and throwing motion of ground objects, the determination of comet orbit, precession and the degree of conformity between tidal phenomena and gravity. And for the first time, the movement of the ground and the movement of celestial bodies are linked mathematically.
Newton's view of time and space is absolute, although it cannot correctly reveal the unity of time and space as a form of material existence.
Sex cannot correctly reveal the unity of matter and motion, but it correctly reflects the classical theory when the speed is much lower than the speed of light.
The foundation is a scientific summary under the experimental conditions at that time and a milestone for human beings to understand nature.
1.2 famous Newton's three laws
After defining these concepts and establishing the concepts of time and space, Newton brilliantly expounded the famous three laws of motion.
This law holds that unless a strong force is applied, any object will remain at rest or move in a straight line at a uniform speed.
Force it to change this state. "
"The change of the law motion is directly proportional to the applied power, and it occurs in the straight direction of the applied force."
"Every action of the law always has an equal reaction force and its relative resistance, or two objects are mutually resistant.
Roles are always equal, pointing to each other. "
Newton's three laws were discovered on the basis of observation and experiment, and have been recognized as macroscopic natural laws and become mathematics.
The basis of deduction. The first law is based on the laws of inertia of Galileo and Descartes, which is of great significance to today's things.
For Neo-Confucianism, it almost naturally became the basis of mechanics. The second law is that after defining the concept of quality, Galileo
The development of dynamic thinking is the core of the three laws of motion. Newton's first and second laws are closely related. The first law
It shows that a particle without disturbing force maintains its original motion state, and the second law shows that force can only cause its original motion.
Dynamic changes. So these two laws deny that before the Galileo-Newton era, it was necessary to be strong to keep moving.
Wrong point of view. The third law can be said to be Newton's most creative and unique contribution to the development of mechanics. It
The establishment of this law points out that every force has its reaction force, thus making a complete summary of the concept of force. Look at these three.
The law of motion of an object, which sounds simple, is the basis of the whole dynamics. This foundation, after Newton laid it,
It has become the basic starting point of modern dynamics and celestial mechanics research, so it has won the attention of physicists, even all scientists and nature.
Great concern of philosophers.
1.3 million law of gravity
On the issue of gravity, Newton conceptually affirmed the identity of gravity on the earth and gravity between celestial bodies, which is of great significance in the history of science. Starting from the establishment of a general mechanical system, he ruled out secondary factors and used superb mathematics to deal with variable problems. On the basis of the inverse square theorem of gravity known by predecessors, he linked the centripetal force with the mass of objects and celestial bodies, and extended it to the universal law of gravitation with his law of reaction. Use everything
According to the theory of universal gravitation, Neptune and Pluto were discovered, which explained many ground phenomena and celestial phenomena in the next few hundred years, such as Halley's comet and the oblateness of the earth. This law has been strictly tested in practice and has been recognized by the whole century. Until today, the law of universal gravitation is still one of the most accurate and reliable basic laws, and it is also the basis of celestial mechanics and space navigation calculation.
The influence and enlightenment of Newton's achievements and the establishment of classical mechanics on the development of modern science
When talking about Newton's achievements, Engels said that Newton "created scientific astronomy with the help of the law of universal gravitation, scientific optics with the help of optical decomposition, scientific mathematics with the help of binomial theorem and infinite series theory, and scientific mechanics with the help of understanding the nature of force". He spoke highly of Newton's scientific contributions. Newton was a great physicist, mathematician and astronomer. The important contributions of his life are 16 and 17 century scientific pioneers' achievements. Marked by the publication of Principles, a complete theoretical system of classical mechanics was established, and the laws of motion of all things in heaven and earth were summarized with a strict and unified theory, which correctly reflected the laws of low-speed macro-motion of macro-objects, thus completing the first comprehensive natural science in the history of human civilization. Mechanics named after Newton is the basis of classical physics and astronomy, and it is also the theoretical basis of modern engineering mechanics and related engineering technology. In addition, in order to explain astronomical phenomena and physical laws, historians also attributed the invention of calculus created by Newton to Leibniz in mathematics. They created calculus and differential equations almost at the same time, which provided the most necessary ideological tools and mathematical means for the later development of natural science and initiated a new era of mathematical development. Similarly, Newton made his outstanding contributions in the fields of heat, optics and astronomy. Like all the great figures in history, Newton made great contributions to mankind, but he was inevitably limited by the times. He attributed the temporarily unexplained natural phenomena to God's arrangement, put forward the so-called "first driving force", and wrote ingenious theological works in his later life. Although Newton had some shortcomings, it was the establishment of classical mechanics that heralded the arrival of a new era and a new scientific civilization.
Newton was the founder of modern theoretical physics. The theoretical system of mechanics established by him can not only explain the phenomena that have been explained by the existing theories, but more importantly, the classical mechanical theory can foresee new physical phenomena and facts, and can prove its correctness through astronomical observation or experiments. Professor Yang Zhenning, winner of the Nobel Prize in Physics, pointed out that there are two driving forces for the development of physics, one is experiment, and the other is the structure of physics itself. Theoretical physics is based on experiments. Without experiments and analysis of objective phenomena, there can be no development of physics. Corresponding to the classical mechanical system, Newton established a new method to study natural science. He stood on the shoulders of giants, based on Bacon's experimental induction, and absorbed Descartes' mathematical deduction system, and formed his comprehensive scientific method, that is, analyzing phenomena through experiments and observations, and then summarizing them into universal laws, that is, comprehensive methods, which opened the door to experimental science and made physics as an experimental science form a glorious system. This has become the wisdom embodiment and one of the important methodologies for human beings to understand the nature of things, and has made immortal contributions to the prosperity of natural science in the past 300 years.
Newton's classical mechanical system and his methodology made physics develop rapidly during the 18 and 19 centuries, and became the program or norm of theoretical physics at that time. It was not until Maxwell's electromagnetic theory was born that human understanding of the objective world extended to electromagnetic field and put forward the concept of electromagnetic field. This can also be considered as a major leap in Newton's theory of gravitational field. The establishment of quantum mechanics and relativity and people's physical understanding of natural processes can be regarded as the systematic development of Newton's thought.
Newton was a great scientist. He occupies a unique position in the history of natural science and has given natural science for more than two centuries.
Both content and structure have their own brands. The physical foundation and methods laid by his classical mechanical system inspire people to conquer.
For more than 200 years, the infinite wisdom of nature has been admired by people. His scientific achievements and philosophical views not only played an important role in promoting the academic and ideological circles at that time, but also influenced some subsequent social changes and had a far-reaching impact on the development of modern science and social progress.
refer to
Gu Shiyi's Outline of Physics History, Tianjin, Science and Technology Press,
Zou, A Concise Course of Physics History, Beijing Normal University Press,
Ding et al. A Concise History of Physics, Shaanxi People's Publishing House,
Zhou Peiyuan's speech at the 300th anniversary of Newton's Principles,
Qian Lingxi, China Encyclopedia of Physics, China Encyclopedia Publishing House,
China Encyclopedia of Physics, China Encyclopedia Publishing House,