A brief history of the development of mechanics

The earliest knowledge of mechanics originated from observation of natural phenomena and experience in productive labor. People use levers, inclined surfaces, water drawers and other equipment in construction, irrigation and other labor, and gradually accumulated knowledge of the balance of the force on the object. Archimedes of Ancient Greece initially laid the foundation for the theory of static mechanics, i.e., the theory of equilibrium. Ancient people also understood some simple laws of motion, such as uniform movement and rotation, from the observation of the operation of the sun and the moon and the use of bows and arrows, wheels and so on. But the relationship between force and motion was only gradually recognized after the Renaissance in Europe, and between the 16th and 17th centuries, mechanics began to develop into an independent and systematic discipline. Galileo through the study of throwing and falling bodies, on the basis of experimental research and theoretical analysis, the earliest elucidation of the laws of free-fall motion, put forward the concept of acceleration, put forward the law of inertia and used to explain the ground objects and celestial bodies of the movement. 17th century, the end of the Newton inherited and development of the results of the previous research (in particular, the Kepler's three laws of planetary motion), put forward the mechanics of motion of the three basic laws, so that the classical mechanics form a systematic theory. classical mechanics to form a systematic theory. According to Newton's three laws and the law of universal gravitation, he successfully explained the law of motion of falling bodies on the earth and the orbits of the planets. Galileo and Newton laid the foundation of dynamics. In the following two centuries, under the research and promotion of many scientists, it finally became a classical mechanics with a perfect theory. Thereafter, the object of study of mechanics from a single free mass, to the constrained mass and constrained mass system. The symbol of this is the D'Alembert proposed D'Alembert's principle, and Lagrange established the analytical mechanics. Subsequently, Euler further applied Newton's laws of motion to the equations of motion of rigid bodies and ideal fluids, which is regarded as the beginning of mechanics of continuous media. The combination of the laws of motion and the laws of physical properties prompted the twinning of the basic theory of elastic solid mechanics and the basic theory of viscous fluid mechanics in the world, and in this regard the contribution of Navi, Cauchy, Poisson, Stokes and others. The establishment of the basic equations of elastic mechanics and hydrodynamics has made mechanics gradually separate from physics and become an independent discipline. The theoretical system from Newton to Hamilton formed the classical mechanics in physics. After the establishment of the basic equations of elasticity and fluid, the given equations are difficult to solve for a while, and many applied mechanical problems in engineering technology still have to rely on empirical or semi-empirical methods to solve. This makes the second half of the 19th century, in the mechanics of materials, structural mechanics and elastic mechanics, hydraulics and hydrodynamics has been a significant difference in style between the beginning of the 20th century, with the emergence of new mathematical theories and methods, mechanics research and vigorously developed, the creation of many new theories, but also solved a large number of key problems in engineering and technology, such as aerospace engineering in the acoustic barrier and thermal barrier problems. engineering, such as the sound barrier problem in aerospace engineering and the thermal barrier problem in aerospace engineering. At this time, the pioneers are Plante and Kamen, who are good at insight into the essence of things from the complex phenomena in the mechanics research work, but also to find a suitable mathematical way to solve the problem, and gradually formed a set of unique methods. Since the 1960s, the application of computers has become more and more widespread, and mechanics has made new progress both in application and theory. The development of mechanics in China has gone through a special process. Almost simultaneously with ancient Greece, ancient China on the balance and simple forms of motion already have a considerable level of knowledge of mechanics, but the difference is not established like Archimedes as the theoretical system. By the end of the Ming and the beginning of the Qing Dynasty, Chinese science and technology had fallen significantly behind Europe.