Scientific experiment is a kind of practical activity with the main purpose of understanding nature. As a research method of understanding nature, it is superior to general observation and production practice in many aspects. Although the seeds and embryonic forms of scientific experiments have appeared in ancient times, they have never been widely used by scientists. With the fierce struggle between natural science, religious theology and scholasticism, a group of philosophers and scientists strongly advocate scientific experiments as a powerful weapon for science to defeat its opponents and enhance its own strength. With the scientific experiment becoming an independent way of social practice, it not only endows modern knowledge of nature with a unique practical foundation, but also promotes the transformation of scientific form, and a brand-new scientific form-experimental science has emerged, which is different from ancient practical science and natural philosophy. Modern natural science is an experimental science based on scientific experiments. As early as13rd century, roger bacon advocated scientific experiments, but due to the limitations of the times, it did not have much impact. In the struggle with church philosophy and scholasticism, Leonardo advocated consulting nature and advocating experimental methods. He believes that science is useless and full of absurdity if it does not come from experiments and ends with definite experiments, because only experiments are the mother of certainty. Leonardo da Vinci is called the pioneer of modern experimental science. Galileo, the founder and main representative of modern experimental science, was born in Pisa, Italy. His father was a poor aristocrat and loved music and teaching. Father's hobbies and personality reappear in his son. Galileo began to study medicine, but because he loved mathematics, he turned to study mathematics and physics. Through the independent study of physical phenomena, he found many serious mistakes of Aristotle, who was regarded as an authority. Although criticized for this, he believes that as long as his views conform to experience and truth, they are correct, and he doesn't care whether they are consistent with others' views. In his life, he not only publicized Copernicus' astronomical theory, but also developed Heliocentrism. He made an astronomical telescope with synthetic lenses and refuted the dogma of scholasticism by observing new facts. Scholasticism holds that spherical celestial bodies are absolutely complete, the sun is flawless, and there can only be one center around the universe. Galileo declared through observation that the sun has sunspots, the moon has valleys, and Jupiter has four satellites, just like a small solar system. Galileo was regarded as a heretic by the church because he supported Copernicus' theory with new discoveries, and was attacked by scholasticism, saying that he violated Aristotle's authority. 16 15, the Roman church summoned Galileo, and Pope Paul V warned him not to "hold, teach or defend" Copernicus. But Galileo didn't give up his view. 1632 published the book Dialogue between Two World Systems (Ptolemy and Copernicus), which caused a sensation in the whole academic circle. This book is called one of the three masterpieces of modern astronomy (the other two are Copernicus's theory of celestial movement and Newton's mathematical principles of natural philosophy). 1633, Galileo was summoned by the Roman church again for publishing a dialogue and was tortured to extract a confession. Galileo was forced to give up his faith, but he was still sentenced to imprisonment. Even so, his passion for science remains. In the case of imprisonment and semi-imprisonment, in the last nine years of his life, he has been carrying out arduous scientific research and completed the book Dialogue and Mathematical Proof on Two New Sciences (the Position of Mechanics and Motion). This book was secretly smuggled to the Netherlands and published in 1638. Galileo's contribution to astronomy is very important, but as far as the development of science is concerned, his contribution to mechanics is even more important. Thanks to Galileo's work, dynamics, that is, the science of moving objects, was established. Aristotle believed that the speed at which an object falls is directly proportional to its weight, so heavy objects fall faster than light objects. 1586, Stevin made an experiment, dropping two balls with different weights at the same time from a height of 30 feet, and found that they fell on the board almost at the same time, and the heavy objects did not fall faster than the light ones.

It is said that Galileo did a similar experiment on the leaning tower of Pisa. Whether Galileo did this experiment or not still has different views in the history of science and technology. In fact, Galileo's important contribution is not that he did an experiment, but that he did a series of ingenious falling body experiments, made a theoretical analysis of the experiments, and expressed the experimental results quantitatively by mathematical methods, thus denying Aristotle's wrong conclusion and establishing the quantitative law of free falling body movement. In order to find out the process and reason of falling body motion, Galileo first introduced the concept of uniform acceleration to distinguish it from Aristotle's uniform velocity. Aristotle believes that force is the cause of motion (speed); Galileo showed through experiments and theoretical analysis that force is the cause of acceleration, and force causes "not the motion of an object, but the change of motion". The speed of free falling body has nothing to do with the weight of falling body, but it increases with the increase of time. The quantitative relationship is that the falling speed v is proportional to the time t, and the falling distance s is proportional to the square of the time t, which is the law of free fall. Galileo verified the above conclusion through experiments of inclined plane and pendulum. Because the speed of free fall is too fast, it is impossible to directly measure the distance and time it takes. Galileo designed and made a smooth slope and plane, and made the brass ball slide down the slope for different predetermined distances. Then, by comparing the time used, it is proved that the ratio of travel distance is equal to the ratio of time square. Some new important facts have been discovered through the slope experiment: the final velocity of the ball has nothing to do with the slope angle, but only changes with the vertical height; When a ball with a certain terminal velocity enters a plane, if there is no external force and the plane is long enough, it will move in a straight line at the original speed and keep moving. This leads to an important mechanical principle, that is, the speed of an object will remain unchanged without the influence of external forces. This is the law of inertia. Before this, since Aristotle, people have always thought that objects can only move if they are constantly subjected to force. The law of inertia completely denies this wrong conclusion and proves that force is the cause of acceleration. In order to eliminate the influence of air resistance on the moving object in the experiment and eliminate the resistance (that is, friction) when the moving object contacts the inclined plane, Galileo carried out a simple pendulum experiment, which proved that the resistance of the medium had little effect on the vibration of the pendulum, and proved that it took the same time for the same pendulum to swing once, regardless of the amplitude of the pendulum. The discovery of the simultaneity of pendulum vibration made Galileo think that it was possible to make pendulum clocks. He once instructed his son and students to develop a simple pendulum clock. After successfully comparing the vibration of pendulum with the motion of falling body, Galileo studied the motion of projectile. According to Aristotle's impulse theory, a projectile rises linearly because of its impulse, and falls vertically under the action of gravity after the impulse is exhausted. Galileo proved that an object moving along a plane, when moving to the end of the plane, on the one hand, should move in the same direction at a constant speed according to the principle of inertia; On the other hand, because the object loses its support, it should fall vertically according to the law of free fall. The combination of these two groups of movements makes the trajectory of the object form a semi-parabola. When an object is thrown along an inclined plane, its trajectory happens to be a parabola. This can be found by the parallelogram law of force. So Newton described Galileo as the discoverer of parallelogram force law.

As the founder of modern experimental science, Galileo not only inspired people how to do natural research with his own experimental results, but also warned people that they must use experiments to obtain the basic principles of physics and test the results of reasoning, instead of blindly trusting books. Galileo, in particular, combined experimental observation with mathematical deduction instead of relying solely on experience. Galileo's experimental methods, mathematical methods and analytical methods have deeply influenced his generation and scientists after him, and become the basic methods of future scientific research. In Galileo's time, some scientists actively advocated experimental methods. Gilbert of England (AD 1540- 1605) is one of them. He appreciates the experience and skills of craftsmen and opposes blind faith in authority. Gilbert did many magnetic experiments and dedicated his books to those who sought knowledge in practice. Because Gilbert was a physician, he had done magnet experiments in front of Queen Elizabeth, so Gilbert's experimental activities and his thought of respecting scientific experiments also had great social influence at that time. The rise of scientific experiments and the establishment of modern scientific methods still depend on the guidance of philosophy. At the juncture of the transformation of science from the Middle Ages to modern times, two outstanding philosophers actively advocated modern scientific methods, which played an important role in promoting the development of science. One is Francis Bacon in Britain (A.D.1561-1626); One is Descartes of France (A.D. 1596- 1650). Although they have different basic tendencies in philosophy and different personalities, they are all people who see the future prospect of new science and use a new philosophy to inspire people to fight for the development of new science. Bacon is a philosopher who insists on the materialism tradition. Among the philosophers in the17th century, he was famous for respecting the craftsman tradition. He believes that the academic malpractice at that time, on the one hand, was that scholars had no experience in contacting craftsmen; On the other hand, the craftsman has no knowledge, and he advocates the combination of the tradition of scholars and the tradition of craftsmen, thus forming a "real legal marriage of experience and rational function." This combination will make the craftsman's craft more effective by using scientific methods; Scholars learn from practical experience and improve their level. In his view, craftsmen's daily operations contain many scientific principles, and these operational experiences are valuable sources of science.

Bacon inherited the ideas of roger bacon, Da Vinci and others, emphasized the extreme importance of experiment to science and attached importance to the role of reason, and finally established the experimental induction method. Bacon believes that in order to obtain correct knowledge, we must proceed from facts, collect a large number of data through experiments, and then make comparative analysis, eliminate irrelevant factors and find out the universal laws in individual things. In New Tools, he not only expounds the importance of induction, but also provides the methods of seeking common ground, seeking differences and * * * changes in inductive logic.

Bacon has never done experiments or put forward the concept of natural science in his life, but he cannot deny his contribution to the development of science. In addition to his contribution to the establishment of the methodology of experimental science, he put forward the idea that "to conquer nature, we must obey nature" on the understanding of the important social functions of science. Because people's scientific understanding of nature and technical control of nature are complementary, Bacon put forward the slogan "Knowledge is power". In his book Utopia, New Island, he outlined the plan of establishing a cooperative group of scholars and emphasized the importance of collective cooperative research of scholars. Under the advocacy of this idea, a number of scientific organizations were established in the17th century, which had an impact on the subsequent scientific development. When evaluating his contribution, Marx and Engels pointed out: "The real ancestor of British materialism and the whole modern experimental science is Bacon." "According to his theory, feeling is completely reliable and the source of all knowledge. Science is experimental science, and science lies in arranging perceptual materials in a rational way. Induction, analysis, comparison, observation and experiment are the main conditions of rational methods. "

Descartes advocated deduction in scientific research and emphasized the significance of mathematical methods. Descartes is a famous mathematician in France. He linked algebraic equations with geometric curves and surfaces, founded analytic geometry, made dialectics enter mathematics, and laid the foundation of modern mathematics-experimental method. He inherited the ideas of Galileo and others and thought that science and mathematics were essentially the same. Philosophically, he is the representative of modern rationalism, emphasizing the role of rationality in the whole process of cognition and advocating relying on human rationality to seek reliable knowledge. He believes that science begins with doubt and advocates rational deduction. In his view, reliable knowledge can only be derived from unquestionable or self-evident axioms and step-by-step reasoning in strict accordance with deductive method. To a certain extent, he saw that experience alone could not provide knowledge about the nature of things, and it was one-sided to think that reason was the source of all knowledge. However, he does not exclude experiments, and thinks that the function of experiments is to establish the consistency between deductive results and physical experiments, which is similar to Bacon's thought.

Descartes devoted himself to observing nature and realized that only "motion" involving space can be dealt with by mathematics. As the founder of analytic geometry, Descartes linked number with geometry, thus showing that space or extension can be expressed by algebraic formula. "He introduced modern mathematical symbols and operation methods, using letters such as X and Y to represent unknown line segments, and letters such as A, B and C to represent known quantities, thus greatly simplifying the solution of algebraic problems. This is a decisive step of great significance in the modern mathematical revolution. Since then, the focus of mathematical thinking has shifted from geometric "shape" to algebraic "calculation". Therefore, Descartes established the unity of science in the research method-mathematics, and the certainty of mathematics ensured the certainty of knowledge, thus establishing the metaphysical foundation for modern science from the perspective of mathematics.

Bacon and Descartes' views seem to be opposite, but in fact they are complementary. Paying attention to experimental experience has become a purpose of the Royal Society and the early French Academy of Sciences. Some French scientists followed Descartes' principles in the18th century and later, and contributed to the establishment of the theory. Bacon and Descartes fully estimated the prospect of science, and thought that natural science would make human beings the rulers and occupiers of nature and bring more benefits to human beings. Because of the spread of scientific spirit advocated by Galileo, Bacon and Descartes, a group of scientists were infected. In order to promote the development of experimental science, many influential societies composed of scientists have been established in various countries. /kloc-Universities established since the 0/3rd century should have contributed to the development of new scientific spirit. However, due to the control of the church, not only philosophy became the handmaid of theology, but also the university became Cinderella in Greek fairy tales. When modern science came into being, the pioneers of modern science were completely divorced from universities. In order to meet the needs of the new era, there must be new organizations that are out of the control of the church. It is in this need that the scientific association was established.

Among the earliest established scientific societies, the most influential one is the Simanto College or experimental society in Florence. It was founded by Vivian (A.D. 1622- 1703) and Torricelli (A.D. 1608- 1647), two outstanding students of Galileo. Before it was formally established, there was already a laboratory funded by nobles, equipped with perfect scientific instruments at that time. Scientists from all walks of life often come here to get together in order to conduct experiments and discuss problems. Simanto College developed from this informal organization. In this experimental society, scientists have carried out many experiments, such as air pressure experiment, solidification experiment of water and its liquid, and also studied basic phenomena such as thermal expansion, electricity and magnetism of solid and liquid. They use complex experimental methods to draw conclusions based on the evidence of observation experiments, rather than relying on speculation. As this is a cooperative research, we can criticize each other. In order to make others accept our own conclusions, the only effective way is to provide experimental observation and calculation results. So that the Royal Society later restricted speculation in this way. For similar reasons, Newton hated the speculative hypothesis in science. Simanto College is an academic group composed entirely of scientists spontaneously, but due to lack of support, it was suspended after only 10 years.

The Royal Society was developed by a group of informal followers of Bacon's experimental philosophy. From about 1645, a group of young scientists led by Wilkins (A.D. 16 14- 1672) met in London every week. In this self-proclaimed "philosophical society" organization, they conduct experiments and discuss scientific issues, covering a wide range of fields, but its members agree that theology and politics are beyond their scope of discussion. Due to population migration and political turmoil, the activities of the Philosophy Association were suspended for some time. At 1660, scientists in London reconvened and proposed to establish a formal scientific institution with the purpose of exploring experimental knowledge. 1662 On July 5th, the Royal Society of King charles ii of Mongolia was chartered, with about 100 members. At the beginning of its establishment, the Royal Society formed a system, that is, specific exploration tasks or research projects were assigned to individual members or groups at the meetings of the Society, and they were required to report the research results to the Society in time. Therefore, in the early meetings of the Society, all members made reports or speeches, demonstrated experiments, exhibited all kinds of strange things and discussed all kinds of questions raised from them. With the passage of time, various special committees have been gradually established to promote the activities of various departments. Disciplinary committees not only carried out research on basic theories such as astronomy, biology and chemistry, but also paid attention to the research on various technical principles and practices, reflecting the characteristics of the connection between science and production in Britain during this period. 1633, the constitution of the society drafted by Hooke, the director of the society, clearly stated: "The task and purpose of the Royal Society is to enhance the knowledge of natural things and all useful skills, manufacturing, mechanical operation, engines and inventions through experiments." The activities of the Royal Society, including the publication of the Journal of Philosophy of the Royal Society, not only attracted a large number of outstanding British scientists at that time, stimulated their creative activities and made contributions in various fields, but also had a far-reaching impact on scientists all over the world. Almost at the same time, a group of French philosophers and scientists started an informal gathering. By 1666, the Royal Academy of Sciences was chartered by King Louis XIV of France, and 12 scientists were appointed as academicians. Scholars are paid by the king, and their research work is also funded by the king. In the17th century, Germany also established many societies, such as the Society for Natural Research and the Society for Experimental Research. But the German scientific society that can really keep pace with the Royal Society and the French Academy of Sciences is the Berlin Society. This college is the result of many years' planning and continuous advocacy by Leibniz (A.D. 1646- 17 16), one of the founders of calculus. Although it was not formally established until 1700, it must be regarded as the product of17th century.

With the support of scientific societies, a new means of academic exchange and knowledge dissemination, namely scientific journals, began to appear. For example, the Journal of Philosophy of the Royal Society published by the British Royal Society, the Papers Report of the Royal Academy of Sciences on History, Mathematics and Physics published by the French Academy of Sciences, the collection of papers and reports of foreign scholars, and the Berlin Institute have also set up their own magazines.

The establishment of scientific societies has promoted the development of experimental science and the progress of scientific instruments. Microscope, telescope, thermometer, barometer, air pump, pendulum clock and some marine instruments were all invented by scientists in experimental activities. The previous tools were all created by craftsmen in production practice. Scientific tools are created in the laboratory, but at the same time they are also applied to other human activities. Of course, the scientific tools at this time are relatively simple, but after all, there is a new beginning. The establishment of early scientific societies marks the transformation of scientific activities, that is, from individual free research of scientists to organized collective research. It makes science a social system and extensive social activities. It is in this organized social activity that scientists have made outstanding scientific achievements. Newton's mechanical system was born under such conditions.