What is science? More details ~~~~

The word science, in English, is derived from the Latin word scio, which later evolved into scientin, and finally into today's writing, which originally means "knowledge" and "learning". Fukuzawa Yuyoshi, the famous Japanese master of scientific enlightenment, translated "science" as "science". In 1893, Kang Youwei introduced and used the word "science". Yan Fu also used the word "science" when translating scientific works such as The Theory of Heavenly Evolution. Since then, the word "science" has been widely used in China.

Why do you call it that? science originally means systematic knowledge, and I think maybe so, science in the nineteenth century has been a very large knowledge system, it has been divided into very fine, that is, divided into many, many specialties, and these professional knowledge is not like other knowledge that is not connected to each other. In addition to the concept of specialization, the basic concepts are the same, the basic method is the same, "science" means classification or hierarchical organization, so I think science corresponds to "science" or more appropriate.

The strict definition of science

In fact, since the word science has never been strictly defined, it can cause a series of confusion and unnecessary arguments. For example: was there science in ancient China? Is Chinese medicine science? What is the difference between science and pseudoscience? What is the difference between science and religion? And so on. And these are very, very fascinating questions. So the times demand that we give proper definitions as early as possible to resolve these controversies. Let's take a look at what I consider to be a very strict definition based on existing textbooks and some authoritative treatises, and then we'll discuss what it means exactly, and try to get a consensus in the academic community.

Definition--Science is a body of knowledge that is as close to the truth as possible without contradiction and is a social enterprise

The qualifier "as close to the truth as possible without contradiction" in this definition was added by myself. The reason it was added was to clarify the meaning of science, i.e., to clarify what kind of body of knowledge science is (I still don't understand why many books don't dare to add it explicitly). The "contradictions" are, of course, logical contradictions.

The "body of knowledge" is the initial understanding of science. As a very practical knowledge, it is of utmost importance that it is highly organized and structured. This is more or less characteristic of any classical work, the most famous of which in ancient times was the Principia Geometria. The most organized of the Chinese classical writings, and perhaps it is because I am not a student, that I think the one that has had the greatest impact on me is The Secret of Orange (a chess book). But science as a system of knowledge is no longer so small and narrowly discussed as some systems of knowledge, but is a very large system of knowledge, whose ambition even attempts to encompass everything and nothing. The fact that such a large system still has to maintain a strong organization and structure makes it unique. But there is more than one kind of knowledge system, so it is necessary to clarify what kind of knowledge system science is. The qualification is given in the earlier part of the definition, so skip a paragraph and discuss it again.

Science was recognized early on as a social enterprise, but its significance was deepened over time. And this is not easily understood by people who lack education. How is knowledge expressed in books a social activity again? Can not be understood by others, can not be repeated by others to verify, which itself is not called knowledge, why emphasize its social nature? This is because the scientific understanding of knowledge is far stricter than any other understanding of it. Whether for sorcerers, religious people, civilians or scientists, knowledge means correct statements, correct foresight, i.e., knowledge is what people think of as "truth". But only scientists scrutinize "truth" very strictly. Not only to see whether its initial statements (often called axioms) are derived from intuition, experimentation, or well-founded, but also to scrutinize any details of the derivation process, and to examine whether any of the derived conclusions are in conflict with experimentation or life experience. None of this work can be done by people without scientific training, and therefore requires education, the ****same labor of many scientists, and the understanding and support of the general public in all respects. As science becomes more and more advanced, the more complex it becomes, the more social it becomes.

"Closest to the truth" is to emphasize the qualities of science, compared with others, science emphasizes the most skepticism, because science is based on the premise that there is no foresight. That all knowledge is human knowledge of the objective world, although the scientific pursuit of the unity of the subjective and objective world, but after all, the subjective world and the objective existence is not the same thing, the knowledge is correct, but also close to the description of the world, not the objective world. For example, the ideal gas model describes gases such as oxygen, nitrogen, and carbon dioxide very well at room temperature and pressure because the linearity of the molecules of these gases is much smaller than the distance between them. Van der Waals' modification of the ideal gas model only approximates the description of real gases like water vapor. Scientists know that their theories are approximations to begin with, so they never expect the conclusions derived from their theories to be free of error from the real world. All knowledge is man-made, a product of the subjective world, and even if aliens existed, they could only be more evolved than earthlings, and they would be wrong. The secret of nature exists in nature itself, which expresses itself in its own variety of characteristics, but does not express itself intelligibly in the form of words through the mouth of God. It can be seen that the use of the term "closest to the truth" emphasizes both the rigor of science and its significance for the understanding of the world.

"As far as possible does not contain self-contradictory" the qualifier reflects the pursuit of perfection in science, emphasizing that science also has a growth process. Ordinary people make mistakes all the time, as do great men, and the most revered figures like Isaac Newton, Albert Einstein, and Karl Marx also had erroneous theories. Russell's writings often depict the contradictions of great men, such as Malthus, who advocated birth control to control the population, had three children in four years; Schopenhauer, who advocated inaction, was ecstatic about his late honor; and Bacon, who is known as the originator of experimental science, was unaware of the theory of the great circulation of the blood invented by Harvey, the man who cured his disease. If this is the case with great men, it would be very difficult for the scientific content of all the great men's wisdom to be free of the slightest self-contradictory flaw, and the larger the system, the more difficult it is to be free of error, especially in new disciplines, which require the test of time. Any science has a maturing process. In addition, with the development of the times, the original science may be an approximation of a certain situation, in the unlimited extension of the contradiction may arise, and science will never pretend not to see, must go to resolve the contradiction, so that science to move forward. The theory of relativity, caused by Michelson's experiment, quantum mechanics, caused by the black body radiation experiment, and the mathematical revolution caused by the barber's paradox, were developed precisely by eliminating those self-contradictions.

I think that the definition of science as above uses the fewest words to both express the classical meaning of science, highlight the characteristics of science, make clear the demarcation between science and others, summarize Kuhn's theory of scientific paradigms and Popper's theory of falsification, and emphasize the evolutionary character of science.

Third, the scientific method

To truly understand science, it is not enough to figure out the definition of science. But it is not necessary to master a lot of scientific knowledge in order to understand science, want to quickly understand the shortcut to science, that only master some of the main scientific method.

Science is to seek the truth, that is, how to get the true statement, the classical scientific method has two categories, namely, the experimental method and the rational method, specifically the main is inductive and deductive method.

Induction: the method of elevating a particular statement to a general statement (or principle of law and theorem). Empirical science from observation and experimentation, a large number of original records into a small number of laws and theorems, the formation of a well-ordered knowledge system, which is the process of formation of empirical science. It can be seen what kind of generalization is valid and reliable, which is the most important problem to be studied by empirical science. Since the strict sense of science since the extension of life, never stopped the exploration and debate in this regard. It can be seen that with deeper study, it is found to be a very complex problem. Far more complex than the deductive method. Perhaps it is for this reason that education does not dare to focus on the popularization of the scientific method, so that the public acceptance of scientific knowledge and acceptance of other knowledge seems to be the same, so that they can not distinguish what is scientific knowledge and what is non-scientific knowledge. Here can not strictly discuss the full content of the inductive method, but in order to illustrate the following series of questions, here are some simple mention of the basic points of induction.

Induction is divided into complete induction and incomplete induction, in which the complete induction method has a small range of applications, because for the vast majority of things, the observable phenomena are often infinite. So the practical method of induction is necessarily incomplete induction. It is divided into two kinds of simple enumeration and scientific induction. Simple enumeration is unreliable and can only yield contingent truths, so scientific induction is the center of discussion of the scientific method.

The so-called scientific induction, also known as exclusionary induction, does not necessarily add to the original statement, but excludes possible hypotheses that can be applied to particular instances. Bacon's "Three Tables" and Muller's "Five Methods" are of this type. Muller's Five Methods are briefly listed below. Note that they are based on the premise that there are only two types of phenomena, each with only three elements, namely, a, b, c (phenomena) and A, B, C (causes), and they both presuppose that (1) there is only one condition for the occurrence of a (cause) and (2) only A, B, C are possible conditions (causes).

1. Method of fit: a occurs with AB and also with AC. It can be known that A is a sufficient condition for a. For example, Example 1: in two wheat fields on the application of nitrogen fertilizer (A), a watering (B), a calcium fertilizer (C), the results of the yield are increased (a). Then it can be conjectured that the application of fertilizer (A) is the cause of higher yield (a).

2, difference method: a with ABC, but not with BC, it can be known that A is a necessary condition for a. Such as, example 2: in a wheat field both nitrogen fertilizer (A) and watering (B) and calcium fertilizer (C), the results of the yield are higher (a); and in another wheat field only watering (B) calcium fertilizer (C) is the same yield. It can be conjectured that the application of fertilizer (A) is the cause of the increase in yield (a).

3, fit difference method: a occurs with AB and also with AC, but not with BC. It is known that A is a sufficiently necessary condition for a. Such as, example 3: in two pieces of wheat on nitrogen fertilizer (A), a watering (B), a calcium fertilizer (C), the results of the yield are higher (a), while in the other piece of wheat only watering (B) calcium fertilizer (C) is the same yield. Then it can be further affirmed that application of fertilizer (A) is the cause of higher yield (a).

4, the residual method: B is known to be the condition (cause) of b, C is the condition (cause) of c, abc and ABC together, it can be known that A is a sufficiently necessary condition for a. Such as Example 4: astronomers have observed the orbit of Uranus tilt phenomenon (a, b, c), known tilt phenomenon a, b is by the attraction of two planets (A, B), it can be guessed that there is another planet (C) influence Uranus orbit tilt (c).

5, *** change: A and a in the same way change, while BC does not change in this way. It can be shown that A is a sufficiently necessary condition for a. For example, if the length of the pendulum (A) is changed, the period of the pendulum (a) is changed, but if the mass of the pendulum ball (B) and the material of the pendulum ball (C) are changed, the period remains unchanged. Then it can be considered that the length (A) of the pendulum determines its period (a).

It may seem possible to find the cause and effect of things with little effort by means of scientific induction similar to Muller's five methods above, but in fact it is very difficult. In the case of Muller's Five Laws, the most difficult conditions to fulfill are those two presuppositions, the first called the deterministic axiom, which is not always fulfilled by the emergence of quantum mechanics and chaos science there are not too many deterministic systems in the real world. The second is called the closed system axiom, which is the most difficult to satisfy in scientific research. For example, although the fit-difference method is a very effective research method for deterministic systems, as long as the system is a bit more complex, its closure is difficult to satisfy, and for a simple system such as a single pendulum, it is easier to figure out what are the possible causes (pendulum length, mass, material, etc.) behind a certain phenomenon such as a cycle, but Example 3 is not simple. There are actually many, many possible causes that affect the yield of a wheat field, so the actual study is never as simple as Example 3.

All this talk about induction is really a bummer; it takes a lot of time to get people to understand that the problem of induction is the biggest problem in science, but it's impossible to get people to understand science without emphasizing it. With regard to the empirical problem, modern philosophy has probably not yet put its main effort into the problem of induction, and is still mainly discussing the most basic problems of empirical science, namely, how to describe phenomena, and what kind of description is meaningful. Phenomenology, logical positivism, and the very obscure philosophy of language all dwell on this aspect of the discussion. Indeed these are very important. In fact, the greatest contribution of Bacon, the originator of experimental science, was not so much the method of summary induction as it was the emphasis on how to get the correct original statements. If the original statement is incorrect or meaningless, then all subsequent inductive deduction is futile.

Deduction: the application of general statements (or axiomatic laws and theorems and principles) to derive special statements, or from a statement to derive another statement. At first glance, it may seem that deduction cannot yield anything new, so Bacon's sharp criticism of Aristotle's trinitarianism is not unfounded. But if you change your mind and think seriously about what is "new", you will realize the importance of the deductive method. From Newton's connection between the movement of the stars in the sky and the falling of apples on the earth to the present theory of the Grand Unification, it is evident that there is indeed a possibility of a unified essence behind material phenomena, and that it is thus entirely possible to deduce the correct statements about the various phenomena of the world with very few statements. In this sense, "new" does not necessarily mean a statement outside the old system, as long as it is another expression that has not been seen before it is new, because all the statements that have a real meaning can be placed within a scientific system.

Descartes seems to have recognized this, which is why he despised Bacon so much, and it was through his efforts that the edifice of true practical reason was finally built. He saw the deductive power of mathematics and raised the focus on rational thinking in ancient Greece to unprecedented heights. In the West Descartes is often called the father of philosophy and the father of science, and I couldn't agree more. When did strict science begin, not with Copernicus, not with Bacon, not with Galileo, but with Descartes. Strictly speaking, there is no science without math. Any science that does not involve math can hardly be said to be valid, much less mature.

But mathematics is often not called an empirical science, and is even sometimes called metaphysics, because it is often a theoretical system deduced from a few axioms. For example, the Principia Geometrica is a thick book of just five axioms, and a variation of the fifth of these axioms leads to the Roche and Riemannian geometries. The axioms of mathematics often come from intuition, so it is often called a priori science, in fact, it is not very different from empirical science in essence, only the laws and theorems of empirical science are less intuitive relative to the axioms of mathematics. Euclidean Geometry is the study of real space, of course, it is easy to intuitively get a few axioms, Algebra, Number Theory, etc. is only the study of numbers and equations, of course, may also be based on a few intuitive axiomatic rules, but the Relativity Theory is to be linked to the study of space-time and matter, the laws and theorems of the law are not readily apparent. Mathematics is considered to be the most abstract, in fact, it is its abstraction that is considered to be the basis, the more concrete the object of study involves more factors. Geometry is the basis of science precisely because everything occupies space, and algebra is fundamental because all concepts must be quantized before they can be studied precisely. Abstraction has two meanings: it is a description of a certain aspect of something, and it is difficult to understand and difficult to imagine. Of course in many cases it means both, because an incomplete description of something is not concrete, and is difficult to imagine. Yet abstract theories are practical precisely because we always prefer to describe and process concrete things part by part. Thus the abstract is often foundational. Descartes obviously recognized this, and further proposed some principles that scientific research must follow:

① Put in my judgment only those things that are so clearly and intelligibly presented before my mind that I cannot doubt them at all;

② Break down the difficult problem into small parts as much as possible until it can be satisfactorily solved;

③ Press to begin with the simplest, easiest objects to recognize, rising little by little to the recognition of complex objects

④ enumerate all circumstances as completely as possible, and examine them as universally as possible, so as to ensure that nothing is left out.

These principles, with the exception of the first, which trivializes the role of experiment, are very pithy. The whole of classical science was built according to these principles. Although modern science has supplemented the methods of classical science, the above classical scientific methods are still the most basic and primary methods of science. The so-called analogy, simulation, experiment, analysis and synthesis, and hypothesis should also belong to the classical scientific method, and the functional simulation method, black box method and information method, which are extracted from the system theory, information theory and cybernetics, can only be regarded as the supplement of the scientific method even in the present day when the computer processing capability is extremely strong. The inverted cognitive process of going from the whole to the details cannot be a mainstream method in any case, and is used only as a last resort.

There is a very obvious problem with saying that deduction can't get something new, in terms of what has come out of applying math to the sciences. Comparatively speaking, deduction has more initiative and freedom than induction, because deduction is free to choose the initial axioms, free to formulate the rules of deduction, and in this way can create a large number of theoretical systems, which immediately show their great usefulness once they are found to be applicable to a certain part of the real world, e.g., Riemannian Geometry is used in Theory of Relativity, Theory of Swarms is used in Particle Physics, and so on. In addition, induction itself often requires deduction, and the degree of correctness of a statement needs to be reflected in numbers, due to the inclusion of mathematics greatly reduces the induction procedure and improves the efficiency of induction. For example, De Broglie based on the wave-particle duality of light and detailed examination of the development of the process of physics, expanding the association of the possibility that all particles have wave-particle duality, this process is almost deductive, but according to this hypothesis can be quantitatively predicted by the results of electron diffraction, through the experimental record of the phenomena, the record of the experimental phenomena and the theory of the derivation of the statement of quantitative comparisons from the effective number of the match can be roughly know the hypothesis The degree of correctness of the hypothesis can be approximated from the number of valid numbers that match. Obviously, the effective number is the core theory of the experiment, there are two effective numbers match means only a few percent of the probability of error, there are eight match means only one in a billion probability of being falsified. So quantitative experiments actually compensate for incomplete induction. A few precise experiments can roughly confirm or falsify hypotheses, otherwise hard-to-observe theories like General Relativity would not be recognized.

At this point, we should be able to understand why math is the queen of science. In some philosophers, the distinction between rationalism and empiricism is often compared to an inverted pyramid and a positive pyramid. It is believed that a priori system once a principle or principle is falsified, the whole system into nothing, while the empirical system even if there are a few principles have been denied, but like the pyramid at the bottom of the pyramid to remove a few stones like the pyramid will not fall (such as Newton's mechanics belongs to the empirical science, which did not because of the theory of relativity overthrow a few of its theorems and popped down). Such an analogy is vivid and appropriate, but it is easy to trivialize reason. In fact, this analogy only warns us to be careful to apply the theory constructed by human beings, while rationality is the essence of science, because deduction is not only used to construct theories and apply theories to derive statements, but also dissolves in the process of induction. Science cannot be separated from logic from reason.

"The scientific method may seem uninteresting and difficult to understand, but it is much more important than discoveries in science." International science theory scholars believe that the scientific method is the most important content of scientific literacy, the public understanding of science, the most important thing is to understand the scientific method and apply these scientific methods to solve various problems in their own life and work, in real life, the blind behavior of some people, but also related to the lack of scientific method. Especially in our lack of rational basis of the country should be emphasized to learn the scientific method of thinking.

Fourth, the spirit of science

Because science is often associated with technology, it is easy to forget that science is part of the superstructure, especially in backward societies without a rational tradition, and even a large part of the people do not know that there is the spirit of science. Indeed, few people summarize the spirit of science or promote it. It is for this reason that the influence of science on backward countries is not very great, at least not in all directions.

While I have been teaching an introductory course on science and technology for several years, I have yet to find a systematic exposition of the spirit of science. Here is an attempt at a brief summary of my fragmentary information. The American sociologist of science, Merton, believes that universality, communality, non-self-interest and methodical skepticism constitute the spiritual temperament of science. China's Professor Cai Decheng summarizes the spirit of science as "six elements", namely: objective basis, rational doubt, pluralistic thinking, affirmative debate, practical test, tolerance of incentives. The two scholars have a lot of **** to recognize. In order to make it clearer, I will summarize the spirit of science in the following terms: impartiality, simple entry, pluralistic thinking, confirmation plus falsification, rational doubt, controversy and incentive. Some explanations follow.

1) Impartiality: observing things from an impartial standpoint. I call this spirit of science the Copernican spirit. Some people say that modern science began with Copernicus, although I do not agree, but the greatness of the spirit of Copernicus but marveled. There is no science without the Copernican spirit, and in this respect the Copernican spirit is indeed the forerunner of modern science. Because the observation is always from their own point of view, so in the natural state, people are difficult to detach themselves from their own point of view to imagine and think about the phenomenon, so the self-centered concept of the unconscious formation, when the concept of rigidity with the growth of age, it is very difficult to stand at a certain height to look at the problem, and therefore it is not easy to grasp things. So it is said that justice is the foundation of scientific thinking. In fact, the development of science has increasingly strengthened the sense of justice. The emergence of the theory of relativity has made people realize that not only the earth where we are is not the center of the universe, but also the center of the sun and the center of the Milky Way is not the center of the universe. the defect of Marx's theory in the 19th century is that it emphasizes too much on the standpoint, and the social sciences need to break down the framework of the class and establish a unity without contradiction, and there should not be a theory of the social sciences of the two antagonistic classes. In fact the modern theory of self-organization has taken this step.