Physics studies the phenomena of force, sound, heat, light and electricity. Like refraction, boiling, etc. Hehehe, a very phenomenological explanation is to study nature, solve various phenomena of The Secret Behind and connect them; Or mathematize nature and apply mathematics to the description of natural phenomena to help us understand and use nature.
What is physics?
This is a very basic question. Open any physics textbook, it is not difficult to find such a definition: physics is a natural science that studies material structure, material interaction and motion law. But this is only the academic definition of physics. The "physics" we are facing is also a course, which needs to be re-understood and re-analyzed from the level of educational significance in order to excavate its rich connotation.
First of all, physics is a science.
Physics is a natural science based on experiments, the most mature and highly quantitative precision science, and the most important basic science with methodological nature. The achievements of physics have greatly enriched people's understanding of the material world and effectively promoted the progress of human civilization. As pointed out in the resolution "The Importance of Physics to Society" of the 23rd General Assembly of the International Federation of Pure Physics and Applied Physics, physics is an international undertaking, which plays a key role in the future progress of mankind: exploring nature, driving technology, improving life and cultivating talents.
At the beginning of last century, the establishment of relativity and quantum mechanics gave wings to the rapid development of physics and made unprecedented brilliant achievements, so that people called the 20th century "the century of physics". What 2 1 century? There is a popular saying: 2 1 century is the century of life science. In fact, the more accurate expression of this sentence should be: 2 1 century is the century when physical science is fully involved in life science. Only by combining life science with physics can we achieve greater development.
Looking forward to the future of physics is full of opportunities and challenges. In the article Challenge of Physics, Mr. Li Zhengdao once put forward four difficult problems in the field of physics in the 2 1 century: Why are some physical phenomena symmetrical in theory, but the experimental results are asymmetrical? Why can't half of the elementary particles exist alone and be invisible? Why are more than 90% of the matter in the universe dark matter? Why is the energy of each quasar 10 15 times that of the sun? These problems have greatly inspired people's courage and enthusiasm for unremitting exploration. It can be predicted that physics will show a brighter future once these dark clouds shrouded in the physical sky are removed.
Secondly, physics is a kind of intelligence.
As born, a German scientist who won the Nobel Prize in Physics, said: "If it is because my published work contains the discovery of a natural phenomenon, it is better to say that it contains a basis for scientific thinking methods about natural phenomena." Physics is recognized as an important science, not only because it profoundly reveals the laws of the objective world, but also because it has formed a unique and effective system of ideas and methods in the process of development and growth. Because of this, physics has become the crystallization of human wisdom and the treasure of civilization.
A large number of facts show that the ideas and methods of physics are not only valuable to physics itself, but also have important contributions to the development of the whole natural science and even social science. According to statistics, since the middle of the 20th century, more than half of the Nobel Prize winners in chemistry, biology, medicine and even economics have a physics background. This means that they have learned wisdom from physics and achieved success in non-physical fields. On the other hand, there has never been a case in which a scientist who is not a physics major won the Nobel Prize in physics. This is the power of body intelligence. No wonder some foreign experts pointed out that a nation without sports literacy is a stupid nation!
Nowadays, the tentacles of physics have extended to many fields and made more and more achievements, so that it is difficult for us to distinguish what physics is with traditional eyes. The 9th International Conference on Statistical Physics/KLOC-0 was held in Xiamen, China from 65438 to 0995. The papers exchanged at the conference cover a wide range, such as inflorescence, DNA drug system, traffic flow, character storage and so on. It seems that these articles are not very substantive. What? What is physics? A few years ago, the American magazine Physics Today asked readers for advice on this issue. Finally, their favorite answer is: what physicists do is physics. This seems biased at first glance, but it is not unreasonable. Because today, physics is more of an intelligence, "representing a set of effective steps and methods to acquire knowledge, organize and apply knowledge." When this method is applied to any problem, the problem becomes physics. " (Chinese in TongFu.kabu)
Third, physics is still a culture.
Culture in a broad sense refers to the sum of material wealth and spiritual wealth created by human beings in the process of historical practice. It includes scientific culture and humanistic culture. Similarly, a large number of physical products and spiritual products created by physicists in long-term scientific practice constitute physical culture. Sports culture is an important part of scientific culture.
As we all know, physics is a science based on experiments, and its basic research method is practice, so it shows "truth" in objectivity; The result of physical creation is ultimately to benefit mankind, which embodies "goodness" in purpose; In addition, physics also embodies "beauty" in many aspects such as human emotion and consciousness. It is precisely because physics itself has the triple attributes of truth, goodness and beauty that we have every reason to say that physics is not only a culture, but also a high-level and high-grade culture.
Physics is seeking truth. Physics pays the most attention to argumentation, and the basic attitude of physicists in scientific research activities is seeking truth from facts, and insisting on practice is the only criterion for testing truth. As physicist Feynman said: "No matter how beautiful your idea is, no matter how smart you are, no matter how famous you are, as long as it doesn't conform to the experiment, it is wrong." Simply put, this is science. " It can be said that the development history of physics is a history of "seeking truth" that constantly corrects mistakes and approaches truth.
Physics is good. Physics is committed to liberating people from nature, moving from the realm of necessity to the realm of freedom, helping people to know themselves constantly and promoting people's life to be noble. This is the value orientation and ultimate goal of physics, so the essence of physics is to be good; In addition, the behavior of physicists is also good. Einstein once commented on Madame Curie and the outstanding physicists represented by her: "The significance of first-rate figures to the times and historical process may be morally greater than their pure intellectual achievements." Their rigorous and realistic attitude, persistence in science and love for the people are undoubtedly particularly precious human wealth for future generations.
Physics is the most beautiful. German physicist Heisenberg said: beauty is the glory of truth; The Roman philosopher Prouddin once again said: goodness is the origin of beauty. Therefore, it is natural that physics is beautiful because of truth and beautiful because of goodness. The beauty of physics belongs to the beauty of science, which is mainly reflected in simplicity, symmetry and unity; Symmetry is unity, and unity is simplicity, which is the basic aesthetic principle of physics.
Turning to the chapter of physics, we can find beautiful notes beating everywhere, which embodies people's pursuit and creation of beauty. Take unity as an example. The development of contemporary physics is extending towards two opposite research directions: the largest universe and the smallest particle. Surprisingly, with the deepening of the research, they did not go their separate ways, but went further and further. On the contrary, they show many signs that different roads lead to the same goal and complement each other. For example, some research results of particle physics are often used by astrophysicists to explore images of the early evolution of the universe; (Because of this, particle physics is also called "cosmic archaeology" in a sense. On the other hand, the study of cosmic physics also provides abundant information and proof for particle physicists. As a result, two opposite branches of physics are so wonderfully connected-just like a strange python biting its tail.
For another example, the British physicist William Slacker first discovered the following amazing relationship between some physical quantities in nature:
Cosmic radius/electron radius ≈ 1040, cosmic age/lifetime of strongly decaying particles ≈ 1040,
Electric power of hydrogen nuclei and electrons/gravitational force of hydrogen nuclei and electrons ≈ 1040, ...
In the above comparison, the universe, the largest system, and the elementary particle, the smallest system, have achieved such a perfect unity, and let us once again appreciate the beauty of the physical world, a fascinating and magnificent beauty. It is these beautiful examples that inspire people's sincere admiration and awe of nature. No wonder Einstein said, "The most incomprehensible thing in the universe is that the universe is understandable."
Through the above analysis, we have a more comprehensive understanding of physics: it is not only a science, but also an intelligence and a culture. As a physics teacher, it is necessary to make a comprehensive investigation and analysis of the physics he teaches. On the one hand, we see that physics has such rich connotations, which makes us more consciously explore and play its educational function and improve the teaching quality in an all-round way; On the other hand, we see that physics has such a beautiful temperament, and we will love physics more and engage in physics teaching more passionately. I think that only a physics teacher who really loves physics can not only teach students to understand and apply physics, but also further guide students to understand and appreciate physics.
Second, why teach physics?
This is a seemingly simple but very basic question, and it is not easy to answer it correctly. The author's understanding of this issue has experienced a tortuous and gradual process from "knowledge-based" to "discipline-based" and finally back to "student-based".
For a long time, I have locked the goal of physics teaching in the knowledge level, thinking that teaching physics is to teach physics knowledge as much as possible for students' later life. Because I believe that "knowledge is power". However, it is puzzling that how much physical knowledge we have given students, including such extremely important knowledge as "F=ma", rarely shows any direct effect in their later life and work. Even after several years, many students almost forgot the physics they had learned, and in their words, "they all returned it to the teacher." I am deeply lost for this; However, whenever I ask them "I didn't study in high school for three years", these students who have left school for many years will give a negative answer in unison, agreeing that high school learning has laid an important foundation for their growth, but they can't tell exactly what knowledge has played a role. I think it's like dinner. No one will deny the significance of eating for survival. However, no one can tell clearly where he grew a piece of meat after eating this meal.
A student who graduated for more than 20 years once talked with the author about his "most impressive" physics class. It turned out that that class was about gravitational potential energy. At that time, in order to explain the relativity of gravitational potential energy, I once asked the students this question: someone stood on the windowsill on the fifth floor and wanted to jump. Do you think it is dangerous? At first, everyone thought it was too difficult, but after careful consideration, everyone was happy again: don't jump out of the window, just jump out of the window. The student found this example very interesting, so he didn't forget it for a long time; But when asked what physical knowledge this example showed, he said he forgot. Just when my face showed regret, what he said at once was comforting. He said, "This example made me understand that everything is relative, and different angles will have different results." Although the physics knowledge taught in this course has been completely forgotten by this student, the ideas and methods condensed through the study of related knowledge are deeply imprinted in his heart. In this sense, isn't this physics class more than 20 years ago extremely valuable to him? After graduating from high school, most students may bid farewell to physics, and the physics knowledge they have learned will eventually be forgotten. Then look back: What did physics teaching leave them? If they do not reflect the wisdom and enlightenment given by physics, it will be the failure of physics teaching. From this perspective, specific knowledge is usually only used as a carrier of teaching, and there are more things worth pursuing behind knowledge. As Professor Qian Weichang, a senior scientist in China, said, "I studied physics in college ... I learned the ability to investigate, collect, analyze and think logically with physics as the object. Physical knowledge is sometimes useful, but these abilities learned through physics are more useful than physical knowledge. " When Qian Lao was studying, it was through the carrier of "physics" that he gained many abilities more important than physical knowledge. Therefore, it is one-sided to equate physics teaching with physics knowledge teaching, and it is short-sighted to establish the goal orientation of physics teaching with "knowledge standard".
With the deepening of teaching practice, teachers are generally more and more familiar with the subjects they teach, and they especially like them. Perhaps influenced by this professional emotion, I once set the goal of physics teaching as "training as many students as possible to become physicists or physicists". Especially when I transferred from rural ordinary middle schools to key high schools, I was faced with smart and studious students, and this desire became stronger and stronger. But I soon found that teachers in other disciplines probably have similar expectations for students because of their professional preferences. In this way, everyone sweeps their own snow and sings their own tunes, failing to condense the components of various disciplines into a joint force, and the actual effect is of course unsatisfactory. What makes me particularly depressed is that there are very few "proud students" who are excellent in physics learning in the class, and even fewer who are directly engaged in physics majors in the future. Just when I was confused, an example of Mr. Yang, the former president of Fudan University, gave me great enlightenment. Fudan University has done a survey on the whereabouts of graduates majoring in nuclear physics. The results show that less than one tenth of the students are engaged in jobs related to nuclear physics after graduation, and the rest change careers and are active in finance, enterprises or administrative positions. In this regard, most people assert that this is a failure of the Department of Physics, while Yang thinks it is a success of Fudan University. Because, after four years of undergraduate physics education, students have a good quality and laid a solid foundation for future development, so they can quickly adapt to work in various fields after graduation. This also confirms Mr. Zhao Kaihua's words: "A person can do anything after learning physics, and his physics is not wasted. In my opinion, people who study physics don't care about' changing careers' ... "
After the above tortuous course of understanding, I gradually see the focus of the ultimate goal of physics teaching, not based on knowledge or discipline, but on our educational object-students.
For the question "Why teach physics", we can also ask in reverse: "If we don't teach physics and students don't learn physics, what shortcomings will they leave for their future development?" An obvious answer is that students won't learn a lot of important physics knowledge. This is true, but it is not comprehensive enough. Because in addition, students will lose more important scientific methods and the cultivation and edification of scientific spirit, which will eventually affect scientific literacy. At present, physics has penetrated into all aspects of society and become the knowledge that every educated citizen must know. For most students, the purpose of studying physics today is probably not to further study physics tomorrow, but to help them face or make decisions on a large number of non-physical problems and lay the foundation for their civilized, healthy and high-quality life in the future. As the book Science for All Americans says, "The highest goal of education is to prepare people for self-realization and responsible life." Accordingly, the most exact answer to the question "Why to teach physics" is to teach in order to improve the scientific literacy of all students. This should be the idea of our physics teaching.
As we all know, biological genes play an important role in biological evolution, and extremely subtle genetic differences often lead to great differences between organisms. Inspired by this, many sociologists are trying to find out what is the core element in the process of human cultural inheritance and development, thus putting forward the concept of "cultural gene" and defining it as "genetic code" in the human cultural system. The core of cultural genes is the way of thinking and values. The evolution of human beings is more complicated than the general biological evolution. It has dual evolutionary mechanisms, including biological gene evolution mechanism and cultural gene evolution mechanism. Education is an important way to promote the cultural genetic mechanism. The essence of school education is not only the display and interpretation of cultural phenomena, but also the inheritance and development of cultural genes. Physics education is no exception. What, what are the "cultural genes" in physics teaching? The author thinks that it is mainly embodied in three aspects, namely scientific knowledge, scientific method and scientific spirit, because these three are the most basic elements of scientific literacy. If we compare scientific literacy to a pyramid, what scientific knowledge is like the tower foundation, the scientific method is the tower body, and the scientific spirit is the spire. The highest purpose of physics teaching is to contribute to the construction of this magnificent tower of scientific literacy. In other words, the core value of physics teaching lies in promoting students to realize three transformations: first, transforming the accumulated knowledge of human society into students' individual knowledge, thus making them objective people; The second is to transform the thinking method of predecessors engaged in intellectual activities into students' cognitive ability, so that they can understand why the world is like this and become rational people; The third is to transform the ideas and attitudes contained in knowledge into students' code of conduct, so that they can know how to make the world better and become creative people.