Feynman, one of the most eminent physicists of the 20th century and winner of the Nobel Prize in Physics, proposed Feynman diagrams, Feynman's rules, and reormalized computational methods, an indispensable tool for studying quantum electrodynamics and particle physics.
He is considered the wisest theoretical physicist since Einstein and the first to propose the concept of nanotechnology.
As a leader in the field of quantum mechanics in the 20th century, why would Feynman say: No one in this world understands quantum mechanics?
In fact, more than one physicist has said this, for example, the founder of quantum mechanics, the leader of the Copenhagen School, Bohr, once said: If someone is not confused about quantum mechanics, it can only mean that he does not understand quantum mechanics.
So many physicists have similar words, and there are certainly many secrets in them.
In the history of physics, there is a bizarre, even terrifying experiment, which is called the double-slit interference experiment.
This experiment has confused scientists a lot, in simple terms: the experiment has observers and no observers and the final results of the experiment are different.
During this experiment, photons are imaged on the screen after passing through the double slit, and if they are not asked, interference fringes appear.
If you add a detector to the experimental device to observe how the photons pass through the double slit, a completely different experimental result will appear.
Isn't that amazing?
At first, scientists did not believe it, but after many repeated experiments, this result has not changed.
That is to say, an ordinary physics experiment that eventually involves the observer in it, you say weird?
Whatever the experiment is, theoretical physicists have to describe it in terms of theory.
Around the 1920s, Heisenberg proposed matrix mechanics to describe it, and Schrödinger proposed Schrödinger's wave equation to describe it.
Later, Dirac mathematically proved that the two were equivalent.
In fact, by Heisenberg, Schrödinger and Dirac were already scientists in the third generation of quantum mechanics.
Previously, the first generation was Planck, Einstein; the second generation was Pol, Sommerfeld, Bonn; in addition to Pauli, de Brogli and others.
The gang was not only studying the theory, they also quarreled and split into two factions.
One faction is the Copenhagen School led by Bohr, and the main leaders are Heisenberg, Pauli and others.
The other faction is also very large, led by Einstein, and the main cadres will be Schrödinger, de Broglie and others.
What exactly are they arguing about? To put it bluntly, they are fighting for "this uncertainty."
Heisenberg proposed the uncertainty principle, describing the physical phenomena of the microscopic world.
He believes that the position and momentum information of microscopic particles cannot be measured at the same time, and if one is measured, the other is inaccurate.
So how to understand this?
Let's take, for example, in the hydrogen atom model, we generally think that electrons are orbiting the nucleus of an atom, which is similar to the Earth orbiting the sun.
But Heisenberg believes that the so-called "orbit" is actually imaginary, does not exist, and is not pure enough.
Based on the experimental phenomena of the time, he proposed the uncertainty principle and used this theory to describe the motion of electrons. Specifically, it is described by "probability". Electrons can appear anywhere below, but the probabilities at each location are different, so they can be described by an electron cloud.
This "uncertainty" is something that Einstein could not explain, as he once said in a polemic with Bohr: God does not roll the dice.
And Pol fought back: Einstein don't dictate what God does.
The main leader of the opposition, Schrödinger, even proposed an ideological experiment: Schrödinger's cat.
Satirize the Copenhagen School with the superposition of the cat's dead and alive.
Whether it was Einstein or Schrödinger, one of the big reasons why they couldn't understand quantum mechanics was that they couldn't empathize.
So, who is doing the best job in the current use of quantum mechanics?
Quantum computers in the United States: On October 23, Google published a research paper in Nature to officially declare that it has achieved "quantum hegemony", the traditional supercomputer needs to calculate tens of thousands of years of computation, and its sycammore quantum processor can complete target computing in 200 seconds.
China Quantum Satellite (Mozi): On August 16, 2016, the world's first quantum science experimental satellite "Mozi" was launched at the Jiuquan Satellite Launch Center.
Recently, China has achieved a new breakthrough in the field of quantum.
The team led by Professor Pan Jianwei, a Chinese scientist, has achieved the entanglement of 18 optical qubits for the first time, and this work has always been a very difficult project in the international community.
This time, China has refreshed the world record for the largest entangled state preparation in all physical systems.
For more than 20 years, Professor Pan Jianwei and his colleagues have been working the research path of multiphoton entanglement and interferometry, it can be said that the contribution is indispensable, Professor Pan Jianwei's team has been leading the development of this field of the whole world, and not only in terms of theory, China has been in the first place in the world, and in the future, China can also be further applied to large-scale, high-efficiency quantum information technology to accelerate the development of quantum communication.
All in all, in this era when science and technology determine strength, the progress of science and technology in a country determines the improvement of the overall strength of the country.
The study of physics is certainly inseparable from mathematical knowledge, and Yang Zhenning is one of the few scientists in the physics community who uses mathematics a lot.
He once said: Most of my colleagues in the physics community take a utilitarian attitude towards mathematics. Perhaps because of my father's influence, I appreciated mathematics more. I admire the values of mathematicians, and I praise the beauty and power of mathematics: its tactical ingenuity and flexibility, and its strategic foresight. And, miraculously, some of its wonderful concepts govern the basic structures of the physical world.
Yang Zhenning proposed to "find a wonderful geometric structure", that is, to use mathematics to study physics.
In 1983, when Yang Zhenning introduced his learning process to middle school students, he specifically mentioned a person.
He said: "There is a Mr. Liu Xuanyu, who is a mathematician who has written many articles on mathematics that are easy to understand and extremely interesting. I remember reading an article he wrote about an intelligence test and learning about the extremely important mathematical concepts of permutation and parity. ”
Liu Xuanyu is a famous Chinese mathematician and educator, and he is still a classmate of Yang Zhenning's father.
How good is he? Let me give you an example.
In the history of China, there was a god-like middle school: Chunhui Middle School.
The art teacher at this school is Feng Zikai.
Music teacher: Li Shutong.
Chinese language teachers: Zhu Ziqing, Zhu Guangqian.
Calligraphy class: Yu Right Ren.
In addition, there were Cai Yuanpei, Jiang Menglin, He Xiangning, Ye Shengtao, Zhang Daqian, Ba Ren, Liao Zhongkai, Huang Yanpei, Chen Wangdao and so on.
And who is the math teacher? It is Liu Xuanyu.
Therefore, in this field of mathematics education, Liu Xuanyu is definitely a master-level existence of the Republic of China. For example, the art teacher Feng Zikai often consulted Liu Xuanyu.
Feng Zikai said:
"After I met Kaoru, he made these articles. Every time he published, I read, and tempted me to read, their interesting subjects. I was often unwittingly lured into the world of mathematics.
Every time I think, if there had been such a math book, maybe I wouldn't have abandoned math...
Among them, the "Han Xin Dianbing" article gave me a very bad recollection:
When this article was published, I was suffering from an eye disease, and the doctor told me not to read under the lamp, and when I received the magazine, I read it in one breath under the lamp. The next day, my eyes hurt and I went to the doctor again. ”
I specifically found Liu Fuyu's book to show to my children, my child is in the sixth grade, usually also tutor mathematics, he sometimes feels that going to cram school is a bit boring. But when he read this book, he found it very interesting, and he could also apply what he had learned in the cram school. I looked at it for an hour. Usually, he sits for fifteen minutes to move his ass.
There are three books in this set of books that I read to my children, one is "Mr. Ma Talks about Mathematics", which mainly talks about how to solve some of the four problems of arithmetic using the graphical method
The second book, "Mathematical Fun", mainly talks about the mathematical problems encountered in daily life, we say that all things are mathematics, and learning mathematics through all things is the fastest.
The third book is The Garden of Mathematics, which is a bit more difficult, and it talks about the concepts of functions, continuums, induced functions, differentiation, integrals, and sums, as well as the basic principles of their operations. Although it is a little deep, the method of explanation is very good, my child is in the sixth grade, and he can still understand part of the content.
This book is suitable for elementary school students and junior high school students, and can be used as a self-study textbook for them. Enable them to learn on their own.
This set of books is not expensive, three volumes as long as 69, free shipping to home.
Click on the link below to join the group, this set of books can enlighten such a great physicist as Yang Zhenning, and will certainly get your child's likes:
【There is a room】Liu Xuanyu Mathematics All three volumes ¥68 purchase