Shen Qi visited the Institute for Advanced Study in Princeton, and he found that there were no high-end experimental equipment here.

The people here are generally older, but there are also a very small number of young people.

Whether they are old or young, people are leisurely, drinking coffee, looking out the window at the tall maple trees, writing a few symbols and strings of formulas on the blackboard from time to time, and communicating with their peers.

"As you can see, there is no experimental equipment for condensed matter physics or other advanced equipment in the Institute for Advanced Study. Witten said.

"Well, Edward, this is indeed a mecca for theoretical research. Shen Qi saw with his own eyes that the most advanced physical experimental instruments in the Institute for Advanced Study were springs, hooks, small balls, and dynamometers.

Through these simple instruments, Witten demonstrated to Shen Qi the most classic physics experiment: the interaction force between objects.

"First get the basic laws of universality, and then deduce the whole universe. Shen Qi was inspired by this high school student's physics experiment.

According to Shen Qi's field trip, the main work of the bigwigs in the Institute for Advanced Study is: thinking, drinking coffee, continuing to think, returning to simplicity, and then rebuilding complexity from simplicity.

It is understandable that the math bosses, history bosses, and social science bigwigs in the institute all rely on their brains to complete their work tasks.

The big names in the natural sciences, such as Witten, also rely on brain supplements for most of their work, and he hardly does those so-called high-end experiments.

Witten hasn't done an experiment with a cost of more than $20 for a long time, but that doesn't mean he doesn't understand condensed matter physics: "Generally speaking, there are two directions of condensed matter physics, the first is to study the properties and uses of condensed matter and put it into application as much as possible, and the second is to provide theoretical support for the first." For example, we study the theoretical system of topological and geometric properties of defects, while crystal experiments and large-scale applications are left to applied scientists. ”

"Understood, Edward. Shen Qi has experienced some experience through this trip to the Institute of Advanced Study, he and Witten heroes cherish heroes, in the minds of the two, the basic theory is above all else, and the theory has supreme command and direction.

Witten: "If you need to use the regular lab equipment of the physics department at Princeton, I can say hi for you." ”

"Not for now, Edward, thank you. ”

Shen Qi left the Institute for Advanced Study, and he decided to cut in the second direction of condensed matter physics.

Dislocations have quite complex geometric configurations, and their moving properties are mainly determined by their geometric configurations, which are constrained by their basic topological properties.

There are generally two types of dislocations in cubic crystals, blade dislocations and spiral dislocations, as well as the two most basic types of motion, slip and climbing.

The application of the Volterra process in crystals is well known, and the Burgesses vector is the smallest lattice vector in the crystal, so the dislocation definition is gradually clarified.

You can find the relevant knowledge points in any general condensed matter physics textbook, that is, "topological and geometric properties of defects" in condensed matter physics.

The single crystal plane is oriented using an X-ray Laue direction finder, followed by slow wire cutting to a square emission plane with a cross-section.

The resistivity and emitted current density of the crystalline plane-oriented samples rotated in the magnetic field with the applied voltage were measured on the physical property measurement system PPMS, and the crystal plane characteristics were observed by scanning electron microscope and transmission electron microscope.

It took months or even more than a year to produce an article, and more than half of the content of this paper was boring charts and pictures...... Shen Qi doesn't do this kind of thing, which is no different from an ordinary graduate student in the Department of Physics, and is inconsistent with the identity of an internationally renowned master of basic theory.

What Shen Qi wants to do is to complete more than $200 million worth of work at a cost of $20. High efficiency and energy saving, low carbon and environmental protection.

Under normal circumstances, theory precedes experiments and guides experiments. Of course, there are experiments that are ahead of the theory.

The theoretical branch of topology and geometric properties of defects is usually applied to crystal experiments, and it is constantly tested and challenged by various crystal experiments.

Under the prompting of Witten, Shen Qi was keenly aware that the existing defect topology theory based on homotopy groups was really flawless.

He wants to start from this field and find a more perfect theory to support the world's tens of millions of crystal experiments every day and large-scale applications.

"It's exciting. Shen Qi became excited, and at the same time felt pressure, if this project is really completed, I'm afraid it will be more than 200 million US dollars, right?

Only a master of mathematics and physics who is proficient in the theory of condensed matter physics, and is equally proficient in topology, group theory and other mathematical tools, can complete this innovative theoretical research work.

Shen Qi began to build a framework, which had to be applied to an extremely complex mathematical tool—algebraic topology.

Ordinary physicists with a sparse foundation in mathematics can't do this job, and Fields Medal-winning physicists are best suited to do innovative work, such as Edward Witten and Shen Qi.

Suddenly, Shen Qi had an epiphany, and mathematics and physics were rapidly merging in his brain.

Crisscross!

Open and close!

All in one piece!

Shen Qi took the case: "To break this game, the only way to stabilize the ball is to stabilize the Tonglun group!"

The condensed matter physics experiment equipment purchased by Shen Qi is very energy-saving, with a box of A4 paper and a few pens.

Not many people can understand this theoretical research work, which is basically made up by the brain.

Shen Qi doesn't need too many people to understand, he amuses himself, anyway, the academic task of the Department of Mathematics has been completed this year, and "History of Number Theory" has been published and sold.

The study of condensed matter physics is Shen Qi's side job, not even a side job, he is not from the Department of Physics of the University of Liberal Arts, nor is he a researcher or doctoral student in the Department of Physics of the Institute for Advanced Study.

Shen Qi's side job is to teach students, in addition to leading two graduate students, he is also responsible for teaching some professional courses for graduate and undergraduate students.

Princeton has a hard and fast rule that no matter how awesome a professor is, even if he is a Philippine Prize winner or a Nobel Prize winner, he must complete a certain number of hours of graduate and undergraduate teaching tasks every semester.

Today there is a section of Professor Shen's professional course, functional analysis, and graduate course.

Functional analysis is a difficult mathematics major course, which should be studied by both undergraduate and graduate students.

Functional analysis at the graduate level can be seen as an enhanced version of the undergraduate level.

Shen Qi walked into the classroom with his hands in his hands, looked at him for a week, and was very satisfied, no one skipped class.

Not only did no one skip class, but there were also students standing in the corridor between the seats with books and books, and some people sat directly on the ground, waiting for Professor Shen's lecture with great interest.

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(It's super busy these days.,There's only one update today.,Tomorrow's update will be a little later.,Make up for it on the weekend)