Research in the field of basic science always makes people feel obscure, but we can often see the meaning from some "small things".
On May 6, a screenshot of WeChat chat sent Wei Dongwei, an assistant professor at Peking University, to the hot search again:
According to this screenshot, a technology company made a cluster with PS5 to simulate the physical performance of products, but the more complex the model, the higher the simulation distortion. It took the team including six doctors more than four months to solve this problem. The team guessed that this was "the handling problem of Navistokes equation", but it was not clear where the problem was.
Later, they turned to Wei Dongyi for help. After Wei Dongyi sent all the equations, the team successfully debugged them in one day, and the matching rate with the previous real experimental data was as high as 99.8%.
At the end of the story, Wei Dongyi refused to pay, saying that it was "too easy to ask for money". Finally, the company gave Wei Dongyi a municipal bus card. ...
After listening to this process, some netizens said: "This ending is amazing, and there is a feeling of reading cool articles on the Internet. 」
The unpretentious Wei Dongyi
Wei Dongyi's unintentional "popularity" at first was also due to a hot search.
In May, 20021year, when some media visited the campus of Peking University, they interviewed Wei Dongyi. In the interview video, Wei Dongyi holds a 1.5L mineral water bottle and two steamed buns in plastic bags. His simple image once caused a heated discussion, and he was called "Shen Wei" and "sweeping monk of the Department of Mathematics of Peking University".
Wei Dongyi was promoted to the middle school affiliated to Shandong Normal University in 2007. When I was a freshman, I participated in the 49th International Mathematical Olympiad (IMO) and won the gold medal with full marks. In 2009, when he was a sophomore, Wei Dongyi participated in the 50th International Mathematical Olympiad and won the gold medal again with full marks.
20 10, Wei Dongyi walked to Peking University to study; 20 14 After graduation, I continued to study in Peking University. 20 18 After graduation, he worked as a postdoctoral researcher in Beijing International Mathematical Research Center. 20 19 was hired as an assistant professor in Peking University. His doctoral thesis "Axisymmetric Naville-Stokes Equation and Viscous Damping" won the excellent doctoral thesis of Peking University 20 18.
At present, Wei Dongyi's mathematical research fields mainly focus on analysis, partial differential equations and random matrices.
Physicist Feynman once said that turbulence may be the last unsolved problem in classical physics.
NS equation: the cornerstone of fluid mechanics
Numerical simulation of fluid mechanics is very important for simulating many physical phenomena, such as weather, climate, aerodynamics and plasma physics. Usually, fluid can be described by Navier-Stokes equation (ns), but it is still a difficult problem to solve this kind of equation on a large scale, which is limited by the computational cost of solving the minimum spatio-temporal characteristics.
It was named by French engineer and physicist Claude-Louis Naville and Irish physicist and mathematician George Stokes. It is a set of partial differential equations, which expresses the conservation of momentum and mass when Newtonian fluid moves.
The equation asserts that the change rate (force) of fluid particle momentum comes from the pressure change, dissipation viscous force and gravity acting inside the liquid. Among them, viscous force is similar to frictional force, which is produced by molecular interaction. The thicker the liquid, the stronger the effect.
NS equation relies on differential equation to describe the motion of fluid. Different from algebraic equations, it does not seek to establish the relationship between the variables studied (such as speed and pressure), but seeks to establish the relationship between the rate of change or flux of these quantities. In mathematical terms, these rates of change correspond to the derivatives of variables. Among them, in the simplest case of zero viscosity, NS equation is transformed into Euler equation, which shows that acceleration (derivative of velocity) is directly proportional to the derivative of internal pressure.
This means that for a given physical problem, at least calculus can be used to solve the Naville-Stokes equation. In fact, only in the simplest case can the known solution be obtained by this method. These situations usually involve non-turbulence in steady state (the flow field does not change with time), in which the viscosity coefficient of the fluid is very large or its velocity is very small (low Reynolds number).
For more complicated cases, such as the global weather system or the El Ni? o phenomenon, at present, the numerical solution of Naville-Stokes equation can only be obtained with the help of computers. This scientific field is called computational fluid dynamics.
It is a chaotic model, and when the input is slightly inaccurate, the prediction results will be very different.
Because of its importance, "Naville-Stokes Existence and Smoothness" was listed as one of the seven Millennium Awards in 2000 by Clay Institute of Mathematics in the United States, with a prize of $6,543,800+0,000. Other problems juxtaposed with it include Poincare conjecture, P/NP problem, Hodge conjecture, Riemann conjecture, Jan-Mills theory, Bell and Swanton-Dale conjecture, and so far only Poincare conjecture has been solved.
Back to this matter, the dean of the School of Mathematics of Peking University said in the media reply that someone had sent it to him. He said: "It is common for Wei Dongyi to do things that others can't do. First, Wei Dongyi is very clever. Second, he is very absorbed in doing math. He just lives a simple life, and we respect his wishes. 」
In addition, because the source of the news is only a screenshot of the chat, the authenticity of this incident has also caused some doubts:
what do you think?
Reference link:
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