John continued: "Your father's algorithm is indeed the most brilliant work of mankind, but it is far from powerful. So, we can't make the fusion device smaller, and every reactor is like a mountain, which is just too rough. ”

Zhang Yuan looked at these turbulences, some bright, some dim, and some spinning, and fell into deep thought.

Convincing or not, John's complaint was true.

A small ambition arose in his heart, which took root like a seed.

"The question that my father did in the past, perhaps...... Can I too?! ”

The turbulence problem, the last mountain in classical physics. About 400 years ago, the Navier-Stokes equations, also known as the N-S equations, theoretically described the physics of fluids. It is generally difficult to find an exact solution to this equation, so scientists usually use some simplified theoretical models or resort to numerical simulations to predict the motion of fluids.

However, using a simplified model to simulate plasma turbulence is too inaccurate. If these plasmas are not properly constrained, they can cause huge damage to the fusion engine.

The vigorous development of informatics has led to some loosening of the turbulence problem, but it is only a loosening that can be simulated more accurately, but it cannot understand its true nature.

John sighed: "We may never find a mathematically exact solution to the turbulence problem, or we may say that the complete precision is hidden in a more microscopic superposition of probabilities, and in our ability, we are completely unaware." ”

John Wilson is the epitome of pessimism.

He believes that the upper limit of human technology is likely to be the current one, and with human intelligence, it can only go around in such a small circle.

Although there are still some small things to be polished, it is impossible to truly achieve qualitative change.

So, this group of pessimistic scientists wants to board a spaceship and see the world three thousand years from now.

This statement is not unreasonable, a turbulence problem that has not been completely solved for 400 years.

In cutting-edge physics, except for condensed matter, which is still vigorous, everything else has gradually declined. High-energy physics is plagued by the "great desert of energy levels", and other disciplines, such as chemistry and semiconductors, use some approximate theories, and the most important thing is that these approximate theories can indeed solve some problems.

As for mathematics, it is also slowly declining.

The Riemann conjecture has stood tall for 400 years; Goldbach's conjecture, 600 years.

The "Mathematical Unification" project is still just a framework, and it is still tens of billions of light-years away from completion.

The New Civilization School believes that the current 23rd century, plus the 24th and 25th centuries, is likely to be the last golden age of mankind. After that, the overall human intellect cannot continue to develop.

Once the development of science and technology stagnates, human civilization is likely to be like the ancient Xia Kingdom, and the phenomenon of historical reincarnation will continue to occur. To use academic terms, it is difficult to fall into the "trap of mediocrity" and make great historical progress.

Zhang Yuan actually agrees with some of the views of the New Civilization School, but he is neither pessimistic nor optimistic about this issue.

In fact, he doesn't believe that human beings will be stupid enough to fall into the foreseeable trap, and it is difficult to imagine what the future world will be, and maybe there will be some technology to transform the intellect.

In addition, he is engaged in a direction that is more inclined to engineering and technology. Technology and science are still very different, and there is still a lot of room for human application technology improvement.

"Zhang, you're too optimistic."

John shrugged his shoulders and said helplessly: "In history, there are many phenomena, such as Latinization, the middle-country income trap, and so on. Even if some countries know it, they still can't cross it, because there are many things in a country that leaders can't do when they are aware of them. It depends on the strength of the whole. ”

"But the collective power of human beings is not as strong as you think."

"yes, you're right." Zhang Yuan said: "But we have to be optimistic, don't we?" Pessimism is unlikely to solve anything. ”

Bidding farewell to the sentimental Brother John, Zhang Yuan returned to his laboratory seat and began to continue reading the literature.

I stumbled upon a book.

"100,000 Unsolved Mysteries" ......

From astronomy to geography, from mathematics to physics, there are so many puzzles that cannot be solved. For example, the "3x+1" conjecture, the happy ending problem, the Gaussian circle problem, the Erdos-Graham ternary problem...... Just one of them, the difficulty is comparable to that of Li Chai .

I don't know why, looking at the countless problems, Zhang Yuan always has a slight sense of annoyance in his heart.

Perhaps, as a member of the scientific researchers, I can't completely penetrate the instinctive anger of nature.

Zhang Yuan secretly clenched his fists.

At this moment, he finally made up his mind to solve a world-renowned problem.

It doesn't matter whether you gain or lose, you just follow your own heart.

"Turbulence problem!"

"Give it a try!"

It takes a lot of courage.

It is likely that it took a lot of time, nothing could be done, and the sunk cost was huge. Only a young man like him, with his enthusiasm, can move forward bravely.

After making up his mind, Zhang Yuan let out a long breath and slowly calmed down.

From a purely mathematical point of view, there is basically nothing very possible.

Zhang Yuan does not feel that his current strength can write more accurate and effective equations than the N-S equation.

"Perhaps, some informatics methods can be created to solve this problem."

The first method, which was used by my father, is the well-known "spectral method of wavelet transform", which is also the best algorithm in engineering applications at present. It successfully solves the problem of multi-scale turbulence simulation of the internal flow of the engine in time and space.

Essentially, it draws on the transmission of signals in neurons to describe the burst mechanism of turbulence in the duct.

The second method is the direct numerical solution.

By solving the "N-S equation" of incompressible fluids, the isotropic turbulence in a three-dimensional periodic cube is simulated. However, this method is highly computing power-intensive and is suitable for calculating simple turbulent motions with low Reynolds numbers, such as channel or tube turbulence.

Of course, there is the third "RNGκ-ε model", the fourth "Spalart-Allmaras turbulence model", the fifth method "internal and external iterative method", and so on.

Human creativity is unlimited, but there are only a few algorithms that are truly meaningful and have application value.

"Are you looking at turbulence? It's not complicated! ”

Zhao Qingfeng glanced at his screen and said with interest: "I have also studied this aspect of the content, the core reason is that the problem itself is too difficult, strong nonlinear, infinitely dimensional system, chaotic system, these three difficulties do not have very suitable mathematical tools at present. ”

"So if you want to do it, I don't have any particularly good advice for you."

"I know, just take a look." Zhang Yuan hurriedly said.

Senior Brother Zhao smiled and sighed that it was good to be young, if it was him, he would definitely stay away from this kind of problem.

But he didn't care too much, there were many things, as long as he understood it, he would retreat.