Wandering Spaceship in Deep Space Chapter 89: 100,000 unsolved mysteries

　　 John continued: "Your father’s algorithm is indeed the most outstanding work of mankind, but it is far from powerful enough. Therefore, we cannot make the nuclear fusion device smaller. Each reactor is like a Like a mountain, it's too rough."

　　 Zhang Yuan looked at these turbulences, some were bright, some were dim, and some were spinning, lost in thought.

　　Whether he is convinced or not, John's complaint is indeed correct.

　　 There was a small ambition in his mind, which took root like a seed.

　　 "The problem that my father once did, maybe... I can too?!"

　　 Turbulence problem, the last mountain in classical physics. About 400 years ago, the Navier-Stokes equation, also known as the N-S equation, had a theoretical description of the physics of fluids. This equation is generally difficult to find an accurate solution, so scientists usually use some simplified theoretical models or resort to numerical simulation methods to predict the motion of the fluid.

　　 But using a simplified model to simulate plasma turbulence is too inaccurate. If these plasmas are not well restrained, it will cause huge damage to the fusion engine.

The vigorous development of 　　 informatics has caused some loosening of the turbulence problem, but only some loosening, which can be simulated more accurately, but cannot understand its true nature.

　　 John sighed: "We may never find a mathematically accurate solution to the turbulence problem. Perhaps it is completely accurate hidden in a more microscopic superposition state of probability. With our ability, we don't know at all."

　　John Wilson is a typical representative of pessimism.

　　 He believes that the upper limit of human technology is probably already the current one. With human IQ, you can only move around in such a small circle.

　　 Although there are still some minor details to be polished, it is always impossible to truly achieve a qualitative change.

　　 So, these pessimistic scientists want to board the spacecraft and want to see the world three thousand years later.

　　This statement is not unreasonable. A turbulence problem has not been completely resolved after four hundred years.

　　In cutting-edge physics, in addition to condensed matter which maintains vigorous vitality, everything else has gradually depressed. High-energy physics is plagued by the "energy-level desert." Other disciplines, such as chemistry and semiconductors, use some approximate theories. The most important thing is that these approximate theories can indeed solve some problems.

　　 As for mathematics, it is slowly going downhill.

　　 Riemann’s conjecture, stood for 400 years; Goldbach’s conjecture, 600 years ago.

　　 The "Mathematics Unification" project is still only a framework, and there are 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 intelligence cannot continue to develop.

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

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

　　 He actually doesn't believe that human beings will fall into a foreseeable trap. It is also difficult to imagine what the future world will be like. Maybe there will be some technology that transforms intelligence.

　　 In addition, his direction is more engineering and technical. There is still a big difference between technology and science. There is indeed a lot of room for the improvement of human application technology.

　　 "Zhang, you are too optimistic."

　　 John shrugged his shoulders and said helplessly: “In history, there are many phenomena, such as Latin America, middle-income traps, etc. Even if certain countries know it, they still can’t cross it, because a country’s Many things can’t be done without the leader’s awareness. It depends on the power of the whole."

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

　　 "Yes, you are right." Zhang Yuan said: "But we have to be optimistic, don't we? Pessimism can't solve any problems."

　　 Saying goodbye to this sentimental brother John, Zhang Yuan returned to his laboratory seat and began to read the literature.

　　 flipped to a book accidentally.

　　 "One Hundred Thousand Unsolved Mysteries"......

　　 From astronomy to geography, from mathematics to physics, there are too many problems that cannot be solved. For example, the "3x+1" conjecture, the happy ending problem, the Gaussian circle problem, the Erdos-Graham ternary problem...any one, the difficulty is comparable to that of the Lebanese guess.

　　 I don’t know why, looking at countless problems, Zhang Yuan always feels a slight irritation in his heart.

　　Perhaps, as a member of a scientific researcher, I cannot thoroughly penetrate the natural instinct of irritation.

　　 Zhang Yuan squeezed his fist secretly.

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

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

　　 "Turbulence problem!"

　　 "Try it!"

　　 It takes a lot of courage.

　　 may have spent a lot of time, nothing can be achieved, and the sunk cost is huge. Only a young man like him can move forward courageously with his blood.

　　 After making up his mind, Zhang Yuan let out a long sigh and slowly sinked his mind.

　　From a purely mathematical point of view, there is basically no big possibility.

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

　　"Maybe ~IndoMTL.com~ can create some informatics methods to solve this problem."

　　 The first method is the famous "wavelet transform spectral method" used by my father, and it is also the best algorithm in current engineering applications. It successfully solved the problem of multi-scale turbulence simulation of the internal flow of the engine in both time and space.

　　 In essence, it uses the signal transmission process in neurons to describe the bursting mechanism of turbulence in the pipeline.

　　 The second method is a direct numerical solution method.

　　 simulates the isotropic turbulence in the three-dimensional periodic cube by solving the "N-S equation" of the incompressible fluid. However, this method requires high computing power and is suitable for simple turbulent motions with low Reynolds numbers, such as channel or tube turbulence.

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

　　 People’s creativity is limitless, but there are only so few algorithms that are truly meaningful and useful.

　　"Are you looking at the turbulence problem? This thing is not so complicated!"

　　Zhao Qingfeng glanced at his screen and said with interest: "I have also studied this aspect. The core reason is that the problem itself is too difficult, strong nonlinearity, infinite dimensional system, chaotic system, these three For this difficulty, there is currently no very suitable mathematical tool."

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

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

　　 Senior Brother Zhao smiled, feeling that being young is so good, if it were him, he would definitely be far away from this kind of problem.

　　 But he doesn't care too much, there are many things, as long as he understands it, he will retreat.