After a while, the tea was boiled.

A thick mist floated on the purple clay pot.

After picking up the teacup and taking a sip, and moistening his throat, the old gentleman spoke slowly.

"Of the many problems with partial differential equations, the Navier-Stokes equation is probably the most difficult direction. Except for a few problems, we cannot directly solve the partial differential equations constructed by the Navier-Stokes equations, and can only retreat to the approximate solution. ”

"As for the phenomenon of turbulence, as far as I know, the Clay Institute has been studying it and has invested a lot. However, although there have been some results, they are not big results. ”

"As for the plasma turbulence that you're trying to study, it seems to me to be even more difficult. First, today's computers can't handle that kind of operation, so we can only do approximate solutions. Second, we can't get accurate observation data, and we only have inaccurate diagnostic data to rely on. ”

Lu Zhou: "Why? ”

Mr. Qiu smiled: "Because we don't have an effective observation method for plasmas at equal high temperature pressure. For example, we take a nano-scale probe and poke it into a general gas to collect data on gas molecules, which can basically ignore the disturbance of the probe itself on the movement of the gas. ”

"But high-temperature pressure plasma is different, and we can use electrostatic probes and magnetic probes for mild plasma, but for high-temperature pressure plasma, any small disturbance can lead to the collapse of the whole system. The end result is that the electromagnetic field can no longer confine the plasma, which hits the first wall directly. ”

"Therefore, we can only obtain the relevant plasma parameters from the electromagnetic waves emitted by the plasma itself, so as to build a image-only model. However, because the spectrum of electromagnetic waves emitted by plasma is very broad, although the amount of information is large, the information contained in it is also quite messy, and the image-only model established is only accurate to a limited extent. ”

Lu Zhou asked thoughtfully, "Is there a solution?" ”

"No, this is a technical ceiling," Mr. Qiu shook his head after putting down the teacup and continued in a joking tone, "If you can design an experiment to observe high-temperature pressure plasma, the contribution to plasma physics is probably no less than the contribution of cryo-EM to biology." ”

Hearing this, Lu Zhou's smile was a little helpless.

Although the system includes engineering in the hierarchy, human energy is limited after all, and he has never studied this field in depth, and even if he has obtained a talent improvement, this improvement has not brought him a more intuitive feeling.

It might be okay to let him design experiments.

But to ask him to design experimental instruments is really beyond his ability.

"My personal suggestion is, since there is no way to solve the problem of experimental tools now, why not try to refine the theoretical tools first?" After a pause, the old gentleman looked at Lu Zhou suspiciously, "It stands to reason that mathematics is your strength." ”

The moment he heard this, Lu Zhou was slightly stunned, and a trace of realization suddenly occurred in his heart.

That's right.

Mathematics is my forte.

Since experimental tools can't solve the problem, why not start by refining the theoretical tools?

For example, the NS equation itself is used as a proposition to study, and the relevant theoretical tools are improved while studying the NS equation. Just like when he first studied additive number theory, if there was no previous series of mathematical propositions as a foreshadowing, let him challenge the Goldbach conjecture as soon as he came up, there is a high probability that it will be unsolvable.

Thinking of this, Lu Zhou's thoughts gradually became clear.

In the following time, the problems exchanged by the two were basically focused on the field of mathematics.

For the research in the field of partial differentiation, Mr. Qiu has his own experience.

Although the NS equation is not his research direction, he still has some opinions about the problem of the century that is open in the field of partial differentiation. And these insights are also very helpful for Lu Zhou.

In this way, the minutes passed by minute by second, and the wall clock on the wall unconsciously went through two circles.

The mist on the tea table had long since dissipated, and the tea in the cup had long since cooled.

I don't know how many cups of tea it is, but Zhao Yi, who was sitting next to him, fidgeted and moved his buttocks.

Listening to the two bigwigs exchanging mathematical problems, he, a doctoral student, couldn't insert a word, and wanted to leave but was embarrassed.

I have to say, this is really a painful thing.

Moreover, this pain does not only come from the mental, but also from the physical.

Just now, in order to hide his embarrassment and ignorance by drinking tea, he accidentally drank too much......

In the third hour, the conversation between the two finally ended.

After Lu Zhou said goodbye to Mr. Qiu, Zhao Yi was finally liberated.

Quickly rushed into the toilet when he went downstairs, Zhao Yi, who had finished untying his hand, trotted out of the toilet, caught up with Lu Zhou's footsteps, and asked breathlessly.

"Big guy, what did you just talk about?"

Lu Zhou was in a very good mood, and said with a pleasant face: "We talked about some interesting things." ”

Zhao Yi's eyes rolled and asked, "I heard controlled nuclear fusion, that thing...... Is it true? ”

If it's true, it's just pretty impressive.

Lu Zhou did not answer this question, but asked rhetorically: "What do you understand to be 'true'?" ”

Zhao Yi was stunned for a moment, and described his problem in some general terms: "That is, the kind that can be realized." ”

Lu Zhou said with a smile: "The meaning of science is to use scientific methods to realize those things that cannot be realized, and the problems that have been solved, can they still be studied?" You can't just go through the literature. You're all Ph.D. students, why do you still ask such layman's questions. ”

Zhao Yi's old face turned red when he was asked, touched the back of his head, and smiled embarrassedly.

"Big guy, I want to invite you to dinner, do you have time to see for a while?"

Lu Zhou nodded: "Okay." ”

It's almost time for dinner.

If someone asks him to eat, he won't refuse.

……

After communicating with Mr. Qiu, Lu Zhou was greatly inspired.

As Mr. Lao said, before solving a problem, it is more important to create tools to solve the problem. Compared to the former, the latter is the crux of the matter.

In short, he needed to build a ladder for himself before he could climb over this wall.

And before that, what he had done was like circling around an impenetrable wall.

After the Harvard trip, he returned to the cabin in Princeton, and Lu Zhou, who redefined his research ideas, only felt that every cell in his body was full of inexhaustible inspiration.

Sitting in the study impatiently, facing the brand-new white paper, Lu Zhou turned the ballpoint pen in his hand and whispered to himself.

“…… Building a theoretical model of a plasma, or a more accurate image-only model, requires more accurate observations rather than diagnostic data. ”

"Since the experimental tools can't solve it for the time being, let's start with what I can solve!"

With a slight movement of his neck, Lu Zhou raised his pen and wrote a line of headings on the blank paper.

"Study on the Global Existence of Smooth Solutions of Three-Dimensional Incompressible Navier-Stokes Equations at Specific Initial Values"

Looking at this line of headlines, his eyes were full of energy.

Next, it's time for the happy liver burst again!

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