Chapter 683 If I Don't Dig a Hole for the Devils, Wouldn't It Be a Waste of Time to Travel Through Time? (Part 1)

"What?"

In the base office.

Hearing what Xu Yun said.

Li Jue subconsciously stood up from his chair and stared at Xu Yun:

"Xiao Xu, can you get meat from abroad?"

Xu Yun nodded slightly. He had actually considered this plan a long time ago:

"Well, I am quite confident - but the meat obtained by this method can only be used for making dumplings in our base at most, and it can only be done once."

"Imagine the long-term and huge amount of winter wheat traded with the bears. This is completely impossible."

Xu Yun was telling the truth.

In a sense, the product of Coke is a unique copy. Its position in the bear trade is irreplaceable and cannot be replicated. Even if Xu Yun wants to come up with another similar product, it is unlikely.

So his goal this time is very clear, which is to prepare enough meat for the New Year's Eve dinner on New Year's Eve.

"It doesn't matter if it's only once!"

Li Jue quickly waved his hand and said:

"Xiao Xu, as long as we don't use our domestic reserve meat, you can do whatever you want with the New Year's Eve dinner this time!"

Xu Yun's expression relaxed slightly:

"Then Director, can you guarantee that the meat won't be stolen?"

These days, domestic academic stealing is relatively rare, but material interception often happens.

And the interception of materials during this period is basically related to words such as human feelings and friendship, a bit like the way the brigade commander in "Bright Sword" asked Li Yunlong for the cavalry battalion - [We are so old, it's okay to take something from you? ]

This kind of thing related to friendship is more complicated than official interception, especially for a big man like Li Jue who has complicated relationships in the army. Xu Yun doubts whether there will be five cows left when the fifty cows are delivered to the base.

But what made Xu Yun relieved again was

Li Jue nodded vigorously again, and pointed his chin towards Lao Guo:

"Don't worry, if you can really get beef and mutton from abroad, I will let Lao Guo and the Fifth Division come forward and use the relationship with the Academy of Sciences to approve the meat."

"As long as the meat you bring back can pass the customs inspection, I guarantee that not a single beef will be missing when it is delivered to the base!"

Xu Yun:

"."

Then Li Jue paused and asked Xu Yun:

"Xiao Xu, you don't have to worry about picking peaches. The key to this matter is actually..."

"Who are you going to do this business with? The Russian bear? Europe? Or across the sea?"

"And what are you going to use to convince him We? It can't be Coke again, right? "

Faced with a series of questions from Li Jue, Xu Yun shook his head slightly:

"Director, I'm not thinking of doing business with the bear or Europe this time. I'm going to change my target. Ahem, change my target. "

"Actually, speaking of beef. Director, we have a neighbor next door who is very good at beef."

"Neighbor?"

Li Jue was stunned for two seconds, and then he thought of something:

"Xiao Xu, are you talking about Neon?"

Xu Yun laughed twice, and an inexplicable light flashed in his eyes:

"Yes, it's Neon!"

As everyone knows.

As a famous island country, Neon's terrain is mainly mountainous and hilly, with marine climate characteristics and warm and humid climate.

In addition, there are many volcanoes in the country, the soil is fertile, and the domestic vegetation coverage rate is as high as 60%, so it is a natural beef farming country.

Probably after the Meiji era.

Neon cattle breeds and foreign cattle breeds mate to produce four types of cattle, namely black-haired Wagyu, brown-haired Wagyu, Neon hornless cattle and Neon hornless cattle.

These four types of mixed-blood cattle are what later generations call "Wagyu".

Of course.

At this time, the Wagyu breeding industry chain is not as complicated as later generations, and Neon has not carried out large-scale hunger marketing for Wagyu. Therefore, there is still a clear difference between Neon's "Wagyu" and the later 5A Wagyu.

The characteristic of Neon Wagyu during this period is that it has a lot of fat. Neon's annual beef cattle production is about 70,000 heads.

More importantly.

The main reason why China banned the import of Neon beef for a long time in later generations was the outbreak of mad cow disease in 2001:

At that time, all cattle-raising countries in the world except Australia and New Zealand were affected by mad cow disease. Neon banned the import of feed from across the sea in 2003, because it was common to crush beef and bones and add them to feed across the sea, which was later considered to be an important cause of mad cow disease in cattle.

Even until 2023, Japan is still a mad cow disease epidemic area.

But what is interesting is that.

In Japan's list of wagyu exporters, Cambodia has been ranked first for 7 consecutive years, which is worth pondering - are these wagyu really eaten by Cambodians?

Ahem

Let's return to reality.

Although mad cow disease is considered a serious disease in later generations (why is this sentence weird), Japan's beef is still quite safe at this time.

Moreover, the fat of Japanese beef is not greasy at all for the current base employees. If they can really exchange a batch of beef from Japan.

Thinking of this.

Li Jue couldn't help licking his mouth and asked Xu Yun:

"Xiao Xu, what are you going to use to exchange beef with the Japanese?"

Then, without waiting for Xu Yun to answer, Li Jue added:

"By the way, if it is some important or helpful technology to Japanese people, I advise you to think about it first."

Lao Guo beside him also nodded in agreement. He also thought so.

Although the New Year's Eve dinner for the base staff is very important, if some important technology is taken away for this meal, it will be a bit of a loss.

Lao Guo and Li Jue are not worried about Xu Yun's awareness, but they have never been very confident about Xu Yun's values ​​or cognition - they are afraid that Xu Yun will think that some technology has no value in the future and will just throw it away in exchange for a meal.

Facing Li Jue's concerns, Xu Yun shook his head:

"Director, don't worry, I'm not giving the Japanese any important technology this time."

"On the contrary, if they are not careful, they may fall down on it."

"Fall down?"

After hearing these three words, Li Jue hadn't reacted yet, but Lao Guo understood Xu Yun's meaning first:

"Xiao Xu, are you going to dig a pit for the Japanese?"

Xu Yun nodded heavily, and then, fearing that Lao Guo and the others would not be able to bear to do such a thing, he deliberately added:

"Engineer Guo, this is what the Japanese deserve, I'm just going to return the way they originally tricked us to them."

Lao Guo's eyebrows immediately raised.

Xu Yun's words were full of meaning.

Then he thought for a few seconds and asked Xu Yun:

"Xiao Xu, what are you going to use to exchange with the Japanese?"

Xu Yun glanced at him and slowly uttered a few words:

"Mixed angle of neutrinos."

After that,

Xu Yun's eyes also showed a trace of emotion.

Neutrino.

This is the earliest particle that humans have come into contact with, but it is also the most mysterious one.

As we all know.

Any physical phenomenon should satisfy the law of conservation of energy, momentum, and angular momentum, and nuclear reactions are no exception.

However, scientists have found that the beta decay of the nucleus (releasing an electron) does not seem to satisfy this situation.

In order to explain this phenomenon, physicist Pauli proposed that the nucleus will also emit a kind of uncharged particle that is difficult to detect during fission.

This is the neutrino.

It is worth mentioning that Chinese physicist Wang Ganchang, the comrade Wang Jing who is now tinkering with the accelerator in the base, proposed a method to detect neutrinos in 1941.

But China was still in the war of resistance at that time, and there were no experimental conditions at all.

Later, neutrinos were discovered by two other American physicists and won the Nobel Prize.

Neutrinos are a bit similar to quarks, and there are also three "flavors" in total:

electron neutrinos, muon neutrinos, and tau neutrinos.

They are produced in nuclear reactions involving electrons, muons, and tauons, respectively, and can only react with corresponding particles.

These three types of neutrinos can convert into each other while flying at close to the speed of light. Physicists call this phenomenon neutrino oscillation.

In the future that Xu Yun traveled to.

Neon's Super-Kamiokande detector, China's Daya Bay reactor, and Jinping Deep Earth Laboratory, which is the underground experimental center where Xu Yun and his team verified dark matter, have been conducting neutrino-related research for a long time.

The country with the most achievements in neutrinos in the future is naturally Neon, and they have won the Nobel Prize many times for their neutrino-related research.

But few people know that

In the process of studying neutrinos on Earth, Neon once pitted the Chinese physics community.

This pit is the mixing angle of neutrinos.

Mentioned above.

Neutrinos have three different "flavors", and these three flavors of neutrinos can be converted into each other with corresponding leptons through weak interactions, such as anti-electron neutrinos and protons undergo reverse β decay to produce positrons and neutrons.

But in fact,

There is another more magical way for neutrinos to transform, that is, neutrino oscillation.

This is a quantum mechanical phenomenon that refers to the transition between different flavors of neutrinos as they propagate through space.

In 1957.

Theoretical physicist Bruno Pontikov first proposed the conjecture of neutrino oscillation, and a series of experiments have observed this phenomenon since then.

To understand the principle of neutrino oscillation, you first need to know two things:

First, neutrinos have mass, and second, the flavor eigenstates and mass eigenstates of neutrinos are not exactly the same.

According to the special theory of relativity, massless particles must move at the speed of light.

If neutrinos have no mass, then they cannot change their speed and cannot oscillate.

However, experimental observations show that neutrinos do have non-zero masses, although they are very small.

The absolute mass of neutrinos has not yet been directly measured, but their relative masses can be inferred by observing the squared difference in mass between them.

Then there is the eigenstate.

In particle physics, an eigenstate refers to a state in which a physical system has a definite value on a certain observable quantity.

For example, a neutrino with a definite value of e, μ or τ in the flavor observable is a flavor eigenstate, and a neutrino with a definite value of m1, m2 or m3 in the mass observable is a mass eigenstate.

If these two eigenstates completely coincide, then there is no neutrino oscillation.

But in fact, these two eigenstates are connected by a unitary matrix U, which is called the PMNS matrix, which can describe the conversion relationship between the flavor and mass of neutrinos.

The PMNS matrix contains three mixing angles θ, θ and θ and a CP violation phase δ for parameterization.

Mixing angles are important physical quantities that describe the neutrino oscillation intensity. They reflect the degree of coupling between neutrinos of different flavors.

These mixing angles cannot be predicted theoretically and can only be measured experimentally.

Among the three mixing angles.

θ and θ have been measured long ago, and θ is the most difficult to measure because its corresponding value is very small.

However, θ is of great significance for detecting the CP violation phase angle δ and determining the neutrino mass order (that is, the size relationship between the three mass eigenstates). Therefore, measuring θ is an extremely important and challenging task.

Later, the rabbits carried out the measurement of θ at the Daya Bay reactor. This is also the first international cooperative basic scientific research project with a truly important international influence that the rabbits have participated in since the founding of the People's Republic of China.

The test station project was approved in 2006 and officially started in 2007.

However, in the first two years, the 17 sets of data provided by the Neon Super-Kamiokande Detector Laboratory, which was responsible for providing basic parameters, were all wrong.

The rabbits spent two full years and about 7 million yuan (another saying is 15 million yuan) for this. Although the angle of θ was finally accurately measured by the rabbits, the cost was still too high.

This is not over yet.

If the timeline is pushed back 18 years from the period when Xu Yun and his team were, the Japanese will do something about neutrinos.

At that time, a Japanese person would give the rabbits a set of theoretical physics teaching books mixed with a lot of wrong knowledge together with the [interest-free loan] at that time on the grounds of supporting the rabbits' education.

Then the so-called [interest-free loan] was more than doubled due to the Plaza Accord, which caused the yen to appreciate against the US dollar by more than double, and the depreciation of the Chinese currency, which eventually made the rabbits actually repay the yen debt more than double the loan.

And that set of theoretical physics teaching books misled two whole classes of Chinese theoretical physics college students, so if you look at the educational records of those academicians, you will find that there is a talent gap in time in these few years.

At that time, some turbulent periods had ended for many years. The main reason for this talent gap was the problems in that set of physics books.

For example, the perturbation calculations in that set of textbooks.

The path integrals in that set of textbooks were completely randomly expanded, resulting in additional interactions in the kernel term.

At that time, due to the domestic knowledge blockade, many scholars thought that this was a brand-new derivation method in the world.

For example, in order to make the functional method they invented seem reasonable, the Japanese even discussed an ordinary differential equation to obtain an approximate solution, and then compared it with the numerical solution for reverse deduction, and built a "theoretical framework" that did not exist at all.

Researcher Chang Yuan of the Department of Physics at Jinling University spent a full five years studying this set of ordinary differential equations. After learning the truth, this matter became a pain point in his life.

It was a coincidence.

The person who donated those textbooks to Huaxia at that time was Xu Yun's old acquaintance Suzuki Atsuto.

Now that the Japanese side's research on neutrinos is still in its initial stage, facing this account that is only little known but actually has a great impact, how could Xu Yun not calculate it carefully?

Note:

The reader group is reopened