Reborn and become a Great Scientist

Chapter 305 44 Chicago Tuner

Mr. Lu Xun once said, "When I see short sleeves, I immediately think of white arms, immediately think of the whole body, immediately think of reproductive organs, immediately think of sexual intercourse, immediately think of hybridization, immediately think of illegitimate children. This is the only imagination of the Chinese people. The first level can make such a leap forward (from "Xiao Zagan", originally published in the first issue of the fourth volume of the weekly "Yusi" on December [-], [-])."

From Lake Como to "Star Wars", from "Star Wars" to aliens, Chen Muwu's performance seemed to perfectly confirm Lu Xun's above-mentioned famous saying before he had time to say it.

But in the end, bringing up the matter of aliens was definitely not a whim of Chen Muwu's sudden explosion of association, but something he did deliberately.

The master said: "When three of us walk together, there must be my teacher."

The situation around Chen Muwu is similar now. Among the three of them on the shores of Lake Como, there is also an "expert" who has considerable experience and achievements in alien research.

This person was definitely not himself, nor was he Dirac, who was "ignorant of anything outside the window and only focused on studying physics", but another Italian physics professor, Fermi.

Fermi's achievements in physics include the thought of "discovering" transuranic elements, but what he discovered was slow neutron nuclear fission, and the construction of the first nuclear reactor in human history, "CP-1" (Chicago Pile 1). No. [-] Pile)", and cultivated many successor talents for the development and inheritance of human physics.

But what many people may not know is that Fermi also studied the subject of "whether aliens exist" and proposed a paradox named after him, the "Fermi Paradox."

Fermi was not only a physicist, he was also very interested in astronomy.

Otherwise, he would not have become good friends with Hubble after going to the United States, and helped the latter to promote the feasibility of using astronomical achievements to win the Nobel Prize in Physics.

Also during a walk to lunch, Fermi and several colleagues had a chance conversation about the UFO reports at the time and the possibility of faster-than-light travel.

Because it was a casual chat, after a few words, everyone's conversation shifted to other topics. However, after the meal was served, Fermi blurted out this sentence, "But, where is everyone?"

The "everyone" in his words refers to aliens that may exist on other planets in the universe.

Fermi was actually not the first person to propose the Fermi Paradox. The real first one was when Chen Muwu wanted to "accidentally" discover the superconducting magnetic effect at the David Faraday Institute. Wells, who was accompanied by Huxley, mentioned the Soviet space pioneer Tsiolkovsky.

He once implicitly and euphemistically mentioned such a thing in his unpublished manuscript.

"Paul, Professor Fermi, I don't drink. I just drank a cup of coffee in the morning, so what I just said was not nonsense.

"I just thought of an interesting thing. Why do we humans deny the existence of intelligent life on other planets in the universe? I think there are only two reasons:

“The first is because if such creatures existed, they would visit Earth;
"The second is that if such civilizations existed, then they would give us some hints of their existence."

Chen Muwu was not shy about the contents of Tsiolkovsky's manuscript, because he had not written it yet.

Dirac and Fermi were confused from the beginning. Why did Dr. Chen suddenly say something about aliens?
The two of them now looked at the Asian who was talking with confusion, waiting for Chen Muwu to continue.

And Dr. Chen did not disappoint: "But, do you think aliens really don't exist? I don't think so.

“It only takes a simple calculation to see that there are some contradictions.

“First of all, from astronomical observations, there are billions of stars similar to the sun in the Milky Way.

"Then among these stars, there should be some planets like the Earth, which means that as long as there is enough atmospheric pressure, liquid water can exist on the surface of the planet.

"And many of these stars and their planets are older than the sun. If the terrestrial planets develop like the earth, then some of them may have developed intelligent life a long time ago.

“Since Dr. Einstein proposed his theory of relativity in 1905, people have begun to consider the possibility of interstellar travel. Those planets developed earlier than us, and their development progress should be faster than ours. It’s impossible to say for sure. Some of these civilizations may have discovered methods of interstellar travel.

"Even if their travel speed cannot reach the speed of light, or even much slower than the speed of light, the Milky Way can be completely traversed within a few million years.

"And many stars similar to the sun are billions of years older than the sun.

“Taking the above together, we should have reason to believe that the Earth has already been visited by alien civilizations, or at least by their detectors.

"But there is currently no convincing evidence on Earth that this has happened."

Previously, when Chen Muwu had not elaborated on his thoughts, the expressions on Dirac and Fermi's faces were unclear.

But now that he had finished speaking all his inner thoughts, the two of them had become dumbfounded.

Dirac even made a rare joke: "Aliens exist. Of course aliens exist. Aren't you a living example, Chen?"

"Paul, stop joking."

It was rare to experience humor from this dull British man, but Chen Muwu would never admit it when faced with Dirac's accusation.

One second he admits that he is an alien, and the next second he will probably be captured. Maybe the mysterious Area 51 in the United States will appear in advance because of his existence.

Besides, I am not an alien at all, so why do I admit this?
However, Chen Muwu was not interested in drinking. It didn't matter what Dirac said. He was always waiting for Fermi's response.

In addition to his achievements in physics research, Fermi also had another unique skill, that is, his estimation level was particularly superb.

Of course, the estimation mentioned here is definitely not a simple and boring question like "how many meters high is this tree" or "how heavy is the mass of this watermelon", but a way to analyze the problem through dimensional analysis. A kind of qualitative and semi-quantitative calculation that uses simple and limited known information to calculate quantities that seem to be impossible to calculate, and make reasonable guesses based on this.

You only need to break a large problem into parts, decompose it into several related smaller problems that are easier to solve, and then estimate them one by one to get an approximate value.

This estimation method is also named after Fermi and is called the "Fermi problem".

A very classic example is called "How many piano tuners are there in Chicago?"This question was overheard by Fermi while chatting with his colleagues when he was presiding over the construction of Chicago React No. [-] at the University of Chicago.

Without specific statistical data, it seemed impossible to answer this question, so the conversation quickly turned to other aspects.

But Fermi didn't think so. He felt that he only needed to adopt some assumptions to divide and conquer the problem.

About 900 million people live in Chicago;
And in Chicago the average household has two people;

About one in twenty homes needs regular piano tuning;
And a regularly tuned piano needs to be adjusted once a year;
Each piano tuner takes about two hours per tune, plus travel time on the road;
Each piano tuner works eight hours a day, five days a week, and works about fifty weeks a year.

With the above assumptions, we can roughly calculate the number of pianos that need to be tuned in Chicago each year:
（900万人）/（2人/家）×（1架钢琴/20家）×（钢琴被调整1次/1年）=在芝加哥每年要调整22万5千架次钢琴。

I don’t know whether the number of more than 20 is too much or too little for Chicago, a large city in the United States.

But no matter how many, it can explain another thing, that is, there are many five-star good citizens in Chicago. Everyone loves to perform some hand, especially finger movements, either sitting in front of the piano and playing the piano gracefully, or He was typing furiously on the typewriter he held in his arms.

Using the same method, it can also be calculated that the average piano tuner tunes a thousand pianos every year.

By dividing the two figures obtained above, you can easily get that there are approximately 220 five tuners in Chicago.

Fermi regarded this matter as a pastime outside of the work of building nuclear reactors. He simply thought about it for a few minutes and then made the above judgment to his colleagues.

Because he was a new immigrant who had just arrived in the United States a few years ago, and he was assigned to a leadership position. Although he had the Nobel Prize, Fermi's position was still not stable.

So after listening to Fermi's speculation, someone was very unconvinced and went to a famous musical instrument store in Chicago to find the owner and piano tuner to investigate.

After a lot of hard work, he got the data that there were about 290 piano tuners in Chicago, which was almost the same as Fermi's estimate after a few minutes.

Of course, Fermi's most remarkable estimate was not an elegant but boring problem like that of a Chicago piano tuner.

That was on the night of July 1945, 7, after the most famous "Trinity" atomic bomb explosion experiment was successfully detonated at the shooting range of the Los Alamos Laboratory in New Mexico.

While Oppenheimer was busy saying his famous saying, "Now, I have become Death, the destroyer of worlds," Fermi, who was also at the observation point near the atomic bomb explosion point, did something else.

Holding a handful of shredded paper that had been prepared for a long time, he suddenly jumped up and threw it into the air. The air wave generated after the atomic bomb exploded quickly swept away the paper.

Fermi ran a few steps after the piece of paper and estimated the yield of the nuclear explosion based on the distance the paper was pushed out.

His estimate was that the energy released by this nuclear explosion was equivalent to 1 tons of TNT.

The official result given afterwards was [-] tons of TNT.

In other words, the difference between Fermi's estimate and the official result is less than ten times, and they are in the same order of magnitude.

After Chen Muwu suddenly saw Fermi today, he raised the question of the existence of aliens on the shore of Lake Como, in order to attract attention and let him make a qualitative and semi-quantitative estimate on this matter.

Historically, it was Fermi who estimated this matter and obtained "the number of highly intelligent civilizations on other planets that may have come into contact with us in the Milky Way", and then found that the existence of extraterrestrial civilizations was too high. It is estimated that there is a contradiction between it and the lack of relevant evidence on the earth, so there is the "Fermi Paradox" named after him.

Sure enough, after listening to Chen Muwu's description of the problem and Dirac's "humorous" answer, Fermi fell into a deep thinking state.

Chen Muwu was looking forward to his answer, but looking at the "tour guide" standing still, Dirac just felt like he was crazy again.

It’s okay for Dr. Chen’s thinking to be a bit wild sometimes. Why would anyone really think seriously about the obviously joke question he raised about aliens?
It is no wonder that the level of Italian physics has declined rapidly since modern times.

Even if such a person can be a professor, doesn't that mean something?

Chen Muwu waited expectantly for Femi's response to this question, but after a few minutes, the other party still made no progress.

It can be seen that Fermi is indeed thinking about the problem, but maybe what Chen Muwu is facing is not the complete form of Fermi. Calculations that will be insignificant to him in the future are actually a bit difficult for Fermi now. Difficulties to overcome.

In this case, there is no need to wait any longer.

Dirac, who wanted to travel around, had already been delayed at the hotel front desk once. Chen Muwu didn't want his good friend to stay where he was and waste time because of his own problems.

"Forget it, Professor Fermi, this is just my unintentional remark, please don't take it too seriously. Let's continue to visit the beautiful scenery around Lake Como. Whether aliens exist or not, it doesn't matter to us. It has no impact on my life.”

But Fermi was as stubborn as Dirac's eyes, and the expression on his face was still serious: "Dr. Chen, I think you raised a great question. At least it is very interesting to me. When I get back, , I want to study this matter carefully."

Chen Muwu couldn't control what other people's brains thought. Since Fermi wanted to continue research, let him go.

The question he raised about aliens was not without merit. At least since then, Chen Muwu and Dirac no longer heard lame tour guides in their ears, and they could finally enjoy the scenery of Lake Como and the Alps in peace. .

　This year's Nobel Prize in Physics has been announced. Unfortunately, no one who has read this book has won the prize.

　　just kidding.

　　As an aside, there seemed to be a bunch of condensed matter physics predictions beforehand...

　　
　
(End of this chapter)