Vol 2 Chapter 887: Engineering, the new world! (During)

"Boom~!"
Li Zexuan held up his hands and made a gesture of "embrace the world", his posture was extremely chic, but the words he just said were nothing more than dropping a depth bomb, making all the people in the auditorium uneasy!
Zulu! This is the ancestral rate that has troubled the ancestors for so many years! Even now, there are very few people who can accurately calculate the ancestral rate, but Li Zexuan just played a small game with everyone, and easily got the approximate value of the ancestral rate. This is a miracle!
"This... how is this possible?"
"It should be a coincidence?"
"But the head of the mountain just mentioned the ancestor rate to us first. If it's really a coincidence, wouldn't the head of the mountain say all the things he said before?"
"It's definitely not a coincidence. Shanchang's face is always stable from beginning to end. How could it be a coincidence?"
The students talked about it all below, and they all felt incredible. In fact, not only them, but also the teachers of the colleges here, all felt incredible! A big problem in the academia—Zuzi, how could it be calculated so casually?
Li Zexuan secretly said in his heart, no one guessed right! Because it was a coincidence to finally get such an answer, but it was not a coincidence. This experiment is the famous Bufeng needle injection experiment in the past:
One day in 1777, French scientist D? Buffon invited guests to do an experiment at home that Li Zexuan did earlier. In the end, the guests made a total of 2,212 needles, of which 704 intersected parallel lines. The ratio of the total number of 2212 to the number of intersections 704 is 3.142. He said loudly to the guests: "Gentlemen, this is the approximate value of Pi!"
The guests were in an uproar, and there was a lot of doubts, and everyone felt inexplicable: "Pi? This game is not even close to the circle!"
The appearance of π in such a chaotic situation is really beyond people's expectations, but it is a true fact. Since the problem of the needle-throwing test was first proposed by Mr. Buffon, it was called Buffon’s problem in the history of mathematics. The general result obtained by Buffon is: if the distance between two parallel lines on the paper is d, the small needle is long It is l, and the number of needle throwing is n, so the number of throwing needles crossing the parallel line is m, then when n is quite large, there is: π≈(2ln)/(dm). The needle length l used here is exactly half the distance d between parallel lines, so substituting the above formula to simplify it is: π≈n/m.
(This formula can be fully proved by the knowledge of probability and geometry, so I won’t repeat it here for now)
It is worth mentioning that many people followed Mr. Bufeng's footsteps and used the same method to calculate the value of π.
One of the most amazing is the Italian mathematician Lazireni. In 1901, he declared that he had carried out many needle-throwing experiments. Each time the number of needles was 3408, the average number of intersections was 1808. Substituting the Buffon formula to obtain π≈3.1415929 (the needle length l he used is not equal to parallel Half the distance d between the lines). Compared with the exact value of π, the difference does not appear until the seventh decimal place! Using such a lightweight method to obtain such a high-precision value of π, this is really a natural creation, a beautiful clock of good fortune, and so beautiful! If Zu Chong were to be reborn, he would be dumbfounded!
However, people have always criticized a lot about Razreni's result, but it is not unreasonable to get such a result, because in mathematics, it can be proved that the closest to the true value of π, the few fractions with the smaller denominator Yes:
(22)/7≈3.14 (sparse rate)
(333)/(106)≈3.1415
(355)/(113)≈3.1415929 (density rate)
(103993)/(33102)≈3.141592653
However, Razreni actually had a secret rate, and for a throw within 10,000 times, there could be no better results. It is no wonder that many people have raised doubts: "Is there such a coincidence?" However, most people think that Razirini is indeed "good luck" in view of his diligence and caution throughout his life. What the truth is, there is no way to examine it now!
Therefore, the result Li Zexuan just got is a coincidence and not a coincidence. If you are close to luck, the error in the result will be slightly larger, but it is not much larger! This is a question of probability!
In the auditorium, Xu Hongzhi had been doing arithmetic for most of his life, and he was the most shocked. At this moment, he didn't care about being courteous. He instantly stood up from his seat, and then walked directly to the podium!
Halfway through, he realized that he was rude, and hurriedly handed over to Li Zexuan: "Shanchang, can you let the old man go up and take a look? This... the old man has no other meaning, just want to go up and see with his own eyes!"
The latter part of the sentence is somewhat concealed. After all, he would never believe this miracle if he saw it with his own eyes.
Li Zexuan was happy, secretly saying that this old man still suspected that he was cheating? So he amused: "Mr. Xu wants to see, even if he comes up to check, not only that, other gentlemen or students who have questions can come up to check! Be careful not to touch the podium and disturb the position of the needle!"
"Thank you Shan Chang!"
As soon as his voice fell, several people appeared immediately below, including students and gentlemen from the college, Li Tai was among them!
Several "skeptics" quickly came to the edge of the podium and began to count the thin needles falling on the parallel lines on the piece of paper.
"One, two, three...Two hundred twenty-five, two hundred twenty-six, two hundred and twenty-seven! There actually happened to be two hundred and twenty-seven fine needles falling on the black thread!"
Half a quarter of an hour later, four or five "skeptics" who stepped onto the podium had already counted the results, and suddenly couldn't help but let out an exclamation!
Xu Hongzhi was completely convinced at this moment, but he still couldn't figure out how could a simple little game be related to Zu Li? So he looked at Li Zexuan next to him and said excitedly:
"My mentor also used the circle-cutting technique to calculate the ancestral rate in the early years, but after three days, only the first four decimal places were exactly the same as the ancestor’s calculations~EbookFREE.me~ Many times, one step was accidentally calculated incorrectly. If it is done, it will cause all the games to be wrong! Today's Shan Chang's free game can accurately count to the first three decimal places. The old man is deeply impressed! I wonder if Shan Chang can clarify the principle for me?"
At this time, everyone turned their attention to Li Zexuan. Obviously they also want to know the principle? However, I saw Li Zexuan smile a little bit humble, and then said: "You should go back to your seats first! Let's put this question aside for the time being, I will show you a little game!"
Play your sister's game! We must listen to the truth! ! !
When everyone heard it, they almost vomited blood, all of them frantically.
But the mouth is on Li Zexuan's body, he doesn't want to say, can't find someone to beat him up and force him to talk, right? Who has that guts in the auditorium? Besides, who can beat it?
As a result, they could only sit on their seats obediently (depressed) obediently (sullen) and watch what Li Zexuan would do next!
.....................
(End of this chapter)