In fact, this is theoretically the case, but no one has the ability to calculate clearly the superimposed positions of sound wave reflections in an entire opera house.
The amount of calculation is too much. After all, the human brain is not a computer.
But there is also a trick, and that is to use the two focus points of the ellipse. As long as the stage is placed at one focus point of the ellipse, and the sky-sized room is placed at the other focus point, you can easily get the best result.
The listening position. Calculating the two foci of the ellipse is countless times easier than calculating every reflection position of the sound wave.
The original opera houses were all built according to the elliptical pattern. This is the reason. Moreover, when the original opera house was built, the two focal points of the ellipse were not placed parallel to each other, but at an inclined angle.
This way you can make the most of the echo effect.
After Han Du explained, Lao Zhu really seemed to be listening to a book from heaven.
Just when Han Du thought that he was finished and had made Lao Zhu lose face, Lao Zhu nodded calmly with a smile and said: "I didn't expect that Han Du, you are also proficient in arithmetic. Yes, you have a bit of Bowen's style.
"
As soon as Lao Zhu said these words, the Zhu Biao brothers all looked at their father with admiration. Unexpectedly, their father actually understood. In their hearts, the brothers were both respectful and afraid of their father. When Han Du explained just now, they
They also listened with open ears. But except for the first few sentences, which they could barely understand, the rest of them were like listening to a book from heaven.
Especially Zhu Biao felt the strongest. His strong feeling was the same as when he saw Han Du's memorial. He knew every word, but he didn't know what they meant when they were connected.
However, his father was able to understand, which made Zhu Biao sigh that he was still far behind compared with his father. In his opinion, Han Du was talking about arithmetic, while Liu Bowen was known as the best arithmetic in the Ming Dynasty when he was alive.
He is the number one person in arithmetic. Since my father thinks that Han Du is somewhat more elegant than Liu Bowen, he naturally understands.
Han Du's heart was filled with ten thousand grass-mud horses. Sure enough, Jiang was still the best. Lao Zhu pretended to understand and deceived everyone except himself.
Why can Han Du be sure that Lao Zhu is pretending to understand? That’s because Han Du knows the mathematical things he just said. Not to mention Lao Zhu, even if Liu Bowen comes alive and stands in front of him to listen
, he would just look confused and unable to understand.
This is not a gap in IQ, this is a gap in mathematical development.
However, Han Du would not be an idiot enough to expose Lao Zhu. Not only could he not expose him, but in order to avoid losing Lao Zhu's face, Han Du also needed to support Lao Zhu's pretentiousness.
Therefore, Han Du showed an open-minded attitude and said quickly: "Your Majesty is right, I still have a lot to learn."
Lao Zhu took a deep look at Han Du, but said that he had a lot to learn, and did not directly say that he had some of Liu Bowen's abilities. It seems that this kid is very arrogant, thinking that his own arithmetic is no worse than Liu Bowen?
In this case, I will test you to see how arrogant you are.
"Nine hundred and ninety-nine cents. If you buy a thousand pears in time, nine pears will be eleven cents, and seven fruits will cost four cents. How much do pears cost?" Lao Zhu said "Four cents" as soon as he opened his mouth.
The title in "Yuan Yujian", "Four Yuan Yujian" is a collection of books in the palace and is never shown to anyone. Han Du will definitely not have read it. Therefore, Lao Zhu took out this topic to test Han Du.
The meaning of Lao Zhu's words is: Use nine hundred and ninety-nine cents to buy a thousand pears and fruits in total. Nine pears will be bought for eleven cents, and seven fruits will be bought for four cents. If you want to buy pears, how many fruits are there?
How much does each pay?
This question is very difficult for people in this era, even more difficult than the chicken and rabbit in the same cage problem. The chicken and rabbit in the same cage problem only asks how many heads and how many feet are there, these are all integers.
, very easy to understand.
But what appears in this question is fractions. For Ming people who have not systematically studied and understood fractions, it is naturally an even more difficult question.
But for Han Du, isn't the answer obvious? The price of pears is eleven-ninths of a cent, and the price of fruit is four-sevenths of a cent. The unit prices are all there, but we just need to list a formula to calculate them.
, you can know the answer.
Even Han Du didn't even need to list the formulas. He just did a simple mental calculation and knew the answer in just a few breaths.
"Back to the Emperor, I have six hundred and fifty-seven pears, with a total price of one hundred, eighty and three cents. There are three hundred and forty-three fruits, with a total price of one hundred and ninety-six cents."
This, it came out so soon? It can’t be a lie, right?
Zhu Biao and his brothers all looked at Han Du in disbelief. Even Zhu Biao couldn't help but put down his medical skills and turned to look at Han Du blankly.
Several people were very eager to know whether Han Du was deceived, so after they glanced at Han Du, they all looked at their father.
Lao Zhu's face was a little stiff. He asked this question just to embarrass Han. After all, he had also tested Liu Bowen on this question, and even Liu Bowen had spent three full days and used it.
The answer was given after various methods.
But Han Du blurted out the answer in an instant without even a trace of delay. It was as if he knew the answer just after he said the question.
Lao Zhu pondered, looking at Han Du with an inquiring look, and asked: "Have you seen this question before?"
"No!" Han Du heard this and replied blankly without thinking.
Why did Lao Zhu ask this? Is this question difficult? Han Du expressed confusion.
Lao Zhu looked at Han Du deeply, with an unclear meaning in his eyes. He suddenly burst out laughing and said, "Well, it seems that I underestimated you just now. Now it seems that you are comparable to Liu Bowen in terms of arithmetic and mathematics.
"
When Zhu Biao and others heard what their father said, they all looked at Han Du in shock.
Enough to rival Liu Bowen!
These words came from the father's mouth. How high is this evaluation of Han Du? Zhu Biao and others had met Liu Bowen and were deeply impressed by Liu Bowen's wisdom. He was not the number one god in the Ming Dynasty.
A waste of fame.
But now my father has such a high opinion of Han Du. He can do it after Liu Bowen, and he is still so young. Doesn't this mean that the second god of the Ming Dynasty is about to appear? Or that it has already appeared, and it is the person in front of him.
?
Zhu Biao was very happy about this. After all, he and Han Du had a very good relationship and could be regarded as close friends. Since Han Du was the second god of the Ming Dynasty, wouldn't he have a god like his father?