Lu Yunzhou didn't notice Xie Ziyuan's careful thoughts, and when he heard Xie Ziyuan say this, he just smiled, looked at the others again, and said, "What do you think?"

Only Duan Heng glanced at Xie Ziyuan worriedly, he was Xie Ziyuan's cousin and the person who knew Xie Ziyuan's mind best.

Zhongsun Xuanhua propped his head and said, "When I listen to the old people in the family chatting, they all say that the shadow is the soul of a person, right?"

Ma Chengjia agreed: "I've heard it too!"

Fang Yong echoed: "I've heard of it too!"

The shadow is the soul of man, this is the common cognition of the ancients, this superstitious idea will appear, it is not surprising, for the ancients, things that do not understand, will be blamed on ghosts and gods.

Zhang Cang's eyes rolled and he said tentatively: "The shadow is very similar to the night, both are black, is the shadow related to the night?"

Lu Yunzhou had a smile on his face, Zhang Cang was worthy of being a famous figure in the Han Dynasty, and he was really smart since he was a child, and praised: "Clever, the reason for the formation of shadows is indeed the same as the reason for the formation of the night - that is, the direct rays of the sun!"

Direct rays of the sun!

When everyone heard this, they were stunned and began to think about it......

Some people even began to observe the shadows behind them, and found that everyone's shadows were on the opposite side of the sun!

Shi Wenqi perked up, slapped his leg violently, and said excitedly: "Yes, the light is direct, and there is no way to bypass anything and shine on the ground, so there will be shadows!"

Duan Heng said with a smile: "This statement is indeed reasonable, it is a quarter of noon, and the sun is close to the position of the overhead slightly to the east, so our shadows are facing the west." ”

Seeing that everyone else was nodding their heads, Lu Yunzhou said with a smile: "Then this problem can be passed, and the next question, Zhang Cang and I will demonstrate it, and we will understand!"

With that, he stood up and stepped aside.

When Zhang Cang heard this, he immediately stood up and walked over with a smile: "With my help, you will be lucky, and the truth will soon be revealed!"

At this time, everyone had an inexplicable confidence in Lu Yunzhou, believing that he could really explain this mysterious question.

Xie Ziyuan looked at the vacant seat left by Shanrou's side in a daze, his face suddenly turned red, and he was entangled in his heart, should he sit down? No one should find out. Xie Ziyuan looked left and right, and just as he wanted to move to Shanrou's side, he saw Duan Heng looking at him worriedly, his heart was shocked, and he had to give up for the time being.

Lu Yunzhou and Zhang Cang stood facing each other, Zhang Cang frowned at him and grimaced, Lu Yunzhou smiled: "You should have heard it before, I explained that the earth under my feet is a sphere, called the earth." ”

Everyone nodded with strange faces, although they heard Lu Yunzhou's explanation just now, it was still very difficult for them to fully accept that they were standing on top of a sphere for a while......

Lu Yunzhou said with a smile: "That's good, now Zhang Cang's head represents the earth!"

Zhang Cang was immediately happy, and laughed heartily: "Okay, okay, now you are all on my head!"

When everyone heard this, they were all overwhelmed.

Lu Yunzhou compared Zhang Cang's head with both hands and said: "In the huge cosmic space outside the earth, there are countless spheres like the earth, and they are all called planets, among which the planets that do not shine like the earth are called planets, and the planets that shine like the sun are called stars!"

"So the earth under our feet is a ball similar to the sun?" Shi Wenqi suddenly realized.

"That's right!" Lu Yunzhou said with a smile.

Min Jianzhang was puzzled: "But the sun is so small, are we standing on such a small ball?"

Without waiting for Lu Yunzhou to answer, Shi Wenqi hurriedly said: "The sun is not small at all, we look small because it is far away, do you look at people in the distance, will they be much smaller than those in the near distance?"

The reason is very easy to understand, Min Jianzhang nodded, indicating that he understood.

Lu Yunzhou thought to himself, it seems that it is relatively easy to teach these things to the ancient people, so he smiled and said: "Senior Brother is right, the sun is not only not small at all, but also much larger than the earth, 1.3 million times the volume of the earth, and 149.6 million kilometers away from the earth, so although it is extremely huge, in the eyes of people on the earth, it is very small. ”

As soon as Lu Yunzhou said this, everyone looked at him with inexplicable eyes, Lu Yunzhou used metaphors to explain those problems before, and they could barely accept it, but how did these specific numbers about the sun come about? Could it be that he took a ruler and compared them in person?

Xunzi and Zou Yan nodded, deepening their views even more, Lu Yunzhou is really from the sky, he has seen it with his own eyes in the sky, of course he knows best!

Shanrou glared and asked questions for everyone: "That, Qi Yu, how do you know these specific numbers?

Now everyone looked at Lu Yunzhou with suspicion, what Lu Yunzhou said was originally difficult for them to accept, and now they feel that Lu Yunzhou is actually fooling them.

"Uh. Lu Yunzhou sweated wildly...... How can he explain that he is from the future? Countless astronomers have observed these data for a long time, and these are all required by the exam teacher to memorize, in fact, he does not know how these data are derived?

If you say that, you will probably be considered crazy.

However, this is not a big deal in the Spring and Autumn Period and the Warring States Period, Lu Yunzhou will be regarded as a grotesque person like Zhuangzi at most, and will not be persecuted for telling the truth like scientists such as Galileo and Bruno.

It is only because of the different times that medieval Europe was a world ruled by religion, and those persecuted scientists were destroyed by the Holy See because their truth violated the so-called majesty of God.

And the Spring and Autumn Period and the Warring States Period was an era of contention between hundreds of schools of thought, an era of ideological explosion, in this era, as long as you have a set of rhetoric and can justify yourself, then there is no problem in saying anything. Zhuangzi can say that "Kun is so big that I don't know how many thousands of miles it is." "Peng's back, I don't know how many thousands of miles it is" and other exaggerated figures, Gongsun Long can bluff people with a set of crooked theories of "white horses are not horses", Lu Yunzhou said that how big the sun is and how round the earth is is not a problem!

Even if it is pushed back a few decades and the world is unified, in any subsequent dynasty, Lu Yunzhou will not dare to say these things in public, because in the era of great unification, there will be the idea of great unification, Lu Yunzhou said this, if the central court does not take him seriously, it will be fine, if he is investigated, it is possible to die!

Therefore, the Spring and Autumn Period and the Warring States Period are indeed the best era, the era of scholars, the era of those who pursue the truth, the era of cultural and technological progress and development, and the era when smart and wise people can be like fish in water!

It's a pity that the unification of the Qin Dynasty has ruined too many achievements of wisdom in this era!

Lu Yunzhou snorted, quickly pretended to be mysterious, and opened the topic: "What about this...... Yes, someone has observed it, but it's not me!"

Zou Yan suddenly relieved the siege and said: "What Qi Yu said is the truth, the old man can be sure!"

Everyone was stunned, even Lu Yunzhou was stunned, not knowing why Zou Yan suddenly spoke for him.

But Zou Yan's words are the most effective, Zou Yan is famous all over the world for "Wude always says", is a representative of the Yin and Yang Five Elements School, and is sought after by rulers and scholars of various countries, in the eyes of everyone in this era, earthly things may not have appeared a person who can grasp all the right to speak and convince everyone, but in the heavens, Zou Yan is definitely the most powerful person!

Zou Yan's words made everyone stop pursuing it, only Shi Wenqi and Zhang Cang looked at Lu Yunzhou with inquiring eyes.

"Ahem", Lu Yunzhou cleared his throat and resolved the embarrassment before saying: "Then I will continue to demonstrate, now I represent the sun, Zhang Cang represents the earth, Zhang Cang can circle around me." ”

Zhang Cang smiled and walked around Lu Yunzhou, tilting his head to look at Lu Yunzhou.

Lu Yunzhou smiled: "This is the rotation of the earth, the cycle of the earth's revolution is about 365 days, so a year is 365 days, and the difference between spring, summer, autumn and winter is because when the earth revolves around the sun, the orbit is elliptical, and the distance from the sun is not the same." ”

Everyone suddenly had a feeling of uncertainty, in short, they felt that it made sense!

Lu Yunzhou said again: "Now Zhang Cang is starting to circle in place!"

Zhang Cang smiled and spun around in place.

Lu Yunzhou said: "This is the rotation of the earth, and it takes twelve hours for the earth to rotate once, which is one day and one night." As you already know, the sunlight is direct, so I can see the part of Zhang Cang, which is the day, and the part where Zhang Cang's back to me is the night, which is the reason for the day and night!"

The moment Lu Yunzhou finished speaking, Zhang Cang suddenly stopped, no longer smiling and turning in circles, and was suddenly stunned.

Everyone was stunned!

Although Lu Yunzhou did not explain the set of data just now, he explained all the other theories clearly!

Light and dark, but what is the time?

This problem that has plagued people for thousands of years, this question that Qu Yuan asked to the heavens, was solved?

All of them had a sense of sobriety that seemed to have been empowered, but it was full of unreality......

"Young Master, you're awake!"

A confused call woke everyone's minds up, and Lu Yunzhou looked in the direction where the voice came from, and couldn't help crying and laughing.

It turned out that Qi Xin came out of the room, he slept darkly, he didn't know what was going on, he didn't know that a lot of things had happened, and he had missed a big meal! Seeing so many people suddenly in the courtyard, and the mess with the full table of cups and plates, he couldn't help but grow his mouth.

"Young Master, are you ...... When did you wake up?"

Qi Xin rubbed his sleepy eyes and asked in a daze.