The little boy jumped around a few times under the sandbag with his short legs, but couldn't reach it even with his hands.
Princess Chengyang also ran over and tried a few times, barely touching the sandbag.
Princess Gaoyang also walked over, clenched her fist and punched it, a mask of pain on her face, "It hurts!"
"You little girl!" Princess Yuzhang walked over and took Princess Gaoyang's hand, "Are you okay?"
"It should be fine!" Princess Gaoyang rubbed her fists.
"Tiehuan, are you practicing?" Li Lizhi didn't expect Cheng Tiehuan to be like this.
"Dean, I like to hit it a few times when I have nothing to do, otherwise I will feel uncomfortable." Cheng Tiehuan was a little embarrassed, not knowing whether Li Lizhi would allow him to do so.
Xiao Ran was also at a loss whether to laugh or cry. She was obviously a beautiful girl, but she was like a violent maniac.
"It's fine as long as it doesn't affect other people." Li Lizhi didn't object. It was really no big deal.
As the bell for class rang in the Royal Academy, students returned to their respective classrooms one after another.
Princess Gaoyang was a lazy person. She didn't like reading or going to school. She preferred to wander around.
Xiao Ran also had to accompany Li Lizhi, and the two little princesses accompanied Xiao Ran.
There were three people, including two vice presidents, attending the class as auditors.
Li Lizhi was holding a piece of chalk and explaining the knowledge points of planting and grafting at the podium.
This teaching model was learned from the 21st century.
You are not allowed to talk or play in class to disturb Li Lizhi and other students.
The two little princesses sat next to Xiao Ran, one on the left and one on the right. Li Lizhi's lecture seemed to be able to hypnotize them, and soon the two little princesses fell asleep.
Not to mention the two little princesses, Xiao Ran also felt like he was back in his student days.
I couldn't help yawning and felt very sleepy and lacked energy.
Li Lizhi also noticed the condition of Xiao Ran and the two little princesses, but did not say anything.
As the bell rang for the end of get out of class, the two little princesses woke up.
Li Lizhi walked up to Xiao Ran and asked, "Young Master, are you feeling unwell or haven't rested enough?"
"Neither. This is the aftereffect of my previous studies. I need to go out for a walk." After class, I naturally felt more energetic.
Just as I walked out of the school, I saw Li Shimin and Li Chunfeng coming, and Qiao'er was with them.
"Uncle, Li Changshi..."
"Sister~" The little princess ran to Qiao'er and pulled her arm.
"Young Dean!"
The two little princesses were very pleased with Qiao'er's call of "Little Dean", and she received green beans and candies from the two little princesses.
The two little princesses were very generous to Qiao'er and gave her a lot of snacks.
Anyone who knows a little about the market knows that these things are not cheap at all and can be easily sold.
Qiao'er also accumulated a fortune, which was a huge sum of money for her.
Behind them were students from the School of Astronomy and Geography, carrying a globe.
"Grandpa, Li Changshi, is there something wrong?" Li Lizhi asked.
"I have some questions I want to ask Xiao Ran. I happen to be interested too, so I followed him here." Li Shimin pointed to the globe.
"What's the problem?" Xiao Ran was also curious. Li Chunfeng was a great scholar, and he didn't know anything about it. It must be something complicated.
Several people put down the globe.
"Young Master, if the Earth we live on is a sphere, does the Sun revolve around it?"
The earth is a spherical head, which has a great impact on some concepts of this era.
Fortunately, it was not in Western Europe. The Tang Dynasty was very tolerant at that time.
The Tang Dynasty royal family is not the Pope, otherwise Xiao Ran would probably be burned to death as a heretic if he said these words.
"Xiao Ran, I am also curious about this question." Li Shimin followed for this reason.
The earth is a sphere, which overturns many previous cognitions.
"This is what I can imagine. The sun is like an egg." Li Chunfeng took out an egg and rotated it around the globe. "So the sun rises in the east in the morning, sets in the west, and rises again in the east the next day."
The little princess stared at the eggs in Li Chunfeng's hand and suddenly felt a little hungry.
"That's not the case." Xiao Ran denied Li Chunfeng's guess.
"Please explain it to me, young master!" Li Chunfeng looked eager.
"First of all, I want to tell you that the sun is very big. The volume of the sun is 1.3 million times that of the earth, which is where we live."
Li Lizhi and other students from the Agricultural College also came over curiously.
"1.3 million? Ten thousand? Is that so exaggerated?" Li Shimin widened his eyes.
Others were also shocked. They didn't expect it to be so much bigger.
In ancient Greece, some scholars such as Aristarchus proposed the heliocentric theory, which believed that the sun was much larger than the earth. However, this view was not widely accepted at the time.
In ancient China, people generally believed that the sky was round and the earth was flat, and there was no clear comparison between the sizes of the sun and the earth. In most cases, people regarded the sun as a celestial body and had a vague concept of its size.
Generally speaking, most people in ancient times did not have a clear concept of the comparative size of the sun and the earth. Although some scholars with scientific thinking had some opinions, they failed to become common knowledge.
"The weight of the sun is 330,000 times that of the earth. The sun and the moon look similar to us, but in fact, there is a big difference." Xiao Ran continued.
"Young Master, aren't the moon and the sun the same size?" Li Chunfeng frowned.
"In fact, the Earth is 49 times the volume of the Moon and 81 times the mass of the Moon."
Xiao Ran's words once again overturned the cognition of Li Shimin and others.
Some ancient cultures may have thought that the sun and moon looked similar in size. For example, the ancient Egyptians, in their observations, may have believed that the difference in size between the sun and moon in the sky was not much due to their visual perception.
China’s is a little different, but I didn’t expect it to be so different.
"Is it because of the distance?" Li Chunfeng reacted.
"Yes, the moon is relatively close to us, and the sun is very far away, so even if it is very big, it looks very small."
"How far is it exactly?" Cheng Tiehuan was also interested in this.
Everyone is familiar with the sun and the moon, so they are definitely curious when they hear something that subverts their cognition.
Xiao Ran thought for a moment, "The sun is about 150 million kilometers away from the earth, and the distance from the sun to the moon is 10,000 kilometers. The distance from the moon to the earth is only 380,000 kilometers. It takes more than 8 minutes for light from the sun to reach the earth, while light from the moon only takes a little over 1 second to reach the earth."
Li Shimin, Li Lizhi and others were shocked by the gap, but they didn't quite understand these units.
"Kilometers? Minutes? Seconds?" Li Chunfeng asked the key question.
The little princess looked up and said, "A thousand meters, okay?"
"You can't eat this." Xiao Ran rubbed the little princess's head. "In the Tang Dynasty, one foot is 30 centimeters, one meter is 100 centimeters, and a kilometer is a thousand meters... Do you understand?"
Everyone nodded, and they had roughly an idea.
While the others were in a daze, the little princess took Li Chunfeng's eggs.
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