After finishing the simple supper, General Gao cleaned up the endgame, and the moon had risen.

Zhao Hao turned the two-foot-long telescope towards the direction of the moon, and let the two of them watch it in turn.

But this viewing experience is definitely not a pleasant one...

When the moon, which was far away in the sky, came to their eyes, the two clearly saw that there was no sea, no forest, and no sign of life on the entire moon.

Originally, they thought it was a osmanthus tree, a toad palace, and a jade rabbit, and all of them were bumpy rings.

That round of the moon, which was as bright as a silver plate and flawless as their ideal, turned out to be a big and scaly face.

"How could this be the case..." Wang Wuyang and Hua Shuyang looked at each other dejectedly, unable to accept it. The Moon Palace, which carries countless beautiful legends, was actually a dead and barren land...

Zhao Hao's previous experiments only aroused their interest in science, but now their observation of the moon directly challenged their worldview.

"There is nothing strange about this." Zhao Hao said calmly: "The moon is a planet like an orange. There are no Chang'e, Wu Gang, no osmanthus, and even no water and air on it."

"The moon is a planet?" The two of them were afraid of missing something, so they didn't care about the shock in their hearts and quickly asked the teacher: "Master, what is a planet?"

"The planet is a spherical celestial body that runs according to some law in the universe." Zhao Hao said in a deep voice: "The sun, the moon, gold, wood, water, fire, Saturn... and the earth are all planets."

"If this is the case, why can you see the full moon only in fifteen every month?" Wang Wuyang asked in confusion: "It's like today, the moon is obviously missing one piece!"

"No!" Hua Shuyang suddenly slapped his thighs when he heard this, and hurriedly observed again: "I just saw that there was obviously a black shadow in the quid part of the moon. If that black shadow was included, the moon would still be round tonight!"

"Really!" Wang Wuyang also leaned over and took a look. Sure enough, he could clearly find that the overall outline of the moon was round, but part of it was blocked by something.

"What is it covered?" the two of them asked in unison.

"I'll demonstrate it, you'll know." Zhao Hao said, holding a small white ball the size of a pigeon egg beside the lamp. "Because the moon itself does not shine, the so-called bright moon shines, but the reflected sunlight."

The two of them looked at the orange ball reflected in a vague understanding and asked in a low voice: "That should always be the full moon."

"Yes, but as I said just now, all planets move according to some law." Zhao Hao said, and took out another large ball painted blue, blocking the small ball representing the moon and the candlelight representing the sun.

Then Zhao Hao slowly moved the small ball and rotated around the big ball, clearly demonstrating the changes of the moon to the two of them.

"The so-called full moon and short moon are actually how many places on the earth can be seen illuminated by the sun. Because the moon rotates around the earth. On the first day of the first day, it is in the middle of the earth and the sun, and we can only see the backlight side of it, so we cannot see its existence with our eyes. On the seventh day of the first day of the first day, the moon moves to our side. At this time, we are on the earth who are bystanders, and we can see that it is dark in the east and bright in the west, which is the so-called "chinous moon". When it is on the fifteenth day of the day, the moon circulates to the back of the earth again. At this time, we can see its complete light-watching surface, which is the day of the full moon..."

"I understand!" Hua Shuyang suddenly realized: "Then it continued to rotate. When it reached the eighteenth and nineth, that is, today, it would be dark in the west and bright in the east, becoming a crescent moon!"

As he said that, he clapped his hands and Ying Wu said, "It's exactly one month to go around!"

"You can teach me." Zhao Hao nodded in praise, then looked at Wang Wuyang and said, "He understands, where are you?"

"I probably understand, but as the master teaches..." Wang Wuyang pointed to the blue ball in Zhao Hao's hand, and his voice trembled: "Aren't we living on a ball too?"

"Yes, Master, isn't it a perfect place?" Hua Shuyang asked in disbelief.

"Of course not." Zhao Hao took out the last teaching aid globe from the wooden box!

He turned the blue sphere similar to the armillary sphere, then gently pressed it down, and said to the two students: "This is the earth we live in. Three quarters of it is covered by sea water, and the remaining quarter is land."

The two students looked at the blue globe, the land marked with different colors, and soon saw the location of the Ming Dynasty.

"Is our Ming Dynasty here?" Hua Shuyang leaned closer and looked carefully: "Is this place like a bug next to him... Japan?"

"Ah, Folang Ji is here! It's so many countries from us. It turns out that the countries in Taixi are so far away from us?" Wang Wuyang shouted on the other side: "It's really not easy for Folang Ji people to sail to the Ming Dynasty!"

"Yes, although I don't want to say that, I still have to admit that the countries of Taixi have gradually caught up with the Ming Dynasty, and even surpassed us in the fields of navigation, astronomy, mathematics, etc.." Zhao Hao sighed and said, "For example, the earth is round, which they discovered and proved first."

"How did they prove it?" Hua Shuyang asked in shock.

"A hundred years ago, the theory of earth-round had spread in the countries of Thailand, but there were always people who did not believe this. So forty or fifty years ago, a captain named Magellan resolutely decided to sail around the world. Because if the earth was round, as long as he kept sailing in one direction, sooner or later, he would return to the starting point."

Both of them understood this principle, but they just nodded slowly and didn't say anything.

They were completely shocked by the feat of that great navigator.

Zhao Hao slowly said to the two in a low voice: "In 1519 AD, that is, the 13th year of Zhengde, Magellan led five ships and two hundred and seventy sailors from the port of San Rocar in Spain to start this greatest expedition in human history!"

As Zhao Hao said, he slowly drew lines on the earth with a brush and said: "They first crossed the Atlantic Ocean for seventy days, came to the coast of Brazil, and then went south along the coast, bypassed South America, and entered the Pacific Ocean. They sailed in the Pacific Ocean for more than a hundred days and came to Luzon."

The place name "Luzon?" is well known to both of them, and it has entered the traditional sphere of influence of the Ming Dynasty.

"Then they crossed the Indian Ocean and arrived in Africa, bypassed the Cape of Good Hope, headed north along Africa, and finally returned to Spain..." Zhao Hao expressed his respect for the pioneers in a low voice: "At that time, they had only one last boat left, eighteen sailors, and even Magellan himself had already died halfway."

"But they used the most indisputable method to prove that the earth is round!" Finally, Zhao Hao raised his tone and looked at the two people with bright eyes and said, "This matter is already well-known in the countries of Taixi. You will definitely meet Taixi people in the future. You will know the truth and falsehood when you ask."
Chapter completed!