The Ming Dynasty: The opening scene features Zhu Di angrily accusing him of illegitimate succession.

Yao Guangxiao looked down at Lin Yue and slowly nodded in agreement: "This man's knowledge and vision are indeed extraordinary."

His Majesty's decision to establish the Treasure Ship Academy despite strong opposition appears to have been the right one.

Downstairs, Lin Yue's voice rose as he meticulously unraveled the mysteries of the lunar eclipse, following the diagram of three circles in a straight line.

Lin Yue pointed to the blackboard behind him and declared confidently: "A lunar eclipse never happens randomly; it always occurs on the night of the full moon on the 15th or 16th of the lunar calendar."

That's because our world is a sphere, which I call Earth.

The moon revolves around the earth, and the earth revolves around the sun. Only during a full moon does the moon move to the side of the earth that faces away from the sun, making it possible for the three to align in a straight line!

Lin Yue spoke with great passion and enthusiasm, giving him a sense of satisfaction in imparting knowledge to the people of the Ming Dynasty.

"The sun's rays are like arrows, traveling straight without bending, while the Earth, being an opaque sphere, casts a dark shadow when it blocks the light. This shadow falling on the moon is what we call a lunar eclipse..."

Lin Yue didn't care whether the audience could understand him or not, and began his rapid explanation.

They also talked at length about how the synodic month and the nodal month determine the time, and then applied the conditions for the moon to enter the umbra to calculate the accurate time using the eclipse calculation formula.

After speaking vehemently for half an hour, Lin Yue turned around and said to everyone with unwavering resolve.

"That's the whole explanation of the causes of a lunar eclipse, and the simple method for calculating it."

The scene was completely silent.

It wasn't because of shock, but because almost no one understood it.

Lin Yue glanced around and saw that everyone was either frowning and staring blankly, or looking at each other with blank expressions, so he couldn't help but ask.

"Did you all understand the principle of a lunar eclipse that I just explained?"

The audience remained deathly silent, except for Zhu Gaosui, who subconsciously shook his head. The movement was small, but it was quite noticeable.

Lin Yue asked again, his tone somewhat tentative: "I remember that lunar eclipse calculations should be covered in the Great Calendar. Has anyone else understood this in a similar way? Why don't you come up and explain?"

Still, no one answered.

Lin Yue suddenly realized he had gone too far.

He was just focused on reasoning and analyzing the reasons. Although he didn't mention any knowledge that was too far ahead of its time, the specific calculation of the lunar eclipse was still based on the geometry and experience of the Datong calendar.

Even so, it is still too difficult for the people of the Ming Dynasty, especially ordinary people who are not related to astronomy, to understand.

It's not that the calculations are difficult, nor that they can't calculate the timing of the lunar eclipse, but rather that their basic physics knowledge is lacking.

Zhu Gaoxu finally couldn't hold back any longer, slammed his hand on the table, and stood up.

"Lin Yue, what nonsense are you spouting? I didn't understand a word of it!"

A lunar eclipse could mean either the moon is eaten by a celestial dog or it's a warning from heaven. Why all the fuss? And what does this have to do with the structure of the world?

The people present looked at each other, and a few eunuchs recognized Zhu Gaoxu, but no one spoke up in agreement.

Everyone present was a scientific talent of the Ming Dynasty, carefully selected by Lin Yue, and many of them were even transferred from the Imperial Observatory.

These people, regardless of how knowledgeable they are, at least possess basic objective thinking abilities; they are not the cynical scholars in the court who only know the words of sages.

Huangfu Gui hesitated before getting up and bowing, saying, "Lord Lin, the Datong Calendar can calculate the time and magnitude of a lunar eclipse, but we have never known its cause."

Although the elder’s words were obscure, they seemed to be able to resolve this age-old mystery.

However, the core of these theories seems to focus on the celestial sphere theory and... the idea that the Earth revolves around the sun. I wonder if what I've said is correct.

"Huangfu Gui, is it? You do have some talent. As for the matter of the Earth revolving around the sun, you can come to me privately later."

Lin Yue glanced at everyone present, then decided to stop explaining and directly state the result.

"It doesn't matter if you don't understand. I'll just state the result directly: there will definitely be a lunar eclipse on the 15th day of the 10th month of the first year of Yongle."

Moreover, I can pinpoint the exact minute: at 12:48 noon, the lunar eclipse will begin, initially appearing at the eastern edge of the moon, and reaching its totality at 14:51.

Upon hearing this, Huangfu Gui did some calculations and was immediately shocked: "Lord Lin, is what you say true? The Great Calendar calculates the eclipse magnitude to be 85%, but the exact time is unknown. How did you calculate such a precise time, sir?"

In the Ming Dynasty, only officials of the third rank or above were addressed as "Sir" by lower-ranking officials. Huangfu Gui's use of this term to address Lin Yue was purely out of respect for his scholarship.

Lin Yue glanced at the shocked expressions on everyone's faces, too lazy to explain.

"If the Datong Calendar cannot be calculated, it means that the Datong Calendar is not accurate. You can observe and verify it yourselves at that time. If what I say is accurate to the second, then you will know that what I said today is true."

In a private room on the second floor, Zhu Di looked at Yao Guangxiao again: "Daoyan, is Lin Yue's statement true? Is his calculation even more accurate than the Datong Calendar? Is his explanation of the cause of the lunar eclipse true or false?"

Upon hearing this, Yao Guangxiao slowly shook his head and then nodded: "I believe in my heart that Lin is right, but I do not know whether he is right or wrong."

Zhu Di was even more surprised. He used to be able to offer some comments, but now he couldn't even give an evaluation.

Emperor Yongle looked down at Lin Yue, a thought flashing through his mind.

Could it be that Lin Yue's knowledge has surpassed everyone else's to a certain extent, to the point that others can't even catch up with him?

Seeing the puzzled looks on everyone's faces, Lin Yue raised his hand and waved, deciding to explain something simple.

He thought that all the people who came were top scientific and technological talents of the Ming Dynasty. He originally wanted to talk about latitude and longitude and the alternating appearance of constellations to prove what Hun Tian said. But now it seems that it is better to go back to the basics.

Lin Yue turned around and drew two poles of equal height on the wooden board.

One was labeled "Nanjing," and the other "Qiongzhou," each with shadows of varying lengths.

Lin Yue succinctly stated: "If the same stick is used to erect the same height pole in Nanjing and Qiongzhou, the shadow in Qiongzhou will be half a length shorter than that in Nanjing, and on the summer solstice, there may even be no shadow at all!"

If the earth were flat, the length of the shadows should be the same under the sunlight, so how could there be such a big difference?

The reason is simple: the earth is round, and Qiongzhou is closer to the equator than Nanjing, closer to the point where the sun shines directly. The angle between the pole and the sunlight is smaller, so the shadow is naturally shorter.

This is easily verifiable information; anyone who doesn't believe it can measure it themselves!

During the Ming Dynasty, there were descriptions of the equator. Ordinary people called it the midline or Rinan Road, while the Imperial Astronomical Bureau called it the equator.

Lin Yue saw that everyone was still confused, and many people simply couldn't understand how the length of the shadow could be related to the fact that the earth is round.

Seeing this, Lin Yue simply abandoned the theoretical part and went straight to the point.

"Forget it, it doesn't matter if you don't understand these convoluted principles. We Ming people do things by being practical."

Lin Yue pointed out the window and said in a booming voice, "Our Longjiang Shipyard is destined to dominate the seas."

Today I swear an oath to oversee the construction of the world's largest, fastest, and strongest treasure ship, so that Eunuch Zheng can lead the fleet from here, sailing westward along the sea, never to look back!

Zhu Gaoxu was taken aback: "Going west all the way? Wouldn't that mean drifting to the ends of the earth?"

"If the earth were flat, it would naturally never end, but if it were truly round..." Lin Yue slammed his hand on the lectern.

"The fleet will sail forward and one day it will circle back to Nanjing!"

When the ship returns, and the people return, bringing back exotic treasures and exotic products from the West, wouldn't that prove the Earth is round?