Taichang Ming Dynasty

Chapter 431 The World's Most Advanced Academic Salon

Tang Ruowang hesitated for a moment and then said, "I boldly request that Your Majesty allow Deng Yuhan to present the memorial on my behalf."

"Why?"

Tang Ruowang replied solemnly, "As early as the 39th year of the Wanli reign, Deng Yuhan was accepted as the seventh member of the Lynx's Eye Academy in Rome. He was already renowned throughout Europe before coming to China. His attainments in astronomy far surpassed mine. In terms of seniority, I can only be considered Deng Yuhan's student. Furthermore, these magical instruments were also collected by him from Europe. Without his assistance, I would have accomplished nothing."

"Lynx Eye Academy, is it very famous?" Even Zhu Changluo had never heard of this institution.

"This..." Tang Ruowang was stunned. He didn't know how to explain to the Chinese emperor this membership-based academy founded by Western aristocrats. Tang Ruowang hesitated for a long time, his face flushed, and finally Deng Yuhan explained it himself:
"I have the audacity to present this to Your Majesty. Lynx Eye Academy is similar to Donglin Academy, both for studying classics and exchanging knowledge. However, compared to Donglin Academy, Lynx Eye Academy is much smaller. It was at Lynx Eye Academy that I met and became friends with Galileo, the inventor of the astronomical telescope."

Deng Yuhan had previously heard from Johann Adam Schall von Bell that the emperor was quite interested in the astronomical telescope and its inventor, Galileo, and had even given him the Chinese name "Galileo" based on its pronunciation, so he mentioned it in passing.

The Emperor, genuinely interested, leaned forward. "Is Galileo also a member of the Lynx Eye Academy?"

"In reply to Your Majesty, I was the seventh person to be admitted to the Lynx Eye Academy, and Galileo was the sixth. In terms of the time of joining the academy, he joined almost ten days earlier than me." Deng Yuhan replied.

Zhu Changluo nodded and asked, "Do you know Kepler?"

"Kepler?" Deng Yuhan didn't quite understand how these three Chinese pronunciations corresponded to Western names.

"Johannes Kepler."

"Hiss!" Deng Yuhan's eyes widened in shock. He turned his head to look at Johann Adam Schall von Bell and gave him a questioning look, but in the end he only got a blank shake of his head.

"It seems that you two do know each other." Zhu Changluo smiled faintly.

Deng Yuhan nodded woodenly and said, "Kepler and I are both Romans. According to the Celestial Empire's saying, we can even be said to be from the same hometown. I am from Konstanz and he is from Weil der Stadt. Both places are in Baden-Württemberg. Kepler and I have a good friendship and we get along very well. Before I set off for China, I also corresponded with him many times to exchange ideas on astronomy. He is a true master of astronomy." At this point, Deng Yuhan's face showed a look of sudden enlightenment.

Deng Yuhan always carried Kepler's reply with him. He thought that the emperor must have learned this through the report submitted by the Translation Bureau of the Censorate.

"Since you are friends with a master of astronomy, I guess you must be a master of astronomy too. Please speak." The emperor's smile was full of kindness, which immediately broke the image of a terrifying dictator that Deng Yuhan had constructed in his mind before the audience.

"Thank you, Your Majesty." Johann Adam Schall von Bell and Deng Yuhan bowed at the same time.

At this time, Wang An also signaled the eunuchs on duty in the hall to carry those magical instruments over.

The first magical instrument that was brought before the crowd was a fixed ninety-degree or quarter-circle instrument.

Deng Yuhan took a deep breath and slowly exhaled. Once his breathing had stabilized, he began to speak slowly, "This instrument is called a quadrant because it is shaped like one-fourth of a full circle. As the Book of Changes says, 'The Tai Chi gives rise to the two opposites, and the two opposites give rise to the four images,' we have further transformed it into a quadrant. This instrument is used to measure the latitude of a celestial body, that is, its altitude above the horizon. To observe, simply rotate the quadrant ring."

Deng Yuhan's trembling voice was suddenly drowned out by the emperor's voice. "Instead of sitting here and looking around, why not take a closer look?" Zhu Changluo leaned forward and patted Zhu Youxiao on the shoulder. "Go."

"Yes." Zhu Youxiao had long wanted to take a closer look, and now with his father's permission, he stood up and walked in front of Deng Yuhan. "Thank you, sir." Zhu Youxiao gave Deng Yuhan a student's salute.

"This..." Deng Yuhan's face flushed instantly, and he hurriedly returned the greeting. "How can a commoner like me deserve such courtesy from Your Highness?"

"Teacher, how can you not be grateful to your students for teaching and answering your questions?" Zhu Youxiao smiled and waved his hand. "Please continue your explanation, sir."

Deng Yuhan's face was flushed with joy, and his voice rose two degrees. He fiddled with the components of the quadrant while explaining, "To observe, simply rotate the quadrant ring and align the vernier with the star to be measured. Once you see the star through the peephole, look at the scale on the arc indicated by the vernier to determine its altitude above the horizon."

Deng Yuhan then introduced many Chinese and foreign instruments one by one, including the goniometer, astronomical telescope, armillary sphere, and celestial globe.

Zhu Changluo studied political economy and psychology in addition to his undergraduate studies, but he was not proficient in mathematics and astronomy, and his understanding of astronomy was limited to the basics or common sense. However, even so, he was very clear that many of Deng Yuhan's statements were wrong.

For example, the armillary sphere was a demonstrative instrument used to display the movement of celestial bodies. Celestial coordinates, obtained using various measuring instruments such as quadrants, clinometers, telescopes, and armillary spheres, were ultimately inscribed on the armillary sphere. This served to visually depict the relative positions of celestial bodies and reflect changes in celestial phenomena.

The fundamental premise of creating an armillary sphere is to assume that the sun, moon, twenty-eight constellations, and other celestial bodies are located on a sphere with an infinite radius, sharing the same center and axis of rotation as the Earth. All objects in the sky can be considered projections onto the celestial sphere. The Earth's equator and geographic poles projected onto the celestial sphere form the celestial equator and celestial poles.

The celestial sphere embodies both the spherical earth theory and the geocentric theory, which states that the earth is round and the celestial bodies revolve around it. The former is undoubtedly correct, while the latter is completely due to cognitive limitations.

Zhu Changluo listened quietly until Deng Yuhan finished speaking, then he said, "Is the calendar you compiled based on the geocentric theory?" As soon as the emperor opened his mouth, everyone in the hall focused their attention on him.

Deng Yuhan was stunned for a moment and asked, "Your Majesty, I'm a simpleton, but I'd like to ask you, what is 'geocentrism'?" "Oh," Zhu Changluo remembered, remembering that there's probably no such Chinese translation for it. Even Johann Adam Schall von Bell had previously translated "heliocentrism" as "sun-centered theory." "Ground is the Earth, and heart is the center. Geocentrism means that the Earth is a sphere, and the stars in the sky revolve around it."

"Your Majesty is wise and intelligent, and I, the common people, bow down to him." Deng Yuhan suddenly realized and praised him heartily. "The theoretical basis for compiling this calendar is indeed geocentrism."

As soon as Deng Yuhan mentioned the original text of the book, Johann Adam Schall von Bell immediately responded by pulling out the first draft of the book from his pocket. "I present you with the first draft of the book," Schall von Bell knelt on the spot, holding up the small, not-too-thick booklet with both hands.

"Give it to me." Zhu Changluo waved to Wang An.

"Yes." Wang An understood and immediately ran out from behind the emperor, took the booklet and handed it to the emperor.

Zhu Changluo took the booklet and said to Deng Yuhan, "Go on."

"Yes," Deng Yuhan continued. "After much discussion with Deputy Supervisor Tang, the common people, and other scholars with a basic understanding of astronomy, we have decided to adopt the theory proposed by Danish astronomer Tycho Brahe in the Wanli reign." Deng Yuhan quickly converted the numbers. "He proposed the theory in his article 'On Comets' in the 11th year of the Wanli reign. It states that the Earth is the absolute center, the Sun revolves around the Earth in a circular motion, and the planets, other than the Earth, revolve around the Sun in a circular motion. All our observations and calculations are based on this."

"Tycho Brahe" Zhu Changluo asked, "Who is this?"

At the beginning of the audience, Deng Yuhan would have been hesitant to introduce Tycho Brahe to the emperor, but with the previous conversation as a prelude, Deng Yuhan was able to answer immediately. "Tycho Brahe is considered to be Johannes Kepler's teacher."

"Tycho Brahe, Kepler's master." Zhu Changluo pondered for a moment, then suddenly realized. "Tycho Brahe!"

"Your Majesty's translation is very exquisite." Deng Yuhan immediately praised the emperor.

"Then why don't you adopt Copernicus' heliocentric theory? Weren't Galileo and Kepler both supporters of it?" Zhu Changluo narrowed his eyes. "Is it because the Vatican opposes heliocentrism?" While the Jesuits were not without their share of mathematicians and astronomers, the Jesuit order had been the Vatican's most loyal supporter since its inception.

Tang Ruowang sensed a danger in the emperor's tone and hurriedly said, "The reason we chose geocentrism over heliocentrism was not because of the influence of the Vatican, but because Copernicus's heliocentric theory was unsuccessful in actual measurements and had large errors, while Tycho Brahe's observations and deductions achieved unprecedented precision and rigor. Therefore, we believe that even though Galileo and Kepler both advocated heliocentrism, it is fundamentally wrong. If we force our calculations based on heliocentrism, we will not obtain correct results."

"Does Xu Qing think so too?" Zhu Changluo casually flipped through the original draft of the French theory and soon found a simple introduction to Copernicus' heliocentric theory.

Xu Guangqi was once again astonished by the emperor's wisdom and insight. He had assumed this meeting would simply be a brief introduction to calendar revision and Western instruments. Little did he know that the emperor was not only well-versed in the theories of European scholars who had made significant contributions to astronomy, but he even subtly guided the conversation.

Xu Guangqi, with his keen sense, could easily have discerned that the emperor actually supported adopting heliocentrism as the basis for compiling a new calendar. However, he did not agree with this idea. Instead, he cautiously stated, "In reply to your Majesty, before the calendar revision was interrupted last time, I, Pang Diwo, Xiong Sanba, and other external officials conducted numerous calculations. At that time, we concluded that heliocentrism was wrong and that only by adopting Tycho Brahe's improved geocentric theory could we reach an accurate conclusion."

In the 38th year of the Wanli reign, the Imperial Astronomical Observatory's prediction of a solar eclipse was again inaccurate. Calls for calendar revision reached an all-time high, both within the government and the public. Against this backdrop, the Ministry of Rites initiated multiple approaches to calendar revision, one of which was the "Westernization" approach advocated by Xu Guangqi, Li Zhizao, and others. This approach was interrupted in the 44th year of the Wanli reign by the Nanjing Incident. Pang Diwo and Xiong Sanba, who participated in the revision work, died in the 46th and 48th years of the Wanli reign, respectively. Had it not been for the emperor's wisdom and his decision not to impose widespread punishment for the Shenyang Incident, the renewed revision work would have likely stalled.

"The heliocentric theory is indeed problematic," Zhu Changluo said as Xu Guangqi paused, closing the booklet. "But the geocentric theory isn't necessarily correct either. It might just be that the observational conditions were relatively favorable, and the calculations were more accurate."

The booklet presented by Johann Adam Schall von Bell only listed the basic points of Copernicus' heliocentric theory without discussing it in detail, but these basic points were enough to expose its shortcomings.

The biggest wrong assumption is that the orbits of celestial bodies around the sun are circular orbits, and they are in circular motion at all times.

"Has anyone ever proposed the hypothesis of elliptical orbits of stars around the sun in Europa?" Zhu Changluo looked up at Deng Yuhan and handed the booklet to Zhu Youxiao. "It is better to have no books than to believe them blindly. You must read them critically. But don't get confused."

"I understand." Zhu Youxiao took the booklet but did not open it immediately. He looked at Deng Yuhan silently, waiting for his answer.

Deng Yuhan had already entered a state of flow. He felt as if he wasn't simply playing a musical instrument, but rather engaging in an academic discussion with the "Emperor of Philosophy" before him. This was the world's most exclusive academic salon! If news of this could reach Europe, it would surely make his classmates, colleagues, and peers envious!

Deng Yuhan answered excitedly, "Yes! Yes! That person is Kepler! In the 37th year of the Wanli reign, Kepler published an article. In it, he said that based on the changes in the coordinates of Mars measured by Tycho Brahe over the past few decades, he calculated that the orbit of Mars is elliptical. Based on this, he speculated that all planets should move in elliptical orbits centered on the sun."

"However, the article only listed and analyzed the coordinate changes of Mars, without including coordinate data for other planets. Therefore, it wasn't widely accepted by Europa's astronomical community. Furthermore, the Vatican firmly opposed the heliocentric theory, so the elliptical orbit hypothesis wasn't widely circulated. At least, when I left Europa, this hypothesis was still circulating within a small circle and was heavily criticized."

In the 1609th year of the Wanli reign ( AD), Deng Yuhan was still in the laboratory of the Lynx Eye Academy, discussing with Galileo how to improve the Dutch-invented "mirror" that could see distant views, and was trying to make the first prototype.

Zhu Changluo did not intend to use his imperial authority to force them to accept the "common sense" that "celestial bodies orbit the sun in elliptical orbits." Instead, he asked in a friendly and highly seductive tone: "Deng Yuhan, I have a question for you. Are you willing to use more observational data to verify this elliptical orbit hypothesis? Even if this hypothesis contradicts the Vatican's prohibition?"

"Yes!" Deng Yuhan didn't care about the Vatican's ban and immediately nodded excitedly.

　Historically, the Ming dynasty's calendar reform debate lasted from the 35th year of the Wanli reign to the 16th year of the Chongzhen reign. In August of the 16th year of the Chongzhen reign, the emperor resolved to promulgate the Chongzhen calendar, based on the Tycho system. That same month, Sun Chuanting swore an oath at the Guandi Temple in Xi'an and marched out of Tongguan to engage Li Zicheng in a decisive battle.

　　
　
(End of this chapter)