As we all know, for the appearance of this world, the ancients in our country firmly believed in the theory of "round place in the sky", believing that the earth is a square earth, and the sky is a dome, which is buckled on this square earth. Due to the backwardness of China's geographical science, until the Qing Dynasty, the ancients in our country still firmly believed in the "common sense" that the earth was square.
And what do Westerners think? As early as the 5th to 6th centuries BC, the ancient Greek philosopher Pythagoras believed that the earth was round. But he was not based on scientific inference, but in his eyes, the sphere was the most perfect of all geometric cubes. So, he thought that the Earth was also a flawless sphere.
It was not until aristotle, who saw that the projection of the earth was round during a lunar eclipse, that he gave preliminary evidence that the earth was round. Then came Magellan in 1519, who used circumnavigation to truly prove that the earth was a round sphere.
Therefore, the first realization that the earth is round orb, or Westerners. By the time China knew the true shape of the earth, it was already during the Kangxi dynasty of the Qing Dynasty. And the first Chinese to know that the earth is a sphere is naturally the Kangxi Emperor, as a representative monarch of the feudal era, how can he accept the subversive traditional view of "the circle of the earth"?
Among them, it is inseparable from a foreigner named Nan Huairen. A native of the Spanish Netherlands (present-day Belgium), he trekked through thousands of mountains and rivers to the Qing Dynasty in 1658, when the Kangxi Emperor was still a 4-year-old child.
Later, Nan Huairen entered the palace and spread some Western knowledge to the palace. Kangxi Nahui was in the stage of a thirst for knowledge, and under the influence of Nan Huairen, he developed a strong interest in Western scholarship, especially in geography.
In order to make it easier for Kangxi to learn geography, Nan Huairen and another Western missionary wrote a copy of the Western Essentials and drew an atlas, "The Complete Map of Kun you". These two books made Kangxi so precious that he had to read them almost every day. At the same time, Kangxi also had an idea to draw a map of the Qing Dynasty.
That is, on the eve of preparing to draw the map, Nan Huairen and Kangxi expounded the Western "earth circle theory" since ancient times, Kangxi laughed after listening to it, and felt that Nan Huairen was joking, in his view, "heavenly circle place" This is the unchangeable truth of eternity, and he also used the ancient people's sentence "The sky is like a round cover, the land is like a chess game" to refute Nan Huairen.
Nan Huairen listened without comment, he knew that the hard line of explanation could not shake the traditional common sense of Kangxi. Just as Copernicus insisted on the "heliocentric theory" in those years, he was eventually burned alive by the feudal European church. In order for Kangxi to understand that the earth is round, he must use evidence to convince Kangxi. Therefore, Nan Huairen decided to take the opportunity of Kangxi's map of the Qing Dynasty to correct Kangxi's views.
Soon, the task of mapping was issued, and each state capital had to map and describe the county road. With the help of Nan Huairen and various missionaries, the map was drawn using latitude and longitude measurement and triangulation, which took 9 years to draw. The name is "Imperial Public Opinion Overview Map", which is the most accurate ancient map of all Asia during the Qing Dynasty.
After getting the map, Nan Huairen used the territory of the Qing Dynasty to explain to Kangxi why the earth was round. At that time, the north-south latitude spanned by the territory of the Qing Dynasty was close to 50 degrees, and under such a large latitude difference, the length of the southernmost and northernmost latitudes was very different. However, in the theory of the circle of heavens, each parallel line is of equal length, and there is no change in the length of the parallel line.
It was with such a solid map of the Qing Dynasty as an explanation that Nan Huairen quickly made Kangxi understand that the earth was not flat. After seeing the map, Kangxi also suddenly realized, ashamed, but also marveled at the magic of geographical science.
After the Kangxi Dynasty, the "Diyuan Theory" began to become popular in China. However, Kangxi's understanding of the "circle of the earth" was not entirely accurate, until the end of the 17th century, Newton, through the rotation of the earth and mechanical analysis, further determined that the earth is a bipolar flat, equatorial bulge ellipsoid, and this is the real shape of the earth.
Although Kangxi's "earth circle theory" was not entirely correct, his attitude towards science was quite admirable. Whether it was a monarch before him or an emperor after him, few could be as enlightened as Kangxi. Since the feudal era, human beings have been searching for the truth of the world, and the process is full of twists and turns and dangers. If there were more emperors like Kangxi, perhaps the path to the search for truth would be more open.