"Who made a sundial out of such a superb green jade? Surely this can't be kept in the sun often, right? Isn't it wasted?"

Qi Tengyun said that although the sundial cannot be seen in life, it can still be seen in books and some public buildings, which is simple and simple with a sense of mystery, which is indeed quite in line with some architectural styles.

"It's certainly not something to be used, it's something to be appreciated. I wonder why there is such a large piece of superb green jade, why should it be made into this sundial? It is much more ornamental and valuable to make other objects!"

Liu Musheng groped and said, he found that the sundial plate and the chassis below were connected, intact, not individed, and the surprise in his eyes was even stronger.

I don't know if the ancients at that time used a whole piece of green jade to dig out such a shape, or was the raw material of green jade originally similar to this shape?

He prefers the latter, and even if he has money, he doesn't play like this.

"Do you say that the above timekeeping is accurate? The ancients relied on this to see the time? Isn't it how many times I watch TV?"

Shao Dengfeng said curiously.

"If it is a practical sundial, it must be accurate, and from it you can accurately see not only the time, but also the solar terms and the month. However, this sundial is so beautifully made, although it is not practical, it should be strictly required and there will be no mistakes. ”

Zhao Tianming said.

Zhang Heng had already invented a geodynamic instrument that could predict earthquakes in the Eastern Han Dynasty, and he also believed that the universe was infinite, that the movement of celestial bodies was regular, that moonlight was the reflection of sunlight, that the moon orbited the earth, and that the lunar eclipse was because the earth blocked the sunlight.

He recognized certain laws of the sun's movement and correctly explained the causes of the long nights in winter, the short nights in summer, and the day and night of the spring and autumn equinoxes. Of course, at that time he did not know that it was the cause of the rotation of the earth.

Even so, after observing the movement of certain celestial bodies, he came to the conclusion that the day of the week is 365 degrees and one quarter of a degree, that is, the time of a return year, which is not much different from the current value of 365 days, 5 hours, 48 minutes and 46 seconds for the earth to circle the sun. I don't even know how he was able to measure it at the time, but I don't know.

And Zu Chongzhi, the people of the Northern and Southern Dynasties, have calculated pi to the last seven decimal places, is it 3.1415927 or how much? This is nothing, he also accurate the time of the year to eight decimal places, I remember that the first few are the same as now, and also introduced the precession, so as to re-revise the "Ming calendar" and the method of setting leap months. And at that time, he had already measured that Jupiter's orbit cycle was more than 11 years, nearly 12 years.

In addition, Zhang Sui, an astronomer of the Tang Dynasty, improved Zhang Heng's "armillary sphere" and created the "armillary bronze instrument" in order to revise the calendar, measure the position of the sun, moon and stars in their orbits and grasp the laws of their motion. When he used the "armillary bronze instrument" and the "zodiacal travel instrument" to observe celestial phenomena, he could directly measure the coordinate positions of the sun, moon, and stars in orbit. He deduced that the stars on celestial bodies were moving, more than a thousand years before the British astronomer Halley!

There are many such examples, digging deep and exploring, maybe they have already broken the shackles of 'the sky is round and the place' and formed a scientific theory, and Qu Yuan has issued a "Tianwen" thinking, but it is a pity that the way of thinking of our people is more focused on application and ignores the theory. ”

Yang Quan said with emotion, sometimes he is anxious for the ancients, that veil is there, and he has discovered the existence of the truth too many times, but unfortunately no one has pierced it.

Perhaps this is also related to the ancient Chinese idea of the official standard! Many inventions and applications are actually in the service of politics.

"The big guy didn't expect you to be quiet and know so much?"

Qi Tengyun was a little surprised, some of them were just what he had learned before, but now he had already returned them to the teacher.

"Ignore him, this guy used to be a top student. ”

Liu Musheng said that for him, high school is the time when he has the most abundant knowledge points, and the peak of his life has long passed.

"The wisdom of the ancients, in fact, a lot is still reflected in life, you look at this sundial is simple, in fact, it has a lot of exquisiteness.

Sundials, no matter what form they take, have a pointer at the same angle as the ground level, and point to the North Pole correctly, that is, a pointer parallel to the Earth's axis of rotation. By observing the projection of this pointer in a specified area, the time can be determined.

You see this equatorial sundial, the angle between this chassis and the dial is not arbitrary, it must take into account the angle of this chassis and this pointer. And the geographical latitude is different from place to place, which everyone knows, if you are too far away, the time will not be accurate. There is also this pointer, which must be fixed to point to the North Pole. ”

Zhao Tianming explained.

"So that ancient people could accurately know the latitude and longitude of their place?"

Qi Tengyun said in surprise, this is completely impossible in his mind, and the statement of latitude and longitude, in his impression, should have been transmitted from the West in modern times, right?

"Now the concept of specific latitude and longitude is indeed imported from the West, but not in modern times, but in the Ming Dynasty Xu Guangqi. Moreover, in the past, the ancients had a theory of latitude and longitude, and it was said in "Confucius's Family Sayings" that the east and west of the earth are the latitude, and the north and south are the longitude.

In astronomy, the application of latitude has already begun, and it can be accurately measured, called extremely high, which is measured according to the North Star.

The North Star has many applications in astronomy, far more than just pointing directions, so after the introduction of Taoism, it was called the Emperor Star.

At the same time, the ancients could also plan scales in the heavens to correspond to the earth.

The ancients had the concept of the ecliptic and the white path a long time ago, the ecliptic is the trajectory of the earth's orbit around the sun, although they did not know that the earth revolves around the sun, but they have mastered the route of this trajectory, that is, one year, the white path is the trajectory of the moon around the earth, that is, one month.

Through this law, the ancients formulated a calendar, with the ecliptic trajectory cycle as one year, and the white path estimated cycle as one month, which is the lunisolar calendar that has been used in ancient China, because it can accurately guide agricultural production, so it is also called the lunar calendar. ”

赵天明 says:

Moreover, the superstitious saying of the ancients that 'the heavenly dog eats the moon' has long been seen through the truth in the eyes of astronomers, Sima Qian summed up that there is a periodic law in the occurrence of lunar eclipses according to the lunar eclipses of previous dynasties, and he put forward the data of a lunar eclipse cycle for the first time in Chinese history.

In the Book of Heavenly Officials, it is said: "The first day of the lunar eclipse is six in May, five in June, six in May, one in June, five in May, five in May, and one in one hundred and thirteen months. Therefore, the lunar eclipse is often also. ’

They have known for a long time that lunar eclipses are regular and very normal. ”