Chapter 660: Number of Days

"Lü Li Zhi" in the Book of the Later Han Dynasty says: "The creation of calendars is to set up instruments to check the scenery of the day. If the scenery is long, the sun will be far away, which is the end of the heaven."

The sun rises to its peak, and the week progresses into the year, but its scenery is no longer there.

There are four hundred and sixty-one days around, and the scenery returns to its original state. This is the end of the daily journey.

Divide the day by the week, and you get one quarter of three hundred and sixty-five days, which is the number of days in a year."

The translated meaning is that if the winter solstice of the first year occurs at noon, the winter solstice of the second year will occur a quarter of the day after noon.

The winter solstice in the third year will occur one-half day after noon, that is, at midnight.

The winter solstice in the fourth year occurs three-quarters of the day after noon.

It wasn't until the fifth year that the winter solstice returned to noon again.

If you use a standard table to measure it, you will find that the first year has the longest shadow, the second year is slightly shorter, the third year is the shortest, the fourth year has the same shadow as the second year, and the fifth year returns to the first year.

The appearance is the same.

Due to rain, slight changes in the sun's shadow and other reasons, the measurement error is still very large.

It was Zu Dada who proposed a new method of determining the time of the winter solstice with relatively strict mathematical meaning.

He used the idea of ​​symmetry to measure the length of the shadow of the sun a few days before and a few days after the winter solstice, and then worked out a set of algorithms to calculate the exact time of the winter solstice based on the law of subtraction and increase of the sun's shadow.

Zu Dada's method has led the world for more than 700 years, but it still has errors.

This error comes from two astronomical assumptions made by Zu Dada: First, the change of shadow length before and after the winter solstice is symmetrical. Second, the change of shadow length is uniform within a day.

However, this cannot be blamed on him. Due to the limitations of the measurement technology of the Han Dynasty, being able to achieve this step is already a great talent that has not been seen in thousands of years.

However, the Tianshi Mansion has far more precise weights and measures than the ancestors, a more powerful astronomical observation network, a more convenient way of expression, and more reasonable statistical tables. After more than ten years, Zhang Tianshi has mastered the accurate value of the Tropical Year -

—Three hundred and sixty-five days, five hours, forty-eight minutes and forty-six seconds.

365.242199074 days, nine decimal places.

In the third month of the year of Gengxu, Wang Anshi asked to set up a Bureau of Classics and Meanings to revise the meanings of the three classics: Shi, Shu, and Zhouli.

Wang Anshi personally promoted the promotion, and Lu Huiqing and Wang Yu co-edited it. The emperor wanted to summon Cheng Hao to intervene in his affairs, but he could not do it, so he stopped.

On the same day, Zhang Tianshi arrived in Beijing and presented the Tianshi Mansion's achievements in chemistry, astronomy, geography and medicine.

Su You asked the Reform Secretary Tianjian to formulate a new calendar based on the Tianshi Mansion's observation and calculation results and methods;

At the same time, more precise weights and measures were used to transform astronomical instruments;

A more scientific system of longitude and declination is used to mark the twenty-four solar terms of the year.

Zhao Xu readily agreed to these two things.

On the same day, three things were placed in Si Tianjian - the sun, moon and five-star meridian and leveling instrument provided by Tianshi Mansion, the pendulum timer provided by Songyang Academy, and the Taiping Armillary Sphere provided by Taishi Bureau.

The Taiping Armillary Sphere was a water-borne armillary sphere created by Zhang Sixun, an official in charge of Tianjian in the 4th year of the Taiping and Xingguo reigns of the Song Dynasty. Later, the machine rope broke, and due to the lack of knowledge of its manufacturing method, it could not be repaired.

Su You proposed a big goal and a small goal to everyone in Si Tianjian.

The big goal is to integrate the three components of the armillary sphere, the armillary image and the time-telling device into one, so that it has the ability to observe the movements of celestial bodies, demonstrate changes in celestial phenomena, and accurately tell the time.

This thing may be very big, so it is called the instrument platform.

The small goal is to get an accurate timing tool that automatically rings a bell every hour, so it is called a clock.

The two goals, one large and one small, are actually a huge project, which must start with the translation of French writings on instruments by Zu Chongzhi, Zhang Heng, Liang Lingzan, Zhang Sixun and others.

It also involves a lot of design, modification, mechanical invention, finalizing the design using scientific and engineering drawings, and then making models.

Su You's requirement is that it must be written into a book so that all those who like to study, from theoretical principles to basic design, from calculation to verification, must be able to understand it for future generations. It should not be like Zu Dada's "Zhu Shu".

After being cut off for hundreds of years, only a fragment was obtained.

As for the bells and drums, new calendar, astronomical observation instruments, etc. requested by His Majesty, they became simple things.

The basis of all this is weights and measures.

After intense discussions in Si Tianjian among the world's top scientists, they finally came up with a new measurement plan that blinded everyone.

Based on the theory proposed by Chen Zhaoming, everyone calculated the height of the celestial sphere from the ground, and then took one ten thousandth of the distance from the celestial equator to the North Pole as the standard length.

After this value was calculated, all the scientists immediately looked at Su You like a monster and asked for an explanation first!

Su You could only rub his nose and smile: "Coincidence, purely coincidental..."

People today don't know the concept of stars being infinitely far away from themselves. They think that they move on a sphere. Nowadays, people stand on the ground and observe the starry sky. Therefore, in the calculation process, they regard themselves as a point and the starry sky.

Treat it as a sphere.

The result is that it turns itself into the center of the earth, and regards the distance from the earth's surface to the center of the sphere as the distance from the celestial sphere to the ground.

So the calculated number is the distance from the Earth's equator to the North Pole divided by 10,000.

In the Song Dynasty, one foot was equivalent to 31.68 centimeters in later generations. Su You used three feet as one meter and created the centimeters and micrometers. The resulting values ​​are extremely close to today's astronomical values.

I don’t know if this news will become a solid proof that Tan Hwa Lang has descended to earth.

With the length measurement, there is the volume measurement, and then the weight measurement can be obtained through the weight of the unit volume of pure water.

Su You reported this plan to the court, which immediately caused an uproar.

There are those who support it and those who oppose it.

But those who objected could not give any reliable reasons. To say that weights and measures cannot be changed, Wang Anshi, Sima Guang, Liu Xun and other famous scholars in classics, history, epigraphy, etc. can provide evidence to prove that weights and measures were not changed from the pre-Qin Dynasty to the Han and Tang Dynasties.

By the Song Dynasty, there had been great changes.

To say that changing the weight standard from hexadecimal to decimal is unreasonable, Su You said that current scales use either the spring principle or the lever principle, and the decimal system is more convenient for calculation of proportional relationships.

The hexadecimal system is simple to make weights and measures, but it leads to measurement troubles. With the current technology of the Song Dynasty, this problem can be completely solved.

Sima Guang also mentioned a serious problem: Huang Zhongzhenglu, there is still no accurate finalization, which has become a huge obstacle to the restoration of the ritual system in the Song Dynasty.

If the ancients could also obtain the number of days and use the number of days system to measure it, why would there be such trouble today?

Therefore, Si Tianjian of the Song Dynasty was able to create such an unchanging weight and measure, which can be said to be a great achievement that created the world.

When Qin Shihuang unified the six kingdoms, the first thing he did was to unify writing and measurement.

Zhao Xu immediately captured Zhao Zongyou from Zhengzhou and explained to him what this "rice" was all about.

But he didn't dare to look for the younger sister. In Zhao Xu's feudal and superstitious mind, the younger sister's belly was pregnant with the crystallization of the highest IQ in the Song Dynasty. It must be a treasure. You can't be too careful.

So Zhao Zongyou spent three days twisting Zhao Xu's brain into a ball of paste, but he still couldn't understand how the length was calculated.

However, the general idea is clear. In short, this is - this scale, the heavenly number of the Shangzong came into being, and it is the balance of the human world based on the odds of Haoming.

This weight and measure that can last forever is indeed very easy to associate with destiny and the dynasty through the ages.

Some ministers even took this as a congratulation and asked him to be honored as Emperor Shao Tianxian, Guwenwu Renxiao Emperor.

Zhao Xu laughed and refused, saying that it was not a good idea.

Although the Song Dynasty received heaven in my generation, this was just to encourage me to continue to practice heaven and practice the Tao. Those who should be humble should still be humble.

This pretentiousness is really too outrageous.

Therefore, at the end of March in the sixth year of Xining, Zhao Xu issued an order, and ordered Si Tianjian to make a new instrument. In addition to the traditional three types of weights and measures of length, volume, and weight, temperature and concentration were added. This was regarded as the standard for all generations and was promulgated throughout the world.

The first three sets of new utensils are made of platinum and glass, and are dedicated to the Ancestral Temple, Si Tianjian, and Hanlin Academy respectively.
Chapter completed!