Starting with a Wei Wu soldier

Chapter 287 Astronomy and Calendar

The 24th day of the twelfth lunar month in the third year of the Qiming era. A day for sweeping away

Every household in Chang'an was busy cleaning and tidying their courtyards in preparation for the New Year. The palace servants at Taiji Palace were also extremely busy, wiping windows, sweeping the eaves, changing lanterns, and pasting paper-cut window decorations. The entire imperial city was immersed in a busy and festive atmosphere.

However, in a secluded courtyard in the southwest corner of the palace, the atmosphere was quite different.

This is the Imperial Observatory—the court's agency in charge of astronomy, calendar, and meteorology. The compound is small, with only three courtyards, but its layout is well-organized. The main hall is the "Observatory," with several bronze instruments mounted on its roof: an armillary sphere, a simplified armillary sphere, a gnomon, and a water clock, gleaming dimly in the winter sun. The east and west side halls served as the library and council chamber, while the rear courtyard housed the director, deputy director, and several resident officials.

At this moment, a heated debate is breaking out in the main hall.

"The Dayan Calendar has been used for nearly a century. Although it has some errors, the people of the world have long been accustomed to it! To rashly change the calendar would be like pulling a thread that affects the whole system. Agriculture, festivals, taxes, and sacrifices—which of these wouldn't be thrown into chaos? Absolutely not!"

The speaker was an elderly man with white hair and beard, surnamed Cui, named Ming. He was the former deputy director of the Imperial Observatory, having served in the Observatory during the previous dynasty and through two reigns. He had personally witnessed the chaos caused by the three calendar reforms. His face was flushed, his voice trembled, and his finger almost poked the young man's face.

The young man opposite him was no more than thirty years old, surnamed Li, named Chun. He was a newcomer selected from the Imperial Academy's mathematics department to join the Imperial Observatory last year. He neither dodged nor avoided Cui Ming's gaze, his voice steady yet firm:

"Deputy Supervisor Cui, it is precisely because the 'Dayan Calendar' has been used for nearly a hundred years that the error has become increasingly large. Last year's winter solstice solar eclipse was predicted half an hour early; this year's spring equinox, the shadow of the sun as measured by the Imperial Astronomical Observatory differed from that in the calendar by three-tenths of an inch. The common people may not care about a moment, but for spring plowing and autumn harvest, and for worshipping heaven and earth, a difference is a difference. It cannot be hidden from heaven, nor can it be hidden from people."

"You—" Cui Ming's beard trembled with anger, "What do you know about the world, you mere brat!"

Li Chun stood firm: "I understand that the way of Heaven is constant; it does not exist for Yao, nor does it perish for Jie. If the calendar does not conform to Heaven, it is wrong. And if it is wrong, it should be corrected."

"you--!"

"alright."

A deep voice came from the palace gate.

Everyone turned around and saw a middle-aged man in a blue cotton robe standing at the door. He was not tall, with a thin face and deep-set eyes, but his eyes were exceptionally bright, as if they could see through everything.

The Director of the Imperial Observatory was surnamed Shen and named Kuo.

Shen Kuo was specially summoned from the common people by Chen Xing last year. It is said that when he was young, he traveled all over the country, observing celestial phenomena, recording the climate, and collecting local agricultural proverbs wherever he went. The "Record of Differences in Solar Terms in Various Prefectures and Counties of the World" that he brought with him was a thick three-volume book, which recorded the timing of solar terms and phenological changes in more than 300 prefectures and counties in different years. Chen Xing was greatly amazed and immediately appointed him as the Director of the Imperial Observatory.

Shen Kuo walked into the hall, his gaze sweeping over Cui Ming and Li Chun, finally settling on the armillary sphere.

"What's all the fuss about?" he said calmly. "The sky isn't going to spin an extra circle just because you're arguing."

Cui Ming and Li Chun both shut their mouths.

Shen Kuo walked to the armillary sphere and gently plucked the bronze ring. The ring turned, emitting a faint friction sound that was particularly clear in the silent hall.

"I am aware of the errors in the Dayan Calendar," he said. "But revising the calendar is not like revising an article, which can be done by simply rewriting it. The calendar has far-reaching implications; one mistake leads to a series of mistakes. If we are to revise it, we must do it step by step."

He turned his head and looked at Li Chun.

"Reorganize your observation data. List out the time, frequency, and magnitude of any errors clearly. Next spring, we'll select a few counties in the capital region to pilot the new calendar and see how it goes."

Li Chun was taken aback for a moment, then bowed deeply: "Yes."

Cui Ming was also stunned for a moment, his lips moved, but he ultimately didn't say anything more.

On the 26th day of the twelfth lunar month, the debate within the Imperial Observatory reached Chen Xing's ears.

Inside the Wenhua Hall, Chen Xing was staring blankly at the armillary sphere. He had placed it there himself the night before his ascension to the throne. Two years had passed, and small scratches had appeared on the bronze rings, marks left by his unconscious manipulations while he was thinking.

After Jia Wen briefly reported the dispute within the Imperial Observatory, Chen Xing remained silent for a moment, then suddenly asked:

"Prime Minister Jia, tell me, where did the stars in the sky come from?"

Jia Wen was taken aback. He was well-versed in classics and history, but there was no answer to this question in those texts.

"This old minister...does not know."

Chen Xing did not press further. He simply gazed at the twenty-eight constellations engraved on the armillary sphere and slowly said:

"I don't know either. But I want to know. The less I know, the more I want to know."

He paused.

"That Shen Kuo is a wise man. He knows that calendar systems can't be rushed or chaotic; they have to be implemented step by step. But I also want to know—could he move a little faster?"

The fourth year of the Qiming era, the eighth day of the first month. The eve of the Lantern Festival.

On the star-gazing platform in the backyard of the Imperial Observatory, Shen Kuo stood alone, gazing up at the night sky.

There was no moon tonight, and the Milky Way was exceptionally clear. That band of light, stretching across the sky from northeast to southwest, divided the heavens in two. Shen Kuo stared at it, muttering to himself, his fingers tracing lines in the air as if measuring something.

"Supervisor Shen is in high spirits."

A voice came from behind. Shen Kuo turned around and saw a young man dressed in black casual clothes walking up the stone steps.

He froze for a moment, then hurriedly knelt down: "Your Majesty—"

"Don't kneel," Chen Xing said, helping him up. "It's the middle of the night; kneeling like that will wake up the people downstairs."

Shen Kuo was helped up and was momentarily at a loss for words. The emperor's visit to the Imperial Observatory in disguise late at night was unprecedented.

Chen Xing walked to the edge of the observatory and looked up at the dazzling Milky Way. The night wind was biting, blowing his clothes, but he seemed oblivious.

"When I was a child in the north," he said, "I couldn't sleep at night, so I would get up and look at the stars. Back then, I felt that there were more stars in the sky than lights on the ground. Later, I fought wars, campaigning in the north and south, and I looked at the stars less often. But when I did glance at them occasionally, I still felt... how vast the world is, and how small we are."

Shen Kuo listened quietly without responding.

Chen Xing remained silent for a moment, then suddenly asked, "Supervisor Shen, tell me, what exactly is so difficult about this calendar?"

Shen Kuo was taken aback, then carefully considered his answer and replied:

"Your Majesty, the difficulty lies in two points. First, the measurements are inaccurate, and second, the generalizations are inconsistent."

"The inaccuracy of measurement refers to celestial matters, which are difficult for us mortals to accurately measure. The sun, moon, and five planets move according to certain rules, but these rules are not immutable. Small deviations, accumulated over centuries, can lead to major errors. The inconsistency refers to the countless people on earth, each with their own way of life. Farmers need to follow the solar terms to plant crops, merchants need to follow the days to travel, and officials need to follow the hours to work. Even a slight change in the calendar affects the lives of millions of people."

He paused, then looked up at the starry sky.

"During my year at the Imperial Observatory, what I did most was not to change the calendar, but to observe. I observed the rising and setting of the sun and moon, the movement of the stars, and the movement of the wind and clouds. The more I observed, the more I realized how little I knew."

Chen Xing turned his head and looked at him.

"So how long do you think it will take to fix this calendar?"

Shen Kuo remained silent for a long time before slowly saying:

"I dare not say. It may be five years, it may be ten years, it may be... I could never finish it in my lifetime."

Chen Xing was neither disappointed nor did he urge him. He simply nodded and gazed at the starry sky.

"Then take your time. If you can't finish it, pass it on to future generations. If they can't finish it, pass it on to their descendants."

He paused, then suddenly said:

"I've heard that when you were young, you traveled extensively, recording the seasons, phenology, and celestial phenomena wherever you went. Do those records still exist?"

Shen Kuo was taken aback, then nodded: "Yes. I have been compiling this for ten years; it consists of three large volumes and is in the library."

Chen Xing nodded: "Next spring, I will have all the prefectures and counties do the same thing. Turn your three large volumes into three hundred volumes, three thousand volumes. Record the timing and energy of the heavens and the earth in every inch of this land. Record it for ten years, twenty years, one hundred years. When that time comes, let's look at the calendar again and see if it can be calculated more accurately."

Shen Kuo was stunned.

He never imagined that the calendar could be done this way.

"Your Majesty... this... how many people and how many years would that require?"

Chen Xing looked at him and smiled slightly.

"Shen Jianzheng, you once said that things in the heavens are hard to measure accurately. But things on earth can be measured slowly. The more you measure, the more accurate it becomes."

He turned around and stepped down from the observatory.

Behind him, Shen Kuo stood alone on the star-gazing platform, looking up at the Milky Way, motionless for a long time.

On the second day of the second month of the fourth year of the Qiming era, the dragon raised its head.

Chen Xing issued an edict: each prefecture and county shall establish a "meteorological observation point" to record daily weather conditions, including sunshine, rain, snow, wind direction and force, temperature and phenology, and report to the Imperial Observatory monthly. The necessary expenses shall be allocated by the imperial court; those who neglect their duties shall be punished for dereliction of duty.

This imperial edict caused quite a stir in the court.

Some people think this is making a mountain out of a molehill, some think it's a waste of resources and manpower, and others think that His Majesty has been misled by Shen Kuo and is neglecting important matters by engaging in some kind of "investigation of things".

But the imperial edict had already been issued, and there was no point in opposing it.

The prefectures and counties had no choice but to comply. Some places took it seriously, sending people to observe and record; others were perfunctory, finding anyone literate to look up at the sky each day, fill out a form, and that was it; still others simply falsified records, copying last year's records, changing the dates, and submitting them.

Chen Xing knew all of this. He didn't rush to investigate, but simply instructed the Censorate to collect and store the records reported by various prefectures and counties.

"Keep it," he said. "Ten years from now, it will be clear who is serious and who is perfunctory."

In May of the fourth year of the Qiming era, the Imperial Astronomical Bureau presented the "Draft of the Qiming New Calendar" to Chen Xing for the first time.

Shen Kuo wrote in his memorial:

"Your Majesty, we have consulted seven calendars from previous dynasties, collected over three thousand meteorological records from various prefectures and counties, observed the sun, moon, and stars for over a thousand nights, and repeatedly deduced and verified them. We propose to add or delete three definitions of solar terms, revise five algorithms for predicting solar and lunar eclipses, and adjust two rules for leap months. The new calendar is more in line with celestial phenomena than the 'Dayan Calendar,' and the error can be reduced to no more than a quarter of an hour within a hundred days."

Chen Xing read it carefully, then wrote two words on it:

"It's worth a try."

In the autumn of the fourth year of the Qiming era, several counties in the capital region began to pilot the Qiming New Calendar.

At first, the farmers didn't pay attention; the almanac was issued every year, the same every year, so why bother trying it? But gradually, they realized something was wrong—

This year, it really frosted on the day of Frost's Descent. In previous years, there was always a few days' difference between the date of Frost's Descent and the actual date, but this year it was exactly one day off.

On the winter solstice this year, the shadow was the shortest. Someone stuck a stick in the ground, and sure enough, at noon, the shadow was the shortest.

The news slowly spread. Some said it was because the new calendar was accurate, some said it was because the heavens had granted their wish, and others said it was because His Majesty was wise and had moved the heavens.

There are all sorts of opinions.

But the people at the Imperial Observatory knew that it wasn't divine intervention, but the result of three years of day and night observation and repeated deductions.

The 23rd day of the twelfth lunar month is the Little New Year.

Chen Xing returned to the Imperial Observatory.

This time, he didn't arrive incognito at night, but rather openly in the afternoon. The entire Imperial Observatory was filled with trepidation and lined up to greet him.

Chen Xing waved his hand, dismissing everyone and leaving only Shen Kuo behind.

The two climbed onto the observatory and stood side by side.

The afternoon sun shone brightly, casting a warm glow on the bronze instruments. In the distance, the faint sounds of bustling activity drifted from the streets of Chang'an, as people prepared for the Little New Year.

"Supervisor Shen," Chen Xing suddenly asked, "do you think the stars in the sky will still be rotating like this a hundred years from now?"

Shen Kuo was taken aback, unsure how to respond.

Chen Xing didn't wait for his answer, but instead gazed at the bright, sunny sky and slowly said:

"I don't know either. But I do know that a hundred years from now, there will be people using the calendars we use today to look at the stars, farm, and live their lives. They may not remember our names, but they will remember—there was once an era when we calculated celestial matters a little more accurately."

He paused, then turned to look at Shen Kuo.

That's enough.

Shen Kuo bowed deeply and remained standing for a long time.

Sunlight shone on the two of them, on the bronze instruments, and on the distant, densely packed city walls of Chang'an, bright and warm.

It's another Little New Year.

Another year has passed, and it's almost over.