Lee Soon-ji and the other new researchers, along with the existing researchers, were doing their best to wrestle with the numbers to solve the tasks assigned by Hyang.
While some tasks were easily resolved with the addition of new personnel, there were still many that were not.
Among the unsolved problems, the most representative was the correction of the calendar.
Late at night.
"Hmm... I don't understand..."
With a book full of formulas spread out, Lee Soon-ji tilted his head to one side.
What he was struggling with was that the formula for correcting the calendar contained too many variables.
"If we just add a leap month according to the old custom, and adjust the solar terms based on the Chinese calendar, it wouldn't make sense to revise the current calendar."
Suddenly, Lee Soon-ji, who had been moving the teacups around a central teapot, stopped.
"Wait! What if the center of this rotation is not the earth we live on?"
Lee Soon-ji raised his finger and began to draw an imaginary orbit, entering into calculations.
Like a madman, Lee Soon-ji waved his hands and muttered, then came to a conclusion.
"The formula works if the sun is the center! We need to place the sun at the center!"
Lee Soon-ji brought over a stack of blank papers and began to quickly write down the formulas.
As if possessed by a deity, Lee Soon-ji wrote down the formulas frantically and, at some point, put down his pen and clenched his fist.
"Of course! The variables for variables are gone! Hahaha! Woo!"
Lee Soon-ji laughed and screamed as if he had lost his mind.
A greater pleasure than the first time he experienced the joy of discovery was hitting him.
Lee Soon-ji stood up, opened the window, and shouted.
"The center of the world is not this earth! This earth is merely one of the variables!"
* * *
After the sudden enlightenment last night, Lee Soon-ji, who had found the solution, was fully engaged in organizing the formulas he had discovered.
He had already given up on leaving the office, and sometimes even skipped meals, which started rumors among the researchers.
"Lee Soon-ji has gone mad!"
Hearing the rumors, Jeong Choe and Jeong In-ji came to check on Lee Soon-ji and were stunned by the pile of papers next to him.
"What is this...?"
Jeong Choe and Jeong In-ji, who were skilled in arithmetic, soon recognized the value of the formulas Lee Soon-ji was writing.
Jeong Choe, with a tense expression, looked at Jeong In-ji.
"I will report this to His Majesty immediately. You stay here and keep an eye on him."
"Yes, sir."
After some time, Hyang, who had received an urgent report, rushed from Area 51 to examine the problematic papers.
Hyang's face was seriously wrinkled as he looked at the content of the papers.
'Damn! This level is beyond me!'
While others didn't know, Hyang had chosen a liberal arts path in the 21st century due to his struggles with mathematics. His strength lay in solving problems through physical confrontation.
Although he didn't fully understand it, Hyang grasped the general idea and ordered Jeong Choe and Jeong In-ji.
"Summon the royal physician immediately!"
"Yes, sir!"
"And, keep this matter confidential until this researcher formally reports to His Majesty."
"Yes, sir!"
"And... it seems I've won the debate."
"Ugh..."
Jeong Choe and Jeong In-ji groaned in response to Hyang's question.
* * *
When the research institute was established and the calendar revision began, a debate arose between Hyang, Jeong Choe, and Jeong In-ji.
The debate centered on "The Earth is round" and "The Earth revolves around the sun."
The revision of the calendar required astronomical observations, and this process led to a clash of concepts.
The debate over "The Earth is round" was easily won by Hyang, thanks to the observation report that "the horizon seen from a high mountain by the sea forms an arc" and the help of the Huihui (Muslim) scholars.
However, the heliocentric theory sparked a lengthy debate, as Hyang, with his superficial knowledge from exam preparation, could not provide a perfect rebuttal.
As a result, the debate ended in a draw, and the浑天仪 (armillary sphere) was not placed in the exhibition hall of the institute.
"Oh! The drawbacks of exam preparation, knowing only the names of Galileo and Copernicus and the concept of precession!"
Hyang, who knew only the names but not the content, shouted at the sky about the drawbacks of exam preparation.
* * *
A month later, Hyang gathered Sejong and the ministers for a presentation on "Calendar Correction."
The presenter was Lee Soon-ji, who had even taken a calming pill to ease his nerves and proceeded calmly with the presentation.
"...That's all."
When Lee Soon-ji finished his presentation, Sejong, who had been listening intently, praised him.
"Good job. It's a fine theory. Crown Prince, what do you think of this researcher's theory?"
"I compared it with the records of past calendars and the occurrences of solar and lunar eclipses, and there were no discrepancies."
"Then, we must finally consider this our own calendar?"
In response to Sejong's question, Hyang corrected the term.
"It's a correction method, Your Majesty."
"Right, 'correction method.'"
Sejong nodded with a bitter smile and looked at the ministers.
"What do you think, gentlemen?"
In response to Sejong's question, Hwang Hee answered on behalf of the others.
"The correction of the calendar should be implemented immediately. However, the problem arises when it is used for education. The book will inevitably be released to the public, and there will be issues. Some sentences need to be omitted."
"Omit sentences?"
In response to Sejong's question, Hwang Hee explained.
"The parts stating 'The world is spherical' and 'The world revolves around the sun' could cause problems with the Ming Dynasty."
"Hmm... That's true."
Sejong nodded in agreement with Hwang Hee's point.
The prevailing worldview was that "The world is flat, and the center of the world is China."
However, the theory from the institute contradicted this.
On the other hand, omitting these sentences did not sit well with Sejong.
Of course, the Ming Dynasty was the superior state, and due to the power disparity, they had to be cautious. However, it hurt his pride.
"Is there another way?"
In response to Sejong's question, Hwang Hee answered again.
"We can emphasize that it is merely a simple law of nature."
"A simple law of nature? Hmm... That's true."
As Sejong nodded, Hwang Hee added.
"To make such a claim, we need solid evidence to prove it. The evidence provided by the institute is insufficient."
"That's true. Crown Prince, I command you."
"Yes, Your Majesty."
"Do you understand what needs to be done?"
"Yes, I will gather more evidence to solidify the theory."
"I see. Then, what should you do, gentlemen?"
In response to Sejong's question, Yi Jik stepped forward to answer.
"We need to explain that this is merely a simple law of nature and does not deviate from the principles of serving the superior state."
"I understand. Minister of Rites, this is a heavy responsibility."
In response to Sejong's words, the Minister of Rites bowed deeply.
"I will do my utmost to fulfill Your Majesty's command!"
"Very well, let's conclude here."
When Sejong declared the end of the presentation, the ministers left their seats and headed out.
"Phew~."
"Minister Yi, good work."
"Minister Yi, you have a tough road ahead."
As the other ministers commented, Yi Jik burst out.
"Damn! Why does the Crown Prince have to do something unnecessary...?"
"Minister Yi!"
Yi Jik, who was about to criticize the Crown Prince and the institute, immediately shut his mouth at Hwang Hee's rebuke.
"Unnecessary? Do you really think so?"
"It's just that, so far, it has been... adequate."
"How can you be so narrow-minded! Many people have suffered because the solar terms were not accurately set. And you're still a minister!"
"I apologize."
Due to Hwang Hee's criticism, the Minister of Rites had to bow his head.
In Joseon, where agriculture was the backbone of the economy, setting the solar terms accurately was crucial.
If the solar terms were not set correctly, the people's criticism would all be directed at the king, who would then have to hold the responsible parties accountable.
"Understand that the burden on you and the Ministry of Rites has increased! However, it is your duty to resolve this! How can you only look for what is convenient for you? If you don't want to be criticized, don't do things that will get you criticized! If you feel wronged, write a petition or resign! Resign!"
Thanks to the pressure to change, the ministers' work efficiency improved.
A typical example was when Hwang Hee, sensing Sejong's desire for mass production, had a talk with the Minister of Works in advance and was able to present records of iron production to Sejong.
As a result, the ministers heard less of the most annoying phrase.
"Compared to what we've heard, it's quite... inadequate."
* * *
Hwang Hee and the ministers were recently troubled by one issue.
The issue they were grappling with was "iron supply."
With the decision to mass-produce the 갑식장총통 (Japchae) and 비격진천뢰 (Bigeukjinchunrye), the court needed a large amount of iron, specifically wrought iron.
Until the early Joseon period, the 염철제 (Yeoncheolje) system, where iron was directly collected from the people, was in place, but due to strong resistance from farmers, the system had to be changed.
The solution chosen to replace the 염철제 was the 철장도회제 (Cheoljangdohoeje), where iron workshops were established near iron mines, and farmers were mobilized during the agricultural off-season to produce iron.
However, this system also had many problems, as it involved the forced mobilization of farmers, leading to resistance and decreased motivation.
In the end, Sejong's answer was simple.
"Purchase items that meet the specified standards and quality!"
However, the ministers and officials responsible for the practical aspects were in a bind.
"There is no budget! No budget!"
Ultimately, the ministers, who could not find a good solution even after brainstorming, informed Sejong of the problem.
"Your Majesty, there is a problem with implementing the measures Your Majesty has ordered."
"Problem? Hmm... Is it the budget?"
"Yes, Your Majesty."
Sejong clicked his tongue in frustration at the ministers' response.
"Tsk!"
However, this time, the ministers also had something to say.
"Your Majesty, we are diverting the iron supply from the 철장도회제 to address the budget issue, but there is not much left after setting aside the necessary amount."
"Your Majesty, even after diverting, the budget is still insufficient to purchase the remaining iron."
"Your Majesty, to solve this budget issue, we need to address the tax collection problem, which is still not well-prepared."
"Your Majesty, the problem is not just the budget. We need to pay for the iron, and the supply of grain and cloth for payment is limited. To solve this, we need to manage currency, but we are still not prepared."
"Damn..."
Sejong was also frustrated by the ministers' responses. He wanted to implement his plans enthusiastically, but Joseon's limited capabilities were holding him back.
"Let's think a bit more."
"Yes, Your Majesty."
After dismissing the ministers, Sejong sighed.
"Phew~. What kind of country is this... Not even a bright future...?"
Hearing the rumors, Hyang clicked his tongue.
"Tsk! It's so difficult to build up...?"
Hyang found a blank sheet of paper and began to write.
"The best solution would be a state-owned enterprise. POSCO! How great would that be?"
* * *
Sejong, who received the petition proposing "the establishment of a state-owned enterprise to manage iron supply," immediately slapped his knee.
"Right!"
However, the ministers who read Hyang's petition shook their heads.
"How can the state engage in commerce...?"
"Even if it's a state-owned enterprise, it will still seek profit. How can the court pursue profit?"
"Tsk!"
Sejong clicked his tongue at the ministers' reactions.
As soon as Sejong clicked his tongue, the ministers became tense and reviewed their statements.
"How can you be so short-sighted, gentlemen? If the court produces iron, only the court will benefit? Iron is not produced everywhere in Joseon. In regions where iron is produced, it is cheap, and in regions where it is not, it is expensive, causing hardship for the people. If the court produces iron directly, it can solve this problem. Why can't you see that? And it can also address the mining issue."
"Oh..."
"Think a bit more, will you?!"
The ministers, who were reduced to silence by Sejong's rebuke, were left speechless.