"If we're on a 'ball', then from here we go west, all the way west, and eventually ...... It is possible to return from the east. Pen Fun Pavilion wWw. ｂiquge。 ｉｎfo”

Before Pang Ji's words fell, Yao Hongyi stared at his face, his teeth clenched, and his dilated pupils were full of fear.

Go west and keep going.

If it is indeed a huge ball at their feet, then ...... Theoretically, it is possible to return from the east.

It's just that this idea is too ...... Too ......

He really couldn't think of an idiom to use to describe it.

Whimsical?

Shocking?

Yao Hongyi felt that his heart was beating fast, very fast!

His throat burned like fire, and he said in a hoarse voice, "In case, in case ......"

Fear made him unable to even speak. Exhaling briefly and spasmodically, Yao Hongyi barely calmed down before continuing to ask: "What if this 'ball' is so huge that it can't be completed in the rest of his life?"

Pang Ji let out a long sigh.

How could he not think of this question?

How could he not have asked?

He still remembers that it was an afternoon more than ten days after the summer solstice.

The cicadas chirp incessantly.

Mixed with the roar that lingered in his head, it was almost impossible to think.

Pang Ji thought to himself that his face must have been ugly white at that time.

- "Ah Song, have you ever thought that if this 'ball' is unimaginably big, then ......?"

He asked in a trembling voice.

Le Song just curled his lips and smiled, but did not answer.

- "Da da da, da da!" The sound of horses' hooves came from far and near.

Pang Ji was stunned.

The sound of horses' hooves?

This is the study of the Marquis of Anguo's mansion......

"Less insurance. ”

Le Song's call made Pang Ji suddenly come back to his senses.

His student was already a few inches taller than himself, standing opposite to each other, and he had to look up slightly to meet Lesong's eyes.

Le Song caressed his jaw, and there was a faint blue fibrous root on his lips.

The smile is indescribably weird.

"You and I will know how big this 'ball' is today. ”

Pang Ji was at a loss, and he didn't know what to say.

Just as he was about to ask questions, the sound of horses shouting, neighing, and the sound of hurried footsteps came from outside the door.

- "Bang Dang!"

The door of the study was vigorously pushed open.

Pang Ji turned his head and saw that it was Kan Jingyun.

Sweat on his back, messy beard on his cheeks, messy hair like a bird's nest, mud stains, and watermarked clothes.

There is also a sour smell that can be smelled from a foot away.

Pang Ji frowned, unconsciously reaching out to cover his nose.

Kan Jingyun didn't notice his impoliteness.

Even, he may not have noticed that Pang Ji was also present at all.

"Have you collected all your records?" Kan Jingyun took out a tightly wrapped bag from his arms, walked quickly to Le Song, and asked impatiently.

Le Song replied: "Qi, Jinzhou, Fenzhou, as well as the Yunnei Prefecture of the Liao State, the Buna Prefecture of the Bai Dadan Division, and even the records of Irusha County of the Wugu Enemy Lie Division, have all been delivered quickly. ”

When Kan Jingyun heard this, he was overjoyed: "That's the record that only owes me?"

"Exactly, Mr. Kan is all right on this trip, right?"

"Everything is as expected, the well in Xunzhou, the noon sun on the summer solstice day does penetrate the bottom of the well. ”

Kan Jingyun said as he untied his burden. In the baggage, first there were several layers of linen, and then layers of oiled paper. If you don't know, you think it's a priceless treasure in it. When it was dismantled to the last weight, it turned out to be just a few pieces of rice paper, on which were densely written words.

"I also spelled out the records of Yongzhou, Shaozhou, and Xiazhou along the way. He touched a handful of sweat, sighed, and was relieved: "The people have repeatedly assured that it is the record of noon on the summer solstice, and it should be no worse." If it hadn't been for the heavy rain for several days and a long delay in Junzhou, I would have arrived the day before yesterday. ”

Le Song smiled with satisfaction, took the rice paper, and said loudly: "Let's start the calculation." ”

"Good!"

After finishing speaking, the two tacitly took out a piece of rice paper, compared it, and quickly wrote and scratched on the bookcase.

Just without any worries, he put Pang Ji aside.

"What are you talking about?"

Pang Ji asked hard, wanting to be involved.

Only the air of silence responded to him.

There are also the chirping of cicadas outside the window.

His eyes sank, and his face was as dark as mud in a deep well.

From the unwillingness and anger at the beginning, to the jealousy and embarrassment later, and then to the helplessness and indifference now.

Pang Ji is used to it.

It is customary for the two to be separated by an invisible, thick wall whenever they are in the same place.

Outside the wall.

watched the two of them discuss things they didn't understand at all, and were busy with "experiments" and "calculations" that they couldn't understand at all...... So excited, so eyebrows fluttering.

He is not unlost.

However, he really couldn't fit into that world.

It's a madman's world.

If he was Kan Jingyun, seeing the bright red palm prints on Le Song's face, he would definitely be concerned about it.

If he was Le Song, seeing Kan Jingyun coming in a tired and embarrassed car, he would definitely persuade him to wash and rest first.

But they just ignored it like this, and started "calculating" without saying a word.

Pang Ji sighed gloomily.

It's because he's not crazy enough that he doesn't fit in with them.

……

- "Okay?"

After a long time, just when Pang Jidu was about to doze off with boredom, Le Song suddenly asked.

"It's a little bit worse in Xiazhou. ”

"Good!"

Le Song put down the brush, held the tea cup in his hand, raised his head and drank it, and drank the cold tea to the bottom.

"Alright!" Kan Jingyun stopped writing and said.

"How much does Xiazhou count?" asked Le Song.

Kan Jingyun replied: "Seventy-five thousand eight hundred miles." Yongzhou is 75,300 li, and Shaozhou is 75,900 li. ”

He asked again, "What about you?"

"Jinzhou is 76,300 li, Fenzhou is 74,900 li, Liaoguo Yunnei is 76,600 li, Baidadan is 77,300 li in Buna, and Wugu is 75,500 li in Irusha County. ”

Lesong replied fluently.

"It's not much different. ”

"Hmm. ”

The two nodded in unison.

Pang Ji finally found the gap in questioning: "What mileage are you counting?"

When Kan Jingyun heard this, he turned his head to look at him, and blurted out in surprise: "Why is the huge person here?"

He really hadn't noticed Pang Ji before.

Le Song said: "Isn't it too lonely for only the two of us to know about such a feat? I want Pang Shaobao to witness it together." ”

Kan Jingyun was stunned, then smiled heartily, and said: "What you say is reasonable, what you say is reasonable." ”

Then he asked, "Did you tell him the idea of 'the earth is round and the sky is square'?"

"That's it. ”

"Well, in that case, it's easy to explain. ”

After that, Kan Jingyun picked out a piece of rice paper full of calculations and explained to Pang Ji: "There is a deep well in Xunzhou, and it is said that on the day of the summer solstice, the sunlight can directly hit the bottom of the well. ”

Pang Ji hurriedly said: "I have also heard about this matter, the matter of Sham Tseng has been famous for a long time, attracting many travelers from the neighborhood to watch, and it has been recorded by the local county chronicles, which is one of the wonders of Guangnan East Road. ”

"Well, yes!"

Kan Jingyun was unaware of his deliberate trickery, and said to himself: "We speculate that this is because the sun is located at the zenith of Xunzhou on the day of the summer solstice. Nowhere else has I heard of such a spectacle, which means that the sun is not at the zenith of the summer solstice. If the ground is really spherical, there must be an angle difference......"

Pang Ji's heart froze, and he didn't understand what the other party was saying at all.

But in order not to show his cowardice in front of the two, he pretended to understand, stared intently into Kan Jingyun's eyes, and nodded lightly from time to time.

Kan Jingyun thought he understood, his eyes suddenly brightened, his smile was full, and his speech became faster and faster: "Set up a wooden pillar in Xiazhou, just north of Xunzhou, and measure the length of the shadow of the wooden pillar at noon on the summer solstice, so that the angle between the wooden pillar and the sunlight rays can be obtained......"

As he spoke, he took three brushes from the pen stand, placing two of them parallel to the bookcase, one on top of them.

"If a line crosses two parallel lines, their opposite angles are equal. We observe that this angle in Xiazhou is one-tenth of the circumference, so in the same way, the section from Xiazhou to the center of the circle, and from Xunzhou to the center of the circle, the fan-shaped angle formed by them should also be one-fiftieth and three-tenths of the circumference......"

Kan Jingyun pointed to an equation on rice paper and concluded: "The arc length corresponding to this angle, that is, the distance from Xiazhou to Xunzhou, should also be equivalent to fifty-third of the circumference of the sphere. Later, by consulting the county records of various places and measuring the number of steps, we learned that the distance from Xiazhou to Xunzhou was about 1,430 miles. Then the circumference of the sphere is simply multiplied by this number of fifty-three, and the result is seventy-five thousand eight hundred li......"

Pang Ji tilted his head slightly, staring at the rice paper, as if looking at a page of heavenly books. Kan Jingyun's voice lingered in his ears, but he didn't understand half of it.

"For the sake of prudence, we used the same method to measure the angles between the wooden pillars and the sun's rays in the northward direction from Xunzhou, such as Jinju and Fenzhou, Yunnei Prefecture in Liaoguo, Buna Prefecture in Baidadan, and Irusha County in Wugu Enemylie Division, and calculated the distance between each and Xunzhou......"

Kan Jingyun quickly danced the brush in his hand and wrote down one calculation after another, as if he wanted to recalculate it in front of Pang Ji.

"Mr. Kan," Le Song had known Pang Ji for a long time, and when he noticed his strangeness, he stopped Kan Jingyun and said coldly: "If he doesn't understand, you can just say the conclusion." “

Kan Jingyun's hand holding the pen trembled, looked up at Pang Ji, found the blankness in the other party's eyes, and asked in a daze, "Are you...... Don't understand?"

Pang Ji was stabbed by Le Song's indifferent and impatient look, frowned, and stubbornly confessed: "I don't understand, I don't understand at all." ”

"Ah...... That's right. ”

Kan Jingyun put down the brush and scratched the back of his head in a daze, his hair, which was already messy, became more messy at the moment, and said with a wry smile: "I don't know why, it's a little lonely." ”

For a moment, he looked at Pang Ji and said, "It would be great if a huge person could also experience the joy and ecstasy of the calculation process.

Pang Ji's heart trembled.

There was no trace of sarcasm in the man's eyes, and he was as clear and sincere as a child.

It's full of regrets, regrets, and losses.

Le Song's eyes didn't even blink: "I can't force it." ”

"Yes...... That's why it's lonely. ”

Kan Jingyun echoed, and he said to Pang Ji: "The conclusion is: the circumference of the sphere we are in is between 75,000 li and 77,000 li, and the error is not too big. ”

……