From Chief to Ball

Chen Jian hurriedly said, "Mr. Benchu ​​must believe that the world is round, right?"

"That's natural. Those of us who look at the stars still believe in this. Is this the world?"

Looking at this big white ball with nothing on it, Mr. Benchu ​​felt a little bit empty.

Chen Jian took out a pen and said with a smile, "It just so happens that Mr. Benchu ​​is here, and he is about to pick up a pen and draw where Mincheng is."

Mr. Benchu ​​picked up the pen, laughed and said, "How do you draw this?"

Then he took a look at the ball, thought about the height of Mincheng's shadow and the angle of the North Star, shook his head and said, "I can only guess which arc Mincheng is on, but I don't know where Mincheng is."

"Mr. Benchu ​​was joking. Now that you know which arc it is on, any point on this arc can be Min City. Once Min City is settled, the rest of the place can naturally be determined. Anyway, this is a The ball can’t be divided randomly up and down, but things can. Only by setting a point at will can there be something corresponding to this point. Therefore, as long as Mincheng is drawn on that arc, it doesn’t matter where it is drawn. Other places , of course the city of Fujian shall prevail."

After thinking about it for a while, Mr. Benchu ​​understood what it meant. With a laugh, Chen Jian hurriedly handed over various measuring tools.

After finding a line of northern latitude, Mr. Benchu ​​casually clicked a point on it, pointed to it and said, "This is Mincheng. I know that the capital is in the north, and I know the latitude of the capital, but I dare not It's easy to stipple on it because you don't know anything."

"Mr. Benchu, things are relative, because there are magnets and the North Star, and the north is cold and the south is hot. But between east and west, the warmth and heat are the same, and there is no East Pole Star. This thing can only be said, it can only be compared."

"Yes."

"Then why don't Mr. Benchu ​​help to draw another line. The meridian that runs through the north and south can just pass through Mincheng."

Mr. Benchu ​​seemed to have thought of something, passed Mincheng and the apex of the North and South Poles, and drew a meridian running through the north and south.

Returning the pen to Chen Jian, Chen Jian took out a measuring tool and drew 36 dotted lines vertically and horizontally from north to south on the spherical surface like cutting a watermelon.

The theory of warp and weft existed as early as when weaving. Chen Jian said it was warp thread, and Mr. Benchu ​​thought it was very appropriate.

"Mr. Benchu, you are a master of calendars and a scholar of stargazing. Since the meridian you drew across Mincheng, I think it is called the Prime Meridian. Based on this, the east is the east meridian, and the east is the east meridian. The west is the west meridian. The prime meridian passes through Mincheng. Isn’t it obvious where Mincheng is?”

"where?"

"North latitude is 28 and a half degrees, and the longitude is zero. If the longitude and latitude are known, isn't it obvious where Mincheng is?"

"Hahaha...Your longitude is self-proclaimed. I said that it is the zero-degree meridian elsewhere, and the location of Mincheng has not changed, but it has changed when I said it."

"That's right, it's just that I made this thing first. It's up to me to divide the longitude into something. The latitude is created by heaven and earth and cannot be changed, but things depend on people. Maybe it's the sea. There is another world outside, and it is not necessarily true that people have separated things.”

Mr. Benchu ​​looked at this crude globe with only longitude and latitude lines and a Fujian city, nodded and said: "The world is [-] miles wide, and maybe there are other worlds. I don't know. Since the location of Mincheng has been determined, the capital city is in where?"

Chen Jian laughed and said: "That's beyond what I can know. It depends on you, Mr. Benchu. This longitude line is named after you. Is it possible that you still don't want to contribute? Now that the latitude is no longer a problem, then once the longitude is determined , isn’t it easy to calculate where you are and the geometry of the land?”

Mr. Benchu ​​recalled those complicated atlases, tapped a point on the top of Min City, and said: "About here. Sure enough, after setting up Min City, setting the longitude, the city can tell the latitude and longitude. It's just Latitude is easy to measure, but longitude is hard to know."

A long time ago, the length of the meridian was deduced by measuring the length of the sun shadow at the interval between north and south. If the earth is regarded as a pure ball-in fact, people have been doing this all the time. Mr. Benchu ​​figured out the orbit of Yinghuoxing It wasn't perfect before someone had a basis for doubting whether it was a pure ball-then looking at this ball, it was truly felt that China's territory is actually not big.

This intuitive gap made Mr. Benchu ​​wonder, is there really only one civilization in such a vast world?

Frowning and thinking about it for a long time, he raised his head and asked Chen Jian: "You suddenly told me these things, it must not be aimless. What are you going to do?"

Chen Jian laughed and said, "You must have heard that I'm going to trade in Qi State."

"I heard about it when I came to Mincheng, and everyone knows it."

"I want to verify whether it is true that the world is round. If it is true, as long as the height of the shadow of the sun in the two places is the same, you can go straight from east to west along the latitude. This is a route that no one has traveled, I think Try it. I think there is always a book that records the height of the stars and the length of the sun and shadows of the ports in Qi State, but it is so vast that it is difficult for me to find it. Mr. Benchu ​​is proficient in stargazing, so I must have an impression on it. I read it in which book, this is exactly what I want to ask."

Mr. Benchu ​​recalled it for a while, nodded and said: "I have an impression, there should be records."

"If you can find a short route, it will be much more convenient for you to do business or other things in the future. If you can roughly measure the longitude, even if you lose your way, you can roughly know which direction to go on the vast sea. "

"How to measure?"

"At twelve o'clock in the day and night, the world rotates, and it rotates thirty degrees in one hour. If the earth under your feet is a pure sphere, twice the meridian is the length of the equator circle. Knowing the latitude, use the chord of the rectangular triangle to calculate the radius of latitude and longitude The distance of one degree can be known. The time of Mincheng must be different from the time of the capital. As long as you know the time difference, you can know where the capital is. Therefore, I need to ask Mr. Benchu ​​to help me accurately measure the time of Fujian with the shadow of the sun. The exact time in the city, the smaller the difference, the better."

After thinking about it for a while, I understood the key point and what Chen Jian meant, and asked with a smile, "Does that mean I still need the help of one of my disciples? Otherwise, how do you know the time on board when you are on the ship? Have you looked at the star map and measured the time at Qi’s port?”

"That's what it means."

"This is a good thing. If I hadn't been old, I really wanted to follow along. But unfortunately I am old... I can find someone for you. I'm afraid you had such thoughts when you were in the capital. Bar?"

"Even if I had such thoughts at that time, there was no excuse. Now the meridian that divides things is marked by your name, so it has something to do with you. My Mr. Xuegong is too young to speak out. How many people listen to it, but they can only trick you into the pit."

Mr. Benchu ​​laughed, and asked again: "Even so, how do you know the time in Mincheng at sea? There is no sound transmission technique for thousands of miles in the world, not to mention the huge clocks, and the daily time difference is huge. The waves were choppy and wet."

Chen Jian took out some items from the box that had already been pre-ordered. They looked like hand warmers commonly used by wealthy families in the cold northern regions.

The design is very delicate, no matter how shaken, the small bowl inside will not tilt, and it will always remain flat.

"In the north, this hand warmer can ensure that the charcoal fire will not be poured out. On the sea, Sinan can be placed inside this thing to ensure that the north and south are accurate. I also asked someone to make some small hourglasses, which are inverted every quarter of an hour. The most used For fine sand, please hire the best craftsmen.”

"There are nine ships in total. The hourglass is matched with the gimbal of the hand stove. Two people are appointed to take care of the hourglass on each ship. Based on the time of Mincheng when sailing, calculate how much time has passed and what is the time in Mincheng. Nine ships , taking the average value, the difference will not be too great. As long as there is a person on board who can accurately see the time and moment on board at this time, he can calculate the approximate longitude at this time."

"I don't know it for the first time, but as long as you go through it once, and if you go the second time, as long as the hourglass is in the boat, you will never get lost too far. Even if you deviate, it is only a hundred miles away."

"So, the key lies in someone telling me the angle between the port of Qi State and the star of the North Pole, the length of the shadow of the sun, the exact time of Min City, and someone who is familiar with the stars and the sun and knows what time it is by looking up. On a boat, of course, it’s best to have two, because it’s easy to get sick on board.”

Mr. Benchu ​​looked at Changping Sinan, who was converted from a simple hand warmer, and said with a smile: "It's such a shabby way to make people cry."

"Helpless."

Turning around, he looked at the prime meridian drawn by himself and the only ink dot named Mincheng that he had drawn by himself. Mr. Benchu ​​smiled, and said with emotion: "When you come back, tell me the state of Qi as soon as possible. Where should the port be?"

Chapter 128 Prime Meridian

"That's for sure. Once it succeeds, the new route and navigation positioning data will be more useful than before, and it will naturally be promoted. At that time, your name has already been drawn on the map. It is difficult to rot, unless One day China will be defeated, literature and history will be extinct."

After complimenting him a few times, he showed the octant and other things to Mr. Benchu, and gave it away as a small gift.

In this way, two more important and indispensable people were tricked into boarding the ship.

In addition to looking at the star chart to calculate the sun shadow and time, these professional figures can calculate the solar eclipse and use the calendar method, which will be very useful for some people in the future.

Furthermore, Chen Jian was deliberately trying to please this Mr. Benchu.Those in charge of astronomy and calendar must have a bunch of skilled craftsmen under their hands, making things like celestial globes and armillary spheres.

The craftsmen who make these things must be very high-level.

Instruments related to astronomy can be perfect clocks and watches with a little modification. Those craftsmen must have a deep understanding of hairsprings, escapements, pendulums, thermal expansion and contraction, and other things.

The level of astronomy is to some extent equivalent to the level of time measurement and ocean navigation. Some people can't hire them with money and can only rely on other influential people.

It's useless to die, especially in today's era, when you are one step behind and you have to pay with your flesh and blood after a few decades.

In addition to flesh and blood, there is also soul.

It's like a simple prime meridian, a simple division of the Eastern Hemisphere and the Western Hemisphere, a term that sounds familiar to the Middle East and the Far East, the name of the islands and the strait, the names of people before the New York-meter-joule law...

These are the souls that this world of great struggle is fighting for.