Into Unscientific

in the long history of mankind.

The right and wrong between the round earth theory and the flat earth theory has always been a very controversial topic.

When introducing Zhang Zai earlier, he mentioned the origin of the theory of the circle of the earth:

Later generations generally believe that the theory of the circle of the earth officially appeared in the 6th century BC.

That is, the ancient Greek mathematician Pythagoras first proposed the concept of the earth.

Wait until the 3rd century BC.

Eratosthenes, a scientist living in Alexandria, established the concept of the earth with geometric methods and calculated the diameter of the earth.

What was not explained at the time, however, is that Eratosthenes' method was actually quite stupid:

He accidentally learned that at noon on the summer solstice every year, the sun's rays would shine directly on the bottom of a deep well in Saiyin, which is Aswan in Egypt.

at the same time.

In Alexandria, which is about 5,000 Greek miles north of Saiin, the sun's rays have an angle of 2π/50 radians, or 7.2°, with the vertical line of the ground.

Assume the sun's rays are parallel.

Then according to the calculation formula of the circumference of a circle, a value can be obtained:

That is, the circumference of the earth along the meridian passing through the north and south poles=5000×2π÷2π/50 = 250000 Greek miles.

This is just a theoretical derivation, and it can only be said to unify the cognition of some people.

In fact, the theory of the circle of the earth does not mean that the earth is flat with one punch as the data or formulas are unraveled.

Throughout human history.

In almost every dynasty and generation, there are people who do not believe in the theory of the circle of the earth.

Even in the later 21st century, supporters of the flat earth theory are not uncommon.

For example, now, there is a flat-Earth theory conference held across the sea every year-more than 600 people even attended the latest meeting.

The actual number of participants on the Internet reached 124,000, and the popularity of the live broadcast platform in China reached millions in minutes.

Youtube is also full of videos that claim to prove the Earth is flat.

Today's local minke can be regarded as a kind of derogatory term. For example, you can see various design guides like gossip arrays on the design drawings, or ghost symbols comparable to Xu Yun's calligraphy.

But in front of supporters of the flat earth theory, these folk sciences are really not enough.

Proponents of the flat earth theory believe that the round earth theory is a complete hoax:

The photos of the outer space of the earth are false images taken by the rulers to confuse us, and they are false truths for captive and enslaved human beings.

Among them, NBA star Irving is a well-known supporter of the flat earth theory.

Precisely.

He is a 'believer' of one of the 'Sects of Pac-Man':

This sect believes that the earth is flat, if you reach the boundary of the earth, you will appear from the other side of the earth in an instant, so you can't find that the earth is flat...

The kangaroo country is the opposite country. At one time, there was a kangaroo singer with cerebellar atrophy who was regarded as a defective product where time stopped.

By the way.

Another star Curry believes that the moon landing is fake and a complete hoax.

without any exaggeration.

In the flat earth sect, there are countless such strange and weird remarks.

They have the name of not being able to fully trust authority (just saying this sentence is actually true), but what they do is all kinds of anti-intellectual and even horrible things.

Actually.

The flat earth theory is the key fulcrum of the Communist Party's layout, and it is also the core basis of conspiracy theories.

The specific content is too sensitive and will not be repeated here.

all in all.

The world is much crazier than we imagined.

This is the case in later generations, let alone the ancient times when the theory of a round earth is not axiomatic.

Let’s just talk about the three people in the house at this time:

As a professional astronomer who has drawn star maps, Lao Su has a higher degree of acceptance of the theory of the circle of the earth than others.

Even he himself has some tendency to think that the earth is round.

But Xiao Li and Xiao Zhao are different.

Although these two young people are very interested in science.

But they have never received any systematic and correct scientific education.

Therefore, when Xu Yun mentioned earlier that the earth is round, some doubts naturally arose in their hearts.

If it wasn't for the fact that Lao Su listened with gusto.

Xiao Li might have interrupted Xu Yun a long time ago and questioned him angrily.

in the house.

Looking at the enthusiastic old Su and the bewildered little Li, Xu Yun pondered for a moment and said:

"Sir, have you ever been to the seaside?—I mean the endless sea."

Old Su nodded when he heard the words, and recalled:

"Nine years ago, the old man was ordered to go to Dengzhou to check the marine division's rations, so he must have seen the ocean.

The end is the sky and the water, the tail is the sky, and the old man was so shocked that he almost turned pale on the spot. "

Dengzhou.

It is the later Penglai City, Shandong Province.

There is the famous Dengzhou Port here, and it was also the core place where the navy was stationed in the Song Dynasty.

Penglai is close to the Bohai Sea and the Yellow Sea, but it is indeed boundless.

Then Xu Yun turned his head and looked at Xiao Li and Xiao Zhao.

Xiao Li thought for a moment, then shook his head:

"My father was an official in Huangzhou earlier, and he only encountered the river, but never the sea."

Xiao Zhao at the side glanced at Xiao Li and said slowly:

"This king is different from Miss Li. Two years ago, this king went to Changguo County to buy medicinal materials for brother Wang.

Changguo is adjacent to the East China Sea, so it is fortunate to have seen the majesty of the sea. "

The state of Chang in the Song Dynasty is now Zhoushan, Zhejiang Province.

It is connected to the East China Sea and is also the mouth of a vast world.

Three people, two have seen the sea.

Although this ratio is not perfect, it is much higher than Xu Yun expected.

Then Xu Yun pondered for a moment, and asked Lao Su and Xiao Zhao:

"My lord, His Royal Highness Jian Wang, I wonder if the two of you have seen sailboats approaching from afar while enjoying the sea view?"

Later generations have been quite controversial about the time when sailing ships appeared in ancient China, and they are mainly divided into two views, the Spring and Autumn theory and the Han Dynasty theory.

But no matter which of the above situations, the timeline is much earlier than the current Song Dynasty.

So sailing boats are now very common at this time, especially on the coast.

Therefore, Xiao Li and Lao Su just looked at each other, then nodded together and said:

"I have seen it."

Xu Yun slightly nodded towards the two, took a deep breath, and threw out his trump card:

"Since that's the case, did you two pay attention to one thing when you saw the sailboat?"

"What's up?"

"Which part of the sailboat first appeared in the two's field of vision?"

Hearing Xu Yun's words, Lao Su and Xiao Zhao were stunned.

"Which part?"

Xiao Zhao had only seen Haihai two years ago, so his impression was relatively deep, so he said first:

"If I remember correctly that day @I ascended the heights to view the sea, the first thing I saw seemed to be the white sails, followed by the hull of the ship"

Hearing what Xiao Zhao said, Lao Su also recalled some scenes.

He couldn't help but nodded slightly in agreement.

But after thinking about it, he suddenly realized something.

His eyes widened sharply, and he looked at Xu Yun, the corners of his mouth trembling faintly:

"Xiao Wang, do you mean that we saw the sail first because the earth is round, so the sea blocked the hull behind?"

Xu Yun was silent for a moment, then nodded solemnly and firmly:

"That's right."

A boat on the sea sees the sails first, and then the hull.

This is a strong evidence that Aristotle once mentioned when he proved the shape of the earth.

Of course.

In real life, if you want to verify this statement with the naked eye, it is actually quite troublesome.

Because according to R+d=(R+h), it can be calculated that a person with a sight height of 1.75 meters can see a horizon distance of 4.65 kilometers.

If you stand on a mountain or a high-rise building, you can see farther.

It is actually difficult for ordinary people to distinguish the sails, masts and hulls of this kind of vision range starting from more than ten kilometers.

In this case, the so-called first sight of the sail is largely due to the conspicuousness of the sail, which has nothing to do with the sea level.

But it's worth mentioning.

The two places of Dengzhou and Changguo are very special, different from the general coast:

They are all the important places of the navy in the Song Dynasty, and they are also the location of the well-known sea market in the Song Dynasty.

Right now is the most developed period of Haishi in the Song Dynasty, and the trade connection is not the mainland, but the surrounding countries.

And all the ships that trade across the ocean are often of unusual size.

For example, the well-known ancient ship of the Song Dynasty, Huaguang Jiao No. 1, was excavated and restored.

The hull of the whole ship is 20 meters long, 6 meters wide, and 3-4 meters deep, which was only a medium-sized ship in the Song Dynasty.

For example, in Dengzhou and Changguo, two sea cities and military important places.

If you are lucky, you may even see a two-thousand-level sail auxiliary car and boat.

As for the so-called two thousand materials.

It is almost 45 meters wide, 11 meters wide and 5 meters deep.

That is, the displacement of the kiloton class is about 40% of that of the largest treasure ship in Zheng He's fleet.

For a large ship of this size, as long as the weather is good, it is not difficult to distinguish the sail and the hull from a very far distance.

One of Lao Su and Xiao Zhao is the former prime minister, and the other is the younger brother of Song Zhezong, who belong to the top group of people in Song Dynasty.

When they went to Haishi, they wanted to see this kind of boat, it was as easy as drinking water.

Of course.

From the perspective of later generations, seeing the sails first does not necessarily mean that the earth is round.

Because from the perspective of possibility, there is actually a possibility of a donut model.

But at this time, Old Su obviously didn't think of that much, and his thoughts were almost completely focused on what Xu Yun said.

As the top astronomer in China or in the world at the moment—it is still one of them.

Old Su's obsession with the stars has almost reached a crazy point.

mentioned earlier.

Lao Su once made a telescope that can only magnify five or six times, and the observation effect of this telescope is only slightly higher than that of the naked eye.

And in AD 1084.

In order to observe a star in the west direction, Lao Su even ran to Tibet with this useless telescope!

That's right.

Tibet!

To know.

Tubo in the Song Dynasty was not like later generations. At this time, U-Tsang and the Central Plains could be regarded as two different regimes, and there were even small-scale conflicts between them.

Not to mention the long journey from Bianjing to Tubo, the risks are also astonishingly great.

But in order to pursue the truth, Lao Su did it without hesitation-the result is 17 stars on Su Song's star map.

This is Lao Su, a master of the era who is so persistent that he is not afraid of life and death.

Otherwise, with the same level of technology, Lao Su could draw a star map with hundreds more stars than the Europeans, did he really think it was all due to luck?

And as a seeker who spent a lot of effort on the star chart.

While looking up at the starry sky, Old Su naturally thought about another thing:

What do those stars in the sky and the land under my feet look like?

Unfortunately.

Lao Su's telescope is said to be telescopic, but in fact it hardly plays any substantial role in front of the starry sky.

The real telescope in human history was not invented by Hans Lieber until 1608, and Galileo transformed it into an astronomical telescope. Only then did humans really see the appearance of the stars above their heads.

before that.

Even for an unborn genius like Lao Su, the only round planets visible to the naked eye are the moon and the sun.

After all, what is special about him is his brain, not the mutation produced by his body.

But now with the example of sailing boats mentioned by Xu Yun, Lao Su suddenly realized that

It turned out that the truth was once so close to him!

at the same time.

Perhaps it was inspired by Xu Yun's words.

Another memory fragment came to Lao Su's mind:

More than ten years ago, he once went to Fengcheng in ancient Fengzhou, which is the capital of the favorite ingredients of later generations of Guangdong people.

One day during the night, he enjoyed the cool in the courtyard, and raised his head to look up at the starry sky as usual.

Not long after.

According to his accumulated habits and experience, he discovered the eternal Ziwei star in the north.

But watch and watch.

A strange feeling suddenly appeared in Lao Su's heart:

The Ziwei star he saw in Fengcheng seemed to be a little lower than the one he saw in Bianjing.

But at that time, Lao Su didn't think too much:

He just thought that he was a little tired from the exhaustion of traveling and traveling, and there were some deviations in his judgment, so he went back to sleep in the house.

After all, the reduced distance difference is not very obvious, slightly weak, almost nothing.

If it wasn't because he often looked up at the galaxy, he probably wouldn't even have that weird feeling.

But right now, if according to what Xu Yun explained, the whole land is a circle

Then this height problem can be explained:

Because the earth is a circle, Ziwei star is in the extreme north.

Therefore, the farther you go north, the higher the Ziwei star will be, and the further you go south, the higher the Ziwei star will be.

lower!

That's right.

see here

Presumably many students have already guessed Ziweixing's identity.

It is the North Star called by later generations, Gou Chen Yi!

But what Lao Su didn't know was.

The so-called eternal North Star in his eyes is actually not a fixed star, but a fixed title.

It's like the emperor's throne, where different people can sit on it. Today you will be him tomorrow, laughing on the Chongzhen tree haha.

At present, Gou Chenyi, the North Star that is very romantic in China, is called Alpha Ursa Minor in the world.

It's actually about 30 arc minutes away from the North Celestial Pole, about as far away as a moon.

well known.

Due to precession, the direction of the Earth's rotation axis on the celestial sphere is constantly changing.

So every once in a while, a planet comes to that location.

For example, friends who have lived from 12,000 BC to the present should know that,

At that time, the Polaris was not Gouchenyi, but Vega.

The North Star in 3000 BC was α Draconis, the right pivot.

It is a faint fourth-magnitude star, very inconspicuous in the sky - for comparison, Gouchen is a 2nd-magnitude star, and Vega is a 0th-magnitude star.

By 4000 AD, Polaris will become Gamma Cepheus.

From a theoretical point of view, there may only be three long-distance runners on the planet who have a chance to live to that time.

By the way.

The South Pole also changes on the celestial sphere.

For example, right now, there are no bright stars near our South Pole.

But by 8000 AD, there will be a bright South Pole star - ι Carinae, also known as Haishi II, which is also a 2nd-magnitude star.

By 9000 AD, the south pole star will be the brighter δ Vela, which is Tianshe III.

But at this time, Lao Su didn't know this mystery, and he only had another question in his mind.

"Xiao Wang, although the example you gave seems to be able to explain the theory of a round earth, it is still not as good as seeing it with your own eyes."

I saw him staring at Xu Yun firmly, and he clenched his fists tightly:

"So. Do you have a way. Let the old man and others see the appearance of the stars with their own eyes?"

Xu Yun glanced at him and nodded:

"have."

Plop——

Lao Su's heart suddenly thumped heavily, his eyes widened, and he subconsciously blurted out:

"any solution?"

"telescope."

"Astronomical telescope? Then how to prepare it?"

Hearing Lao Su's words, Xu Yun spread his hands at him innocently:

"The villain doesn't know."

"you do not know?"

Old Su's voice suddenly rose a little bit, with a strong doubt on his expression:

"How could you not know?"

Hearing this, Xu Yun glanced at Lao Su with a very puzzled look, and spread his hands innocently:

"Master, don't you think the villain knows everything?"

Old Su was stunned for a moment.

Seeing that his words seemed to have some effect, Xu Yun continued:

"Master, I have only seen this kind of tool in the books of the Fenglingyue Shadow Sect, but I can barely remember the principle.

But in order to build an astronomical telescope that can see the stars clearly, as well as the microscope mentioned before, there is a problem that must be solved first. "

"what is the problem?"

An inexplicable brilliance flashed in Xu Yun's eyes, and he said:

"Mathematical calculation."