Great Song

After writing a letter against the "Gong Ju Law" and being summoned by the emperor, Su Shi thought he would be sent to know the imperial edict or an admonishing minister, but he did not expect to be sent to Kaifeng Mansion as a pusher.

However, he didn't pay much attention to this arrangement.After all, my younger brothers are all in the Third Department of Regulations, so what's the point of being a promotion official? After all, he is also a Beijing official, isn't he?So Su Shi took office simply and neatly.

There are two left and right halls in Kaifeng Mansion, and each hall has one pusher to hear cases in turn.Tokyo is a metropolis with millions of people, and there are countless criminal and prison lawsuits every day, and there are many cases involving dignitaries, which are even more difficult to resolve.However, Su Shi is not afraid of these. He is quick-witted, decisive, and not afraid of power.

Of course, no matter how busy his official duties were, Su Shi, who was naturally lively and lively, did not stop making friends.No, when he heard that Shen Kuo had gained something in terms of atmospheric pressure and invited Ling Xiaozi and Su Song to discuss it, he couldn't bear curiosity and came over.

"Isn't Zizhan busy with business recently, how can he still have the heart to go to the meeting?" Seeing Su Shi, Shen Kuo couldn't help snorting.No wonder he looks like this. When he proposed to the court to reform mathematics, Su Shi was merciless.Shen Kuo was not as sharp-tongued as Su Shi, and he was so scolded that he almost lost his temper.

Su Shi, on the other hand, was open-minded and didn't confuse public and private matters. He said with a nonchalant smile, "Brother Cunzhong is a master of Qi in the world, and he has a new theory on Qi. How can I miss it?"

When Su Shi's mouth is poisonous, he can stab people to embarrassment.But when he holds people in his arms, he is full of tongues and witty words.After being praised by him, Shen Kuo couldn't care less, and coughed dryly: "This is also Ling Xiaozi's point, which finally allowed me to measure the atmospheric pressure."

Without waiting for everyone to ask questions, he ordered his servants to fetch an extremely weird utensil.On top of this object is a long, thin glass tube that is three feet high. The tube is covered with a thin copper shell, and the scale is marked on the shell.Below is a wooden box, because it is hollowed out and carved, you can see the leather bag inside.There is also a copper needle on the box, which is pointing to the lower end of the glass tube.

The appearance of this thing is too strange, others are still looking at it, but Zhen Qiong's eyes widened: "Brother Cunzhong, is it possible that this tube is filled with mercury?"

Others may not be able to tell the difference for a while, but Zhen Qiong, a Taoist priest, will definitely not fail to recognize it.Shen Kuo smiled and said: "When you used a glass tube to verify the atmospheric pressure, you said that this method might be able to measure the air pressure value. I went back and tried for a long time, but I still couldn't get it right. After thinking about it, the density of water should be too small. The atmospheric pressure was too high, so I replaced the liquid in the tube with mercury. The density of mercury is more than ten times higher than that of water, and the atmospheric pressure needs more force to hold it. After several experiments, I found that As long as the three-foot-long glass tube is filled with mercury, and then placed upside down in the glass tank filled with mercury, the mercury in the tube will drop to about two feet and three minutes, leaving a vacuum. The mercury Isn't the height of the column exactly where the value of the atmospheric pressure is?"

Zhen Qiong was dumbfounded, and didn't care about the value, and asked first: "Don't you know that mercury is poisonous?"

After pouring mercury, you have to pinch the mouth of the nozzle and stuff it into the mercury tank, even for a Taoist priest like Zhen Qiong, it sounds a little scary.Mercury is very poisonous, even he has to wear a mask and gloves when refining it, and he doesn't touch it unless he can.Shen Kuo was able to figure out the density difference of mercury, and even tried it himself, which is really courageous enough.

"I know that lead and mercury are poisonous. So after measuring the air pressure, I found a craftsman to make this thing." Shen Kuo touched the long and thin glass tube cherishingly, "This thing is The principle of pouring mercury into the skin bag is exactly the same as the previous experiment. Just adjust the knob so that the copper needle points to the starting point of the scale, and the value of atmospheric pressure can be accurately measured.”

When he tested with mercury, he wore a mask, and he didn't know how many times he washed his hands.However, the experiment is cumbersome and the mercury is poisonous, so it is not easy to use it every time.So I thought of a way to make this instrument for measuring air pressure.Under airtight conditions, mercury is difficult to evaporate, as long as the glass tube is not damaged, it can be measured at any time.

Li Gonglin and Mi Fu didn't understand, but they didn't delay to look at the structure of the instrument and the mercury scale on the top.Su Shi was a little confused: "Why am I a little confused. This atmosphere can only hold down two feet and three cents of mercury? How is it completely different from Baoying Temple's performance?"

How much is two feet three cents of mercury?The Baoying Guan performance is an iron ball that took sixteen horses to pull away.The pressure shown by the two seems to be completely different.

Hearing this, Su Song laughed: "Didn't the deposit say that the density of mercury is ten times that of water? If the glass tube is replaced with water, the tube must be made three feet high, right?"

He also knew the density measurement method, and after a little mental calculation, he got an approximate value.

Shen Kuo nodded happily: "Brother Zirong's calculation is not bad, which is why it is difficult to pump water if the well is more than three feet deep."

The three-foot-long glass tube immediately gave Su Shi an intuitive concept. He couldn't help but exclaimed: "This air pressure is really powerful! The top section is also a vacuum, so there is no atmosphere? Didn't I mention it before, mountaineering or Feeling stuffy during a thunderstorm may be due to a change in atmospheric pressure, can this be measured?"

He could remember what he said when he first discussed atmospheric pressure.Going up the mountain and entering the water, the air pressure has changed, but the original guess was not accurate. Now that there is something that can measure it, why can't we find out?

Speaking of this, Shen Kuo's expression was shocked: "Zizhan is on point. After making this thing, I climbed Fanta to test it. Fantai is 240 feet high, far inferior to the mountain peak. I thought I can't measure the change. Who would have thought that the mercury column would change after only climbing three floors. After measuring each floor, the mercury column can be reduced by one point for every 120 feet you climb. When you reach the top of the tower, it just falls Two points!"

Su Shi hissed softly: "Is the air pressure really low at high altitudes?!"

Is it because of the lack of vitality or the change of air pressure that the feeling of breathlessness and dizziness when climbing the mountain is caused?What kind of changes will happen to the mercury column in the glass tube if one climbs a thousand-foot peak?

Thinking of this, Su Shi felt itchy: "Hurry up! Take this barometer and let's go to Fanta to have a look!"

Hearing that Mi Fu immediately jumped up to agree, Zhen Qiong's face turned green, and hurriedly stopped her and said: "Climbing the pagoda is too troublesome, since Brother Cunzhong has already tested it, why bother to go again? Sit down and discuss, or study the truth." yes……"

Mi Fu snorted, "Brother Zhen is afraid of heights, right?"

I know you talk too much!Zhen Qiong glared at him with a dark face.

Su Shi really likes the saying of "sitting and discussing the Tao". It is certainly interesting to go to the Fanta to watch the changes in the mercury column, but in the final analysis, it is still necessary to ponder the deep meaning.With a flash of inspiration, he said, "Could it be that the higher the altitude, the thinner the atmosphere, so the air pressure will decrease? In this way, wouldn't it prove that the sky is a vacuum?"

This statement is simply flawless!Su Shi felt inexplicably excited when he thought that his theory had been confirmed again.

Su Song gently twisted his beard: "If the air pressure is low at high places and high at low places, there must be repulsion between them. The wind comes from the sky, is it also because of this?"

The guesses of the two were ingenious, making people think about it, but Shen Kuo shook his head lightly: "What I think is, why is the air pressure high at low places? How much can the atmosphere change when it is only a few hundred feet away? When you go to the top of Fanta Pagoda, you can breathe just as freely, and the atmosphere is no different from the ground. If you enter the valley or even dive into the deep sea, will the air pressure continue to rise, much higher than it is now?"

This question stunned everyone for a while.Zhen Qiong only felt that these words were familiar, but couldn't think of where she had heard them.Fortunately, Shen Kuo didn't let them think for too long, and directly gave the answer he imagined: "It is an eternal law that everything comes from top to bottom. But why do raindrops fall from the top of the sky? Why do rice and wheat mature? Will the tassel be slightly lowered? Why is it that when you throw something, no matter how hard you use it, it will always fall on the ground..."

He used many questions in his remarks, but none of them seemed to have anything to do with air pressure?Everyone was still confused, but Zhen Qiong suddenly slapped her thigh: "It's gravity!"

This shout was too abrupt, and the people around were startled, but Shen Kuo showed a smile on his face: "Yes, there must be a force deep in the earth, like a magnet, which attracts everything to the ground. The closer you are to the center of the earth, the greater the force. Therefore, the atmosphere will descend further and the pressure will increase."

These words were like thunder, which made everyone dazzled for a while.There is also gravity on the ground?Could it be some outrageous joke?The good earth, why should it produce strength to bind all things?

However, Su Song was stunned and looked at Shen Kuo.Doesn't this gravitational force complete the theory of the roundness of the earth?Because of this ubiquitous force, everything in the world can be attracted to the earth, down to the birds and beasts, up to the atmosphere, and blended into one.Furthermore, is it also because this force has a limit, so the higher you go, the less air you can absorb, so the air pressure is lower.Until the end of the sky, there is no more power, no more energy, it becomes a vacuum, and other stars float in it...

Seemingly noticing Su Song's probing gaze, Shen Kuo nodded at him unobtrusively, confirming his guess.Both of them know the heliocentric theory, how could they not understand the deep meaning?

At this moment, even Su Song was a little lost.The last piece of the jigsaw puzzle was put together, a lofty, boundless, and irrefutable avenue, and they found it like this?

Everyone here is also shocked at this moment, and their imaginations are running wild.Su Shi is good at poetry and prose, but also has a strong curiosity, and he has a subtle observation of the world.Mi Fu and Li Gonglin are painters. They pay more attention to the details around them than others, and they think of a lot of what they have seen and heard in an instant.This truth seems to be beyond reproach?

After a long sigh of relief, Su Shi sighed: "What I said today is shocking. I never thought about what I saw in the ordinary world, but I actually hid the truth...Brother Shen, this matter should be told to the world!"

He couldn't bear to be lonely, not to mention the measurement method of atmospheric pressure, but the speculation of this "gravity" made people fascinated and indescribably shocked.

However, Shen Kuo sighed: "Ordinary people may not be able to understand this truth, and I am struggling with how to publish the article."

This is not a simple theory, but a pre-requisite theory involving the theory of earthquakes.Unfortunately, he has not yet been able to calculate a fixed formula, nor can he prove the relationship between air pressure and gravity.And even if the formula is written out, it may backfire if it is published in the "Ri Xin Bao".

Su Shi frowned when he heard the words, and just wanted to persuade Shen Kuo not to look forward and backward, but to write boldly and spread it among scholars.Han Miao, who sat on the sidelines for a long time without opening his mouth, smiled slightly: "It is true that this astonishing truth should not be published in a newspaper, but it is not impossible to make it public. Brother Cunzhong has already contributed articles to "Ri Xin Bao". There are dozens of articles, which have quite an audience. Why not compile these essays into a volume and publish a book? Since it is a new book, it is okay to add some articles to it."

When Shen Kuo heard this, his eyes immediately lit up.This makes sense!Publishing a book is no better than running a newspaper, and most ordinary people in the market will not buy it.Those who want to collect must be scholars, and most of them are people who have strange ideas in their hearts and agree with Meng Xisheng's little theories.And among these people, there is no shortage of smart people. If the theory of "gravity" is spread, it will inevitably cause discussions.As long as someone talks about it, you are not afraid that no one will agree.After all, this is the way, simple but irrefutable, it is the truth in the world!

Feeling turbulent in his heart, Shen Kuo immediately cupped his hands: "I'm going back to write the manuscript right now, I'm going to bother Jing Sheng about publishing the book!"

The author has something to say: I searched and found that Su Dongpo's official position was called "Tui Guan" instead of a judge. Change it to orz

The mercury barometer comes from the famous Torricelli experiment, and the finished product is more similar to Fortin's mercury barometer.In terms of measurement, the Song ruler is a little shorter than the modern city ruler, and one point is not very accurate, so an approximation is used.Normally, the atmospheric pressure is reduced by 12 mm Hg for every 1 meters you rise.