Li forgot to worry about separating oxygen and nitrogen from the air. But it is not difficult to prove that there is nothing in the air.

The existence of oxygen can be proved by combustion test.

The famous physical experiment, madeborg hemispheric experiment, is more sufficient to prove that air is not empty, and to clearly and intuitively prove the existence of atmospheric pressure.

"It\'s not difficult to prove what I just said. Your majesty, your lords and your master once told me that each of us is under the pressure of the air at any time. Well, it\'s probably equivalent to..."

Li Qieyou silently converted it in his heart and gave an answer: "it\'s about equivalent to the weight of two hundred stones."

A standard atmospheric pressure is equivalent to ten tons of weight per cubic meter. One ton is one thousand kilograms, two thousand kilograms, which is roughly equal to the twenty stones of the Tang Dynasty.

After studying physics in junior high school, we all know that because the atmospheric pressure in the human body is balanced with the external atmospheric pressure, the human body will not be flattened by atmospheric pressure, and the human body can not feel the existence of atmospheric pressure.

Atmospheric pressure is common sense in later generations, but Tang people can\'t understand it.

Hearing this, Li forgot to worry, it was pure nonsense.

Wang Ying jumped out as if she had caught Li forgetful\'s painful foot.

"Ha ha, I thought you could say something wonderful, but I didn\'t expect it to be such nonsense. If each of us had air weighing 200 stones, wouldn\'t we have been crushed to death?"

He said, ignoring his old arms and legs, he jumped twice on the hall.

"Plum worry, do you think I\'m also an immortal? Can I run and jump with the weight of 200 stones?"

Wang Ying\'s words suddenly burst into a burst of laughter in the Tai Chi hall.

Li forgets what he said before. People don\'t know whether it\'s true or false, but they don\'t dare to refute it. But it would be nonsense to say that everyone is under the pressure of two hundred stones. None of the officials believe it.

Several aristocratic family officials immediately laughed and echoed: "didn\'t Li Gong have an illusion with Taoist ancestor Xiuxian? Such ridiculous remarks can be said?"

"Hey, hey, it turns out that someone is so powerful that he can carry the weight of 200 stones and walk fast. Tut Tut, it seems that someone is going to become an immortal."

"Yes, we are all in the immortal class. If Li Gong hadn\'t told us, we wouldn\'t know it. Ha ha ha."

When his teacher was ridiculed like this, Ma Zhou and others naturally showed their displeasure.

Although what Li forgot to worry about said, even in their view, it was difficult to understand. However, out of their "blind trust" in their teachers, they have no doubt about the truth of what Li forgets to worry about.

But they don\'t know how to refute their teachers.

Li had not taught them about atmospheric pressure before, so Ma Zhou, Yan Liben and others did not understand the truth.

In fact, the ancients also had contact and understanding of atmospheric pressure.

For example, tea sets made by using the siphon principle and cupping in traditional Chinese medicine all use the function of atmospheric pressure.

As early as the end of the Eastern Han Dynasty, Kewu for irrigation appeared, which used the siphon principle for irrigation.

But it is also limited to this. The ancients did not have in-depth theoretical research on atmospheric pressure.

In the face of the wanton ridicule of Wang Ying and others, Li forget worry is not angry at all. He just watches these people perform as fools.

Li Er sat on the throne and frowned.

Li forgot to worry about these words, he also could not understand.

But he also trusted Li Qieyou and knew that his nephew would never be aimless. If he dares to say such a thing, he will naturally rely on it.

"Ziyou, please tell me. Since we are carrying 200 stone heavy air anytime and anywhere, why can\'t we feel it?"

As soon as Li Erjin opened his mouth, those officials who were still mocking Li forgetful could only feel shut up. They turned to Li forgetful again and waited for his explanation.

Li forgot to worry and shrugged his shoulders with a smile. "Your Majesty, it\'s complicated, but it can\'t be explained clearly in one or two words. But the minister has a way to let your majesty and the public see the existence of air pressure. Er, the teacher respectfully calls it atmospheric pressure."

Li forgot to worry suddenly found that it was really good to talk about a Taoist father as an excuse for his master.

Anything in the future can be pushed to the Taoist ancestor.

The earth is round!

The earth revolves around the sun!

The moon is a desolate big sphere. There is no Moon Palace, no jade rabbit, no Chang\'e and Wu Gang, and no osmanthus tree!

Who disagrees?

Go and argue with Daozu! These are all taught by the Taoist ancestors to me!

Thinking of this place, Li forgets to worry and feels dark and cool in his heart. I\'m going to work hard to make sure that Lao Tzu is his master.

"Oh? What can I do? Ziyou, show me quickly." Li Er is also very curious at the moment.

Li forgot to worry, but shook his head: "Your Majesty, I need to prepare for this. If you don\'t stay for ten days, I\'ll ask your majesty and the princes to move to the Academy, and I\'ll show you to your majesty? Hey hey, by the way, I\'ll teach the students of the academy and let them see what atmospheric pressure is with their own eyes."

To prove the existence of atmospheric pressure, the most ornamental and shocking is the madeborg hemispheric experiment in history.

Li Qieyou plans to cast the hollow copper ball for the experiment and the vacuum pump for air extraction in ten days.

"But!" Li Er nodded without hesitation and agreed: "that\'s it. In ten days, I will lead all officials to the academy to witness what atmospheric pressure is. Let me also broaden my horizons and see the wonderful knowledge handed down by the Taoist ancestor."

The gaozhen and eminent monks immediately bowed down: "Your Majesty, please allow me and others to go to the Tang Royal Academy in ten days to see a miracle."

"But!" Li Er nodded naturally.

At this point, Wang Ying and others are naturally inconvenient to say anything. They can only sneer in their hearts.

In their opinion, it was just Li\'s delaying strategy to show it to the public in the Academy ten days later.

They absolutely don\'t believe it. They weigh two hundred stones on their bodies.

After retiring from the court, Li forgot to worry and led a group of disciples such as Yan Liben to serve as supervisors to make copper balls and other instruments. What happened in the court today was spread all over Chang\'an city at the speed of light with the help of intentional people.

This naturally makes Chang\'an city lively again.

Whether it\'s Li forget you who claims to be a disciple of the Taoist ancestors, or what Li forget you said, everyone\'s body is pressed with the air of 200 stones, which makes the people in the city talk endlessly.

From a hundred officials, scholars and scholars to traffickers and soldiers, everyone can only get together and talk about these two things.

There is no final conclusion about Li Qieyou\'s claim that he is the disciple of the Taoist ancestor in the world.

But if we say that everyone is under the weight of two hundred stones at any time, almost no one believes it.

After all, atmospheric pressure is beyond the scope of Tang people\'s knowledge, difficult to understand, but it is also normal.

Before the madeborg hemispheric experiment in 1654, few people believed in the existence of atmospheric pressure, and the Italian physicist Torricelli was ridiculed wantonly.

A thousand years later, not to mention the Tang Dynasty.

All the people in Chang\'an city are waiting for what kind of news Li forgets to worry about in the Datang Royal Academy in the next ten days