Xie Jin did not find out about Li Jie's arrival, after he experienced the initial self-doubt, he quickly cheered up and listened carefully to the class, in academics, he is a person who is easily unwilling to admit defeat, otherwise he would not have been admitted to the Jinshi at a young age, although there are some things that Wang Sichen said on the stage that he can't understand, but he uses his ability to never forget, and he keeps all the other party's words in mind.

After Wang Sichen finished speaking, someone immediately stood up and asked his own questions, Wang Sichen also answered them one by one, Xie Jin also wanted to stand up and ask questions, but he hesitated again and again and finally gave up, first, because he was embarrassed, and second, because he had too many questions in his heart, so he didn't know where to start.

After answering the questions raised by everyone, Wang Sichen also stepped down from the podium, and then another person gave a lecture, but what was surprising was that this person was wearing the costume of a small official, and he did not talk about astronomy, but talked about an experience he heard from a craftsman.

It turns out that craftsmen have long discovered that when using a movable pulley to lift things, they can save half the effort, but if the pulley is fixed at a high place to hang things, it cannot save effort at all.

When was the above phenomenon discovered, there is no way to verify, craftsmen have used this method for generations, but they have never considered the reason, and this little official has read books after all, so he quickly became interested in the role of pulleys, but he does not have an accurate explanation, and he put it forward today, just to explain the truth with the help of everyone's strength.

Many people were also very interested in the phenomenon of this pulley, and at this time they also expressed their opinions, and finally even Xie Jin couldn't help but stand up and speak, right, for the time being, but this warm atmosphere made him want to participate.

Li Jie also stood up and walked to the podium at the end, when he appeared, everyone was quiet, but Li Jie did not help these people answer the previous questions, although he could easily tell these people the answer, but the so-called teaching people to fish, it is better to teach people to fish, the key is to let them have the spirit of seeking science, so Li Jie will only give them some key points in some key places, but rarely tell them the answer directly.

I saw that after Li Jie came to the stage, he looked around at everyone, and when he saw Xie Jin, he also deliberately greeted the other party with a smile, and then cleared his throat and said: "Today I will bring you a very interesting little thing." ”

Li Jie said and took out a small box from his arms, then took out a teardrop-shaped glass from the box, and showed it to everyone: "Everyone should know glass, the glass workshop is not far away, so I want to ask, do you think glass is strong?" ”

"Glass, like porcelain, should be a very fragile thing, even if it falls in place, it will break, far from being strong!" At this time, someone below immediately replied in a loud voice.

"Yes, glass is fragile, but believe it or not, the glass in my hand can't be broken with a hammer?" Li Jie asked with a smile again.

"Li Banyu, you can't be joking, right?" At this time, Zhu Yunxi also shouted in disbelief, although he came with Li Jie, he didn't know the content of Li Jie's lecture.

"Since Your Highness doesn't believe it, why don't you try it yourself?" Li Jie smiled again.

"Good!" Zhu Yunxi immediately agreed, stood up and went on stage.

Li Jie also took out the prepared hammer, and asked Zhu Yunxi to test it, and after confirming that there was no problem with the hammer, Li Jie put the drop-shaped glass on the table, and then asked Zhu Yunxi to smash it against the big head of the glass.

Zhu Yunxi didn't dare to push too hard at first, but gently knocked on the glass, and found that the glass was nothing at all, which made him slowly increase his strength, but the glass on the table was still the same, and finally he was in a hurry, and smashed it down with all his might, but the seemingly fragile glass was still unharmed.

"Strange, Li Banyu, are you sure this is glass, not transparent steel or something?" Zhu Yunxi smashed it a few times, and finally gave up, but he began to doubt the authenticity of the glass.

Li Jie laughed, and did not rush to explain, but said to the people below again: "If any of you still want to try it, you can come on stage!" ”

The people below couldn't wait for a long time, and immediately went to the stage to test, but even if so many of them tried their best to smash the glass, but that small piece of glass was nothing at all, and in the end, everyone had the same suspicions as Zhu Yunxi.

Seeing that everyone had given up, Li Jie smiled again: "You don't have to doubt it, this is an ordinary piece of glass, but you can't break it with a hammer, but I can turn it into powder in an instant!" ”

Li Jie said and took out a small iron tong, then clamped the tail of the drop-shaped glass, and asked Zhu Yunxi and the others to stand a little farther away, and turned his head over, and then he used a light force, only to hear the sound of "bang", the drop-shaped glass was like an explosion, and it completely turned into a sub-glass powder and splashed everywhere.

"Boom~" Everyone exploded at this time, after all, this phenomenon is so amazing, the glass that they can't break with a hammer is actually shattered by Li Jie's light clip, if they don't see it with their own eyes, they won't believe it at all.

"Li Banyu, can you not succeed in spells?" Zhu Yunxi was the first to exclaim in shock, he really couldn't think of any other explanation other than spells.

"This is not a spell, but a physical phenomenon, this teardrop-shaped glass, in fact, is formed after the glass melts, it is poured into the water, and this shape of glass has a characteristic, that is, the head is extremely hard, it can't be broken with a hammer, but as long as you gently clamp its tail, it will explode and shatter with a slight force." Li Jie explained with a smile.

This is actually the glass product that was later called Rupert's Tears, but now that Li Jie has made it out, there is really no need to add the name of a British colonist.

After Li Jie finished speaking, he took out a few drop-shaped glasses from the box and asked Zhu Yunxi to test them by themselves, but this thing is still a little dangerous when it explodes, and it will be troublesome if it splashes in the eyes, so Li Jie also told them to be careful.

Zhu Yunxi and the others were a little skeptical at first, but after testing it themselves, they also had to believe in this magical phenomenon, which also made them surround Li Jie and began to ask the reason for this phenomenon.

Li Jie still didn't explain, but just said that they should study it themselves, but in fact, Li Jie himself couldn't explain it, because this phenomenon involved materials science and mechanics in later generations, and even people with university education could rarely understand this phenomenon, let alone these ancients.

After the class was over, it was time to end, Li Jie and Zhu Yunxi packed up their things and prepared to leave, but at this moment, Xie Jin came to Li Jie and hesitated for a moment before he spoke: "Brother Li, that ...... Can you give me one of that teardrop-shaped glass? ”

"Brother Xie, do you like this?" Li Jie was also surprised when he heard this.

"I'm intrigued by it, so I want to go back and take a closer look." Xie Jin's face turned red and said, Li Jie's demonstration just now aroused his great interest, and even seemed to open a window for him, allowing him to see an unprecedented world.

"No problem!" Li Jie said and picked out a drop-shaped glass from the box and gave it to the other party, and then smiled again, "In fact, this drop-shaped glass, as well as the previous pulley phenomenon, are the characteristics of all things in the world itself, I collectively refer to them as physics, such as why the wind flows, why the boat can float on the water, etc., these seem ordinary, but they contain endless truths, I hope Brother Jie, you can solve these mysteries for the people of the world in the future!" ”

"Physics?" Xie Jinyan also chewed on the meaning of these two words, and the window opened in his heart seemed to be brighter, and a road that he had never seen before seemed to appear in front of him.

"Brother Li, can I still come to the class in the future?" Finally, Xie Jin asked again with a firm expression.

"That's natural, this textbook is open, anyone can come to listen to the lecture and express their own opinions, and I hope that Brother Xie will actively participate in the future!" Li Jie immediately nodded and said, this is the purpose of him letting Xie Jin come, with Xie Jin's ingenuity, it is too wasteful to put it in the officialdom.

In the next few days, Li Jie also often came to the hot air balloon workshop to take classes, every time he would see Xie Jin, at first the other party just listened carefully to the class, and then began to actively participate in it, and even took the initiative to give a speech on stage, although Xie Jin was a monk halfway, but with his ingenuity, he quickly followed, and even expressed some novel views, which attracted the attention of many people.

This class in the hot air balloon workshop was originally just an unintentional work of Li Jie, originally just to teach arithmetic to the officials of Qin Tianjian, but later the content of the lecture became more and more complicated, and some content of physics, chemistry and even biology began to be moved to the stage to give speeches, and this also attracted more interested people, including officials and officials, and even some scholars in the capital also came to visit.

Although the scale of this class is still very small, and it is only spread in a small circle, Li Jie believes that with the passage of time, the scale of this class will become larger and larger, and more and more people will participate, and the content generated in the class will slowly spread out, and sooner or later it will cause qualitative changes.

As time went by, Li Jie was also going to Ningbo, but on this day, Mu Sheng suddenly came uninvited, carrying a jar of spirits in his hand, and when he saw Li Jie, he immediately said: "Brother Li, I came to you for a drink, let's not get drunk today!" ”

Li Jie was startled when he saw Mu Sheng's appearance, only to see that the other party's eyes were red, his cheeks were sunken, the whole person was thin and out of shape, his hair and beard were messy, and he looked depressed.