"Is the earth round?" The students couldn't understand that their eyes were wide one by one.

Zhu Youzhen handed out ten globes to the students, and the students were immediately divided into more than a dozen small groups, and the teachers in the back row also joined the ranks of the students, groping for the globes with their hands, and worried that they would break it, just like children playing with firecrackers, both loving and afraid.

Zhu Youzhen did not stop the curiosity, questions and various speculations of teachers and students, which was the strongest spark to guide students and even teachers to the road of scientific research.

"My classmates have seen that this is the earth we live on -- it's really round." Zhu Youzhen's words immediately suppressed the students' discussions.

"Teacher, but I see that the place where we live is very flat!" One student said weakly.

"This classmate asked very well, the place where we live does look flat, but the earth we live on is too big, and our vision is not far enough - you are all deceived by your own eyes." Zhu Youzhen did not forget to be silent.

"Teacher, how can we know that the earth is round?" The student just now was unrelenting, and it seemed that he had great potential to pursue the truth.

"Of course I can prove to you that which of you has a house by the sea? Who has ever seen a sailing ship returning from afar? Zhu Youzhen's eyes searched among the students.

"I, I." Several students raised their hands, and Zhu Youzhen felt that they were either from Fujian or Guangdong, and the dialect was particularly strong, could it be that Hokkien and Cantonese existed in the Ming Dynasty?

"Then I ask you, when you stand on the seashore and see the sailing ship returning home, do you see the mast first, or the hull first, or the whole ship at the same time?" Only by convincing people with reason and based on facts can we cultivate students' scientific spirit and stimulate their interest in scientific knowledge.

"Mast, it's mast, I've seen ......it by the sea," one student said as he pondered, and finally came to a conclusion.

Several of the students who raised their hands nodded in agreement.

"I saw the whole boat at the same time, and I remember it clearly." One student retorted.

"You're right," Zhu Youzhen will never discourage the enthusiasm and curiosity of the students, "if the mast of the boat is too low, or the area of the water is too small, for example, the boat is in a river, we will see the whole boat at the same time." ”

Zhu Youzhen picked up the chalk made of lime and clay, drew a round sphere on the blackboard, and drew a boat and a person next to the sphere, "You see, because the earth is round, the person standing on the shore will see the mast first, and then see the hull, if the surface of the earth is flat, the person standing on the seashore should directly see the entire hull." Zhu Youzhen drew a straight line and compared it with the sphere.

Simple and easy to understand, clear and clear.

The students are still digesting Zhu Youzhen's sketches.

"If you have the opportunity to go to the seashore and observe the sailing ships returning from a long voyage, you will be convinced that the earth on which we live is indeed round; If you don't have the opportunity to go to the sea, it doesn't matter, someone has already proved this great discovery - there is a country in Europe called Spain, and there is a man in Spain named Magellan, who has already traveled around the world, and under the guidance of the compass, he sailed from west to east, and finally returned to the place where he started. You say, Is the earth round or flat? ”

With the help of the guidance of the globe, the students were still chewing on Zhu Youzhen's words, and it was difficult for them to digest all this knowledge for a while.

These geography students may not be able to become Newton and Galileo, but as long as they adhere to their interest in geography and adhere to their research direction, Zhu Youzhen believes that sooner or later navigators will appear in the Ming Dynasty.

The rise of Europe did not originate from the Industrial Revolution in England, not from the Renaissance in Italy, but from the great maritime discoveries in Portugal and Spain.

Before the end of class, Zhu Youzhen particularly emphasized: "Students, I am not a professional geography teacher, so the maps and globes I sent you are not accurate, and it is up to you to draw an accurate map of the Ming Dynasty and even the world." ”

In the second period of chemistry class, Zhu Youzhen asked the guards to carry a large wooden food box to the podium.

"What is Chemistry? The teacher must have told you, so I won't repeat it. For example, cement used in road construction is fired chemically, ceramics are also fired, and this. Zhu Youzhen took out a beaker from the box and put it on the podium.

"Crystals?" The students in the front row whispered.

"It's not crystal, it's glass." Zhu Youzhen corrected, "This is glass that was fired not long ago. ”

"Glass? What is glass? "Only a very small number of students have heard of glass, and most of them have seen such pure glass for the first time, after all, there are no newspapers, no television, and no Internet.

Zhu Youzhen took out some glass catheters, beakers, and jars, "These are all glasses, but their firing methods are different from those of ceramics and cement." Let's use these glasses to make two real yàns, so that students can see what chemistry and chemical change are. ”

The whole class was silent, and their eyes widened one by one, even the teacher who was listening.

Zhu Youzhen took out a beaker filled with water from the food box, and inserted a glass catheter into the beaker, "Which of you is interested?" Come up and make a real yàn? ”

A boy in the front row slowly walked up to the podium.

"You first pass through the guò catheter and blow hard into the cup to see what happens to the water in the cup." Zhu Youzhen glanced at the student, who seemed a little strict.

The student holds the catheter in his mouth, puffs out his cheeks, and blows into the cup with all the strength he can to feed, but the water does not change in any way.

"Oh, I'm sorry, I got the wrong bottle, it should be this bottle." Zhu Youzhen took out a beaker filled with water from the food box, "This classmate, you try again." ”

The student, who had just been a little embarrassed, blew hard.

"The water is getting muddy." After a while, the students in the front row noticed the change in Qing Shui, and he shouted excitedly.

The crowd in the back row, which could not be seen clearly, began to crowd the front row, and even the student who was blowing down the catheter to see what had happened in the cup.

"It's the same glass of water, the cup just now hasn't changed, but now it's milky white, why is that?" Zhu Youzhen paused slightly, "Because the latter cup is not water, but lime water." ”

Zhu Youjian explained the principle of the reaction of lime water with carbon dioxide in the air to generate water and calcium carbonate, "Liangguang, Jiangnan and other places in the Ming Dynasty have world-famous stalactites, which is the reason for the formation of stalactites. ”

Students' minds move from inside the classroom to outside the classroom, and from outside the classroom back to the classroom.

"Make another real yàn. May I ask you, students, how can you fry raw eggs with your life experience? Although Zhu Youzhen has never been a teacher, he also knows from the experience of students that doubting, acting, solving doubts, and inducting are the most basic methods for learning chemistry.

"Fire, of course." This time, there were more than one or two students who answered, and it seems that these students are not people who do not eat fireworks in the world.

"But, I can fry eggs without fire." For safety, Zhu Youzhen asked the students in the front row to move back.

"The classmates are optimistic, this is an ordinary egg." Zhu Youzhen took out an ordinary white porcelain bowl from the food box, and then took out a fresh egg, in order to convince the students that this was not magic, he put the egg in the students' hands and let the students take a closer look.

When the student returned the egg to Zhu Youzhen's hand, he opened the egg in front of the student and poured it into the porcelain bowl, "Look, I can fry the egg with just a glass of water." ”

Zhu Youzhen took out a thin-mouthed bottle with a lid from the food box, and the bottle was filled with water.

Under the watchful eyes of the students, Zhu Youzhen poured the "clear water" from the jar into the porcelain bowl, and then quickly retreated to a safe distance.

The "clear water" in the porcelain bowl immediately boiled and made a "crackling" sound, which could be heard in the back seats in the silence of the class.

When the porcelain bowl fell silent like a class, Zhu Youzhen stepped forward to take a look, obediently, the egg was really fried, and there were some black paste spots on it.

"Students, you come up in turn to see if the eggs are cooked, but don't touch the porcelain bowl, and don't taste it with your mouth - I forgot to put salt."

The students had forgotten that Zhu Youzhen was the emperor, and they swarmed towards the podium as usual.

"Take your time, line up, and stay safe." Under Zhu Youzhen's reminder, the students finished reading the hard-boiled eggs in the porcelain bowl in turn.

After reading it, the students couldn't resist the temptation of curiosity, and several teachers in the back row also stepped forward, and they returned to their seats in surprise when they saw that the eggs were really cooked.

"Could it be that there is no water in the cup?"

"How can this bottle have a lid and the others don't?"

"Why can't you eat hard-boiled eggs? Is it really because there is no salt? ”

……

The students talked a lot, as if the teacher had asked them to discuss in groups.

"Students, your observations are very careful, and your judgments are also accurate. It is true that the bottle is not water, but a substance called sulfuric acid. When it encounters the water in the egg, it can release a lot of heat, as if it is roasting it over a fire, so the egg is cooked. ”

The students' expressions are different, some are holding their cheeks, looking thoughtful; Some of them were so excited that their faces turned red, and they longed for Zhu Youzhen to do some more of this kind of reality, this kind of reality that they had never heard of; Some sat quietly in their seats, waiting for Zhu Youzhen's next words.

"Chemistry is vast and profound, and I can't learn all the knowledge thoroughly, and there is still a lot of knowledge that you need to explore. For example, the output of Daming iron has reached more than 200 million catties, but it can't make a Lumi gun, why? Because the Ming Dynasty can't make good steel. ”

Zhu Youzhen has long hoped to improve the smelting level of the Ming Dynasty, hoping to make excellent steel and refined copper to lay the foundation for the development of the heavy industry of the Ming Dynasty, but Zhu Youzhen is the emperor, and it is impossible for him to have a lot of time to engage in scientific research, unless he is willing to be like Song Huizong and Tang Houzhu.

So Zhu Youzhen seized the opportunity and founded the Daming Academy of Sciences.

That's why Zhu Youzhen came to the Academy of Sciences to give a lecture today.

It is impossible to produce a master of science in a lecture, but since the seed has been planted, as long as it is properly watered and fertilized, Zhu Youzhen believes that one day, it will grow into a towering tree.

After leaving the Academy of Sciences, as soon as he returned to the Qianqing Palace, Zhang Yixian, the eunuch of Si Li Bingbi, followed: "Your Majesty, Liaodong Military News." ”

"Oh? What good news does Liaodong have? "Zhu Youzhen has become accustomed to one victory after another in Liaodong.