On the second day, early in the morning, Zhang San beckoned Li Si to buy a small piece of crystal ground into thin flakes, and then made a bamboo dragonfly by himself, so that it would be convenient to explain the principle of aerodynamics. Pen ~ fun ~ pavilion www.biquge.info

Zhang San was holding a carving knife to laboriously sharpen bamboo chips, Yifei came over and asked curiously, "Huh?" Third brother, are you making bamboo dragonflies? ”

Zhang San put down the carving knife and asked, "Do you recognize this?" ”

Yifei nodded and said: "I know, I used to see that it was often sold in the market, and a few days ago when the carpenter master was fine, he also made a few games for the children in the front yard." ”

Zhang San put down the carving knife awkwardly and said, "Oh, is the third brother bored and playing?" Has your fourth brother come back? ”

Yifei said: "I didn't see it, do you want me to take a look." ”

Zhang San shook his head and said, "Don't run blindly, it's going to be class right away, you have to study hard." ”

Yifei said shyly: "Got it, third brother." With that, he ran away.

Now that there is a bamboo dragonfly, Zhang San no longer bothered to make it himself, thinking that he would prove the existence of air later, so it would be better to have a living creature such as a mouse. Zhang San went to the front yard to find a monkey and asked him to catch a few live voles. The monkey immediately took Xiao Feng and went to the outside of Zhuangzi with a shovel and a net cage.

After a while, Li Si came back, took the crystal piece and looked at it, the transparency and size of the palm were not satisfactory, and it cost two or three dollars, but fortunately it could barely be used, Zhang San first asked him to find a wooden barrel to inlay the crystal on it, so that he could see the inside, saying that there are places that are sealed with glue and there can be no leakage.

An hour later, the monkey and Xiaofeng came back to catch more than a dozen fat voles, Zhang San was preparing here, and Wen Huanzhang came to Zhang San's door at ten o'clock.

Zhang San went to the courtyard to greet him, pulled him and walked to the living room. In the living room, Zhang San deliberately asked the important personnel to temporarily put down the work at hand and come over to watch together.

After the two of them sat down in the living room, Wen Huanzhang spoke first: "I recently measured around Tokyo, and found that the earth does have an arc as you said. It's just that those questions have been bothering me yesterday, as well as things such as solar and lunar eclipses, I wonder if San Lang can answer them for me? ”

Zhang San smiled and said: "This is not difficult, but this one takes a long time, we need to talk about it in detail, let's talk about the clouds first." ”

Zhang San waved his hand and said, "I want to ask Mr. Wen, what will happen if this oil is poured into the water?" ”

Wen Huanzhang thought about it and said: "The oil will float on the water. ”

Zhang San asked, "Why?" ”

"This." Wen Huanzhang repeatedly thought about it and said: "Because oil is lighter than water." ”

Zhang San nodded and said, "Exactly." Mr. Wen should have seen that a bowl of water has been left in one place for a long time, and it slowly becomes less, why? ”

Wen Huanzhang thought about it again and said, "I don't know." ”

Zhang San smiled and asked, "Does Mr. Wen know that after this pot of water is boiled, it will be boiled and dried for a long time, where does the water go?" ”

Wen Huanzhang said: "Of course, it turned into steam and flew into the sky. ”

Zhang San nodded and said, "So has Mr. Wen ever thought about whether this static water will drift into the sky like boiling water?" ”

Wen Huanzhang thought about it and shook his head: "I don't know this." ”

Zhang San said with a smile: "The rivers have never boiled, where do the clouds in the sky come from?" ”

Wen Huanzhang shook his head and said, "I don't know this." ”

Zhang San said with a smile: "So I speculate that this heaven and earth are like a pot, the sun is the fire, the earth is the pot, the water of the rivers, lakes and seas is heated and rises into clouds, and the clouds in the sky meet cold air and turn into rain and then merge into the rivers, lakes and seas." ”

Wen Huanzhang was surprised and learned from Zhang San and asked, "How to prove it?" ”

Zhang San said with a smile: "This matter is easy, Mr. knows that in summer, a piece of clothing is washed and dried outside, and it takes at least half a day to dry clothes in winter." The more powerful the boiling water, the faster the water boils and dries up, so it can be proved that the hotter the water, the easier it is to go to the sky. ”

Wen Huanzhang nodded and said, "It should be the reason." ”

Zhang San said with a smile: "In summer, the copper basin contains ice, the ice is in the basin, and there is water outside the basin, why not?" Condensation due to the surrounding water vapor encountering cold air. ”

Wen Huanzhang was a little skeptical when he heard this, and asked, "Oh? Is that really the case? ”

Zhang San smiled and said This matter is easy, Mr. Come with me, so Zhang San pulled Wen Huanzhang and walked to the room where the wine was made a few days ago, and the wine maker here was slightly improved in order to improve efficiency after the last time, and set two copper pipes. Two pipes on one pot are also used to improve the utilization rate of air conditioning, and now it is just right to use it for comparative testing.

Zhang San first added water to the pot, signaled Wu Decai to boil the pot, and then took the copper basin and poured water on it and put saltpeter, and after a while, the cold air in the basin came out, and Wen Huanzhang said with a smile: "This is saltpeter to make ice." Unexpectedly, Saburo also studied Taoism. ”

Zhang San said with a smile: "Here are the same two copper pipes in a pot, and I will put an ice basin under one copper pipe for a while, and leave one behind, so that it can prove that the cold air can make water condense." ”

When Wen Huanzhang heard this, this was indeed the truth, and he didn't speak at the moment, this time it was just an experiment, so he didn't add much water, and after a while, the water was boiled, and the same amount of steam came out of the two copper pipes. Zhang San wrapped the ice basin under one of the copper pipes. After a short while, there were significantly more water droplets in the tube than on the other side.

Zhang San was afraid that Wen Huanzhang would think that he was cheating, so he moved the ice basin under another tube and got the same experimental result, Wen Huanzhang pondered for a while and asked, "Is San Lang doing this thing only for this experiment?" ”

Zhang San said with a smile: "No, I will have the opportunity to discuss the function of this thing with Mr. Wen in detail in the future." ”

After the two proved this experiment, Zhang San took Wen Huanzhang back to the hall, and after he was done, Zhang San asked, "Sir, now believe that there is water vapor all around us?" ”

Wen Huanzhang nodded and sighed: "This is the avenue of heaven and earth, people often say that the hundred rivers go east to the sea, why return to the west day by day, but I didn't expect this sea to return to the west day by day." It's really better to listen to your words than to read a book for ten years. But why does this water vapor go up to the sky? ”

Zhang San smiled and said: "Mr. Wen doesn't have to be in a hurry, listen to me slowly, Mr. Wen knows what people are exhaling and breathing for?" ”

Wen Huanzhang nodded and said: "This is to absorb the subtleties of heaven and earth, and spit out its own turbidity." ”

Zhang San smiled again and asked, "What is subtlety?" ”

Wen Huanzhang looked at Zhang San suspiciously and didn't understand Zhang San's question, this subtlety is subtlety, what else can subtlety be? After thinking about it, he said: "Subtle, the essence of heaven and earth." ”

Zhang San squinted his eyes and said: "Between this heaven and earth, from small mice to rhinoceros, they need to breathe in and out, I often wonder why they need to breathe in and out? ”

At this time, Zhang San motioned to Li Si to bring the wooden barrel and basin he had prepared, and poured water into the large wooden basin first, and put a wooden frame in the water, on which was placed a small cage, in which a vole was placed, and a candle was placed next to the vole.

Zhang San took the wooden barrel and showed it to Wen Huanzhang, and said, "Sir, please see, I deliberately inlaid a crystal on the wooden barrel so that you can see the situation inside." The confined space of the bucket is isolated from the outside world, and we can know what subtlety this vole is sucking. ”