I know it rains because the weather is dry and the steam is floating upward. In today's science class, the teacher asked us to go home and do a small experiment "making rain", and explained in detail how to make rain. Of course, the first thing to do when you get home is to do experiments. First, I took some ice out of the refrigerator, put it in a glass, put a glass cover on the glass mouth, and put the glass on the balcony. But I waited for a long time, but it still didn't rain. I'm really annoyed. I picked up the receiver and called my classmate Huang Qiuyang to ask him if the experiment was successful. His answer was unsuccessful. I called several other students again. Did the experiment succeed? Similarly, they did not succeed. I didn't believe it, so I buried my head and read a science book. As soon as I read this book, I knew why the experiment was unsuccessful. Because the sunshine at night is too weak! Water vapor can't be increased. What shall we do? I thought about it, and soon found a way to increase the steam, and asked my mother to help me heat it on the gas stove. In this way, there is fog in the glass. Many things happen. The fog soon turned into small water droplets and gathered under the glass cover. Soon, the rain began to tick. I shouted happily, "I succeeded, I succeeded!" " "Mom is also very happy to see it, and praises me for thinking. After this incident, I was greatly inspired: to do a good job, don't be discouraged when encountering difficulties, study more, think more ways, dare to practice, and will certainly succeed. Dear students, have you heard the story of Columbus laying eggs vertically? Columbus broke the egg and stood up. In fact, you can stand up without falling, but it takes about five minutes, which is really too much trouble. Because when the center of gravity is directly above the triangle, the egg can stand upright. When the center of gravity is not above the triangle, the egg falls. The so-called center of gravity refers to the point where the resultant force of gravity acts on all parts of the object. From this we can think of an object, which can not only stand up, but also cannot be pushed down. Needless to say, if you are smart, you will definitely think this is a tumbler. Interesting tumbler, no matter how hard you push, you won't fall down. Even if you put it sideways, it will stand in front of you. Why doesn't the tumbler fall? Oh! On the one hand, because the top is light and the bottom is heavy, there is a heavy iron block, so the center of gravity is very low; On the other hand, the lower part of the tumbler is made into a smooth sphere. When it leans to one side, its center of gravity rises and it is in an unstable state. Under the action of gravity, it moves to a stable and balanced position. Due to the inertia of the sky, it will swing back and forth several times and finally stay in its original position. Ah! It turns out that science is everywhere around us. In order to benefit mankind, we must do more scientific experiments, learn more scientific knowledge and study hard. After reading the composition "An Experimental Class", I doubt that the atmospheric pressure outside the sphere can really press the two hemispheres together. I redone atmospheric pressure today. Want to know the result? Take your time. After school, I asked several students to do atmospheric pressure experiments. First, I took out two iron hemispheres, which were the same size and hollow, and a thick rope was tied to the top of each hemisphere. At first, I slowly pumped air out of the air hole and quickly plugged the air hole with a rubber plug. Finally, tie the rope at the top of the iron ball to the leg of the table. When it was ready, all my friends rushed to do it. I think they are so messy, so I'll sort them out one by one and come in order. When I gave the order, the first one pulled hard to the side, and the iron balls seemed to be cast together and could not turn. We all cheered for him, but in the end we didn't succeed. The second man came up, and he pulled hard for a few minutes, but he didn't pull it down. At this time, I flew into a rage, biting with my teeth, hitting with a pencil box and hitting with a stone, but I didn't break in half for a while. In this way, one by one failed. There were only a few people left, and they were silent, and none of them dared to pull. They thought that such an iron ball had not been pulled down. I think the method in the book may be really useful. I touched the rope timidly, and my friends gave me courage. I pulled off the rubber plug, and then I pulled off the iron ball with little effort. Afterwards, everyone asked me, "Why can I pull it out?" I said, "This secret must not be revealed. "Why didn't soybeans germinate last week, I made a novel experiment-incubating bean sprouts. Grandma gave me some soybean seeds, but I don't think they are enough. I had to take them out of the plastic bag tied tightly by my mother. My mother said the beans in the bag can't hatch bean sprouts. I don't believe it, so I have to do the experiment. So I separated the two kinds of soybeans and hatched them. According to the introduction in the book and the teacher's guidance, I put these two kinds of soaked soybeans between two layers of wet straw and drench them with water every morning, noon and evening. I think, how can the same bean sprouts not grow in the same way? The next day, I gently opened the straw on the bean sprouts. The soybean seeds in my grandmother's house have expanded to twice the original size, and many beans have short and thick buds on their waists. But the soybeans planted by my mother only grow fat and don't sprout. What's going on here? On the fourth day, grandma's bean sprouts grew much taller, but mom's soybeans changed color, from light yellow to dark yellow, and some of them became light black. It seems that I am really going to be "unlucky" by my mother. On the fifth and sixth day, time passed day by day, and the bean sprouts hatched with grandma's soybeans grew taller and taller, longer and more tender, with jade pillars and golden tops, very beautiful! But mom's soybeans are rotten. Only then did I believe what my mother said was true, but why? I have to ask my mother for advice. My mother smiled and said, "Although the beans are dry, they still need to breathe. Your grandmother's beans are hanging under the eaves, and the air is fresh. Of course, breathing is not a problem. The soybean in that plastic bag is dead because the mouth of the bag is tightly tied, there is no ventilation and it can't breathe. " "Oh, so that's it!" I said thoughtfully. Unexpectedly, dried soybeans will suffocate. Life is full of science!