Can fish talk?
Do you believe that fish can talk? This is an intriguing thing. I wonder if fish can talk.
My family bought two small goldfish, one is all black, and the black one is called Lele, because it is very happy. A red and white name is Xinxin, because it knows how to appreciate. Isn't it fun? They live in a fish tank, which is "unusual". There are mountains, flowers, trees, shells and colored stones. Isn't it beautiful? Let's take a look together!
At about five o'clock in the morning on September 23rd, I was about to breast-feed. I saw such a phenomenon. I spilled fish food into the fish tank, but Lele ate a little and stopped eating.
At 5 pm on September 23rd, I saw the shell in the fish tank turned upside down. Xiao Xin saw it, as if she thought-this little shell was going to die. She swam quickly and reached it with her head. After three or four minutes, I can't reach it. She swam to Lele, swept Lele with her tail, and then touched her head. Lele and Xinxin are together.
Through two observations, I know that human beings have their own expressions and communication languages, and animals also have their own kingdom expressions and communication. This also tells us that if you don't unite, then you will have nothing, and the friendship between friends is really great. At the same time, you should observe more and find more, but you can't hurt small animals just because you are doing experiments on them, because animals are friends of human beings.
Why don't ants get lost?
Ants, I believe everyone is familiar with them. Then who can really understand ants? Why don't ants get lost?
With this question, I consulted some books. According to the book, ants leave some smells along the way after starting from the nest to their destination, and then return to the nest. Touch each other with tentacles and notify other ants. Scientists have done an experiment on this problem. Scientists first identify an ant and vigorously clean up the place where he reaches his destination along the way. When the ant came back, it suddenly stopped at the place where the smell was wiped off. Looking for something while walking in circles. People come to the conclusion that ants can tell their directions by their sense of smell.
In order to confirm this conclusion, I did an experiment. I first prepared a twig about 10 cm, and put the bait-small candy on one end of the twig. I put this device near an ant nest. After a while, an ant came out to explore the road. After I led him to the stick, he went to the place where the sugar was put, as if he were smelling it. I took this opportunity to cut off the broken part of the stick by one centimeter. When the ant came back, it turned left and right where it was cut off, but it couldn't find its way home. After a while, I repeated the above experiment, and the ants still didn't find their way home. Through these two experiments, I finally know the secret of ants not getting lost. It turns out that ants can tell the direction by smell. Knowing the secret of ants, I was thinking: Can you make an ant alarm? When an ant approaches the alarm, the alarm can "smell" the ant and then chirp to let us know that the ant has gone to the cupboard or other places.
The secret of eggshell
"Students, have you brought all the eggshells?" The teacher asked. "I brought it!" We answered with one voice.
In today's science class, the teacher asked us to bring eggshells. What do you do with eggshells? Are you a tumbler? We are all curious. "Today, we are going to do a small experiment with these two and a half eggshells. Before you do it, please guess, I use this pencil to stab the eggshell vertically downward. Is the eggshell with the mouth up broken first or the eggshell with the mouth down broken first? " "Of course, the mouth is first!" Most students scrambled to answer. "Mouth up first!" My deskmate is determined to go against everyone. The teacher smiled and said, "Well, let's do an experiment to see whose answer is correct." The teacher called a classmate to the podium and asked him to point the pencil up at the eggshell. At the teacher's command, the students let go of their hands, and the pencil poked the eggshell, but it didn't break. The teacher asked him to try several times, and when the pencil stabbed for the third time, it finally broke the eggshell. Then, the teacher asked him to poke the eggshell with a pencil. "Once, twice, three times ..." Let's count together; But that half eggshell is like wearing armor, and it won't break after being stabbed more than ten times. "Yes! I guessed right! " The deskmate danced with joy. Although we are not convinced, after many experiments, we found that the same two eggshells, tied vertically with a pencil, are indeed easier to break with their mouths up. The teacher told us that this is because the stress on the eggshell with the mouth up is concentrated, while the stress on the eggshell with the mouth down is scattered, so it is stronger. No wonder all the workers and uncles on the construction site are wearing face-down safety helmets. That's the truth!
Model essay 1: Why is the trunk round?
In the process of observing nature, I happened to find that the shape of the trunk is almost round-an empty cone. Why is the trunk conical? What are the benefits of a conical trunk? In order to discuss these problems, I made more in-depth observation and analysis. With the help of my tutor, I consulted relevant materials and learned that the stems of plants have the functions of supporting plants and transporting water and other nutrients. The stems of trees are mainly composed of vascular bundles. The supporting function of stem is mainly borne by wood fibers in xylem. Although the stems of woody plants will become thicker year by year, in a certain time range, the number of woody fibers in the stems is certain, that is, the cross-sectional area of the stems is certain. Then, based on the assumption that the cross section of the trunk grows into different shapes, we design experiments to explore the reasons and advantages of conical trunk. Through experiments, we find that when the cross-sectional area and length of (1) are fixed, the vertical supporting force of triangular columnar objects is the largest and the lateral bearing capacity is the smallest; The vertical supporting force of cylindrical objects is not as good as that of triangular cylindrical objects, but the lateral bearing force is the largest; (2) For trunks with the same mass and different shapes, the short conical trunk bears the largest wind force; (3) Wind is a natural phenomenon, which affects the cross-sectional shape and height of trees. The approximate cone-shaped trunk has a low center of gravity, and the huge root system is connected with the earth, so the center of gravity drops lower and the stability is greater; (4) The cross section of the trunk is round, which can reduce the damage, has stronger mechanical strength and can resist the wind attack. At the same time, under the action of the wind, the bending degree of the trunk is similar everywhere. No matter which direction the wind blows, the resistance of the trunk is similar, and the trunk is not easy to be damaged. The above experiments reflect the laws of nature, and nature enlightens us: (1) A columnar object with a triangular cross section has the greatest vertical supporting force, and its shape can be used in buildings, such as angle steel; (2) A circular object with a circular cross section has the largest lateral bearing capacity, and similar building materials can be found everywhere, such as TV towers and telephone poles. In the process of observation, experiment and analysis, I gradually explained and revealed the mystery of conical trunk, increased my knowledge, and combined my knowledge with practice, which not only consolidated my knowledge, but also improved my interest in learning, and initially learned the scientific observation and analysis methods.
Fan Wen 2: Why do leather shoes shine brighter and brighter?
Every Sunday, I always finish the task of shoeshine given to me by my mother. Tell you, this is the source of my pocket money for a week! After getting the leather shoes covered with dust, I first wipe off the dust on the vamp, then apply shoe polish and wipe them carefully, and the leather shoes will become bright and beautiful. But why is this? I found two pairs of old and new leather shoes of the same brand and style for comparative observation. I first touched the uppers of two pairs of leather shoes and found that the surface of the new shoes was much smoother than the old ones. Old leather shoes are coated with shoe polish. After careful polishing, it shines a lot, but it is still not as good as new leather shoes. Is there a relationship between the brightness of leather shoes and the smoothness of uppers? I brought a pair of old leather shoes that were not polished, and the uppers were uneven under the magnifying glass. Then, I circled two rough areas A and B on the leather shoes. Carefully wipe area A with shoe polish, and area B without shoe polish as a blank control. I found that the surface of area A is obviously smoother after wiping, and it is more shiny than area B when placed in the sun. Why is there such a big difference between them? I think the teacher once said in physics class that the wall of the theater is uneven, so that most of the sound can be absorbed and the audience will not be disturbed by the echo. Similarly, light will be reflected on the surface of any object. If the plane is uneven, light will scatter in all directions. If this plane is smooth, then we can see the reflected light in a certain direction. The surface of leather shoes is not absolutely smooth. If it is an old leather shoe, its surface is of course more uneven and can't reflect light in a certain direction, so it looks dull. There are some small particles in shoe polish, which can just be filled into the pits on the surface of leather shoes when shining shoes. If you wipe it with a cloth again, the shoe polish will be more uniform, the surface of leather shoes will become smooth and flat, and the reflective ability will be strengthened. Through the experiment, I finally know the secret of shoes getting brighter and brighter!
Model essay 3: What effect does vinegar have on flowers?
Vinegar is a common condiment in life, while flowers can purify the ecological environment and beautify our life. Have you ever thought about the relationship between vinegar and flowers? We explored the subject with curiosity. According to people who have rich experience in planting flowers, applying some vinegar on potted flowers can improve the growth of potted flowers and increase flowers, which are bright and leafy. We soon confirmed this in the experiment. Do different concentrations of vinegar have different effects on flowers? This is the second stage of our experiment. We select four pots of gypsophila paniculata, primrose and Chinese rose with the same growth and divide them into four groups. Each group (three pots) has three kinds of flowers, which are numbered and labeled respectively. At the same time, we prepared edible white vinegar into three solutions with different concentrations: 1% (pH 2~3), 0.0 1% (pH ≈4) and 0.000 1% (pH ≈6), and sprayed vinegar on three groups of potted flowers once a day, while the fourth group did not. Observe and record the growth of flowers every five days. The results of this experiment are as follows: spraying low concentration vinegar (pH ≈6) has no obvious effect on these flowers; The flowers sprayed with moderate concentration of vinegar (pH ≈4) are obviously better than other groups, with more buds, earlier flowering, richer colors and longer flowering period. Spraying high concentration vinegar with pH value of 2-3 will make the flowers wither prematurely. Through this experiment, we can tell you that spraying vinegar properly when planting flowers can make flowers grow better. But to master the concentration of vinegar, excessive acetic acid will harm flowers.
Science at New Year's Dinner
New Year's Eve is a day that everyone likes very much. It is based on the observation of different shapes of the moon by the ancients in China (actually called the moon phase), and on this day, the moon phase is very close to the new moon. Today, you can not only get an annual salary, but also have a sumptuous New Year's Eve dinner, which has a history of thousands of years and contains many scientific truths.
In the south, fried rice cakes and rice cakes are eaten every New Year's Eve. They are crushed by rice, stirred with water and made into cuboids. After molding, put it in a packaging bag, and the air inside will be exhausted, so it can be listed. It makes sense to fry this basic cooking skill. Fried rice cakes also add a lot of vegetables. The temperature in the pot is high, and the molecules in the rice cake and vegetables are doing random thermal exercise, so the taste of vegetables can not only penetrate into the rice cake, but also move in the air, so especially when the rice cake is about to be cooked, the tangy smell will only make people drool. The rice cake is amorphous and will soften slowly after heating. You can install it at a certain level. Therefore, the principle of frying is very simple, that is, let the molecules do random thermal exercise to "flavor".
Let's talk about the north and the south first. You must eat jiaozi during the Chinese New Year, usually from evening 1 1 until the next day 1. In ancient times, it was called Zishi, which means "making friends with young people". Jiaozi looks like an ingot, so it makes sense to put the plate on the table and make a fortune. It's time to talk about the production method of jiaozi. In jiaozi, the general method is to boil, the fire is slowly heated, and the water is slowly heated. Release jiaozi when cooking. Jiaozi absorbs heat quickly, and the water keeps bubbling because of boiling, so jiaozi can "dance" by himself. Because jiaozi expands when heated, its volume becomes larger, so its buoyancy becomes larger. When the buoyancy is greater than its own gravity, jiaozi floats. After a while, the hot jiaozi appeared, which shows that cooking is to make food absorb heat by boiling water.
With the development of economy, science and technology and people's innovation, there are many professional kitchen utensils, which are only responsible for one cooking method.
Steamer, as its name implies, is to live for steaming. Imitate the ancient steamer in China, reduce the size, change the materials, and humanize the design, and enter the homes of ordinary people. The principle of steaming is also very simple. When water boils at the bottom, it boils and gives off steam. Food absorbs heat from gas and is cooked slowly, usually at the top. Maybe you have to ask, why does the top floor cook first when the second floor is closest to the bottom floor? Good question, the top floor is sealed with a pot cover, so the water vapor can't continue to rise under the pot cover, so all the food on the top floor absorbs heat, so the top floor is cooked first.
Pressure cooker, a giant, is famous in the pot industry. Its task is to stew. Add water, food and seasoning. Cover and install the upper limit valve. Let's go The pot is almost completely sealed, and only the air inlet and outlet limiting valve has a small hole, so the air inside is limited. When the temperature rises, the air pressure increases, and the limit valve is "capped" to make it completely closed, so that the air pressure in the pressure cooker rises again, thus increasing the boiling point of water, turning water into steam when it is higher than 100℃, accelerating the irregular thermal movement of water molecules, and having seasoning function. Therefore, the stew tastes more fragrant and the soup is stronger than any other method. However, the throttle valve is very humanized. When the air pressure is too high, part of the gas is discharged to reduce the air pressure and eliminate the danger.
Oven, it appeared for baking. In the past, baking was that food directly contacted fire to absorb heat. Although it is rich in color and delicious, if it is not grasped well, it will be burnt and even fire will occur. And some foods can't be in direct contact with fire, or they will be burnt, such as egg tarts. The originality of the oven is to convert electric energy into heat energy and heat it evenly with the resistance wires inside, so that food that can't be touched by fire can be heated and people can bake food.
Science is actually around us. Sometimes, one more observation may be one more contribution to the scientific community. Sometimes, with a little more patience, you can find a scientific mystery for yourself; Sometimes; With a little more work, you can meet unknown science. Therefore, science is around us, and the study of science is passed down from generation to generation like the Olympic torch. So, let's study the enthusiasm of science!
1, accidental discovery method. One Sunday, Songzi's classmate Hu Changcheng was playing in the ditch behind the house. There are many tadpoles swimming around in the ditch. Suddenly, he found a little tadpole swimming alone, as if it were out of place with other tadpoles. He used twigs to pull the tadpoles out of the group into groups of tadpoles, and soon it swam alone again. He was surprised, so he and several other groups of tadpoles were put in bottles and kept at home for observation. Finally, the unsociable tadpoles became frogs, and the others grew into toads. Through long-term observation, it made clear the difference between the frog and the toad's youngest son and wrote an excellent article.
This kind of topic is not considered in advance, but only interested in the fleeting phenomenon discovered by accident, so as to seize it and seek the source.
2. Classroom extension method. In the primary school science class "Animals and Environment", students studied the relationship between earthworms and light, temperature and humidity, and found that earthworms like dark, supermarket and warm environment, and learned to experiment with the difference method to judge the wrong causal relationship. After class, you can study the living environment of centipedes, crickets, ants and other small animals with the methods you have learned. You can continue to study other mysteries of earthworms: for example, does earthworms have eyes? Can earthworms open their ears? Earthworms' regeneration ability, soil loosening ability, etc.
3. Question inquiry method. The little fly is really annoying, it is the chief culprit of infectious diseases! But he's really weird. He often comes into contact with all kinds of bacteria. Why doesn't he get sick?
Sleeping can relieve fatigue and restore energy. Do fish who wander leisurely in the water all day sleep?
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In daily life and study, you will definitely have some questions you don't understand. Can you use it as the research object of your thesis?
Mao Dengsheng, a fifth-grade student in Daoxian County, Hunan Province, was playing with some classmates in the bamboo forest near the school one day, arguing endlessly about whether the bamboo was empty or what was in it.
Careful Mao Dengsheng has always kept this problem in mind. After school, he consulted materials and did experiments, and concluded with a lot of evidence that bamboo is not empty, but contains air, oxygen, nitrogen, carbon dioxide and other gases. Based on this, the essay "What's in Bamboo" won the first prize of the first national youth scientific essay contest.
4. Teacher guidance method. If you have a small animal or some flowers, but don't know where to start, you can find a teacher to choose a topic according to your actual situation and conditions.
If you join the school's science and technology group, you can tell the teacher the idea of the research and let the teacher determine the research topic, and then you can observe and experiment around the topic.
5. Scientific verification of idioms and proverbs. Most idioms are created by people in their long-term social life and practice, but some of them come from fables, folklore and established ones. A few of these idioms do not necessarily conform to the objective reality. It can be analyzed and verified by scientific methods.
Everyone is familiar with the idiom "a drop of water wears away a stone", which means that a drop of water can wear away a stone. This is a metaphor. As long as you persist, you can do seemingly difficult things even if your strength is small. But common sense tells us that "water drop" is just a drop of liquid, with little force and not too fast impact speed. How can it go through hard rock? Members and students began to doubt the scientific nature of this idiom, and verified the scientific nature of this idiom by doing simulation experiments and consulting materials.
"Spring breeze blows the east wind, and our ancestors get wet" is a well-known meteorological proverb. A classmate made a detailed observation record of the temperature, wind direction and weather in March, and then obtained the application scope of this proverb by using scientific statistics, which provided a reference for meteorological forecast.
Sunflowers bloom to the sun. Is this still fake? However, Hunan native Jiang Linbo challenged this theory. Through two years' experimental observation, he came to the conclusion that "Sunflowers don't always turn to the sun" and "Sunflowers turn with the sun should refer to the bud stage, and don't move after flowering".