1. Popular science knowledge in about 40 words
Popular science knowledge in about 40 words 1. Urgent need of scientific knowledge in 40 to 60 words
Why are stars Will it flash? We see stars twinkling, not because of changes in the luminosity of the stars themselves, but because of the obstruction of the atmosphere.
The atmosphere is between us and the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere. The atmosphere is not absolutely transparent; its transparency varies depending on density.
So when we look at the stars through it on the ground, we will see that the stars seem to be twinkling. 2. Why do people yawn? When we feel tired, our bodies have produced a lot of carbon dioxide.
When there is too much carbon dioxide, oxygen must be added to balance the needs of the body. Because these residual carbon dioxide will affect the functional activities of our body, the body will issue a protective response and yawn.
Yawning is a deep breathing action, which allows us to take in more oxygen and expel carbon dioxide than usual, and also eliminates fatigue. 3. Why can snakes walk without legs? Snakes have many scales on their bodies, which are their outermost layer of armor.
The scales are not only used to protect the body, but also serve as their "feet". When a snake crawls forward, its body forms an S shape.
Each scale on the outside of the S-shape will tilt up to help the snake grasp uneven roads as it moves forward. These scales cooperate with the snake's muscles and can push the body forward, so the snake can move without legs! 4. Why do sunflowers always bloom toward the sun? The stems under the sunflower discs contain a substance called "auxin."
This substance has the function of accelerating reproduction, but it is optically repulsive. Whenever it encounters light, it will run to the backlight side. So when the sun rises, the sunflower stems immediately hide to the backlight side, and it seems that the entire plant is bent in the direction of the sun.
5. Why does hair turn gray as people get older? There is a substance called "melanin" in our hair. The more melanin, the darker the color of the hair. If there is less melanin, the hair will turn yellow or white.
When humans reach old age, various functions of the body will gradually decline, and the formation of pigment will become less and less, so the hair will gradually turn white! 6. Why do fireflies glow? Fireflies emit light because they have luminescent devices at the end of their abdomens. The luminescent devices are filled with many phosphorus-containing luminescent substances and luminescent enzymes, allowing fireflies to emit flashes of light. The purpose of fireflies' light is not only for lighting, but also for courtship, warning, and trapping.
This is also a tool for them to communicate. Different types of fireflies have different lighting methods, lighting frequencies and colors, and they use this to convey different messages. 7. Why does your stomach growl when you are hungry? Your stomach will growl when you are hungry. This is because the food you have eaten is almost finished digesting. Although your stomach is empty, gastric juice will continue to be secreted.
At this time, the contraction of the stomach will gradually expand, and the liquid and gas inside will stir up, causing a gurgling sound. Don’t be embarrassed by your stomach growling next time! Because this is a normal physiological action.
8. Why can’t ostriches fly? They are a type of giant ostrich bird, but they cannot fly into the sky! This is not because their wings don't work, but because their feathers are too soft and their wings are too small, not suitable for flying at all. In addition, the muscles of the ostrich are underdeveloped and the sternum is flat, which is not helpful for flying.
Ostriches live in Africa. Since they have lived in desert areas for a long time, their bodies have gradually evolved into what they are today in order to adapt to the environment. 9. Why does food in cans not go bad easily? Luncheon meat, dace with black bean sauce, and beans in tomato sauce.
These are delicious canned foods that can be stored for a long time without spoiling easily.
This is because the can is sealed and bacteria cannot enter. When people make canned food, they take all the air out of the can and then seal it.
In the absence of air, even if the food inside is contaminated with a few bacteria, they cannot survive or reproduce! 10. Why do babies cry non-stop when they are born? Babies cry loudly when they are born. This is not because they are unhappy, but because they are taking their first breath of air! When a baby is born out of its mother's body, the first breath of air they inhale rushes to the throat, which violently impacts the vocal cords, causing them to vibrate and make a cry-like sound. 11. Why does a lizard still keep bouncing after its tail is broken off? In order to protect themselves, many lizards also use protective colors to hide their appearance. When some lizards are attacked, their tails will break off due to violent muscle contraction.
Because some of the nerves in the broken tail are still alive, it will continue to bounce, thus distracting the enemy so that they can escape. Don't think that their lives will end like this. In fact, it only takes a few months for the tail to grow back and continue to give birth. (I found it).
2. A collection of scientific knowledge (30 words)
Scientific common sense in life:
1. Why does ice cream steam?
The reason why ice cream steams is because there is a lot of invisible water vapor in the outside air. When it comes into contact with very cold ice cream, it liquefies into mist droplets and surrounds the ice cream when it gets cold. It looks like ice cream. Same as "gasping".
2. Why do sunflowers always face the sun?
The stems of sunflowers contain a wonderful auxin. This auxin is very photophobic. When exposed to light, it will go to the backlight side, and at the same time it will cause the cells on the backlight side to multiply rapidly. Therefore, the backlight side will grow faster than the light side, causing the sunflower to develop a phototropic bend. .
3. Why do cicadas shed their skin?
The cicada’s outer shell (exoskeleton) is hard and cannot expand as the cicada grows. When the cicada grows to a certain stage, the cicada’s exoskeleton limits the growth of the cicada, and the cicada will lose its original structure. When the exoskeleton is taken off, it becomes the cicada.
4. How do bees make honey?
The bee first spits the sweet juice from the flowers into an empty hive. At night, it sucks the sweet juice into its honey stomach to prepare it, then spits it out, and then swallows it. This hesitation takes 100 to 240 times before it finally becomes sweet honey
5. When the quartz clock hung on the wall stops moving due to exhaustion of battery power, its second hand often stops. At the "9" position on the dial. This is because the second hand is most hindered by the gravity moment at the "9" position. Scientific knowledge
6. Sometimes when the water pipe is discharging water from a nearby faucet, bursts of sound occasionally occur. This is because the water pipes vibrate when water rushes out of the faucet.
7. When taking pictures in front of the TV screen, you should turn off the camera flash and indoor lighting, so that the picture will be clearer. Because the reflected light of flash and lighting on the TV screen will interfere with the transmitted light of the TV picture.
8. Frozen meat thaws faster in water than in air of the same temperature. A hot iron nail cools faster when placed in water than in air of the same temperature. A cup filled with scalding boiling water cools faster when immersed in water than when immersed in air of the same temperature. These phenomena all show that the heat transfer property of water is better than that of air.
9. When the pot is filled with cold water, the water droplets attached to the outer surface of the bottom of the pot will take a long time to dry on the flame, and until It will not boil even if it is boiled dry. This is because the water droplets, the pot and the water in the pot maintain heat conduction and have roughly the same temperature. As long as the water in the pot does not boil, the water droplets will not boil either. The water droplets evaporate on the flame and are gradually burned. Dry.
10. An aliased mirror will become skewed the farther away you are from the mirror. Because the image in the mirror is formed by the reflection of the silver-plated surface behind the mirror, uneven silver-plated surface or uneven glass thickness will cause aliasing. .
For a mirror that is out of shape, the further away a person is from the mirror, the greater the deviation of the reflected light from the silver-plated surface from the normal position due to the principle of light amplification, and the more out of shape the mirror will be.
3. Ask for 10 pieces of science Little knowledge, just 30 or 40 words each.
Little knowledge about astronomy▲. What is the universe? Answer: The universe is the general term for all things in the world. It has neither edge nor end, nor does it have a beginning or an end.
▲.How big is the Milky Way? Answer: Many stars come together to form a huge galaxy. The galaxy where the solar system is located is called the Milky Way. The Milky Way is like a large discus, about 80,000 light-years wide and 12,000 light-years thick at the center. The total number of stars is more than 1,000.
▲. Why can’t we see the stars during the day? Answer: Because part of the sunlight is scattered by gas and dust in the atmosphere during the day, the sky is illuminated very brightly. In addition, the light radiated by the sun is very strong, making it impossible for us to see the stars. ▲.What celestial bodies are there in the solar system? Answer: There are 9 planets in the solar system.
They are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, Neptune and Pluto. In addition, there are many asteroids, comets and meteors in the solar system. There are 2958 officially numbered asteroids.
The most famous comet is Halley's Comet. ▲.Why do stars have different colors? Answer: The color of a star depends on its temperature.
Different colors represent different surface temperatures: blue stars have high surface temperatures, and red stars have low surface temperatures. ▲.What is the brightest star? Answer: The brightest star in the sky is Sirius in the constellation Canis Major, with a magnitude of 1.46.
It is 8.7 light years away from Earth. ▲.How to find Polaris? Answer: It is easy to find Polaris in the sky: first find the Big Bear, then the Big Dipper.
A straight line is drawn from the two pole stars on the edge of the spoon, and it extends past the North Star. The distance from the North Star to the tip of the spoon is exactly five times the distance between the two pole stars.
You can also find Polaris through "Cassiopeia". ▲.How high is the blue sky? Answer: The "blue sky" is actually the earth's atmosphere.
The atmosphere is the air surrounding the earth. It is divided into 5 layers according to the density of the air. The total thickness is 2000-3000 kilometers. But most of the air is concentrated from the ground to places below 15 kilometers high, and the air gets thinner the higher you go.
The blue sky should be as high as the atmosphere is thick. ▲.Why is the sky blue? Answer: When sunlight hits the Earth's atmosphere, blue light is most easily separated from other colors, diffuses into the air and then reflects back.
The light of other colors has strong penetrating ability and shines on the earth through the atmosphere, so when we look at the sky, we can only see the blue light in sunlight. ▲.Why is the sky red at sunset? Answer: Because sunlight travels a particularly long distance in the atmosphere at sunset.
Except for red light, light of several other colors cannot travel that far and is lost before it reaches our eyes. Only red light travels the farthest and can reach our eyes, so the color of the sky when we see sunset becomes red.
▲.Will the moon shine? Answer: The moon is not a star. It cannot emit light, but it can reflect sunlight. Although only 7% of the light it reflects reaches the earth, it is enough to illuminate the dark nights on our planet.
▲.How many stars can we see? Answer: We can see 7,000 stars from the earth with our naked eyes, but because the earth is round, no matter where we stand on the earth, we can only see half of the sky, and the stars close to the horizon cannot be seen clearly. , so we can actually only see about 3,000 stars with the naked eye. ▲.How high is the temperature of the sun? Answer: The core temperature of the sun is as high as 192,000,000℃, and the surface temperature is 6000℃.
But because the sun is very far away from us, 150 million kilometers, we don’t feel so hot.
▲.Why does the earth spin in circles? Answer: Because the earth has gravity, and it is because of this gravity that the earth rotates.
The Earth's rotation speed is 1,700 kilometers per hour, which is 470 meters per second; its revolution speed is approximately 29.8 kilometers per second. ▲.Why is the sun white at noon? Answer: Because at noon, the sunlight can directly shine on the ground, unlike in the morning and evening when it is blocked by things on the ground (such as mountains, trees, buildings, and turbid air), so it is still the original white light. * ** People dare not open their eyes.
▲. Why is it so hard to walk on the moon? Answer: Because the attraction on the moon is very small, it is easy to slip when walking, and you can only take 20 steps a minute. If you walk in a hurry, you will easily fly up. Once you fly, you will be unable to stand for a long time. Therefore, walking on the moon is very strenuous.
▲.Why doesn’t the earth shine? Answer: Because the temperature of the earth is relatively low, the hottest place (the core of the earth) is only 2,000 to 3,000 degrees Celsius. It is not as high as the sun, which can cause thermonuclear reactions, so the earth does not emit light. ▲.Why can’t people feel that the earth is rotating? Answer: Because the earth is very big and rotates very smoothly, we are also rotating with the earth. We use ourselves as a reference, so we cannot feel that the earth is rotating.
▲.What’s going on with the thunder? Answer: This is a natural phenomenon that occurs when negative electricity and positive electricity meet together. When it rains, some clouds in the sky are charged with positive electricity, and some are charged with negative electricity. When the two clouds come together, they will discharge, emitting very bright lightning, and at the same time they release a lot of heat, which makes the surrounding air It quickly heats up, expands, and makes a loud sound, which is thunder.
▲.What’s going on with the meteor shower? Answer: There are many small celestial bodies in the universe flying according to their own orbits and speeds. Some exploded by themselves, and some collided with other celestial bodies.
But they kept flying forward. When their orbits collide with the Earth's orbit, they fall to the ground like raindrops. This phenomenon is called a meteor shower.
▲. Why do clouds move? Answer: Clouds are water vapor floating in the air. The air is constantly flowing in the air.
The movement of air is the wind, which blows away the clouds. The faster the air moves, the faster the clouds move.
▲. Why can airplanes fly into the sky? Answer: An airplane has two wings, like a bird's wings, and it also has propellers. The wings can generate lift to lift the aircraft in the air; the thrusters can generate power and push the aircraft forward.
Therefore, airplanes can fly into the sky like birds.
4. 50 Little Science Facts
1. Rabbits use their legs to slap the ground to convey information. Most of the rabbits that slap the ground with their hind legs are male rabbits. A way for female rabbits to express their emotions. 2. The largest monkey in the world is the baboon, and the smallest monkey is the tamarin. 3. The real name of the "Sibuxiang" is elk, which is a rare animal in my country. 4. Why is ice cream Angry? The reason why the ice cream steams is because there is a lot of invisible water vapor in the outside air. When it comes into contact with very cold ice cream, it will liquefy into mist droplets and surround the ice cream when it gets cold. It looks like the ice cream is "steaming".
5. Why do sunflowers always face the sun? The stems of sunflowers contain a wonderful auxin. This auxin is very photophobic.
When it encounters light, it will go to the backlight side. At the same time, it also causes the cells on the backlight side to multiply rapidly. Therefore, the backlight side grows faster than the side facing the light, making the cells on the backlight side grow faster. Sunflowers are phototropically bent. 6. Why do cicadas shed their skin? The cicada's outer shell (exoskeleton) is hard and cannot expand as the cicada grows. When the cicada grows to a certain stage, the cicada's exoskeleton limits the growth of the cicada. The cicada takes off the original exoskeleton, which is the process of shedding. .
7. How do bees make honey? The bee first vomits the sweet juice of the flowers it collected into an empty hive. At night, it sucks the sweet juice into its honey stomach to prepare it, then spits it out, and then swallows it again. It takes 100 turns to spit out the sweet juice. ~240 times, finally it becomes sweet honey.
8. Why do stars twinkle? We see stars twinkling, not because of changes in the luminosity of the stars themselves, but because of the obstruction of the atmosphere.
The atmosphere is between us and the stars. When starlight passes through the atmosphere, it will be affected by the density and thickness of the atmosphere. The atmosphere is not absolutely transparent; its transparency varies depending on density.
So when we look at the stars through it on the ground, we will see that the stars seem to be twinkling. 9. Why do people yawn? When we feel tired, our bodies have produced a lot of carbon dioxide.
When there is too much carbon dioxide, oxygen must be added to balance the needs of the body. Because these residual carbon dioxide will affect the functional activities of our body, the body will issue a protective response and yawn.
Yawning is a deep breathing action, which allows us to take in more oxygen and expel carbon dioxide than usual, and also eliminates fatigue. 10. Why can snakes walk without legs? Snakes have many scales on their bodies, which are their outermost layer of armor.
The scales are not only used to protect the body, but also serve as their "feet". When a snake crawls forward, its body forms an S shape.
Each scale on the outside of the S-shape will tilt up to help the snake grasp uneven roads as it moves forward. These scales cooperate with the snake's muscles and can push the body forward, so the snake can move without legs! 11. Why does a person’s hair turn gray as he gets older? There is a substance called "melanin" in our hair. The more melanin, the darker the color of the hair.
If there is less melanin, the hair will turn yellow or white. When humans reach old age, various functions of the body will gradually decline, and the formation of pigment will become less and less, so the hair will gradually turn white! 12. Why do fireflies glow? Fireflies emit light because they have luminescent devices at the end of their abdomens. The luminescent devices are filled with many phosphorus-containing luminescent substances and luminescent enzymes, allowing fireflies to emit flashes of light.
The purpose of fireflies’ light is not only for lighting, but also for courtship, warning, and trapping. This is also a tool for them to communicate. Different types of fireflies have different lighting methods, lighting frequencies and colors, and they use this to convey different messages.
13. Why does your stomach growl when you are hungry? Your stomach will growl when you are hungry. This is because the food you have eaten is almost finished digesting. Although your stomach is empty, gastric juice will continue to be secreted. At this time, the contraction of the stomach will gradually expand, and the liquid and gas inside will stir up, causing a gurgling sound.
Don’t be embarrassed by your stomach growling next time! Because this is a normal physiological action. 14. Why can’t ostriches fly? They are a type of giant ostrich bird, but they cannot fly into the sky! This is not because their wings don't work, but because their feathers are too soft and their wings are too small, not suitable for flying at all.
In addition, the muscles of the ostrich are underdeveloped and the sternum is flat, which is not helpful for flying. Ostriches live in Africa. Since they have lived in desert areas for a long time, their bodies have gradually evolved into what they are now in order to adapt to the environment.
15. Why does food in cans not go bad easily? Luncheon meat, dace with black bean sauce, and beans in tomato sauce.
These are delicious canned foods that can be stored for a long time without spoiling easily. This is because the can is sealed and bacteria cannot enter.
When people make canned food, they take all the air out of the can and then seal it. In the absence of air, even if there are a few bacteria on the food inside, they cannot survive or reproduce! 16. Why do babies cry non-stop when they are born? Babies cry loudly when they are born. This is not because they are unhappy, but because they are taking their first breath of air! When a baby is born out of its mother's body, the first breath of air they inhale rushes to the throat, which violently impacts the vocal cords, causing them to vibrate and make a cry-like sound.
17. Why does the lizard’s tail still bounce after being broken off? In order to protect themselves, many lizards also use protective colors to hide their appearance. When some lizards are attacked, their tails will break off due to violent muscle contraction. Since some of the nerves in the broken tail are still alive, it will continue to bounce, thus distracting the enemy so that they can escape.
Don’t think that their lives will end like this. In fact, it only takes a few months for their tails to grow back and continue their lives. 18. Why do squirrels have such big tails? Don't look at the squirrel's tail! While the squirrel is jumping up and down the tree, its tail is doing a great job.
It allows the squirrel to balance when jumping on the tree and avoid falling and being injured. In addition, this big tail can also play a protective role in winter, tightly surrounding the squirrel's body, which is both convenient and practical.
19. Why can’t people’s thumbs have one or three sections? The average person has five fingers, and the lengths of the fingers vary.
5. A little science knowledge of about 20 words. Thank you
A little science knowledge
Why does the sorbet steam?
The reason why ice cream steams is because there is a lot of invisible water vapor in the outside air. When it comes into contact with very cold ice cream, it liquefies into mist droplets and surrounds the ice cream when it gets cold. It looks like ice cream. Same as "gasping".
Why do sunflowers always face the sun?
The stems of sunflowers contain a wonderful auxin. This auxin is very photophobic. When exposed to light, it will go to the backlight side, and at the same time it will cause the cells on the backlight side to multiply rapidly. Therefore, the backlight side will grow faster than the light side, causing the sunflower to develop a phototropic bend. .
Why do cicadas shed their skin?
The cicada’s outer shell (exoskeleton) is hard and cannot expand as the cicada grows. When the cicada grows to a certain stage, the cicada’s exoskeleton limits the growth of the cicada, and the cicada will lose its original structure. When the exoskeleton is taken off, it becomes the cicada.
6. 50 words of feelings about science knowledge
Feelings about science knowledge
This holiday I read a book called "One Hundred Thousand Scientific Mysteries" ” popular science reading, which allowed me to understand a lot of life knowledge and some scientific principles, which benefited me a lot.
This book has a lot of content and a wide range of knowledge. There are many types of chapters such as scientific mysteries in food, scientific and technological phenomena, transportation technology, electrical equipment, etc., and each type of chapter has its own There are many related knowledge components, such as: The scientific mystery in sports consists of "Why does the revolving lantern rotate?" "Why can't badminton games be held outdoors?" and many other small sports knowledge, of course, every type Each article has relevant knowledge that suits its own type.
7. Do you have any scientific knowledge? The more the better in about 50 words
1. When the seeds of almost all plants germinate in the soil, their roots always grow underground. Why is this?
In the past, people thought that the roots of plants grew underground due to the gravity of the earth. Later, scientists discovered through research that the top of the root is like wearing a "hat", called the root cap. A large amount of calcium accumulates in the cells of the root cap. It is this calcium that controls the growth of plant roots underground.
The attraction of water
Groundwater is also what attracts roots to grow underground. Moreover, roots tend to grow denser in humid places. I don’t know if I don’t tell you
Some trees growing in swamps have roots that extend upward into the mud. This is a special respiratory root that can adapt to the lack of oxygen in the mud.
2□ House next to an overpass
Traditional environmental psychology explanation: Affects wealth
Scientific explanation: Traffic is inconvenient, and high-speed vehicles will cause noise and Spiral airflow will have adverse effects on physical and mental health. Years of clinical experience and research have shown that for some sensitive people, living in such a place is easy to cause neurasthenia.
3□ Houses next to high-voltage electricity towers and TV towers
Scientific explanation: The transmitting power of TV towers is very strong, and electromagnetic waves will cause a decline in human immune function. Houses 300 meters away from electricity towers are generally better.
4□ House next to the gas station
Scientific explanation: Because the oil contains a large amount of lead and other harmful substances, and the parking and starting of vehicles next to the gas station are very noisy, there is no Security.
5□ The house opposite the glass curtain wall.
Scientific explanation: Reflection from glass curtain walls creates light pollution, which is detrimental to eye health and can easily cause a variety of eye diseases, such as glaucoma.
6□ House facing the main road
Traditional environmental psychology explanation: The house is facing the main road, and the "evil energy" pours in, making people susceptible to colds.
Scientific explanation: The privacy is not good, and the noise and dust pollution are relatively large.
8. The popular science knowledge should be about 100 words in a simple way
Khan, it seems that you already know a lot, so let me talk about the formation of "Yusong"
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In early or late winter, a strange phenomenon sometimes occurs: when liquid raindrops falling from the sky fall on branches, wires or other objects, they will suddenly freeze into a layer of smooth and crystal clear ice. It's "Yusong". What's going on with this phenomenon of raindrops turning into ice? In fact, the raindrops here are not ordinary raindrops, but supercooled raindrops. This situation is not common and usually occurs when warm and cold air clash and the warm air is stronger. This is a layer of air near the ground with a lower temperature (slightly below zero degrees Celsius), and above it there is an air layer or cloud layer with a temperature above zero degrees Celsius, and above it there are cloud layers with a temperature below zero degrees Celsius. From here The falling snowflakes melt into raindrops when they pass through the warm layer. Then when they enter the cold air layer near the ground, the raindrops cool quickly. Because the diameter of these raindrops is very small, although the temperature drops below Celsius, they do not have time to freeze. If it falls, when it comes into contact with a cold object on the ground, it freezes immediately and becomes what we call "Yusong".