Why does scientific sorbet get angry? The reason why sorbet bubbles is because there is a lot of invisible water vapor in the outside air. When it comes to cold sorbet, it will liquefy into droplets when it is cold. It seems that the sorbet is bubbling.
Why do sunflowers always face the sun? Sunflower stems contain a wonderful auxin. This auxin is very afraid of light.
When it is illuminated, it will go to the backlight side, and the cells on the backlight side will multiply rapidly. Therefore, the backlit side will grow faster than the bright side, which will bend the sunflower to light. Why does cicada shed its skin? Cicada's shell (exoskeleton) is hard and can't expand with the growth of cicada. When the cicada grows to a certain stage, the cicada's exoskeleton restricts its growth, and the cicada loses its original exoskeleton, which is cicada slough.
How do bees make honey? First, the bees spit the sweet juice of the flowers they picked into an empty hive. At night, they suck sweet juice into their honey stomachs to make it, and then spit it out and swallow it. It takes 100~240 times to make sweet honey. How do birds sleep? During the day, birds shuttle in the branches, chirp and fly freely under the blue sky. At night, they should rest, sleep and recover their strength like us, but the sleeping posture is different! Beautiful mallard ducks and swans hunt and play in the water during the day, but they can't rest when they leave their favorite water at night.
They bend their beautiful long necks, bury their heads in their wings, and then let themselves float on the water, dreaming a beautiful dream, drifting with the tide, very leisurely. Long-legged birds such as cranes, storks and herons always sleep independently on one foot, and when they are tired, they change their other feet, which is a model of combining work and rest.
Partridges like to form a big circle in groups when resting, and then their heads are outward and their tails are inward. In this way, no matter which direction the enemy attacks, they can find and escape in time.
Birds with sweet voices, such as blackbirds and larks, usually bend their legs when sleeping, and their claws bend to firmly grasp the branches without worrying about falling from the trees. And the owl, a "night-shift" raptor, you can always see it standing on a dense branch with one eye open during the day, actually sleeping.
Isn't the owl's sleeping position very different? Is to always monitor the surrounding environment and guard against enemy attacks! = = = = = = = = = = = = = = = = = = Will the fish drown? Fish has gills and can breathe in the water, while fish has swim bladder and can float freely in the water. However, some people say that fish living in water will also drown. Is it true?/You don't say. It sounds ridiculous, but it's true.
The swim bladder is the "lifebuoy" for fish swimming, and it can adjust the specific gravity of fish by inflating and deflating. In this way, when swimming, the fish can maintain a stable state without sinking or floating in the water, and the muscle activity is minimal.
However, when the fish sinks to a certain depth (that is, the "critical depth"), the huge external pressure will make the volume of the swim bladder irreparable. At this point, its buoyancy is less than its own gravity, so it will involuntarily sink to the bottom of the water, can not float up again, and will eventually drown because it can not breathe.
Although fish can still float upward by swinging their fins and tails, it won't help if they sink too deep. On the other hand, fish living in the deep sea can live freely in the deep water because their bones can bear great pressure.
If we quickly let the fish living in the deep sea reach the "critical depth", it will continue to "swell" until it comes to the surface because the pressure inside its body cannot be balanced with the smaller pressure outside. Sometimes, it even spits out its internal organs and "explodes" to die.
= = = = = = = = = = = = = = = = Greedy children become stupid, and gluttony will reduce the blood flow to the brain. If you eat too much at a time, or eat all the time, a lot of blood in the human body, including blood in the brain, will be mobilized to the gastrointestinal tract. Adequate blood supply is the premise of development, and if it is often in ischemic state, its development will inevitably be affected.
Gluttony will lead to overeating in the "obese brain", especially if you eat too much nutritious food, the calories you consume will greatly exceed the calories you consume, and the heat energy will be converted into fat and accumulated in the body. If there is too much fat in brain tissue, it will cause "brain obesity".
Studies have confirmed that human intelligence is related to the number of wrinkles in the sulcus gyrus of the brain. The more obvious the sulcus gyrus, the more wrinkles and the higher the intelligence level. The obese brain makes the sulcus close, wrinkles disappear, the cerebral cortex is smooth, the neural network is poorly developed, and the intelligence level will be reduced.
Overeating can inhibit the physiological function of the intelligent area of the brain. The way of human brain activity is that excitation and inhibition induce each other, that is, when some parts of the brain are excited, some areas of its adjacent parts are in a state of inhibition. The stronger the excitement, the deeper the inhibition on the surrounding parts, and vice versa. Therefore, if the autonomic nerve center responsible for gastrointestinal digestion is excited for a long time because of overeating, it will inevitably lead to the suppression of adjacent brain intelligent areas such as language, thinking, memory and imagination.
If these areas are often suppressed, their intelligence will get worse and worse. Overeating can damage the brain because of constipation. Snacks for children are mostly high-nutrient fine foods, which are easy to constipation.
When constipation occurs, the metabolites accumulate in the digestive tract for a long time, and after the action of intestinal bacteria, a large number of harmful substances are produced, which are easily absorbed by the intestine and enter the blood circulation, causing chronic poisoning of brain nerve cells and affecting the normal development of the brain. Overeating can also promote premature aging of the brain. In a study, scientists found that a substance that can promote premature aging of the brain-fibroblast growth factor, will increase tens of thousands of times after meals because of overeating. This is a substance that can promote arteriosclerosis, so overeating will cause premature aging of the brain in the long run.
Simple and easy-to-learn scientific knowledge The mystery of automatic rotation: Why do cartons filled with water rotate? Materials: empty milk cartons, nails, 60 cm long rope, sink, water operation: 1. Punch five holes in the empty milk box with nails. 2. One hole is in the middle of the top of the carton, and the other four holes are in the lower left corner of the four sides of the carton. 3. Tie a rope about 60 cm long on the top hole. 4. Put the paper box on the plate.
2. Students' scientific knowledge
1. Why do the stars twinkle?
We see the stars shining, not because the luminosity of the stars has changed, but because of the occlusion 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, and its transparency will change according to its density. So when we look at the stars through it on the ground, we will see that the stars seem to be flashing.
2. Why do people yawn?
When we feel tired, a lot of carbon dioxide has been produced in our bodies. When there is too much carbon dioxide, oxygen must be supplemented to balance the needs of the body. Because these residual carbon dioxide will affect our body's functional activities, then the body will send out a protective reaction, so we yawn.
Yawning is a deep breathing action, which will let us breathe in more oxygen and expel more carbon dioxide than usual, and it can also eliminate fatigue.
3. Little common sense about science, about five, urgent, urgent need for tomorrow.
1, washing clothes neckline: sprinkle some salt powder on the neckline, rub gently, and rinse off the salt with water. Because of human sweat
It contains protein, which is insoluble in water, but can be quickly dissolved in salt.
2. Make the toothbrush durable: soak the newly bought toothbrush in hot salt water for about half an hour and take it out, which will make the toothbrush durable.
Use.
3. Egg white paste and small porcelain and glassware: If small porcelain and glassware are broken, you can cover the two broken surfaces with egg white and seal them.
Wipe off the excess egg white around after sewing. After half an hour, the broken part can be completely glued. That is, after standing for a day or two,
So that it will not break when it is rubbed by a large external force.
4, pots, cups, cups and other porcelain, such as tea stains, oil stains, water stains and so on. You can use lemon peel to remove slag and match it with a bowl of warm one.
Soak in water and leave for 4 or 5 hours to remove. Washing with vinegar and salt can also be very clean.
You should eat bread before drinking milk.
Milk is a kind of natural food with the most comprehensive nutrition, the most appropriate proportion and the easiest digestion and absorption by people. But drinking milk is very particular.
If the method is improper, the effect will be greatly reduced. Experts believe that drinking milk is the best.
No sugar. Otherwise, it will not only be difficult to be digested and absorbed, but also stay in the digestive tract, affecting gastrointestinal function. Milk can be heated, but not boiled. because
After boiling, some vitamins will be destroyed, and calcium in milk will form calcium phosphate precipitation, which is not easily absorbed by the human body. Don't just drink milk for breakfast. Drinking milk on an empty stomach will accelerate gastrointestinal peristalsis and cause malabsorption. The correct way is to eat bread, cakes, etc. First, then drink milk, which will make the nutrition more balanced. At the same time, don't eat chocolate while drinking milk. Because oxalic acid in chocolate will combine with calcium in milk to form calcium oxalate, calcium can not be fully absorbed by human body.
Why does milk have a layer of skin after heating?
The skin floating on the surface of milk is solidified, protein. Milk contains all the nutrients necessary for the growth and development of cattle, and protein is one of the most important nutrients. Once heated, protein will solidify. Cooked eggs will solidify, because the protein in the eggs will solidify. Protein in milk will also be solidified by heating. Protein, especially protein in milk, will solidify when it goes bad even if it is not heated. Protein spoilage will produce acid, which can solidify milk. Although yogurt solidified with lactic acid bacteria can be eaten, it is best not to eat naturally deteriorated and solidified milk, because we don't know what kind of bacteria it will contain, which will make people sick.
4. Encyclopedia of scientific and technological knowledge
What are the three parts of sunlight? Among the eight planets, Jupiter is the largest freshwater lake in China and the first of the five mountains in Poyang Lake. The rotation of Mount Tai is around the earth axis passing through the north and south poles, and the direction is from west to east. The farther away from the poles, the greater the speed. The largest mammal in the world is the blue whale. Which city is called the foggy capital of the world, London? What is the main energy of 2 1 century? What kind of pollution is called windmill power generation kingdom in Denmark? What kind of pollution is called the world's number one killer? The nearest planet to the sun is the Mercury Green Mud Observatory. Which country is the British dry ice carbon dioxide in? Bi Sheng of the Northern Song Dynasty in China invented movable type printing. Why is China a land power and a maritime power? With a vast territory of 9.6 million square kilometers, China is the largest country in Asia and one of the largest countries in the world, ranking third in the world after Russian and Canadian countries.
The coastline of Chinese mainland starts from the mouth of Yalu River in the north and ends at the mouth of Beilun River in the south, with a total length of18,000 kilometers and an island coastline of more than 32,000 kilometers. There are more than 6,500 islands; According to the relevant provisions of the United Nations Convention on the Law of the Sea and China's proposition, the sea area under the jurisdiction of China is about 3 million square kilometers. China has vast sea areas and abundant resources, so China is also a maritime power.
Why is space junk so harmful? They have become potential killers of satellites and orbiting space stations, seriously threatening the safety of astronauts. You know, space junk runs at the speed of the universe.
An oncoming metal particle with a diameter of 0.5 mm is enough to pierce the sealed flight suit; Dust that people can't distinguish with the naked eye (such as paint chips and paint powder) can also kill astronauts; A fragment the size of an aspirin tablet can "paralyze" a satellite and send a spacecraft costing hundreds of millions of dollars into a dead end. Because of the huge amount of tiny space debris, it will seriously change the surface performance of spacecraft; Slightly larger space debris will damage the surface materials of spacecraft, cause impact pits and damage surface devices; The high-speed impact of space debris will vaporize itself and the surface material of the spacecraft being hit into plasma clouds, which will eventually lead to the failure of the spacecraft.
Interesting technology once, Newton was so absorbed in his experiment in the laboratory that he forgot the time to eat. His assistant took some eggs and sent them to the laboratory. He said to Newton, "Here are some eggs. Do it yourself. "
Newton said, "OK, thank you. Please put the eggs there. " After that, he immersed himself in the experiment.
After a long time, Newton was hungry and remembered that he hadn't had lunch yet. So, he took a small pot, put the eggs in the pot, put them on the stove, and began to do experiments again.
Half an hour later, Newton finished the experiment. At this moment, he remembered the eggs in the pot.
He opened the lid and found there were no eggs in it, only a pocket watch. Newton was surprised and looked up. The eggs are still on the table, but the pocket watch on the table is missing.
It turned out that Newton was absorbed in the experiment and cooked the pocket watch as an egg. 1, who knows how the sea freezes? Everyone thinks that the sea water is salty and won't freeze.
In fact, after the temperature is lowered, the solubility of water will also decrease, that is, salt will be precipitated. In this way, the water freezes.
2. Who knows if Altair has it now? What we are seeing now is the "light" it gave off a long time ago. As for whether it exists now, only people in the Altair galaxy know that the light we observe from the earth is still the light from a stable star.
In addition, the average life span of stars exceeds 6 billion years. So now the solar cell phone battery that Altair should still exist has come out. This kind of battery is a combination of ordinary lithium battery and other solar cells. Technicians stick a thin layer of crystalline silicon photoelectric conversion sheet on the back of lithium battery. Single crystal silicon receives the current generated by illumination and charges the lithium battery through the protection circuit. In fact, as long as there is light outside the sun, the solar cell phone battery can be automatically charged, and no matter how long the exposure time is, it will not be overcharged because of the holding circuit.
Although it is introduced, this battery can generate 1 minute of electricity when exposed to the sun for 5 minutes, and it can also be used for two or three days when exposed to a desk lamp for one night. In addition, this kind of battery also has the function of ordinary mobile phone battery. If the light is weak, you can use the mobile phone charger to charge.
Sandstorm Sandstorm is a disastrous weather phenomenon in which wind and sand interact. Its formation is closely related to global greenhouse effect, El Nino phenomenon, sharp decline of forests, vegetation destruction, species extinction, climate anomalies and other factors. Among them, overexploitation, excessive logging and excessive reclamation of natural resources caused by population expansion are the main reasons for sandstorms.
As a kind of high temperature disaster, sandstorm does not happen in all windy places. Sandstorms only occur in areas with dry climate and sparse vegetation. * * * The topsoil of the land is easily rolled up by a big storm to form a sandstorm or even a strong sandstorm. Sandstorms do no less harm to people and buildings than typhoons and tornadoes.
Recently, sandstorms have appeared in northwest and even northeast China, especially in northwest China, which has been hit by sandstorms for more than 20 times. Why is the air by the sea so fresh? The waves constantly beat the coast every day, and the tides rise and fall, bringing beautiful scenery, pleasant waves and humid coastal air to the coastal area.
The air in the seashore contains a lot of negative oxygen ions, which are called "air vitamins". They can enter the human body through breathing, improve the ventilation function of the lungs, and increase the inhalation of oxygen and the exhalation of carbon dioxide. In urban public places, negative oxygen ions 10-20 per cubic centimeter, indoor 40-50, green lawn 100-200, and coastal 100000, which are hundreds of times more than indoor ones! Negative oxygen ions are negatively charged ions, which have bactericidal effect and can inhibit the reproduction of bacteria in the air.
A large number of negative oxygen ions improve the function of human sympathetic nerve, make people refreshed and energetic, and also increase the content of hemoglobin in blood. Therefore, there are many sanatoriums on the seashore, because the seashore air has therapeutic effect on people suffering from emphysema, hypertension, neurasthenia, asthma, anemia and other diseases, which is beneficial to human health.
5. Little scientific knowledge
Why does sorbet get angry?
The reason why sorbet bubbles is because there is a lot of invisible water vapor in the outside air. When it comes to cold sorbet, it will liquefy into droplets when it is cold. It seems that the sorbet is bubbling.
Why do sunflowers always face the sun?
Sunflower stems contain a wonderful auxin. This auxin is very afraid of light. When it is illuminated, it will go to the backlight side, and the cells on the backlight side will multiply rapidly. Therefore, the backlit side will grow faster than the bright side, which will bend the sunflower to light.
Why does cicada shed its skin?
Cicada's shell (exoskeleton) is hard and can't expand with the growth of cicada. When the cicada grows to a certain stage, the cicada's exoskeleton restricts its growth, and the cicada loses its original exoskeleton, which is cicada slough.
How do bees make honey?
First, the bees spit the sweet juice of the flowers they picked into an empty hive. At night, they suck sweet juice into their honey stomachs to make it, and then spit it out and swallow it. It takes 100~240 times to make sweet honey.
6. Little scientific knowledge in life
If the cover of a long-standing book is rolled up, it is because the humidity in the air is constantly changing; Because the paper of the book absorbs the moisture in the air, it begins to "evaporate moisture" when the air is dry, and it begins to absorb moisture when the humidity in the air is high, so it is easy to "deform" the paper fiber by constantly absorbing and evaporating moisture, so the paper will curl.
Lever principle.
Using the lever principle, using chopsticks not only saves labor, but also saves distance, making the operation more flexible, but it is more laborious (it doesn't matter if you spend a little effort).
The strength and resistance of the lever refer to the force exerted on the lever, the strength refers to the force exerted by fingers on chopsticks, and the resistance refers to the force exerted by vegetables on chopsticks. To determine the relationship between the force arm and the resistance arm of chopsticks, we need to find the fulcrum. The fulcrum is at the upper end of chopsticks, and the power arm is smaller than the resistance arm. Chopsticks are a laborious lever.
They are all laborious levers. Because the position of food is on the head of chopsticks.
You can feel it with chopsticks.
Its fulcrum should be in the tiger's mouth (index finger and thumb are connected).
Power is the force exerted by fingers on chopsticks, which is generally up and down at the midpoint of chopsticks (even if it is taken down, it can't reach the chopstick head).
Resistance is the force that prevents chopsticks from closing, which generally acts on the head of chopsticks. Unless you put the dish in the middle alone, it will not be used normally. )
Therefore, the power arm is a lever with less water than the resistance arm, which is a laborious lever.
Different people hold chopsticks in different postures, which will cause different degrees of exertion, but they are all laborious levers.
Small changes in procurement costs are enough to have a huge impact on corporate profits, which is the so-called procurement leverage principle. The principle of purchasing lever illustrates the importance of purchasing cost control.
7. What popular science knowledge materials are there?
Popular science knowledge can be divided into natural science, social science and thinking science according to different research objects.
1. Natural science is a specific scientific about natural phenomena, which studies nature and its laws. Such as mathematics, physics, chemistry, astronomy, geography, biology and so on.
2. Social science is a specific scientific of social phenomena, trying to reveal the essence and laws of society. For example, economics, politics, military science, sociology, management, education and so on.
3. The humanities is a specific scientific of human cultural phenomena, which tries to reveal the essence and laws of social and cultural fields. Such as linguistics, history, archaeology, ethics, aesthetics, religion and so on.
Popularization of scientific knowledge, also known as popular science or popular science, refers to the activities of introducing natural science and social science knowledge to the general public, promoting the application of science and technology, advocating scientific methods, spreading scientific ideas, carrying forward scientific spirit and making the public understand, accept and participate in it in an easy-to-understand way. Popular science is a kind of social education.