Knowledge Expansion 丨 This "wonderful" scientific knowledge, you must have never told doll

Text 丨A Guai Illustration丨Jiay

Some time ago, after release of last episode of well-known popular science program "Into Science" on scientific and educational channel CCTV, it was announced that it was completed. This news also caused a discussion among many people, because this program has a special style, it is popular science, but it can always have a “horror” effect. Today, most parents attach great importance to their children's science education and don't feel "disappointed" at all when they buy hundreds of yuan worth of non-fiction books and picture books. some knowledge from them. But in fact, purpose of science education is not only to give children opportunity to learn basic scientific concepts, but also to stimulate children's curiosity and thirst for knowledge. In this issue, team leader collected 12 "remarkable" scientific knowledge that seems to be banal, but bewildering. The head of team is betting that each of following scientific knowledge can pique curiosity of you and your children!

◆ Why do a group of people yawn when one person yawns?

I believe that many people have this experience: in a group of people, while one person yawns, it causes a lot of yawning. It appears that yawning can also be "infected". like a cold. To understand this problem, we must first understand why people yawn. Some medical scientists say that there are many causes of yawning, such as drowsiness, boredom, brain overexertion, etc. It is caused by insufficient blood supply to brain, as well as a normal physiological response when people are tired. When people yawn, they usually close their eyes, relax nerves and muscles of whole body, inhale more oxygen, and temperature of brain also drops. At this time, people also get temporary sobriety and relaxation. . Let's talk about "contagiousness" of yawning. A psychologist once conducted an experiment in which some people were shown a video of yawning, after which almost half of them began to yawn. After analysis, it turned out that those who were "infected" were generally more easy-going and got along well in interpersonal communication. When one person yawns, rest follow suit. The goal is to keep whole group awake. This is easiest way to communicate and express yourself. So, yawning is "contagious", on one hand, to relax our brain, and on other hand, to satisfy our need to express group unity. Not only humans, but other primates are also susceptible to “contagion” of yawning.

◆ Your body belongs to more than just you!

One of three main philosophical questions in life "Who are you". I think everyone can tell who he is. But what would you think if someone told you that your body does not belong to you alone? Scientists have found that average adult has about 10 trillion cells, while number of human microorganisms is 20 times number of cells, and genomes of these microorganisms are at least 10 times larger than human genomes. By seeing this data, you can understand why your body does not belong to you alone. The human body is actually a huge host of microorganisms. These microorganisms live in our body. These are usually bacteria, fungi and viruses. Of course, most of flora is made up of beneficial bacteria, they live in harmony with human body and adapt to each other, forming a symbiotic relationship that lasts a lifetime.

◆Where did all gases go?

After gas produced in human digestive system has accumulated to a certain level, it still has to find an outlet, such as hiccups or farts. However, sometimes in public people will hold back their gases, but have you ever wondered where those held back gases go? Actually, don't worry too much, under normal conditions, these gases simply return to intestinal tract and wait for next release. It's unlikely that holding back gas will lead to serious health consequences, but it's best not to make it a habit. Delay fart usually does not bring serious consequences, but long-term restraint of fart leads to accumulation of a large amount of poisonous gas in intestinal tract, which again enters bloodstream and slowly decomposes in circulation, but some gases cannot be absorbed Expelled, this can lead to gastrointestinal intestinal symptoms such as bloating, pain and sometimes heartburn. In addition, process of restraint is a huge mental stress, which can also cause an increase in blood pressure and heart rate, indirectly damaging health.

◆ Do mosquitoes prefer O blood type?

There is a theory that blood of group O is more attractive to mosquitoes than blood of other groups. Is this statement true? Many people study problem of mosquito bites, and people have found several situations that mosquitoes "prefer": People who sweat a lot have higher body temperature, people with darker skin, lung capacity. big ones, and those who like to play sports or have a fragrant body. Mosquitoes suck blood, but more importantly, they suck sugary substances from human body, and sugary substances have nothing to do with different blood types. Therefore, no study has shown that mosquitoes prefer a particular blood type. Some people say that mosquitoes are easily attracted to them, which may be due to different sensations caused by different body constitutions. For example, some people are not prone to allergies and do not have any reaction after being bitten by a mosquito; bitten, I feel uncomfortable all over my body, and red envelopes will not disappear for a long time.

◆ Does blood type affect personality?

You may have heard saying: people with different blood types have different temperaments, people with same blood type have a common temperament. For example: people with blood type A are introverted and conservative, suspicious and anxious, full of emotions and indecision; people with blood type B are extroverted, active and sociable; people with blood type O are strong-willed, aggressive, brash and aggressive......Aiming at problem of blood type and personality, experts from West China Hospital of Sichuan University have made it clear that statement that blood type determines personality has not been recognized in academia, even for those who report a significant association between blood type and personality studies, results are also mixed, even contradictory. In addition, blood type does not only refer to groups A, B, O and AB. Blood group refers to antigens on surface of red blood cells. Currently, there are 36 systems of red blood cell blood groups and more than 300 antigens. .

◆ Are fish thirsty in water?

We often see that fish in aquarium continues to open its mouth, but those who know this know that it is fish breathing. So question is, do fish that live in water all their lives feel thirsty? How do they drink water? Fish is divided into freshwater fish and saltwater fish. Although freshwater fish soaks in water, it does not drink water. Not only does it not drink, but it excretes water through urine. This is due to fact that concentration of fluid in body of fish living in fresh water is usually higher than in external water, which is based on principle of osmotic pressure. The surrounding fresh water will seep into their bodies from all directions. You don't need to drink water, and you should drain it frequently. That is why water in aquarium at home must be changed regularly. The situation with marine fish is reversed because sea water has a high salinity, which is much higher than that of fish body fluids, and osmotic pressure of sea water is also much higher than that of fish. Thus, sea absorbs water from body of fish every day, so vast majority of fish living in sea are constantly drinking water.

◆ Are there lefties in animal kingdom?

The survey shows that left-handers make up between 10% and 20% of total population. Scientific studies show that this is caused by different development of left and right hemispheres in humans. There are actually a lot of "left-handers" in animal kingdom: if you carefully observe pets, you will find that most cats are "left-handed". They are also left handed. usually they stretch their left claws first when capturing food, crayfish that we often eat are also left-handed. For accuracy of predation, crayfish stretch most powerful claws. This also caused difference between left and right claws of crayfish.

◆ Is bamboo a tree or grass?

Large pieces of bamboo, we used to call it a bamboo forest. But although bamboo is tall, it is a herbaceous plant, not a tree. The biggest difference between herbaceous plants and woody plants is whether they have annual rings. Woody plants will increase their annual rings every year while bamboo is hollow inside and has no annual rings, so no matter how tall bamboo will grow, it will be grass.

◆ Why are traffic lights red, yellow and green?

"Stop at a red light, go at a green light" even children can repeat this sentence, but when children ask you "Why use red, yellow and green", can you actually answer it? Traffic lights originated in Great Britain in 19th century. In city of York in central England, red and green clothes symbolize different personalities of women: a woman in red means I'm married, and a woman in green means she's not married. Later, horse-drawn carriage accidents often occurred in front of London Parliament building, so people were inspired by red and green clothes. On December 10, 1868, first member of signal lamp family was born in London London Square. Houses of Parliament. Coincidentally, color of traffic light is exactly same as scientific argument. According to Rayleigh scattering law, people are more sensitive to red, and at same time, from theory of color spectrum, red spectrum is longest. In same place, red is farthest and first to see, and red penetrates fog well, so red lights are used to remind people to stop and pay attention to safety. Similarly, yellow and green are easy to tell apart: yellow represents alertness and vigilance, while green represents safety and tranquility.

◆ The universe does have a smell!

What does universe smell like? Now space science has found answer. When astronauts are in outer space, some compounds stick to their clothes and return to space station. Many astronauts have reported that they smelled same as "grilled" or "broiled" steak after spacewalk. But this is only smell of solar system, not entire universe. Elsewhere smells are different: The Milky Way smells like a mixture of raspberries and rum, because Milky Way contains a lot of ethyl alcohol. formate esters; currently detectable smell of edge of universe is like a mixture of burning gasoline and hot metal; in depths of Universe, all sorts of strange smells hover, and molecular clouds of dust particles create smell of these places. It smells of "salt".

◆ Is the relationship between husband and wife secure?

Often we find that a couple is clearly not related by blood, but looks more and more alike. Such statements are also called "husband and wife." Research shows that "pictures of husband and wife" are actually real! Biologists have shown that in people living together for a long time, initially different bacterial microecological environment of intestine will become more and more similar, and gradually similar flora will affect behavioral habits and characters of both husband and wife; psychologists use "m "Cherangelo Phenomenon" to answer this statement, husband and wife will unknowingly change or "cut" each other in their long-term daily life. The "look of husband and wife" is not really a similarity in appearance, but rather a similarity in facial expression. The deeper relationship between spouses, higher degree of imitation between them, and easier it is for "husband and wife look" to appear.

◆ The doll is a little short. Can growth hormone supplement make her taller?

I believe that many parents want their children to grow taller. No, many parents choose to supplement their children with growth hormone. However, experts say growth hormone is not something you can take if you want to, and not all kids can take it! In order to use growth hormone, cause of growth retardation must be identified and child/adolescent must be given growth hormone before bones heal. Besides, since growth hormone is a kind of protein-polypeptide hormone, it cannot be taken orally, it can only be injected! Thus, those who claim to "drink oral liquid to supplement growth hormone" are liars. What other unpopular scientific common sense do you know? Welcome to "write a message" to share~

* Sources: "Weird Science You Must Love to Read", "West China Hospital Rumor Squad", Dr. Ding Xiang, etc.