It's no secret that children go through the stage of "why", when they are interested in everything in the world. Some questions of small geniuses puzzle not only parents but also scientists who have been trying for years to sort out the origin of ordinary things.
Not only parents, but also scientists suffer from the curiosity of children who want to get answers to different questions. Often even the banal "why" causes a stupor, since many topics are still being studied by specialists. Your attention - the rating of the most popular children's issues, it is impossible to accurately answer at the moment.
1. Why do people smile?
Psychologists believe that people can use more than 15 types of smiles, for example, happy, fake, seductive and others. Even primates smile to express a wide range of emotions, so they use it to show aggression, exposing teeth, or obedience. The person begins to smile even in the womb of the mother, and this smile is reflexive. The researchers suggest that the children's smile is one of the first ways of manipulation, as they make their parents smile in response.
2. Why do people yawn?
Among the numerous theories that answer this question, the most truthful version seems to be that with the help of yawning one can relieve tension from the brain and improve its work. This justifies frequent yawnings before going to bed, when brain performance is reduced, or when you do not sleep enough. As for the infectiousness of yawning, it is believed that such a habit was formed in people even in ancient times, when the leader yawned to show everyone that is not in the best shape and other members of the pack supported him, thereby increasing collective vigilance. There is another version that yawning is a kind of unifying factor that makes people sympathize with each other.
3. Why does a person "fall" in a dream?
Many people felt and even woke up after an inexplicable fall in a dream, not understanding what really happened. Such a feeling in scientific circles is usually called a "hypnotic jerk", and its appearance is explained by involuntary muscular contraction. The reason for provoking it, scientists describe in different ways. For example, there is a suggestion that this is due to primate reflexes: when they fell asleep on the branches, the jerks of the body could feel the support. According to another version, the "hypnotic jerk" is a kind of switch from the active state to sleep. During the "fall" there is a clash of two brain systems, and flinching is a splash of energy.
4. From whom did all life on earth occur?
Scientists have conducted research for more than one year and eventually concluded that almost all living things contain proteins and nucleic acids. Thanks to the presence of the genetic code, it was possible to reduce everything to one last universal common ancestor (English last universal common ancestor - LUCA). It looked like a cage and about 2.9 billion years ago gave two branches of development: eukaryotes and bacteria.
5. Why does a person with closed eyes walk around in circles?
The films often show how a lost person begins to walk in a circle, and this is not a scenario, but a real fact. This happens if a person closes his eyes, so, first he will gradually turn aside, and then begin to walk in a circle. Doubt? Then conduct the experiment, only together with the assistant, who will control everything. Scientists have investigated this phenomenon and determined that this happens because there is no landmark in space. In the end, relying only on their feelings, a person begins to deviate from the straight path. There is another assumption that the whole thing is in the asymmetry of the body.
6. How does memory work?
For a long time it was believed that human memory is enclosed in the hippocampus (part of the brain) or scattered in an indefinite group of neurons. Recently, scientists have learned to control the memory of mice, influencing some neural connections. Experiments have shown that when memories appear, the same brain cells are involved in the work, which are activated when the experience is received, that is, memory not only accumulates impressions, but also "remembers" them. While scientists could not answer the question, how the brain determines what connection in the brain should be used, but progress is already visible.
7. What is the maximum age of a person?
In different countries there are their long-livers - people, whose age is 90 years and above. Scientists have done a lot of research to determine what determines the age of a person. First it was concluded that women live longer than men. Until 2017, it was believed that the oldest resident of the planet was the Frenchwoman Zhanna Kalman, who died after she turned 122, but her result was exceeded. In Indonesia, a man lived to 146 years. Scientists still can not answer the question of how many years a person can live.
8. Can animals predict an earthquake?
Evidence that before the cataclysms animals behaved strangely, are known even from Ancient Greece, but there is no information what behavior is considered strange and what to perceive for the predictions. The fact is that animals feel changes in natural conditions, but it is impossible to understand what changes the animals react to during the earthquake. To study this, studies have been carried out, but the results are contradictory, therefore it is impossible to say exactly what animals are capable of predicting an earthquake.
9. Why are the letters placed in the alphabet in this order?
Even schoolchildren know that the alphabet was coined by the brothers Cyril and Methodius, who decided to translate the Bible for the Slavs. They studied the sounds that were used in communication and came up with an alphabetic designation for them. The order of the arrangement of new letters resembles a Greek minuscule. Why the brothers decided to do so is unknown. Perhaps it's all about laziness and unwillingness to come up with another sequence, or maybe they did not want to violate the order of the Bible language.
10. Why does the bicycle ride and not fall?
Previously, two physical terms were used to answer this question: the gyroscopic effect (explaining the ability of a rapidly rotating body to hold its position) and the castor effect (constant adjustment based on centrifugal force). These allegations were refuted by an American engineer in 2011, as he built an unusual bicycle model that does not use these physical effects. Research in this area continues, as the reason why the device rides and keeps the balance, has not been found.
11. Why do people have different blood types?
In 1900, Viennese scientist Karl Landsteiner determined that people have different blood counts, after analyzing which, he isolated four blood groups. Thanks to this, the donation began to spread, as the doctors were able to focus on the maximum coincidence of the antigens. There is no consensus on why people have different blood types, scientists do not have, but there is a suggestion that primitive people did not have antigens, and the blood was only one group. The situation has changed due to the influence of climate, food and other factors.
12. Why is ice slippery?
During the winter, many people fall on slippery ice, getting serious injuries, and the reason for the slip was determined - the presence on the surface of a thin layer of water, but that's why it forms - is unclear. Scientists think that this is due to a decrease in the melting temperature of ice due to increased pressure. There is a version that ice melts not because of pressure, but other physical process - friction. Skeptics are absolutely sure of the other, so, they believe that ice always has a liquid layer, regardless of whether it is affected or not.