WHY are electric car manufacturers being forced to artificially increase the noise level?
Today's electric and hybrid cars are virtually silent. This, according to a number of researchers, poses a safety risk for pedestrians, who are used to the hum of the car's engine, and especially for the blind.
Japan and the European Union have already passed laws requiring the manufacturers of such cars to install artificial noise systems.
In the USA, the compulsory installation of such systems with automatic activation of noise when driving at speeds up to 30 km/h has been introduced in 2021.
Today's electric and hybrid cars are virtually silent. This, according to a number of researchers, poses a safety risk for pedestrians, who are used to the hum of the car's engine, and especially for the blind.
Japan and the European Union have already passed laws requiring the manufacturers of such cars to install artificial noise systems.
In the USA, the compulsory installation of such systems with automatic activation of noise when driving at speeds up to 30 km/h has been introduced in 2021.
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WHY do plants signal each other underground?
Plants can "communicate" with each other via chemical signals, but their ability to transmit signals is not limited to airborne communication.
Warnings from one plant to another, such as pest infestation, can be transmitted through mycorrhiza, symbiotic fungi whose structures braid the roots of plants and allow them to get much more nutrients and water from the soil.
When an uninfested plant receives an alert, it begins to secrete repellents against specific pests or other substances in advance that attract the enemies of those pests.
Plants can "communicate" with each other via chemical signals, but their ability to transmit signals is not limited to airborne communication.
Warnings from one plant to another, such as pest infestation, can be transmitted through mycorrhiza, symbiotic fungi whose structures braid the roots of plants and allow them to get much more nutrients and water from the soil.
When an uninfested plant receives an alert, it begins to secrete repellents against specific pests or other substances in advance that attract the enemies of those pests.
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WHY do we frequently pour water into a cup and spill it on the table?
You can thank the Coanda effect for that: when we pour liquid from a vessel, it tends to follow the curve of its edge. If the liquid flow is strong, the jet comes off the edge and everything passes without incident. But if the flow is too weak, the tea will run along the side of the teapot and end up on the tablecloth.
So you should pour liquids confidently, not just a little bit at a time.
You can thank the Coanda effect for that: when we pour liquid from a vessel, it tends to follow the curve of its edge. If the liquid flow is strong, the jet comes off the edge and everything passes without incident. But if the flow is too weak, the tea will run along the side of the teapot and end up on the tablecloth.
So you should pour liquids confidently, not just a little bit at a time.
WHY are extrovert and introvert perfect life partners?
Extroverts tend to be active, sociable. They easily establish contact with others. Also able to inspire and inspire optimism.
And introverts are calm, deep thinkers. Reflect for a long time decisions, analyze all options. They are able to avoid problems. Therefore, the calm introvert keeps from making rash decisions, and temperament extrovert rouse the other half.
Precisely owing to the fact that they have different strengths, they complement each other perfectly.
Extroverts tend to be active, sociable. They easily establish contact with others. Also able to inspire and inspire optimism.
And introverts are calm, deep thinkers. Reflect for a long time decisions, analyze all options. They are able to avoid problems. Therefore, the calm introvert keeps from making rash decisions, and temperament extrovert rouse the other half.
Precisely owing to the fact that they have different strengths, they complement each other perfectly.
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WHY are people called barbarians?
The word barbaros, in Greek, means a meaningless and completely untranslatable set of sounds. The ancient Greeks called barbarians those who did not know their language. Originally, the term "barbarian" did not have any negative meaning. Only much later, in the fifth century BC, during the Greco-Persian Wars, did the Greeks become aware of the spiritual inferiority of their non-speakers, and the term took on a different meaning.
The Romans considered barbaric those peoples who did not live "according to the rules," that is, who did not observe the laws of the empire.
The word barbaros, in Greek, means a meaningless and completely untranslatable set of sounds. The ancient Greeks called barbarians those who did not know their language. Originally, the term "barbarian" did not have any negative meaning. Only much later, in the fifth century BC, during the Greco-Persian Wars, did the Greeks become aware of the spiritual inferiority of their non-speakers, and the term took on a different meaning.
The Romans considered barbaric those peoples who did not live "according to the rules," that is, who did not observe the laws of the empire.
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WHY are there lots of cats in Turkey?
Street cats have long held an essential place in the ecosystem of Turkish port cities, where rodents have always been plentiful.
In the 8th century, tireless hunters saved Istanbul from the plague by exterminating the hordes of rats that swarmed the port docks and streets. To this day, cats still control the population of mice and rats in cities
Street cats have long held an essential place in the ecosystem of Turkish port cities, where rodents have always been plentiful.
In the 8th century, tireless hunters saved Istanbul from the plague by exterminating the hordes of rats that swarmed the port docks and streets. To this day, cats still control the population of mice and rats in cities
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WHY is walking healthy?
Walking outdoors activates blood flow, strengthens the heart and bones, tones muscles, improves sleep and lung function.
Moreover, it helps to relieve stress and fight stress. To get the best results, you need to practice walking for 30-60 minutes every day. Exactly exercise.
Walking outdoors activates blood flow, strengthens the heart and bones, tones muscles, improves sleep and lung function.
Moreover, it helps to relieve stress and fight stress. To get the best results, you need to practice walking for 30-60 minutes every day. Exactly exercise.
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WHY does a regular chair have four legs while an office seat is fitted with five?
The laws of statics indicate that the chair is stable as long as its center of gravity with the person is above the contour described around its supports. Therefore the less the supports are, the more they have to be spread out. However, each successive support makes the structure more expensive, giving less and less contribution to stability.
Ordinary chairs are limited to four legs, for the sake of simplicity of rectangular connections and ease of storage. A swivel chair with a center post, on the other hand, gets important advantages from a fifth leg. Not only does it retain stability with smaller legs, but it's safer if one of the wheels breaks. It's also less likely to wobble on an uneven floor.
The laws of statics indicate that the chair is stable as long as its center of gravity with the person is above the contour described around its supports. Therefore the less the supports are, the more they have to be spread out. However, each successive support makes the structure more expensive, giving less and less contribution to stability.
Ordinary chairs are limited to four legs, for the sake of simplicity of rectangular connections and ease of storage. A swivel chair with a center post, on the other hand, gets important advantages from a fifth leg. Not only does it retain stability with smaller legs, but it's safer if one of the wheels breaks. It's also less likely to wobble on an uneven floor.
WHY is Facebook designed in blue?
In the mid-twenties, Facebook founder Mark Zuckerberg took a color-blindness test and realized that he was color blind. He had trouble distinguishing between shades of red and green. This is one of the reasons why Facebook is designed in blue - all variations of blue are available to Zuckerberg.
Thus, one man's peculiarity has influenced the color scheme of one of the most visited sites in the world, and probably set a whole trend in the field of social media design. Later, Twitter, LinkedIn and Telegram used shades of blue and blue in their design.
In the mid-twenties, Facebook founder Mark Zuckerberg took a color-blindness test and realized that he was color blind. He had trouble distinguishing between shades of red and green. This is one of the reasons why Facebook is designed in blue - all variations of blue are available to Zuckerberg.
Thus, one man's peculiarity has influenced the color scheme of one of the most visited sites in the world, and probably set a whole trend in the field of social media design. Later, Twitter, LinkedIn and Telegram used shades of blue and blue in their design.
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WHY do you sometimes hear yourself echoing when talking on your cell phone?
The words you say on the phone are played back by the speaker on the other person's handset, from where the sound echoes back into the handset's microphone and echoes back to you.
With wired telephony, the echo normally returns after just a few milliseconds and doesn't interfere with the conversation. In cellular and Internet telephony, the signals take longer to process, and the echo can lag noticeably behind your voice, making communication difficult.
Echo cancellation algorithms are used to combat this: they memorize the sounds spoken, look for them in the response signal, and if they are found, subtract your voice from it.
The words you say on the phone are played back by the speaker on the other person's handset, from where the sound echoes back into the handset's microphone and echoes back to you.
With wired telephony, the echo normally returns after just a few milliseconds and doesn't interfere with the conversation. In cellular and Internet telephony, the signals take longer to process, and the echo can lag noticeably behind your voice, making communication difficult.
Echo cancellation algorithms are used to combat this: they memorize the sounds spoken, look for them in the response signal, and if they are found, subtract your voice from it.
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WHY is the Moon receding away from the Earth?
The Moon creates tidal waves on Earth, not only in the ocean, but also in the Earth's crust. As a result of the Earth's rotation, tidal waves are not located strictly on the planet-satellite line, but somewhat ahead of it. The tidal wave near the moon is attracted by it a little stronger than the one on the other side of the Earth.
Therefore, a torque acts on the Earth from the side of the Moon, which gradually slows down the planet's rotation. But as action equals counteraction, the moon receives an equal and opposite effect and accelerates its motion. And this corresponds to moving to a higher orbit, that is, moving away from the Earth.
So the Moon is moving away from us due to the energy of the Earth's rotation at a rate of 4 cm per year.
The Moon creates tidal waves on Earth, not only in the ocean, but also in the Earth's crust. As a result of the Earth's rotation, tidal waves are not located strictly on the planet-satellite line, but somewhat ahead of it. The tidal wave near the moon is attracted by it a little stronger than the one on the other side of the Earth.
Therefore, a torque acts on the Earth from the side of the Moon, which gradually slows down the planet's rotation. But as action equals counteraction, the moon receives an equal and opposite effect and accelerates its motion. And this corresponds to moving to a higher orbit, that is, moving away from the Earth.
So the Moon is moving away from us due to the energy of the Earth's rotation at a rate of 4 cm per year.
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WHY do children resemble their parents?
Owing to the transfer of information stored in the nuclei of cells. The existence of discrete carriers of hereditary properties was discovered by the Austrian monk Gregor Mendel in 1865. He called them "hereditary germs". Yet his findings were ignored.
They were rediscovered only in the 1900s. Their material nature remained unclear until 1944, when it was discovered that the carrier of hereditary information is a molecule of deoxyribonucleic acid (DNA).
In 1953, a model of its structure was proposed, and soon the genetic code was deciphered. Now the genomes of many species, including humans, have been fully read. But how exactly this or that sequence of genetic "letters" determines the characteristics of organisms will be studied for a long time to come.
Owing to the transfer of information stored in the nuclei of cells. The existence of discrete carriers of hereditary properties was discovered by the Austrian monk Gregor Mendel in 1865. He called them "hereditary germs". Yet his findings were ignored.
They were rediscovered only in the 1900s. Their material nature remained unclear until 1944, when it was discovered that the carrier of hereditary information is a molecule of deoxyribonucleic acid (DNA).
In 1953, a model of its structure was proposed, and soon the genetic code was deciphered. Now the genomes of many species, including humans, have been fully read. But how exactly this or that sequence of genetic "letters" determines the characteristics of organisms will be studied for a long time to come.
WHY shouldn't cats be given milk?
Most cats, like many adult mammals, are lactose intolerant.
Kittens, contrary to popular belief, should not be fed cow's milk either. They are able to digest lactose, but the amount of lactose in cow's milk is almost three times the amount of lactose in the mother cat's milk.
If young kittens are growing up without their mother, it's a bad idea to feed them cow's milk. "Orphans" will not get enough nutrients, and may even die from exhaustion.
It is better to buy special "milk formula for kittens" at a pet store. Substitutes contain the necessary amount of proteins, fats and vitamins that contribute to the normal growth of small pets.
Most cats, like many adult mammals, are lactose intolerant.
Kittens, contrary to popular belief, should not be fed cow's milk either. They are able to digest lactose, but the amount of lactose in cow's milk is almost three times the amount of lactose in the mother cat's milk.
If young kittens are growing up without their mother, it's a bad idea to feed them cow's milk. "Orphans" will not get enough nutrients, and may even die from exhaustion.
It is better to buy special "milk formula for kittens" at a pet store. Substitutes contain the necessary amount of proteins, fats and vitamins that contribute to the normal growth of small pets.
WHY are we ashamed of someone else?
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Empathy is an amazing mechanism. Two neural zones in the sympathetic person's head are activated at once. The first one transfers into the other person's thinking. The second creates a neural map of that state. We end up imagining ourselves in someone else's body.
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When a speaker forgets the words of a speech in front of a hundred eyes, we experience discomfort along with him. That's how empathy works. The brain automatically turns on the emotion that a person in an awkward situation is supposed to feel. But sometimes we don't even have to witness someone else's gaffe firsthand. And we experience what is popularly called "Spanish shame": someone else does something stupid, but we feel ashamed.
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Empathy is an amazing mechanism. Two neural zones in the sympathetic person's head are activated at once. The first one transfers into the other person's thinking. The second creates a neural map of that state. We end up imagining ourselves in someone else's body.
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When a speaker forgets the words of a speech in front of a hundred eyes, we experience discomfort along with him. That's how empathy works. The brain automatically turns on the emotion that a person in an awkward situation is supposed to feel. But sometimes we don't even have to witness someone else's gaffe firsthand. And we experience what is popularly called "Spanish shame": someone else does something stupid, but we feel ashamed.
WHY are ancient statues white?
Since their paint has come off.
Several factors influenced the modern look of the statues. First, the natural, non-persistent paint was being erased by weather conditions.
Second, there was no technology in the Classical era that could show the true color of the sculptures, so the architecture and sculpture of the Classical era, as a follower and imitator of antiquity, deprived their works of art of fun patterns and drawings.
Since their paint has come off.
Several factors influenced the modern look of the statues. First, the natural, non-persistent paint was being erased by weather conditions.
Second, there was no technology in the Classical era that could show the true color of the sculptures, so the architecture and sculpture of the Classical era, as a follower and imitator of antiquity, deprived their works of art of fun patterns and drawings.
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WHY do obese people feel hungry when they have lots of calories to spare?
Hunger is mainly triggered by receptors in the hypothalamus that are triggered when blood glucose concentrations drop.
They are triggered regardless of the amount of fat in the body. The feeling of hunger is also triggered by special mechanoreceptors that "follow" the stretching and squeezing of the stomach walls.
Hunger is mainly triggered by receptors in the hypothalamus that are triggered when blood glucose concentrations drop.
They are triggered regardless of the amount of fat in the body. The feeling of hunger is also triggered by special mechanoreceptors that "follow" the stretching and squeezing of the stomach walls.
WHY is already exhausted air bringing a person to their senses during artificial respiration?
As we know, if you stay in an airtight room for a long time, you can suffocate, since during breathing the amount of oxygen in the air decreases and the amount of carbon dioxide increases.
However, contrary to popular belief, a person does not exhale pure carbon dioxide but a mixture of gases that contains 16-17% oxygen and about 4% carbon dioxide. (For comparison: atmospheric air, which is 21% oxygen, contains a negligible amount of carbon dioxide - 0.04%.)
This oxygen is enough to bring a person back to life by artificial respiration - from mouth to mouth or from mouth to nose. Such stimulation sometimes takes a long time, up to an hour and a half.
As we know, if you stay in an airtight room for a long time, you can suffocate, since during breathing the amount of oxygen in the air decreases and the amount of carbon dioxide increases.
However, contrary to popular belief, a person does not exhale pure carbon dioxide but a mixture of gases that contains 16-17% oxygen and about 4% carbon dioxide. (For comparison: atmospheric air, which is 21% oxygen, contains a negligible amount of carbon dioxide - 0.04%.)
This oxygen is enough to bring a person back to life by artificial respiration - from mouth to mouth or from mouth to nose. Such stimulation sometimes takes a long time, up to an hour and a half.
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WHY don't missing dogs find homes by smell?
Animals with good instincts have little sensitivity to their own scent because their bodies smell much stronger than even a fresh trail. Also, during a walk the dog trotts around, crossing the trail he's done, which makes it difficult for him to follow it back. Finally, not only do you need to smell well, but you also need to realize that if you follow your own tracks in the opposite direction, you will get home.
Such an intellectual operation is beyond the capabilities of many dogs. Lost on the walk with their owners, they start looking for their owners first of all. And, rushing from side to side, they confuse their trail even more.
Animals with good instincts have little sensitivity to their own scent because their bodies smell much stronger than even a fresh trail. Also, during a walk the dog trotts around, crossing the trail he's done, which makes it difficult for him to follow it back. Finally, not only do you need to smell well, but you also need to realize that if you follow your own tracks in the opposite direction, you will get home.
Such an intellectual operation is beyond the capabilities of many dogs. Lost on the walk with their owners, they start looking for their owners first of all. And, rushing from side to side, they confuse their trail even more.
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WHY was the "@" sign invented?
The "@" sign, so common in email addresses nowadays, wasn't invented especially for the Internet, as it may seem. The "@" sign has been around since the Renaissance, in the 15th and 16th centuries. In Spanish, Portuguese and French the symbol traditionally meant an arroba, a weight measure of 12-13 kilograms.
The @ symbol then became a variant of the preposition "at" in cursive letters, as it helped to condense notes. Since it was used in accounting documents, it naturally appeared on the keyboards of the first typewriters.
That's where Ray Tomlinson, a researcher at the American company BBN Technology, saw it when he was developing an email program that allowed messages to be sent to a remote computer. That's how the sign became a symbol of e-mail.
The "@" sign, so common in email addresses nowadays, wasn't invented especially for the Internet, as it may seem. The "@" sign has been around since the Renaissance, in the 15th and 16th centuries. In Spanish, Portuguese and French the symbol traditionally meant an arroba, a weight measure of 12-13 kilograms.
The @ symbol then became a variant of the preposition "at" in cursive letters, as it helped to condense notes. Since it was used in accounting documents, it naturally appeared on the keyboards of the first typewriters.
That's where Ray Tomlinson, a researcher at the American company BBN Technology, saw it when he was developing an email program that allowed messages to be sent to a remote computer. That's how the sign became a symbol of e-mail.
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WHY is the axis of Uranus "horizontal"?
Unlike the other planets of the solar system, Uranus "lies on its side" relative to the plane of orbit around the Sun. If the Earth is commonly compared to a spinning, slightly inclined wolf, which moves around the Sun, the movement of Uranus resembles that of a rolling orbital ball.
The reasons for this position of the axis of Uranus remain unknown, but the main hypothesis suggests that during the formation of the solar system (3-4 billion years ago) Uranus collided with a protoplanet the size of the Earth, which led to a change in the tilt of the axis of Uranus.
Unlike the other planets of the solar system, Uranus "lies on its side" relative to the plane of orbit around the Sun. If the Earth is commonly compared to a spinning, slightly inclined wolf, which moves around the Sun, the movement of Uranus resembles that of a rolling orbital ball.
The reasons for this position of the axis of Uranus remain unknown, but the main hypothesis suggests that during the formation of the solar system (3-4 billion years ago) Uranus collided with a protoplanet the size of the Earth, which led to a change in the tilt of the axis of Uranus.
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