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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WHY cannot migratory birds travel across the ocean?
For most birds, a flight of many hours is extremely difficult. And flying across the ocean would require them to stay in the air for several days at a time. Therefore, even relatively small seas birds prefer to fly around the coastline or cross in the narrowest places, such as the Mediterranean between Sicily and Tunisia. Among other things, away from the coast, birds cannot check their course against landmarks. Nevertheless, oceans are not an absolute barrier for birds.
The Little Ruff is a record-breaking species, whose breeding population in Alaska crosses most of the Pacific Ocean to reach its wintering grounds in New Zealand.
For most birds, a flight of many hours is extremely difficult. And flying across the ocean would require them to stay in the air for several days at a time. Therefore, even relatively small seas birds prefer to fly around the coastline or cross in the narrowest places, such as the Mediterranean between Sicily and Tunisia. Among other things, away from the coast, birds cannot check their course against landmarks. Nevertheless, oceans are not an absolute barrier for birds.
The Little Ruff is a record-breaking species, whose breeding population in Alaska crosses most of the Pacific Ocean to reach its wintering grounds in New Zealand.
WHY do espresso and other drinks made from coffee beans bear Italian names?
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Quite simply: because it is their country of origin. Espresso is a method of coffee making invented in Italy at the end of the 19th century, gaining enormous popularity all over the world, especially in the United States.
Drinks such as lattes and cappuccinos also originated in Italy as different ways to add milk to espresso.
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Quite simply: because it is their country of origin. Espresso is a method of coffee making invented in Italy at the end of the 19th century, gaining enormous popularity all over the world, especially in the United States.
Drinks such as lattes and cappuccinos also originated in Italy as different ways to add milk to espresso.
WHY can't you compare the megapixels of cameras with the sensitivity of the human eye?
You have probably seen many factual pictures comparing the human eye to a camera. In fact, scientifically speaking, the eye cannot be equated with a camera. It has about 120 million visual cells, but they don't capture the picture pixel by pixel.
The eye perceives an object with all cells at once, with some cells being responsible for colors and others for lightness. However, according to the latest data, the human visual acuity factor is 1.7. Accordingly, the radius at which the eye distinguishes pixels is -0.39 arcminutes.
If we take the angle of view as 90 degrees horizontally and vertically, it turns out that the resolution of the eye is 324 megapixels. And if you add peripheral vision, you get 576 megapixels.
You have probably seen many factual pictures comparing the human eye to a camera. In fact, scientifically speaking, the eye cannot be equated with a camera. It has about 120 million visual cells, but they don't capture the picture pixel by pixel.
The eye perceives an object with all cells at once, with some cells being responsible for colors and others for lightness. However, according to the latest data, the human visual acuity factor is 1.7. Accordingly, the radius at which the eye distinguishes pixels is -0.39 arcminutes.
If we take the angle of view as 90 degrees horizontally and vertically, it turns out that the resolution of the eye is 324 megapixels. And if you add peripheral vision, you get 576 megapixels.
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WHY do dogs mark trees already marked by other dogs?
By leaving a mark, a dog communicates its presence to its kin and gets an indication of what sex, size and physiological condition dogs have been here. In neutral territory, it is a message that the individual is also using it.
On the borders of the pack territory, the mark means that the area is occupied; the tag of a dog from another pack on the same object is a sort of "boundary post." On someone else's territory, it is a challenge to its owners, a claim on it. Marks are sometimes associated with the assertion of social status and with the search for a sexual partner.
By leaving a mark, a dog communicates its presence to its kin and gets an indication of what sex, size and physiological condition dogs have been here. In neutral territory, it is a message that the individual is also using it.
On the borders of the pack territory, the mark means that the area is occupied; the tag of a dog from another pack on the same object is a sort of "boundary post." On someone else's territory, it is a challenge to its owners, a claim on it. Marks are sometimes associated with the assertion of social status and with the search for a sexual partner.
WHY do cucumbers feature bumps?
Numerous species of wild cucumbers are covered with impressive spines. They prevent animals from eating the fruit before the seeds ripen in them; then the spines dry out and break off.
Still in the ancestors of the cultivated cucumber, which grew in humid tropical climates, the spines were transformed into organs through which excess water drips off. Thus, only tubercles remained of the spikes.
Numerous species of wild cucumbers are covered with impressive spines. They prevent animals from eating the fruit before the seeds ripen in them; then the spines dry out and break off.
Still in the ancestors of the cultivated cucumber, which grew in humid tropical climates, the spines were transformed into organs through which excess water drips off. Thus, only tubercles remained of the spikes.
WHY would the compass fail to work on Mars?
Mars lacks a complete planetary magnetic field. There are only small magnetic anomalies, where the field is about 500 times weaker than on Earth. They are generated by magnetized rocks in the crust of Mars, not by the magnetic dynamo in the planet's core, as in the case of Earth.
Zones of magnetic anomalies are located irregularly, so that even a very sensitive compass capable of picking up their weak fields will not indicate a certain geographic direction.
Mars lacks a complete planetary magnetic field. There are only small magnetic anomalies, where the field is about 500 times weaker than on Earth. They are generated by magnetized rocks in the crust of Mars, not by the magnetic dynamo in the planet's core, as in the case of Earth.
Zones of magnetic anomalies are located irregularly, so that even a very sensitive compass capable of picking up their weak fields will not indicate a certain geographic direction.
WHY do movie theaters sell popcorn?
For every popcorn eater, the owner of the buffet earns about 400 to 700% profit. Also, keep in mind that popcorn makes people thirsty and makes them buy more drinks. And another significant fact is that it can be stored for a really long time.
Therefore, buffet owners decided long ago that this product would be the most profitable.
For every popcorn eater, the owner of the buffet earns about 400 to 700% profit. Also, keep in mind that popcorn makes people thirsty and makes them buy more drinks. And another significant fact is that it can be stored for a really long time.
Therefore, buffet owners decided long ago that this product would be the most profitable.
WHY is the thumb called the "big finger" if it is the shortest of all?
The thumb is opposed to the others; such a position allows us to make varied and precise movements. Only humans are capable of grasping, holding, and masterfully manipulating both large and tiny implements, from a punching machine to a pin. Such diverse functions might be impossible if the thumb were longer or shorter than its actual size.
Despite the thumb's seemingly small size - it appears to consist of only two phalanges - it fully lives up to its name, both in importance and size.
The muscle responsible for the thumb is the most massive in the palm of the hand. Besides, a special part of the brain, unrelated to the one that controls the actions of the other fingers, coordinates its movements.
The thumb is opposed to the others; such a position allows us to make varied and precise movements. Only humans are capable of grasping, holding, and masterfully manipulating both large and tiny implements, from a punching machine to a pin. Such diverse functions might be impossible if the thumb were longer or shorter than its actual size.
Despite the thumb's seemingly small size - it appears to consist of only two phalanges - it fully lives up to its name, both in importance and size.
The muscle responsible for the thumb is the most massive in the palm of the hand. Besides, a special part of the brain, unrelated to the one that controls the actions of the other fingers, coordinates its movements.
WHY did the propensity for concision give rise to the word "laconism"?
The term "laconism" was derived from the name of the ancient Greek region of Laconia, whose inhabitants were noted for their brevity and brevity. Laconia was also the location of the city of Sparta.
A classic example of Spartan brevity relates to the legend of a letter written by Philip II, king of Macedonia, who conquered many Greek cities. In this letter Philip urged the Spartans to surrender immediately, since "if I take Sparta by force, I will mercilessly destroy the entire population and flatten the city to the ground!"
The term "laconism" was derived from the name of the ancient Greek region of Laconia, whose inhabitants were noted for their brevity and brevity. Laconia was also the location of the city of Sparta.
A classic example of Spartan brevity relates to the legend of a letter written by Philip II, king of Macedonia, who conquered many Greek cities. In this letter Philip urged the Spartans to surrender immediately, since "if I take Sparta by force, I will mercilessly destroy the entire population and flatten the city to the ground!"
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WHY is Wikipedia called that?
One of the world's most popular resources is owned by the nonprofit organization Wikimedia Foundation, which has 19 regional offices around the world. The site's name was not chosen by chance: it is based on the Hawaiian word Wiki (the technology of the site, translated as "quickly") and Encyclopedia.
The distinctive feature of Wikipedia is that the technology, on which the site is based, allows any user to create and edit articles - it is enough to register on the site, although in some cases it is possible without registration. Any change to the text immediately becomes available to readers.
One of the world's most popular resources is owned by the nonprofit organization Wikimedia Foundation, which has 19 regional offices around the world. The site's name was not chosen by chance: it is based on the Hawaiian word Wiki (the technology of the site, translated as "quickly") and Encyclopedia.
The distinctive feature of Wikipedia is that the technology, on which the site is based, allows any user to create and edit articles - it is enough to register on the site, although in some cases it is possible without registration. Any change to the text immediately becomes available to readers.