WHY is it easier to swim in salt water than in fresh one?
โSalt is what makes water heavier. And the greater the density (weight) of water, the easier it is to float in.
An object can float in a liquid if its weight is equal to the weight of the water it pushes out (the water is displaced to give room to the object).
You can also look at it from another angle: if you sit in a tub of water, the water level in it rises. If you drain the water that your body has displaced, the weight of it will be equal to the weight of your body.
โSalt is what makes water heavier. And the greater the density (weight) of water, the easier it is to float in.
An object can float in a liquid if its weight is equal to the weight of the water it pushes out (the water is displaced to give room to the object).
You can also look at it from another angle: if you sit in a tub of water, the water level in it rises. If you drain the water that your body has displaced, the weight of it will be equal to the weight of your body.
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WHY don't insects die after falling from a great height?
If we compare the weight of an ant and a human, the difference is several thousand times.
As an example, the free-fall speed of a human is about 50 m/s. And the fall speed of an insect is around 1 m/s.
โThe lower the fall speed, the less damage will be caused. Also, many insects have wings.
If we compare the weight of an ant and a human, the difference is several thousand times.
As an example, the free-fall speed of a human is about 50 m/s. And the fall speed of an insect is around 1 m/s.
โThe lower the fall speed, the less damage will be caused. Also, many insects have wings.
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WHY can't we detect our own body odor?
There are areas of the cerebral cortex responsible for recognizing odors. Information is carried to it by nerves from receptors.
Since our body continuously emits scents, the receptors quickly become accustomed to them. As a result of this malfunction, the nervous system ignores the information it receives.
โ๏ธBut once the smell changes, the nerve endings send a signal to the brain and we perceive a new scent.
There are areas of the cerebral cortex responsible for recognizing odors. Information is carried to it by nerves from receptors.
Since our body continuously emits scents, the receptors quickly become accustomed to them. As a result of this malfunction, the nervous system ignores the information it receives.
โ๏ธBut once the smell changes, the nerve endings send a signal to the brain and we perceive a new scent.
WHY are Chinese inmates forced to play computer games?
Virtual currency is earned by so-called "gold-farmers", who have such games as a regular daily job. The vast majority of them are employed in China, with more than 100,000 total in 2005.
So in many Chinese prisons, bosses and guards force inmates to play online games for illicit profit.
Virtual currency is earned by so-called "gold-farmers", who have such games as a regular daily job. The vast majority of them are employed in China, with more than 100,000 total in 2005.
So in many Chinese prisons, bosses and guards force inmates to play online games for illicit profit.
WHY does Louis Vuitton burn unsold bags?
Louis Vuitton makes some of the most expensive handbags in the world. Remarkably, they never put their goods on sale.
In order to maintain their status as an expensive brand, the company burns all unsold bags so that no one can buy them at a discounted price.
๐ According to statistics, Louis Vuitton is the most counterfeited brand in the world.
Louis Vuitton makes some of the most expensive handbags in the world. Remarkably, they never put their goods on sale.
In order to maintain their status as an expensive brand, the company burns all unsold bags so that no one can buy them at a discounted price.
๐ According to statistics, Louis Vuitton is the most counterfeited brand in the world.
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WHY don't ducks get wet or freeze in winter?
A duck applies and distributes a special fatty grease, which is secreted by the coccygeal gland, all over its body. It keeps them dry.
As for the extra warm fur and subcutaneous fat, it keeps the cold from penetrating the duck's body. That's why ducks are warm in any frost and can take off even after long "water procedures" as their feathers stay dry.
A duck applies and distributes a special fatty grease, which is secreted by the coccygeal gland, all over its body. It keeps them dry.
As for the extra warm fur and subcutaneous fat, it keeps the cold from penetrating the duck's body. That's why ducks are warm in any frost and can take off even after long "water procedures" as their feathers stay dry.
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WHY haven't humans tamed zebras?
As early as the 19th century, colonizers thought of domesticating zebras in Africa to avoid transporting horses to the continent. Zebras are also resistant to diseases carried by the tsetse fly.
Yet unlike horses, which are carefree, zebras are in a constant state of stress, running away and even sometimes fighting savannah predators. Cornered, a zebra can beat a lion to death.
As early as the 19th century, colonizers thought of domesticating zebras in Africa to avoid transporting horses to the continent. Zebras are also resistant to diseases carried by the tsetse fly.
Yet unlike horses, which are carefree, zebras are in a constant state of stress, running away and even sometimes fighting savannah predators. Cornered, a zebra can beat a lion to death.
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WHY do worms crawl out after it rains?
Roughly 50 years ago, biologists believed that earthworms crawl to the surface after it rains to avoid drowning in their own burrows. However, this theory was rejected as they breathe through their skin, and a wet environment is ideal. There are several hypotheses at this point:
โก๏ธFor easy migration: it is easier for them to travel distances by crawling on a wet surface than by creating passages in the soil.
โก๏ธ Escape from the enemy: raindrops hitting the ground are like vibrations from the movement of predators such as moles.
Roughly 50 years ago, biologists believed that earthworms crawl to the surface after it rains to avoid drowning in their own burrows. However, this theory was rejected as they breathe through their skin, and a wet environment is ideal. There are several hypotheses at this point:
โก๏ธFor easy migration: it is easier for them to travel distances by crawling on a wet surface than by creating passages in the soil.
โก๏ธ Escape from the enemy: raindrops hitting the ground are like vibrations from the movement of predators such as moles.
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WHY can't people breathe and swallow at the same time?
The complex structure of the adult vocal apparatus does not allow humans, unlike animals, to breathe and swallow at the same time.
โ๏ธBehind the root of the tongue is the supraglottic cartilage (epiglottis). It closes the entrance to the larynx when a food lump is swallowed, then opens to allow air to pass into the larynx and then through the respiratory tract.
The complex structure of the adult vocal apparatus does not allow humans, unlike animals, to breathe and swallow at the same time.
โ๏ธBehind the root of the tongue is the supraglottic cartilage (epiglottis). It closes the entrance to the larynx when a food lump is swallowed, then opens to allow air to pass into the larynx and then through the respiratory tract.
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WHY do runners get off to a low start?
Before 1887, all athletes started the race from a standing position.
Then, after observing a kangaroo, the American sprinter Sherrill decided to try a new starting position. As for kangaroos, they duck to the ground just before the start.
Despite the protest of the judge and the mockery of the spectators, Sherrill applied the new method and immediately won the race.
Before 1887, all athletes started the race from a standing position.
Then, after observing a kangaroo, the American sprinter Sherrill decided to try a new starting position. As for kangaroos, they duck to the ground just before the start.
Despite the protest of the judge and the mockery of the spectators, Sherrill applied the new method and immediately won the race.
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WHY is it better to breathe through the nose in the cold?
The nasal cavity exhibits a unique ability to raise or lower the temperature of inhaled air. When it is -25 C outside, the air in a person's nasal cavity heats up to +35... +36,6 ะก.
As opposed to the oral cavity, the nasal one heats the air much more effectively. It is like a built-in split system that ensures normal functioning of the lower respiratory tract.
The nasal cavity exhibits a unique ability to raise or lower the temperature of inhaled air. When it is -25 C outside, the air in a person's nasal cavity heats up to +35... +36,6 ะก.
As opposed to the oral cavity, the nasal one heats the air much more effectively. It is like a built-in split system that ensures normal functioning of the lower respiratory tract.
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WHY is a zebra black with a white stripe and not vice versa?๐
Many people are convinced that a zebra is a white horse in a black stripe cause zebras have white bellies.
Scientists posed this tricky question and found out that zebras are black with a white stripe even at the embryonic stage, not the other way around.
โBlack is the main pigment, and white stripes are the lack of it.
Many people are convinced that a zebra is a white horse in a black stripe cause zebras have white bellies.
Scientists posed this tricky question and found out that zebras are black with a white stripe even at the embryonic stage, not the other way around.
โBlack is the main pigment, and white stripes are the lack of it.
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WHY are the "black boxes" in airplanes actually red or orange?
A "black box" is a device installed in an airplane to record information about the technical condition of all devices, as well as the actions and conversations of the crew.
Actually, it is not a box, but rather a ball or cylinder. And its color is not black, but red or orange, to make it easier to find in case of an accident.
A "black box" is a device installed in an airplane to record information about the technical condition of all devices, as well as the actions and conversations of the crew.
Actually, it is not a box, but rather a ball or cylinder. And its color is not black, but red or orange, to make it easier to find in case of an accident.
WHY does stress cause a lump in the throat?
This tells us that the body's autonomic nervous system (ANS) is struggling with the stressful situation. This system is independent of the human will and functions autonomously.
When we're nervous, the ANS tries to oxygenate the body as much as possible. To do this, it forces us to breathe faster and expands a part of our throat called the vocal cleft so that air gets through faster.
๐ The feeling of muscular resistance to closing the throat when we try to swallow is the "lump in the throat".
This tells us that the body's autonomic nervous system (ANS) is struggling with the stressful situation. This system is independent of the human will and functions autonomously.
When we're nervous, the ANS tries to oxygenate the body as much as possible. To do this, it forces us to breathe faster and expands a part of our throat called the vocal cleft so that air gets through faster.
๐ The feeling of muscular resistance to closing the throat when we try to swallow is the "lump in the throat".
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WHY do scorpions have blue blood?
The fact is that the blood of scorpions does not contain hemoglobin, but hemocyanin, its analog. If hemoglobin is an iron-containing substance, then hemocyanin consists of copper.
When in contact with air, this element turns blue and, giving oxygen to tissues, loses its color.
The fact is that the blood of scorpions does not contain hemoglobin, but hemocyanin, its analog. If hemoglobin is an iron-containing substance, then hemocyanin consists of copper.
When in contact with air, this element turns blue and, giving oxygen to tissues, loses its color.
WHY are there no old houses in Japan?
In this country, it is believed that a house loses value from the first day it was built. Within 10 years, such value is halved. After 25 years, it is considered overly old to live in and has no value whatsoever. After that, it is demolished and a new house is built in its place.
Even landmarks and important shrines are regularly rebuilt. That's why there are no examples of old architecture in Japan โ all the houses are modern.
In this country, it is believed that a house loses value from the first day it was built. Within 10 years, such value is halved. After 25 years, it is considered overly old to live in and has no value whatsoever. After that, it is demolished and a new house is built in its place.
Even landmarks and important shrines are regularly rebuilt. That's why there are no examples of old architecture in Japan โ all the houses are modern.
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WHY does a dolphin sleep with one eye open?
Dolphins are able to sleep by alternately turning off one of their hemispheres. The other hemisphere is awake at that moment. Accordingly, one eye is open in order to monitor changes in the environment.
If the right hemisphere sleeps and the left one is awake, the right eye is open. And vice versa.
Dolphins are able to sleep by alternately turning off one of their hemispheres. The other hemisphere is awake at that moment. Accordingly, one eye is open in order to monitor changes in the environment.
If the right hemisphere sleeps and the left one is awake, the right eye is open. And vice versa.
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WHY does the British Queen lack of a passport?
Even though the Queen does not have a passport, she is free to travel around the world.
Since UK passports are issued in Her Majesty's name, the Queen does not need one. All other members of the royal family have passports.
Also, the Queen is the only person in Great Britain who is allowed to drive a car without a license.
Even though the Queen does not have a passport, she is free to travel around the world.
Since UK passports are issued in Her Majesty's name, the Queen does not need one. All other members of the royal family have passports.
Also, the Queen is the only person in Great Britain who is allowed to drive a car without a license.
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WHY are Japanese suicide bombers called kamikazes?
The Mongol khan Kublai twice planned an invasion of Japan, and both times he was prevented by violent typhoons.
The Japanese saw this as a help from above and called them "kamikaze," which means "divine wind." And in World War II they used the term to describe suicide pilots.
The Mongol khan Kublai twice planned an invasion of Japan, and both times he was prevented by violent typhoons.
The Japanese saw this as a help from above and called them "kamikaze," which means "divine wind." And in World War II they used the term to describe suicide pilots.
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WHY do calculators start at the bottom and the phone starts at the top?
The calculator is the successor of cash registers and mechanical counting machines. That's why the numbers on the calculator from zero to nine are from the bottom to the top.
Until the 1960s, dialing on the telephone was done with a dial. Then tone dialing became possible, and the familiar dial was replaced by buttons.
There were many different attempts: they were arranged in a circle, or in two rows... But as a result, the familiar option was chosen, where the numbers are arranged in three rows in ascending order (from top to bottom).
The calculator is the successor of cash registers and mechanical counting machines. That's why the numbers on the calculator from zero to nine are from the bottom to the top.
Until the 1960s, dialing on the telephone was done with a dial. Then tone dialing became possible, and the familiar dial was replaced by buttons.
There were many different attempts: they were arranged in a circle, or in two rows... But as a result, the familiar option was chosen, where the numbers are arranged in three rows in ascending order (from top to bottom).
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