This media is not supported in your browser
VIEW IN TELEGRAM
WHY do cats purr?🐈
The sound and vibration are created by the muscles inside the cat's larynx.
When they move, the vocal cleft expands and contracts. The air vibrates every time the cat inhales and exhales.
What do we end up with? Purring.
The sound and vibration are created by the muscles inside the cat's larynx.
When they move, the vocal cleft expands and contracts. The air vibrates every time the cat inhales and exhales.
What do we end up with? Purring.
WHY does the skin on fingers get wrinkled in water?
Our distant ancestors used to extract from water bodies not only food, but also household items. No special equipment was available, so they had to do it with their bare hands.
Skin wrinkling on palms and fingers made the task a lot easier and changing the skin on feet simplified moving over underwater rocks and other slippery surfaces.
Our distant ancestors used to extract from water bodies not only food, but also household items. No special equipment was available, so they had to do it with their bare hands.
Skin wrinkling on palms and fingers made the task a lot easier and changing the skin on feet simplified moving over underwater rocks and other slippery surfaces.
WHY is limescale in the kettle not considered harmful to humans?
If a person swallows some scale, he or she will only get an unpleasant feeling in the mouth. Limescale is mainly calcium and magnesium salts, physiologically inactive due to their insolubility.
However, these layers do not conduct heat well: settling on the heater, they increase the boiling time of water and are harmful only to the kettle itself.
If a person swallows some scale, he or she will only get an unpleasant feeling in the mouth. Limescale is mainly calcium and magnesium salts, physiologically inactive due to their insolubility.
However, these layers do not conduct heat well: settling on the heater, they increase the boiling time of water and are harmful only to the kettle itself.
WHY does the Eiffel Tower grow 15 centimeters in summer?
It's all about temperature compensators. Thanks to them, steel can expand and contract without being damaged.
When steel heats up, it begins to stretch and occupy a larger volume. It is known as thermal expansion. Conversely, a drop in temperature leads to a decrease in volume.
It's all about temperature compensators. Thanks to them, steel can expand and contract without being damaged.
When steel heats up, it begins to stretch and occupy a larger volume. It is known as thermal expansion. Conversely, a drop in temperature leads to a decrease in volume.
👍1
WHY does motion sickness occur?
It is caused by a malfunction of the vestibular apparatus, responsible for keeping us firmly on feet.
It reacts to changes in the position of the head and body in space, as well as to acceleration.
When a person's body moves and sways in a car or on a boat, the brain receives conflicting information from the different senses, which causes nausea, dizziness, and headaches.
It is caused by a malfunction of the vestibular apparatus, responsible for keeping us firmly on feet.
It reacts to changes in the position of the head and body in space, as well as to acceleration.
When a person's body moves and sways in a car or on a boat, the brain receives conflicting information from the different senses, which causes nausea, dizziness, and headaches.
👍2
WHY are there no thunderstorms or lightning in winter?
In order for a thundercloud to form, warm, moist air rises. Humidity increases as the temperature goes up.
All the particles of precipitation: rain, hail, are electrically charged. When they gather in large numbers, this charge increases.
Wet summer air has a greater conductivity of electricity, and the discharge of the potential difference is accompanied by thunder and lightning.
In order for a thundercloud to form, warm, moist air rises. Humidity increases as the temperature goes up.
All the particles of precipitation: rain, hail, are electrically charged. When they gather in large numbers, this charge increases.
Wet summer air has a greater conductivity of electricity, and the discharge of the potential difference is accompanied by thunder and lightning.
WHY is the highest-paying job in Hollywood a screenplay adaptation?
At the mention of Hollywood, most of us conjure up images of bright spotlights, gorgeous outfits, and rich celebrities.
Yet few people remember that not only actors make money on the movies, but also a tremendous number of people just doing a good job.
For example, a couple of weeks working on the adaptation of the script can make $500 thousand.
At the mention of Hollywood, most of us conjure up images of bright spotlights, gorgeous outfits, and rich celebrities.
Yet few people remember that not only actors make money on the movies, but also a tremendous number of people just doing a good job.
For example, a couple of weeks working on the adaptation of the script can make $500 thousand.
WHY does the wind blow up a fire, but not a match?
Burning wood begins with gasification (evaporation of combustibles by high temperature). In the case of a match, the flame provides the heat. However, the wind takes away the heat, and the match goes out.
A fire is kept burning by coals. The gasification of wood in them occurs in the inner layers when there is a lack of oxygen. The wind replenishes it: the smoldering of coals accelerates, the heat release grows, and the fire is ignited.
Burning wood begins with gasification (evaporation of combustibles by high temperature). In the case of a match, the flame provides the heat. However, the wind takes away the heat, and the match goes out.
A fire is kept burning by coals. The gasification of wood in them occurs in the inner layers when there is a lack of oxygen. The wind replenishes it: the smoldering of coals accelerates, the heat release grows, and the fire is ignited.
WHY do stars twinkle? 🌌
The cause of flickering is the Earth's atmosphere, through which star rays must pass before reaching the eye. Starlight in this case has to penetrate not a homogeneous medium, but gas layers of different temperature, different density, and therefore different refractivity.
Light rays undergo numerous deviations from the straight path, now concentrating, now scattering. Hence the frequent changes in the brightness of the star. And since refraction is accompanied by color scattering, along with fluctuations in brightness, changes in coloration are observed.
The cause of flickering is the Earth's atmosphere, through which star rays must pass before reaching the eye. Starlight in this case has to penetrate not a homogeneous medium, but gas layers of different temperature, different density, and therefore different refractivity.
Light rays undergo numerous deviations from the straight path, now concentrating, now scattering. Hence the frequent changes in the brightness of the star. And since refraction is accompanied by color scattering, along with fluctuations in brightness, changes in coloration are observed.
WHY is yawning contagious?
Scientists have discovered that humans react unconsciously not only to yawning, but even to the word "yawn" written on paper!
According to one theory, the contagiousness of yawning is related to the fact that humans used to live in packs, like chimpanzees, and it was crucial for them to go to sleep at the same time.
So yawning served as a signal that it was bedtime. Perceiving their neighbor's yawn as a signal to yawn and then fall asleep themselves, herd animals got used to sleeping together, keeping each other warm and safe during sleep.
Scientists have discovered that humans react unconsciously not only to yawning, but even to the word "yawn" written on paper!
According to one theory, the contagiousness of yawning is related to the fact that humans used to live in packs, like chimpanzees, and it was crucial for them to go to sleep at the same time.
So yawning served as a signal that it was bedtime. Perceiving their neighbor's yawn as a signal to yawn and then fall asleep themselves, herd animals got used to sleeping together, keeping each other warm and safe during sleep.
WHY should a tree frog not be picked up?
Under no circumstances should these frogs be handled❗
Their skin secretions are strong nerve poisons, providing them with protection from predators and explaining their bright cautionary coloration.
Yet exotic lovers raise tree frogs in terrariums. So what about their venomous nature? The fact is that in most cases it is caused by their nutrition: in the nature they eat small ants and termites and accumulate their venom. In terrariums, deprived of their "poisonous nourishment", tree frogs become practically harmless after a while
Under no circumstances should these frogs be handled❗
Their skin secretions are strong nerve poisons, providing them with protection from predators and explaining their bright cautionary coloration.
Yet exotic lovers raise tree frogs in terrariums. So what about their venomous nature? The fact is that in most cases it is caused by their nutrition: in the nature they eat small ants and termites and accumulate their venom. In terrariums, deprived of their "poisonous nourishment", tree frogs become practically harmless after a while
WHY do bears hibernate?
Hibernating in a den helps bears survive the hungry winter season.
When a bear hibernates, it barely moves. At the same time, its body temperature drops to 30° C and the functioning of the heart and lungs slows down. Such a state of the body contributes to the economical use of the fat accumulated before hibernation.
The bear does not suck its paw because it wants to eat. It does this to moisten its dry feet and to chew off keratinized and coarsened skin.
Hibernating in a den helps bears survive the hungry winter season.
When a bear hibernates, it barely moves. At the same time, its body temperature drops to 30° C and the functioning of the heart and lungs slows down. Such a state of the body contributes to the economical use of the fat accumulated before hibernation.
The bear does not suck its paw because it wants to eat. It does this to moisten its dry feet and to chew off keratinized and coarsened skin.
WHY cannot we feel the air pressure?
An enormous ocean of air lies above our planet. Air presses on humans with a force of more than 15 tons🤯
Imagine having three trucks on top of you. Yet these "trucks" never crush a human being. The reason is that the "air column" presses on us not only from above, but from all sides evenly.
Besides, we also have air inside us. And that air comes under the same pressure. The pressure of the air from inside balances the pressure on the body from outside. That's why we don't notice the pressure on our body.
An enormous ocean of air lies above our planet. Air presses on humans with a force of more than 15 tons🤯
Imagine having three trucks on top of you. Yet these "trucks" never crush a human being. The reason is that the "air column" presses on us not only from above, but from all sides evenly.
Besides, we also have air inside us. And that air comes under the same pressure. The pressure of the air from inside balances the pressure on the body from outside. That's why we don't notice the pressure on our body.
WHY does fire come in various colors? 🔥
The color of a fire is mainly determined by the temperature of the flame and what chemicals are burned in it.
The high temperature of the flame allows the atoms to jump to a higher energy state for a while.
When the atoms return to their original state, they emit light at a certain wavelength.
The color of a fire is mainly determined by the temperature of the flame and what chemicals are burned in it.
The high temperature of the flame allows the atoms to jump to a higher energy state for a while.
When the atoms return to their original state, they emit light at a certain wavelength.
WHY does a bruise appear and changes its color?
When a bump or bruise occurs, the capillaries are damaged. Blood flows from them into the surrounding soft tissues under the skin. Blood contains plenty of hemoglobin, giving it that bright red color.
White blood cells arrive at the site of the injury. They surround the site of the hemorrhage and begin to destroy the blood cells.
Destruction of hemoglobin produces decomposition products — biliverdin (green bile pigment) and bilirubin (yellow-red bile pigment).
When a bump or bruise occurs, the capillaries are damaged. Blood flows from them into the surrounding soft tissues under the skin. Blood contains plenty of hemoglobin, giving it that bright red color.
White blood cells arrive at the site of the injury. They surround the site of the hemorrhage and begin to destroy the blood cells.
Destruction of hemoglobin produces decomposition products — biliverdin (green bile pigment) and bilirubin (yellow-red bile pigment).
WHY is a rainbow shaped like an arc?
A rainbow is an optical phenomenon, the result of the light rays refracting in water droplets when it rains 🌈
Not everyone is aware that a rainbow is a circle. Its center lies on a straight line that runs from the Sun through the observer. Seeing the optical phenomenon completely to a person standing on the ground is prevented by the horizon.
A rainbow is an optical phenomenon, the result of the light rays refracting in water droplets when it rains 🌈
Not everyone is aware that a rainbow is a circle. Its center lies on a straight line that runs from the Sun through the observer. Seeing the optical phenomenon completely to a person standing on the ground is prevented by the horizon.
🌒WHY do solar eclipses occur?
A solar eclipse always takes place during a new moon.
A solar eclipse is the shadow of the Moon on the Earth's surface about 200 km in diameter. Therefore, a solar eclipse can only be observed in a narrow band in the path of the lunar shadow at one time.
Being in the strip of shadow, a total solar eclipse is visible, in which the Moon completely hides the Sun.
A solar eclipse always takes place during a new moon.
A solar eclipse is the shadow of the Moon on the Earth's surface about 200 km in diameter. Therefore, a solar eclipse can only be observed in a narrow band in the path of the lunar shadow at one time.
Being in the strip of shadow, a total solar eclipse is visible, in which the Moon completely hides the Sun.
WHY do volcanoes erupt?
A volcano erupts due to the degassing of magma.
Magma is a thick mass of molten rock with gases and water vapor. It accumulates in what are called magma pockets, which form as a result of the movement of lithospheric plates. They are most likely to be located along the collision line of the plates.
If liquid magma erupts to the Earth's surface, a volcanic eruption begins. Frequently, a volcanic eruption is accompanied by powerful explosions; these are caused by the degassing of magma and the explosion of combustible gases.
A volcano erupts due to the degassing of magma.
Magma is a thick mass of molten rock with gases and water vapor. It accumulates in what are called magma pockets, which form as a result of the movement of lithospheric plates. They are most likely to be located along the collision line of the plates.
If liquid magma erupts to the Earth's surface, a volcanic eruption begins. Frequently, a volcanic eruption is accompanied by powerful explosions; these are caused by the degassing of magma and the explosion of combustible gases.
WHY does stomach rumble? 🐳
When the stomach is empty, gastric juice and gastric gases along with air move in the stomach cavity and interact with each other, resulting in a rumbling sound.
Why is there no such sound when the stomach is not empty? Cause food dampens it by pressing the contents of the stomach against its walls.
Frequent heavy rumbling in the stomach can be a sign of dysbacteriosis. While the rumbling of an empty stomach can be "soothed" by simply eating, dysbacteriosis must be treated.
When the stomach is empty, gastric juice and gastric gases along with air move in the stomach cavity and interact with each other, resulting in a rumbling sound.
Why is there no such sound when the stomach is not empty? Cause food dampens it by pressing the contents of the stomach against its walls.
Frequent heavy rumbling in the stomach can be a sign of dysbacteriosis. While the rumbling of an empty stomach can be "soothed" by simply eating, dysbacteriosis must be treated.