WHY can lack of night sleep result in obesity?
Lack of sleep increases appetite, raising the risk of obesity. Due to insufficient sleep, the body mistakenly believes it is short on energy.
Depending on the individual, a healthy night's sleep is 5-10 hours.
Elementary school students should sleep 8-12 hours, and middle school students should sleep 6.5-10 hours. Most adults get 7-8 hours of sleep.
Lack of sleep increases appetite, raising the risk of obesity. Due to insufficient sleep, the body mistakenly believes it is short on energy.
Depending on the individual, a healthy night's sleep is 5-10 hours.
Elementary school students should sleep 8-12 hours, and middle school students should sleep 6.5-10 hours. Most adults get 7-8 hours of sleep.
WHY is the closest a stall in a public toilet to the door, the fewer germs it contains?
After bacteriological analysis of fifty-one public toilets, experts found that the stall closest to the front door always had the lowest bacteria levels and the most toilet paper. Perhaps the reason is that these stalls due to their proximity to the door seem to people less private, and they instinctively try to get away from possible witnesses.
In any case, you should be careful when visiting a public toilet - as a rule, no one monitors the sterility of latrines, and it's easy to get infected with hepatitis or E. coli.
For urinals, apropos, the opposite is true - the furthest urinals are the cleanest. As a rule, men are more likely to be in a hurry and tend to use the nearest urinal.
After bacteriological analysis of fifty-one public toilets, experts found that the stall closest to the front door always had the lowest bacteria levels and the most toilet paper. Perhaps the reason is that these stalls due to their proximity to the door seem to people less private, and they instinctively try to get away from possible witnesses.
In any case, you should be careful when visiting a public toilet - as a rule, no one monitors the sterility of latrines, and it's easy to get infected with hepatitis or E. coli.
For urinals, apropos, the opposite is true - the furthest urinals are the cleanest. As a rule, men are more likely to be in a hurry and tend to use the nearest urinal.
WHY is a warming of only 2° C so severe for the planet?
The world is about 1.2°C warmer now than it was in pre-industrial times. The 144 countries participating in the 2016 Paris Agreement concurred that the world should limit global warming this century to 1.5°C. That's a highly "stringent" goal, with a lower limit of 2°C.
To realize the criticality of 1.5°C, let's take the last ice age as an example. Everyone agrees that the times of such large-scale frosts were extremely harsh. We are only separated from those global temperatures by... 5°С! At that time, sea level was about 106 meters lower than today by storing a lot of water in the form of ice at the poles. Also, about 32% of the Earth was covered in ice then, compared to about 10% today.
As an example, the oceans provide humans with about 20% of their dietary protein. Ocean acidification caused by climate change could lead to the death of many species, including oysters and crabs. The same will greatly affect the food chain.
The world is about 1.2°C warmer now than it was in pre-industrial times. The 144 countries participating in the 2016 Paris Agreement concurred that the world should limit global warming this century to 1.5°C. That's a highly "stringent" goal, with a lower limit of 2°C.
To realize the criticality of 1.5°C, let's take the last ice age as an example. Everyone agrees that the times of such large-scale frosts were extremely harsh. We are only separated from those global temperatures by... 5°С! At that time, sea level was about 106 meters lower than today by storing a lot of water in the form of ice at the poles. Also, about 32% of the Earth was covered in ice then, compared to about 10% today.
As an example, the oceans provide humans with about 20% of their dietary protein. Ocean acidification caused by climate change could lead to the death of many species, including oysters and crabs. The same will greatly affect the food chain.
WHY are vitamins A, C, E named with letters and B1, B6, B12 with numbers?
Cause the B group erroneously included different vitamins.
At the beginning of the 20th century, vitamins were called by their physiological action. The B vitamins had quite similar effects, and they were generally found in the same foods, so at first their names were all "vitamin B".
Later it turned out that it was a whole group of substances with varying chemical natures and they weren't interchangeable. As they were isolated, they began to be given the indices B1, B2, B3, B5, B6, B9, and B12.
Nowadays, though, only the designations B6 and B12 are usually found in the medical literature, the other B vitamins are commonly referred to by their chemical names: B1 for thiamine, B2 for riboflavin, etc.
Cause the B group erroneously included different vitamins.
At the beginning of the 20th century, vitamins were called by their physiological action. The B vitamins had quite similar effects, and they were generally found in the same foods, so at first their names were all "vitamin B".
Later it turned out that it was a whole group of substances with varying chemical natures and they weren't interchangeable. As they were isolated, they began to be given the indices B1, B2, B3, B5, B6, B9, and B12.
Nowadays, though, only the designations B6 and B12 are usually found in the medical literature, the other B vitamins are commonly referred to by their chemical names: B1 for thiamine, B2 for riboflavin, etc.
WHY are flies attracted to bad smells?
Those smells serving as a warning of the rotting process are attractive to flies for exactly the same reasons. When organic tissue begins to rot, it becomes soft and moist. These are ideal conditions for fly larvae to develop.
Rotting tissue is tempting for females to lay eggs. The larvae can hatch in as little as 12 hours. As soon as they emerge, they burrow into the soft medium, which they feed on for several days. Then they turn into pupae and, after a while, into adults.
Those smells serving as a warning of the rotting process are attractive to flies for exactly the same reasons. When organic tissue begins to rot, it becomes soft and moist. These are ideal conditions for fly larvae to develop.
Rotting tissue is tempting for females to lay eggs. The larvae can hatch in as little as 12 hours. As soon as they emerge, they burrow into the soft medium, which they feed on for several days. Then they turn into pupae and, after a while, into adults.
WHY is it cold in the mountains if the cold air tends downward?
The atmosphere warms mostly from the Earth's surface and gives off heat into space. Greenhouse gases keep the heat from escaping. The higher up, there are fewer greenhouse gases and the heat can escape more easily. That's why the temperature drops with height.
So, why doesn't the cold air rush downward? Actually, it does, but only with those air masses that are colder than the surrounding air at the same altitude and "sink" in it.
The cold upper layers cannot simply displace the underlying warm air, because it is not only warmer, but also higher in pressure and density.
The atmosphere warms mostly from the Earth's surface and gives off heat into space. Greenhouse gases keep the heat from escaping. The higher up, there are fewer greenhouse gases and the heat can escape more easily. That's why the temperature drops with height.
So, why doesn't the cold air rush downward? Actually, it does, but only with those air masses that are colder than the surrounding air at the same altitude and "sink" in it.
The cold upper layers cannot simply displace the underlying warm air, because it is not only warmer, but also higher in pressure and density.
WHY do dolphins enjoy chewing fugu fish?
Dolphins seem more human-like at times than we can imagine. The makers of the documentary noticed a strange thing: teenage dolphins were carefully chewing on fugu fish and passing it to each other.
Fugu is known for containing a lethal dose of a neurotoxin in its body, but in small doses this substance has a narcotic effect, and the dolphins seem to be well aware of this.
Dolphins seem more human-like at times than we can imagine. The makers of the documentary noticed a strange thing: teenage dolphins were carefully chewing on fugu fish and passing it to each other.
Fugu is known for containing a lethal dose of a neurotoxin in its body, but in small doses this substance has a narcotic effect, and the dolphins seem to be well aware of this.
WHY did Nike name its first running shoes "Cortez"?
Nike meant to dub its first running shoes "Aztec," but principle competitor Adidas already had sneakers called "Aztec Gold," and they threatened to sue.
Then one of Nike's co-founders, Bill Bowerman, took the decision to call the new sneakers "Cortez." It was the last name of the Spanish conquistador who invaded Mexico and destroyed the Aztec state.
Nike meant to dub its first running shoes "Aztec," but principle competitor Adidas already had sneakers called "Aztec Gold," and they threatened to sue.
Then one of Nike's co-founders, Bill Bowerman, took the decision to call the new sneakers "Cortez." It was the last name of the Spanish conquistador who invaded Mexico and destroyed the Aztec state.
WHY is Victoria's Secret fragrance more effective than repellents?
Researchers at New Mexico State University tested mosquito repellents popular in the United States. From previous experiments, the authors learned that mosquitoes are attracted to floral and fruity scents, so they used Victoria's Secret Bombshell fragrance in their experiments.
What was the surprise of scientists when they found that Victoria's Secret fragrance was more effective than repellents. That is, the floral scent didn't attract mosquitoes, but, on the contrary, repelled them.
Researchers at New Mexico State University tested mosquito repellents popular in the United States. From previous experiments, the authors learned that mosquitoes are attracted to floral and fruity scents, so they used Victoria's Secret Bombshell fragrance in their experiments.
What was the surprise of scientists when they found that Victoria's Secret fragrance was more effective than repellents. That is, the floral scent didn't attract mosquitoes, but, on the contrary, repelled them.
WHY is the world's worst pain a cluster headache?
Cluster headache, aka "suicidal headache," is so severe that many scientists believe it's the worst pain a person can experience.
Cluster headaches affect men at a greater rate than women. It occurs in series every few weeks or months. Each attack lasts from 15 minutes to 3 hours. Mostly the pain is concentrated around the eyes or behind the eye.
The exact etiology of the disease is uncertain. Pathological activity of the hypothalamus is considered to play a leading role in the development of the disease, as indirectly confirmed by the rhythmic nature of the headache episodes. Triggering factors responsible for triggering new attacks are individual for each patient.
Cluster headache, aka "suicidal headache," is so severe that many scientists believe it's the worst pain a person can experience.
Cluster headaches affect men at a greater rate than women. It occurs in series every few weeks or months. Each attack lasts from 15 minutes to 3 hours. Mostly the pain is concentrated around the eyes or behind the eye.
The exact etiology of the disease is uncertain. Pathological activity of the hypothalamus is considered to play a leading role in the development of the disease, as indirectly confirmed by the rhythmic nature of the headache episodes. Triggering factors responsible for triggering new attacks are individual for each patient.
WHY do launch vehicles fly exclusively in an arc?
Launch vehicles are started on an arc-shaped trajectory to get the spacecraft into orbit properly. At the first stage, the spacecraft moves upwards, overcoming air resistance, and when above 100 kilometers the atmosphere gets thin enough, the rocket changes its trajectory to reach the target orbit with minimum fuel consumption.
If the launch vehicle is lifted directly at an angle to the horizon, the air resistance will be stronger and there is no guarantee it can overcome it and reach a stable orbit.
Launch vehicles are started on an arc-shaped trajectory to get the spacecraft into orbit properly. At the first stage, the spacecraft moves upwards, overcoming air resistance, and when above 100 kilometers the atmosphere gets thin enough, the rocket changes its trajectory to reach the target orbit with minimum fuel consumption.
If the launch vehicle is lifted directly at an angle to the horizon, the air resistance will be stronger and there is no guarantee it can overcome it and reach a stable orbit.
WHY does the cough intensify at night?
When a person remains in a horizontal position, mucus accumulates in the nasopharynx and the airways cannot be cleared.
With a runny nose, secretions from the nose and sinuses drain into the throat and cause a cough reflex, so the coughing is worse when we sleep, especially when turning over from side to side, and in the morning when getting out of bed.
Dust and dry air can make the cough worse. Dry and hot air irritates the mucous membranes and provokes coughing fits.
When a person remains in a horizontal position, mucus accumulates in the nasopharynx and the airways cannot be cleared.
With a runny nose, secretions from the nose and sinuses drain into the throat and cause a cough reflex, so the coughing is worse when we sleep, especially when turning over from side to side, and in the morning when getting out of bed.
Dust and dry air can make the cough worse. Dry and hot air irritates the mucous membranes and provokes coughing fits.
WHY does dizziness follow rotation in place?
When you turn your head, your eyes reflexively move in the opposite direction. It is necessary to keep the gaze on this or that object while moving. Yet, the maximum angle of eye rotation in the eye socket is small. If this angle is reached and the person keeps rotating, the eye jumps back to the central position, then turns again to the side opposite to the rotation.
After a while, the nervous mechanism providing this eye movement (it is called nystagmus) switches to a self-sustaining mode. In this case, if the rotation stops, the eyes continue to perform nystagmatic movements.
Still, the vestibular apparatus informs the brain of the immobility of the body, and this state is perceived as a rotation of the surrounding world.
When you turn your head, your eyes reflexively move in the opposite direction. It is necessary to keep the gaze on this or that object while moving. Yet, the maximum angle of eye rotation in the eye socket is small. If this angle is reached and the person keeps rotating, the eye jumps back to the central position, then turns again to the side opposite to the rotation.
After a while, the nervous mechanism providing this eye movement (it is called nystagmus) switches to a self-sustaining mode. In this case, if the rotation stops, the eyes continue to perform nystagmatic movements.
Still, the vestibular apparatus informs the brain of the immobility of the body, and this state is perceived as a rotation of the surrounding world.
WHY shouldn't we throw away batteries?
Each battery contaminates about 20 square meters of land or 400 liters of water with heavy metals. That's more than the average swimming pool is 25 meters long.
As it turns out, the reason is that batteries contain various heavy metals that, even in small amounts, can be harmful to human health.
These include zinc, manganese, cadmium, nickel, mercury, etc. After throwing away batteries corrode (their metal coating is destroyed) and the heavy metals get into the soil and groundwater. From groundwater, these metals can enter rivers and lakes used for drinking water.
Each battery contaminates about 20 square meters of land or 400 liters of water with heavy metals. That's more than the average swimming pool is 25 meters long.
As it turns out, the reason is that batteries contain various heavy metals that, even in small amounts, can be harmful to human health.
These include zinc, manganese, cadmium, nickel, mercury, etc. After throwing away batteries corrode (their metal coating is destroyed) and the heavy metals get into the soil and groundwater. From groundwater, these metals can enter rivers and lakes used for drinking water.
WHY do I feel a tingling sensation in my mouth when drinking carbonated beverages?
The sharp taste of carbonated water results not from gas bubbles, but from carbonic acid, produced from carbon dioxide when you drink it, that irritates the nerve endings in your mouth.
Although many people naively believe that carbonated water owes its mild sharpness to tactile stimulation of the mouth by the bubbles, it seems increasingly clear that the taste of carbonated water comes mainly from the formation of carbonic acid in the mouth.
The sharp taste of carbonated water results not from gas bubbles, but from carbonic acid, produced from carbon dioxide when you drink it, that irritates the nerve endings in your mouth.
Although many people naively believe that carbonated water owes its mild sharpness to tactile stimulation of the mouth by the bubbles, it seems increasingly clear that the taste of carbonated water comes mainly from the formation of carbonic acid in the mouth.
WHY is it beneficial to sleep during the day?
The point is that sleeping during the day prevents "burnout". It restores the body, reduces stress, and gives you the opportunity to rethink the situation.
Also daytime sleep reduces the risk of cardiovascular disease. Those who sleep in the afternoon at least 3 times a week, reduce the risk of heart disease by 40%.
Scientists claim that daytime sleep is a powerful weapon against myocardial infarction.
The point is that sleeping during the day prevents "burnout". It restores the body, reduces stress, and gives you the opportunity to rethink the situation.
Also daytime sleep reduces the risk of cardiovascular disease. Those who sleep in the afternoon at least 3 times a week, reduce the risk of heart disease by 40%.
Scientists claim that daytime sleep is a powerful weapon against myocardial infarction.
WHY are millipedes the most useful insects in your home?
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Lots of people panic, scream and run away if they encounter nasty millipedes in their homes. However, they are among the most advantageous insects that can breed in human dwellings.
The fact is that a millipede's diet usually consists of insects of other species, including cockroaches, flies, moths, scales, termites, and just about all of the other parasites massing in your home.
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Also, millipedes aren't harmful to humans. They eat plants carrying diseases or affecting homes in a destructive way, and the purpose of their life is, you could say, to rid your own home of any other insects or pests.
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Lots of people panic, scream and run away if they encounter nasty millipedes in their homes. However, they are among the most advantageous insects that can breed in human dwellings.
The fact is that a millipede's diet usually consists of insects of other species, including cockroaches, flies, moths, scales, termites, and just about all of the other parasites massing in your home.
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Also, millipedes aren't harmful to humans. They eat plants carrying diseases or affecting homes in a destructive way, and the purpose of their life is, you could say, to rid your own home of any other insects or pests.
WHY are energy drinks detrimental?
Energy drinks contain plenty of sugar (more than 9-10 cc per 200 ml) - otherwise, the caffeine will reek of bitterness. Sugar, in turn, leads to tooth decay, obesity, diabetes and numerous other diseases.
Consumption of energy drinks greatly increases systolic blood pressure and causes heart rhythm abnormalities - while drinking pure caffeine has no such effects.
In the long run, such consumption affects almost all systems of the body and is highly detrimental to health, up to and including pathologies.
Energy drinks contain plenty of sugar (more than 9-10 cc per 200 ml) - otherwise, the caffeine will reek of bitterness. Sugar, in turn, leads to tooth decay, obesity, diabetes and numerous other diseases.
Consumption of energy drinks greatly increases systolic blood pressure and causes heart rhythm abnormalities - while drinking pure caffeine has no such effects.
In the long run, such consumption affects almost all systems of the body and is highly detrimental to health, up to and including pathologies.
WHY does the heart run for a lifetime without tiring?
The secret is that the heart, although it works throughout a person's life, still "finds" time to rest. Our heart consists of two atria and two ventricles.
The fact is that the ventricles and atria never contract simultaneously - they always work in alternating shifts.
If we calculate the time during which the heart remains in a relaxed state, we get that it rests for approximately the same amount of time as it works.
The secret is that the heart, although it works throughout a person's life, still "finds" time to rest. Our heart consists of two atria and two ventricles.
The fact is that the ventricles and atria never contract simultaneously - they always work in alternating shifts.
If we calculate the time during which the heart remains in a relaxed state, we get that it rests for approximately the same amount of time as it works.
WHY do lions wear manes and other felines not?
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Possibly due to their way of life.
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Unlike other cats, lions lead prides, a community consisting of a male, several females, and cubs of different ages. Pride members encounter each other constantly, not only during the breeding season. In such a way of life, signals regulating aggression are useful, including the ability to determine the sex of a tribe mate from afar.
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The mane, a distinctive feature of the adult male, serves this purpose.
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Possibly due to their way of life.
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Unlike other cats, lions lead prides, a community consisting of a male, several females, and cubs of different ages. Pride members encounter each other constantly, not only during the breeding season. In such a way of life, signals regulating aggression are useful, including the ability to determine the sex of a tribe mate from afar.
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The mane, a distinctive feature of the adult male, serves this purpose.