WHY shouldn't we use the phone before going to bed?
Experts suggest that the main reason why it's hard to fall asleep after using your phone is that you don't have time to settle down. Lots of people play right in bed, some read the news, others flip through their social media feeds. All of these activities can excite you both mentally and physically.
Curiously, many of these actions cause your body to produce cortisol, the stress hormone. Such as if you've read the disturbing news, or if an online game has a monster chasing you. Cortisol doesn't let you sleep, on the contrary, it wakes you up, since you can't sleep under conditions of "anxiety and danger"!
Experts suggest that the main reason why it's hard to fall asleep after using your phone is that you don't have time to settle down. Lots of people play right in bed, some read the news, others flip through their social media feeds. All of these activities can excite you both mentally and physically.
Curiously, many of these actions cause your body to produce cortisol, the stress hormone. Such as if you've read the disturbing news, or if an online game has a monster chasing you. Cortisol doesn't let you sleep, on the contrary, it wakes you up, since you can't sleep under conditions of "anxiety and danger"!
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WHY do insects survive falls from great heights?
It turns out that it's about the shape of the bugs body and air resistance.
Under the first factor is the surface area of the insect's body. As you know, with increasing area, the frontal resistance of the body to the flow of air also grows. When the body falls, gravity acts on it, which is determined by the mass and acceleration of free fall.
The mass of insects, as a rule, is several tens of grams, so the gravity acting on their body is quite small. In this case, the frontal resistance to air flow is significant, due to which the resultant force, which determines the acceleration with which it moves, is relatively small.
It turns out that it's about the shape of the bugs body and air resistance.
Under the first factor is the surface area of the insect's body. As you know, with increasing area, the frontal resistance of the body to the flow of air also grows. When the body falls, gravity acts on it, which is determined by the mass and acceleration of free fall.
The mass of insects, as a rule, is several tens of grams, so the gravity acting on their body is quite small. In this case, the frontal resistance to air flow is significant, due to which the resultant force, which determines the acceleration with which it moves, is relatively small.
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WHY is the gas tank on the left side of some cars and the right side of others?
In European automakers, the gas tank is mostly located on the right side of left-hand drive cars. So the driver doesn't have to worry about the door hitting the gas tank, and it takes longer for fuel vapors to enter the cabin through the open driver's door.
Some Asian brands ship left-handed cars to foreign markets with left-handed throats. This is most likely due to the fact that an additional change in design will increase the cost of manufacturing the car, and the position of the neck, by and large, is not that big of a deal.
In European automakers, the gas tank is mostly located on the right side of left-hand drive cars. So the driver doesn't have to worry about the door hitting the gas tank, and it takes longer for fuel vapors to enter the cabin through the open driver's door.
Some Asian brands ship left-handed cars to foreign markets with left-handed throats. This is most likely due to the fact that an additional change in design will increase the cost of manufacturing the car, and the position of the neck, by and large, is not that big of a deal.
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WHY is walking in a coniferous forest healthy?
Scientists have proven that the air in a coniferous forest is practically sterile (no more than 200-300 harmful bacteria per cubic meter). A walk in the coniferous forest relieves stress and nervous tension, tones the body by activating gas exchange in the lungs and, consequently, improves breathing.
Such walks are vital for heavy smokers and office workers.
Scientists have proven that the air in a coniferous forest is practically sterile (no more than 200-300 harmful bacteria per cubic meter). A walk in the coniferous forest relieves stress and nervous tension, tones the body by activating gas exchange in the lungs and, consequently, improves breathing.
Such walks are vital for heavy smokers and office workers.
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WHY do ancient sculptures appear with "empty" eyes?
Previously, it was thought that ancient sculpture had come down to us in its original form. Yet later it was revealed that ancient Greek sculptors did not leave the eyes of their statues lifeless and the marble creations themselves were not white and cold, they were painted.
Acropolis bark (statues of girls) were found in the 19th century, preserving the paint: dark hair, red lips and multi-colored eyes.
Later traces of the coloring were found on other ancient sculptures as well. A few years ago German scholars attempted to reconstruct the original appearance of 12 ancient marble sculptures. The result is an exhibition with the cleverly titled "The motley gods". The bronze Greek sculptures had not painted, but inlaid eyes.
Previously, it was thought that ancient sculpture had come down to us in its original form. Yet later it was revealed that ancient Greek sculptors did not leave the eyes of their statues lifeless and the marble creations themselves were not white and cold, they were painted.
Acropolis bark (statues of girls) were found in the 19th century, preserving the paint: dark hair, red lips and multi-colored eyes.
Later traces of the coloring were found on other ancient sculptures as well. A few years ago German scholars attempted to reconstruct the original appearance of 12 ancient marble sculptures. The result is an exhibition with the cleverly titled "The motley gods". The bronze Greek sculptures had not painted, but inlaid eyes.
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WHY do the batteries in a flashlight run out on their own?
The same law applies everywhere, that the accumulated charge cannot last forever, and as a consequence, batteries and accumulators have an expiration date not only when they are lying on the shelf in the store, but also when they are inserted into some device which may be a consumer.
Frequently, the current consumption is so low that the components of the circuitry warm up only slightly. However, this consumes the battery, and as a consequence, one gets a dead battery sooner than one expects.
Conductors run from the contacts of the battery to the flashlight switch. Even if the circuit is open, the distance between the switch contacts is about a millimeter. A weak current can flow through this gap and discharge the batteries.
The same law applies everywhere, that the accumulated charge cannot last forever, and as a consequence, batteries and accumulators have an expiration date not only when they are lying on the shelf in the store, but also when they are inserted into some device which may be a consumer.
Frequently, the current consumption is so low that the components of the circuitry warm up only slightly. However, this consumes the battery, and as a consequence, one gets a dead battery sooner than one expects.
Conductors run from the contacts of the battery to the flashlight switch. Even if the circuit is open, the distance between the switch contacts is about a millimeter. A weak current can flow through this gap and discharge the batteries.
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WHY can sound be heard at a great distance on a rainy day?
There is a state of sound refraction caused by temperature inversion. When the ground and air near the ground is colder than the air above, sound travels faster at altitude than it does over the ground.
A sound wave, angled upward relative to the earth's surface, is gradually deflected backward so that it hits the ground a mile or more from where it began. On a rainy day, rain cools the ground, but the air above the clouds remains warm.
The temperature inversion effect was the bane of outdoor rock concerts. They needed a roof to stop the celestial wave. No amount of walls would help.
There is a state of sound refraction caused by temperature inversion. When the ground and air near the ground is colder than the air above, sound travels faster at altitude than it does over the ground.
A sound wave, angled upward relative to the earth's surface, is gradually deflected backward so that it hits the ground a mile or more from where it began. On a rainy day, rain cools the ground, but the air above the clouds remains warm.
The temperature inversion effect was the bane of outdoor rock concerts. They needed a roof to stop the celestial wave. No amount of walls would help.
WHY does snow glisten in the sun?
Snowflakes are ice crystals with many flat facets which act as microscopic mirrors. Those that reflect sunlight directly into the eye give a bright point. And if you move a little bit, the rays of other snowflakes hit your eye.
Therefore, when you keep moving, the shiny dots alternate with each other. Freshly fallen snow is shinier than lain snow, as flat edges of snowflakes are scratched, broken, and melted with time.
Snowflakes are ice crystals with many flat facets which act as microscopic mirrors. Those that reflect sunlight directly into the eye give a bright point. And if you move a little bit, the rays of other snowflakes hit your eye.
Therefore, when you keep moving, the shiny dots alternate with each other. Freshly fallen snow is shinier than lain snow, as flat edges of snowflakes are scratched, broken, and melted with time.
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WHY can sound be heard at a great distance on a rainy day?
There is a state of sound refraction caused by temperature inversion. When the ground and air near the ground is colder than the air above, sound travels faster at altitude than it does over the ground.
A sound wave, angled upward relative to the earth's surface, is gradually deflected backward so that it hits the ground a mile or more from where it began. On a rainy day, rain cools the ground, but the air above the clouds remains warm.
The temperature inversion effect was the bane of outdoor rock concerts. They needed a roof to stop the celestial wave. No amount of walls would help.
There is a state of sound refraction caused by temperature inversion. When the ground and air near the ground is colder than the air above, sound travels faster at altitude than it does over the ground.
A sound wave, angled upward relative to the earth's surface, is gradually deflected backward so that it hits the ground a mile or more from where it began. On a rainy day, rain cools the ground, but the air above the clouds remains warm.
The temperature inversion effect was the bane of outdoor rock concerts. They needed a roof to stop the celestial wave. No amount of walls would help.
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WHY shouldn't trash be burned in volcanoes?
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The reason is that dumping trash into the lava lakes of volcanoes can trigger an eruption. Lava lakes are volatile, so if you pierce their surfaces with something cold, like garbage, you cause a chain reaction of explosions with compressed and acidic vapor.
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Also, all the moisture accumulated in the debris instantly evaporates, the steam expands, comes out, rips the debris and creates bursts of molten rock.
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The reason is that dumping trash into the lava lakes of volcanoes can trigger an eruption. Lava lakes are volatile, so if you pierce their surfaces with something cold, like garbage, you cause a chain reaction of explosions with compressed and acidic vapor.
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Also, all the moisture accumulated in the debris instantly evaporates, the steam expands, comes out, rips the debris and creates bursts of molten rock.
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WHY does tea leave a stain on the cup?
Tea leaves contain phenolic compounds, tannins, giving the strong drink an astringent taste, and alkaloids, primarily thein. When the tea is brewed, these come out in solution and react with each other. As it cools, the solubility of this compound drops and it is partially released on the surface of the liquid as a film.
When the cup is tilted and sipped from it, this film ends up on the walls and dries out. Plaque is not harmful to health, but its regular occurrence is a reason to wonder if the tea you drink is too strong.
Tea leaves contain phenolic compounds, tannins, giving the strong drink an astringent taste, and alkaloids, primarily thein. When the tea is brewed, these come out in solution and react with each other. As it cools, the solubility of this compound drops and it is partially released on the surface of the liquid as a film.
When the cup is tilted and sipped from it, this film ends up on the walls and dries out. Plaque is not harmful to health, but its regular occurrence is a reason to wonder if the tea you drink is too strong.
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WHY are nuclear powered spaceships not made?
Nuclear fuel contains hundreds of thousands of times more energy than chemical fuel, but it is inefficient to heat the working body with it. The limited thermal stability of the materials makes it impractical to raise the temperature higher than in chemical engines. Thus, the jet velocity cannot be boosted either.
Another thing is to use non-thermal acceleration of the working body, as in ion engines, where ions dispersed by the electric field fly an order of magnitude faster than the thermal exhaust. However, the power of such engines is still small, and they have enough energy from solar panels.
Considering the high cost and hazards of nuclear power sources, they serve so far only for power and heating of vehicles exploring the outer part of the solar system.
Nuclear fuel contains hundreds of thousands of times more energy than chemical fuel, but it is inefficient to heat the working body with it. The limited thermal stability of the materials makes it impractical to raise the temperature higher than in chemical engines. Thus, the jet velocity cannot be boosted either.
Another thing is to use non-thermal acceleration of the working body, as in ion engines, where ions dispersed by the electric field fly an order of magnitude faster than the thermal exhaust. However, the power of such engines is still small, and they have enough energy from solar panels.
Considering the high cost and hazards of nuclear power sources, they serve so far only for power and heating of vehicles exploring the outer part of the solar system.
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WHY is the prison uniform striped?
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The striped uniform allowed a fugitive to be found quickly. It did not blend in with the surroundings and helped search for the prisoner. Also, such a color of clothing immediately singled out a fugitive from the crowd of people. The uniforms of modern colors - red, orange and yellow - also do an excellent job of these functions.
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Another purpose of striped uniforms is uniformity. In prisons absolutely all prisoners wore robes with black and white stripes. Such uniformity and identical clothing had a psychological effect, reducing the inmate's initiative.
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The striped uniform allowed a fugitive to be found quickly. It did not blend in with the surroundings and helped search for the prisoner. Also, such a color of clothing immediately singled out a fugitive from the crowd of people. The uniforms of modern colors - red, orange and yellow - also do an excellent job of these functions.
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Another purpose of striped uniforms is uniformity. In prisons absolutely all prisoners wore robes with black and white stripes. Such uniformity and identical clothing had a psychological effect, reducing the inmate's initiative.
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WHY are sewer manholes round?
The greater ratio of the cross-sectional area of the round manhole hole to the length of the circumference of its body than in a square or rectangular. As a result, you can reduce the cost of production by reducing the consumption of materials without compromising performance.
Round shape allows you to ensure that the cover itself will not fall through the hatch during its assembly or disassembly. In principle, this problem can be solved by using a hatch, repeating the shape of any curve of constant width, but the circle of all possible such figures is the most technologically advanced.
The greater ratio of the cross-sectional area of the round manhole hole to the length of the circumference of its body than in a square or rectangular. As a result, you can reduce the cost of production by reducing the consumption of materials without compromising performance.
Round shape allows you to ensure that the cover itself will not fall through the hatch during its assembly or disassembly. In principle, this problem can be solved by using a hatch, repeating the shape of any curve of constant width, but the circle of all possible such figures is the most technologically advanced.
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WHY do crab sticks have nothing to do with crabs?
The recipe for this snack originated in 1973 in Japan and hasn't changed much since then. The need for crab sticks was born out of the fact that at some point the number of crabs, a terribly essential attribute of Japanese cuisine, began to dwindle rapidly.
Ingenious Japanese came up with a replacement. They took as the basis a dish called "Kamaboko" - for its cooking cod fish fillets are used - it is pure white color. These fish fillets are crushed, then ground, and in this way they obtain surimi meat. Potatoes, soy sauce, starch, egg powder and flavorings are added. Then the resulting mass is made into oblong sticks and evaporated to get rid of the fat.
Completing the process is the application of food coloring red or orange.
The recipe for this snack originated in 1973 in Japan and hasn't changed much since then. The need for crab sticks was born out of the fact that at some point the number of crabs, a terribly essential attribute of Japanese cuisine, began to dwindle rapidly.
Ingenious Japanese came up with a replacement. They took as the basis a dish called "Kamaboko" - for its cooking cod fish fillets are used - it is pure white color. These fish fillets are crushed, then ground, and in this way they obtain surimi meat. Potatoes, soy sauce, starch, egg powder and flavorings are added. Then the resulting mass is made into oblong sticks and evaporated to get rid of the fat.
Completing the process is the application of food coloring red or orange.
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WHY is it so hard to win from a toy machine?
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Anyone who has tried to get a toy out of a grabber knows that it's much harder than it appears. Vox explains that it's not the skill of the players, but the machines themselves, which are set up to cheat.
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The edition has studied the manual to one of these machines and found that the "paw" of the manipulator is programmed to only sometimes squeeze the toys with full force. The owner can set the probability of the paw squeezing the toy hard enough and when it only grabs it a little.
The machine also has a "reset" parameter - the owner can set how frequently the "paw" will drop a toy that has already been grabbed.
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Anyone who has tried to get a toy out of a grabber knows that it's much harder than it appears. Vox explains that it's not the skill of the players, but the machines themselves, which are set up to cheat.
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The edition has studied the manual to one of these machines and found that the "paw" of the manipulator is programmed to only sometimes squeeze the toys with full force. The owner can set the probability of the paw squeezing the toy hard enough and when it only grabs it a little.
The machine also has a "reset" parameter - the owner can set how frequently the "paw" will drop a toy that has already been grabbed.
WHY do Japan lack old houses?
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In this country, it is believed that a house loses value from the first day it is built. In 10 years, the value of a house is halved. After 25 years it is considered far too old to live in and worthless. After that, it is demolished and a new house is built in its place. Even landmarks and major shrines are regularly rebuilt.
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So Japanese people have no examples of old architecture; all the houses are modern. This has a negative effect on the appearance of Japanese cities: the architecture in them is quite monotonous and rarely decorated in any way.
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In this country, it is believed that a house loses value from the first day it is built. In 10 years, the value of a house is halved. After 25 years it is considered far too old to live in and worthless. After that, it is demolished and a new house is built in its place. Even landmarks and major shrines are regularly rebuilt.
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So Japanese people have no examples of old architecture; all the houses are modern. This has a negative effect on the appearance of Japanese cities: the architecture in them is quite monotonous and rarely decorated in any way.
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WHY does the Guinness World Records no longer list the world's fattest animals?
The Guinness World Records contains a myriad of incredible entries: the world's tallest man, the world's shortest rivers, the heaviest tumor... However, several things cannot appear in the book.
Like, no more records related to diet and alcohol consumption are accepted: perhaps because the "Book" doesn't want to get sued for doing something stupid and thereby harming itself.
The Guinness World Records once listed the world's fattest fish, and after that, some fish owners started giving their pets too much food in an attempt to break the record - exactly the kind of behavior the Guinness World Records managers would like to avoid.
The Guinness World Records contains a myriad of incredible entries: the world's tallest man, the world's shortest rivers, the heaviest tumor... However, several things cannot appear in the book.
Like, no more records related to diet and alcohol consumption are accepted: perhaps because the "Book" doesn't want to get sued for doing something stupid and thereby harming itself.
The Guinness World Records once listed the world's fattest fish, and after that, some fish owners started giving their pets too much food in an attempt to break the record - exactly the kind of behavior the Guinness World Records managers would like to avoid.
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WHY do many crabs appear to have one claw larger than the other?
The larger claw, with its powerful teeth, is designed for crushing shells of mollusks and shells of sea urchins, the prey of the crabs. The second claw is fitted with an edge for cutting soft tissues or bristles serving as a filtration apparatus.
In males of half land beckoning crabs, one huge claw has turned into a "tournament weapon": it is used for mating demonstrations and in fights between males.
The larger claw, with its powerful teeth, is designed for crushing shells of mollusks and shells of sea urchins, the prey of the crabs. The second claw is fitted with an edge for cutting soft tissues or bristles serving as a filtration apparatus.
In males of half land beckoning crabs, one huge claw has turned into a "tournament weapon": it is used for mating demonstrations and in fights between males.
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WHY do cooking smells spread throughout the house?
Due to the heated air. All odors sooner or later spread throughout the entire space available to them. However, cooking smells tend to have an amplified effect. The thing is, the stove heats the air above it as it cooks.
By rising, it forms currents carrying odorous substances from cooking and roasting foods around the room.
Due to the heated air. All odors sooner or later spread throughout the entire space available to them. However, cooking smells tend to have an amplified effect. The thing is, the stove heats the air above it as it cooks.
By rising, it forms currents carrying odorous substances from cooking and roasting foods around the room.
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WHY does a fly hit the glass when a section of window is open nearby?
A fly exhibits mosaic vision, and its eyes consist of a large number of facets. A fly may have as many as 8,000 of them. Each facet can be viewed as a tiny eyeball. It consists of a lens and a crystal.
The point is that the fly is unable to discern whether or not there is a glass in front of it. It is due to low visual acuity. Therefore, the insect simply tries to fly forward in the hope of luck. And a side-by-side open window doesn't make it any easier for it to enter the street, as the fly has no idea whether it can fly out there without any problems.
In contrast, if you take the insect in your hand and let it go in front of the open bid, it will fly out immediately, without hesitation.
A fly exhibits mosaic vision, and its eyes consist of a large number of facets. A fly may have as many as 8,000 of them. Each facet can be viewed as a tiny eyeball. It consists of a lens and a crystal.
The point is that the fly is unable to discern whether or not there is a glass in front of it. It is due to low visual acuity. Therefore, the insect simply tries to fly forward in the hope of luck. And a side-by-side open window doesn't make it any easier for it to enter the street, as the fly has no idea whether it can fly out there without any problems.
In contrast, if you take the insect in your hand and let it go in front of the open bid, it will fly out immediately, without hesitation.
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