WHY are planets called as planets while stars are stars?
First and most importantly, stars are capable of emitting light and heat on their own, unlike planets, which can only reflect light rays falling on them from other luminaries, being inherently dark bodies.
Stars show much higher surface temperatures than any of the currently known planets. Their average surface temperatures range from 2,000 to 40,000 degrees, not to mention the layers closer to the center of the cosmic body, where temperatures may even reach millions of degrees.
On the surfaces of absolutely all stars, nuclear or thermonuclear reactions are bound to occur, followed by explosions. In turn, these reactions are not observed on the surfaces of planets, well, only in exceptional cases, and then only on nuclear planets and only super-weak nuclear reactions.
First and most importantly, stars are capable of emitting light and heat on their own, unlike planets, which can only reflect light rays falling on them from other luminaries, being inherently dark bodies.
Stars show much higher surface temperatures than any of the currently known planets. Their average surface temperatures range from 2,000 to 40,000 degrees, not to mention the layers closer to the center of the cosmic body, where temperatures may even reach millions of degrees.
On the surfaces of absolutely all stars, nuclear or thermonuclear reactions are bound to occur, followed by explosions. In turn, these reactions are not observed on the surfaces of planets, well, only in exceptional cases, and then only on nuclear planets and only super-weak nuclear reactions.
WHY shouldn't you kill domestic spiders?
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We all have spiders in our homes and there is nothing we can do about it. This fact might be unpleasant or even phobic to some people, but domestic spiders are completely harmless to humans. For sure, they are efficient killers in relation to domestic insects.
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Spiders act quickly and stealthily. Basement spiders prevent entry of woodlice and other moisture-loving insects into apartments. Spiders hiding in air vents prey on midges and mosquitoes. And those that live under the ceiling rid us of greasy buzzing flies.
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Moreover, domestic spiders are not aggressive towards humans and try their best to avoid meetings with us. In contrast to annoying insects, spiders do not need anything from us: they are our little helpers, "orderlies" of our homes. So even if you catch a spider at home and want to get rid of it - do not kill it, and just let it out on the street. The spider will find a new home and benefit someone.
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We all have spiders in our homes and there is nothing we can do about it. This fact might be unpleasant or even phobic to some people, but domestic spiders are completely harmless to humans. For sure, they are efficient killers in relation to domestic insects.
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Spiders act quickly and stealthily. Basement spiders prevent entry of woodlice and other moisture-loving insects into apartments. Spiders hiding in air vents prey on midges and mosquitoes. And those that live under the ceiling rid us of greasy buzzing flies.
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Moreover, domestic spiders are not aggressive towards humans and try their best to avoid meetings with us. In contrast to annoying insects, spiders do not need anything from us: they are our little helpers, "orderlies" of our homes. So even if you catch a spider at home and want to get rid of it - do not kill it, and just let it out on the street. The spider will find a new home and benefit someone.
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WHY is a fir tree always green?
Scientists say that the needles are also a kind of "leaves". As you know, photosynthesis, that is, nutrition, takes place in the leaves. But the bigger the leaf, the more sunlight it needs and the longer this process takes. Accordingly, the smaller the leaf, the faster photosynthesis takes place.
Coniferous needles are very small in size. Therefore, they need less sunlight. They are rapidly photosynthesizing, which leads to the production of chlorophyll. And when there is chlorophyll, there is green!
Spruces have another secret to "evergreenness". Of course, a conifer cannot live their whole life with the same needles. In the spring of firs, pines and cedars cones appear, and needles slowly change, and in place of the old, dry, grow new - fresh ones. We never notice this change of needles, which is why it seems to us that the trees are always green.
Scientists say that the needles are also a kind of "leaves". As you know, photosynthesis, that is, nutrition, takes place in the leaves. But the bigger the leaf, the more sunlight it needs and the longer this process takes. Accordingly, the smaller the leaf, the faster photosynthesis takes place.
Coniferous needles are very small in size. Therefore, they need less sunlight. They are rapidly photosynthesizing, which leads to the production of chlorophyll. And when there is chlorophyll, there is green!
Spruces have another secret to "evergreenness". Of course, a conifer cannot live their whole life with the same needles. In the spring of firs, pines and cedars cones appear, and needles slowly change, and in place of the old, dry, grow new - fresh ones. We never notice this change of needles, which is why it seems to us that the trees are always green.
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WHY is hugging healthy?
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Hugging produces the hormone of happiness, oxytocin. It causes great effects on our body and mainly contributes to a good mood. In addition, oxytocin reduces stress.
That's because we feel a bond with another person and hence feel more confident in various everyday situations. It makes us less vulnerable to stress. Releasing oxytocin keeps us happy and relaxed.
It also helps us sleep better. A hug can make all anxiety disappear, make sleep easier and make sleep more restful. That's why it's worth a hug before bedtime.
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Hugging produces the hormone of happiness, oxytocin. It causes great effects on our body and mainly contributes to a good mood. In addition, oxytocin reduces stress.
That's because we feel a bond with another person and hence feel more confident in various everyday situations. It makes us less vulnerable to stress. Releasing oxytocin keeps us happy and relaxed.
It also helps us sleep better. A hug can make all anxiety disappear, make sleep easier and make sleep more restful. That's why it's worth a hug before bedtime.
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WHY does the heart symbol appear that way?
There are several versions of its origin
- According to legends, the shape of the symbol heart is nothing other than an ivy leaf. Greek amphorae often used the ivy symbol for decoration.
- A pair of swans sailing toward each other forms the shape of a heart at the moment they touch. Swans are a symbol of love, loyalty and devotion, as a formed couple stays together for life, which is extremely rare in the animal world.
- During Antiquity, the ancient Greeks and Romans associated female beauty mainly with the shapes of women's bodies from the back. That is, the symbol of the heart is nothing more than a projection of a woman's buttocks on paper.
There are several versions of its origin
- According to legends, the shape of the symbol heart is nothing other than an ivy leaf. Greek amphorae often used the ivy symbol for decoration.
- A pair of swans sailing toward each other forms the shape of a heart at the moment they touch. Swans are a symbol of love, loyalty and devotion, as a formed couple stays together for life, which is extremely rare in the animal world.
- During Antiquity, the ancient Greeks and Romans associated female beauty mainly with the shapes of women's bodies from the back. That is, the symbol of the heart is nothing more than a projection of a woman's buttocks on paper.
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WHY is it hot when you go to bed fully under a blanket, cold without a blanket, and just perfect when you stick your foot out?
In general, since the blood vessels on the foot are so close to the skin, and there is a large flow of blood to the foot itself, the foot becomes a wonderful heat exchanger (a kind of radiator).
Hence, sticking out the foot discharges excess heat into the atmosphere, which the blanket prevents from losing, and brings the body to the optimum temperature for us.
In general, since the blood vessels on the foot are so close to the skin, and there is a large flow of blood to the foot itself, the foot becomes a wonderful heat exchanger (a kind of radiator).
Hence, sticking out the foot discharges excess heat into the atmosphere, which the blanket prevents from losing, and brings the body to the optimum temperature for us.
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WHY did the old telephones carry letters?
The Americans, the first to encounter seven-digit numbers, found a solution to the problem of memorizing (at the time it seemed difficult to remember seven-digit numbers) by using mnemonic rules - the first three digits were replaced by letters that began with a word.
For technical reasons, no number in America began with one. For historical reasons, zero was always used to call the telephonist. Thus, any American number could begin with any digit except 1 and 0.
Mnemonic rules were used in London and Paris until the mid-60s. The Americans first used the BBB-CTsC (three letters - four digits) scheme. Agree, it is much easier to keep the number TREmont 3106 in your memory than the corresponding number 873-3106.
As new words beginning with the right three letters became scarce, in 1930 New York, and in 1947...48 the rest of the cities were converted to the BBB-CTC scheme.
The Americans, the first to encounter seven-digit numbers, found a solution to the problem of memorizing (at the time it seemed difficult to remember seven-digit numbers) by using mnemonic rules - the first three digits were replaced by letters that began with a word.
For technical reasons, no number in America began with one. For historical reasons, zero was always used to call the telephonist. Thus, any American number could begin with any digit except 1 and 0.
Mnemonic rules were used in London and Paris until the mid-60s. The Americans first used the BBB-CTsC (three letters - four digits) scheme. Agree, it is much easier to keep the number TREmont 3106 in your memory than the corresponding number 873-3106.
As new words beginning with the right three letters became scarce, in 1930 New York, and in 1947...48 the rest of the cities were converted to the BBB-CTC scheme.
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WHY is it better to bite your food in small pieces?
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If you can always take small bites out of your meals, you can prevent overeating and get rid of excess weight, since you will feel full quicker.
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When people eat large portions of food, they cannot adequately estimate how much they have eaten.
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If you can always take small bites out of your meals, you can prevent overeating and get rid of excess weight, since you will feel full quicker.
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When people eat large portions of food, they cannot adequately estimate how much they have eaten.
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WHY is blood type B-negative the rarest?
The fourth positive type is much more common. The fourth group in general is a mystery, because it came from the fusion of two very different types, A and B. It is a young group, and people with it have a flexible immune system.
This group is unique in that it emerged not because of the influence of the external environment, but as a result of mixed marriages. It is worth mentioning that this group is the most biologically complex.
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Antigens sometimes make it similar to the second, and sometimes even to the third. Occasionally, it also happens that this rare group is something like a combination of both of these groups.
Thus, the fourth blood group is thought to have appeared later than all the others, about a thousand years ago, as a result of the mixing of Mongoloid and Indo-European.
The fourth positive type is much more common. The fourth group in general is a mystery, because it came from the fusion of two very different types, A and B. It is a young group, and people with it have a flexible immune system.
This group is unique in that it emerged not because of the influence of the external environment, but as a result of mixed marriages. It is worth mentioning that this group is the most biologically complex.
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Antigens sometimes make it similar to the second, and sometimes even to the third. Occasionally, it also happens that this rare group is something like a combination of both of these groups.
Thus, the fourth blood group is thought to have appeared later than all the others, about a thousand years ago, as a result of the mixing of Mongoloid and Indo-European.
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WHY is there 12 months in a year?
Cause there are 12 new moons in the year. People used to count time using recurring natural phenomena. A year is the time from one flood to the other. Conversely, a month is the period from new moon to new moon, which is about 29.5 solar days.
➡ About 12 such intervals fit into a year, so 12 months were counted annually.
Cause there are 12 new moons in the year. People used to count time using recurring natural phenomena. A year is the time from one flood to the other. Conversely, a month is the period from new moon to new moon, which is about 29.5 solar days.
➡ About 12 such intervals fit into a year, so 12 months were counted annually.
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WHY do baby teeth fall out?
One important function of deciduous teeth is that they "point" to the molar teeth where they will erupt. If a baby tooth falls out prematurely, the permanent tooth "loses its bearings" and can grow crooked.
By the age of 6-7, these teeth will begin to erupt. This process is accompanied by the resorption of the roots of the baby teeth. This causes the baby teeth to loosen. When the shortened root can no longer hold the baby tooth in the hole, it falls out.
One important function of deciduous teeth is that they "point" to the molar teeth where they will erupt. If a baby tooth falls out prematurely, the permanent tooth "loses its bearings" and can grow crooked.
By the age of 6-7, these teeth will begin to erupt. This process is accompanied by the resorption of the roots of the baby teeth. This causes the baby teeth to loosen. When the shortened root can no longer hold the baby tooth in the hole, it falls out.
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WHY does Asians eat with chopsticks?
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Most likely, it was due to the rapid growth of the country's population: food was in short supply, so the Celestials cut it into small pieces to cook it faster and make it easier to divide among a large group.
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Small sliced food is nothing to cut with a knife, however, handy to take with chopsticks, which in addition are extremely easy to make and cheap, so the innovation quickly spread across the country.
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Most likely, it was due to the rapid growth of the country's population: food was in short supply, so the Celestials cut it into small pieces to cook it faster and make it easier to divide among a large group.
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Small sliced food is nothing to cut with a knife, however, handy to take with chopsticks, which in addition are extremely easy to make and cheap, so the innovation quickly spread across the country.
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WHY is it healthy to cry?
The truth is, crying is not only possible, but necessary. And there are plenty of various reasons for that:
✔️ Most people feel a little better and happier after crying. All accumulated emotions and tension are released.
✔️ Tears cleanse the body of harmful substances from stress. No coincidence, all these fluids have been created to get all the bad stuff out of us. Tears are part of the system. A vital and necessary part.
✔️ Cleaning the nose. Especially relevant when mucus has accumulated in the nose and is making it hard to breathe. No need for medicine when there are tears.
✔️ Interestingly, tears can even lower your blood pressure.
✔️ Cleaning the eyes themselves from bacteria and dust.
The truth is, crying is not only possible, but necessary. And there are plenty of various reasons for that:
✔️ Most people feel a little better and happier after crying. All accumulated emotions and tension are released.
✔️ Tears cleanse the body of harmful substances from stress. No coincidence, all these fluids have been created to get all the bad stuff out of us. Tears are part of the system. A vital and necessary part.
✔️ Cleaning the nose. Especially relevant when mucus has accumulated in the nose and is making it hard to breathe. No need for medicine when there are tears.
✔️ Interestingly, tears can even lower your blood pressure.
✔️ Cleaning the eyes themselves from bacteria and dust.
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WHY are people bad at keeping secrets?
In a social environment, owning secrets gives you an advantage over others.
As it turns out, people cannot handle secrets at all. Psychologist Anita Kelly conducted a survey, and 60% of those polled admitted they gave away secrets entrusted to them to their best friends.
Just tell a person that the information you give them is a secret, to increase the likelihood that they share it with others, since the "secrecy" implies its value in their eyes.
In a social environment, owning secrets gives you an advantage over others.
As it turns out, people cannot handle secrets at all. Psychologist Anita Kelly conducted a survey, and 60% of those polled admitted they gave away secrets entrusted to them to their best friends.
Just tell a person that the information you give them is a secret, to increase the likelihood that they share it with others, since the "secrecy" implies its value in their eyes.
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WHY do whales blow fountains of water into the air?
A whale has one or two nostrils, or blowholes, located on the upper surface of the head closer to the back (toothed whales have one blowhole, smooth whales have two). Whales can only breathe through their blowholes, which are directly connected to their lungs. Their mouth is only part of the digestive system.
The blowholes have valves that close when the whale dives to depth. A whale can dive into the ocean to a depth of 2 kilometers and stay underwater for more than an hour. When the whale returns to the surface, it releases a fountain, blowing warm, moist air from its lungs through the blowhole before taking another breath. Water that has accumulated at the top of the blowhole escapes with the air.
Fountains ejected by large whales can sometimes be seen several kilometers away. You can often tell the species of whale by the shape of the fountain.
A whale has one or two nostrils, or blowholes, located on the upper surface of the head closer to the back (toothed whales have one blowhole, smooth whales have two). Whales can only breathe through their blowholes, which are directly connected to their lungs. Their mouth is only part of the digestive system.
The blowholes have valves that close when the whale dives to depth. A whale can dive into the ocean to a depth of 2 kilometers and stay underwater for more than an hour. When the whale returns to the surface, it releases a fountain, blowing warm, moist air from its lungs through the blowhole before taking another breath. Water that has accumulated at the top of the blowhole escapes with the air.
Fountains ejected by large whales can sometimes be seen several kilometers away. You can often tell the species of whale by the shape of the fountain.
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WHY don't snakes blink?
Some people mistakenly answer this question: "Because snakes don't have eyelids". That's not true. Snakes do have eyelids. But they are transparent and fused together. The thin transparent skin that protects the eyes, when molting, comes off with the skin of the snake as a single mass. But if a snake's eyelids were ordinary, it would complicate the molting process considerably.
Thus, snakes sleep with their eyes open because they cannot close them due to their physiology.
When the molt is near, the film obscures the eyes and the vision is severely impaired, but after the skin slides off, it improves again.
Some people mistakenly answer this question: "Because snakes don't have eyelids". That's not true. Snakes do have eyelids. But they are transparent and fused together. The thin transparent skin that protects the eyes, when molting, comes off with the skin of the snake as a single mass. But if a snake's eyelids were ordinary, it would complicate the molting process considerably.
Thus, snakes sleep with their eyes open because they cannot close them due to their physiology.
When the molt is near, the film obscures the eyes and the vision is severely impaired, but after the skin slides off, it improves again.
WHY does coffee make us sleepy?
Coffee contains two natural organic substances, the alkaloids caffeine and theobromine, both of which have different effects on the central nervous system. First, after you drink a cup of coffee, caffeine begins to act, having a bright and invigorating effect on the body, expanding the blood vessels.
But just 20-25 minutes after the caffeine comes the theobromine, also in its own way useful alkaloid, which relaxes the body, has a positive effect on the cognitive abilities and even improves the mood. Only if your body isn't exhausted by endless sleepless nights and doesn't need a quality rest. Otherwise, you are very likely to want to sleep.
Some experts say that if exactly 20 minutes after a cup of coffee to drink a glass of water, you can neutralize this effect by restoring the water-salt balance.
Coffee contains two natural organic substances, the alkaloids caffeine and theobromine, both of which have different effects on the central nervous system. First, after you drink a cup of coffee, caffeine begins to act, having a bright and invigorating effect on the body, expanding the blood vessels.
But just 20-25 minutes after the caffeine comes the theobromine, also in its own way useful alkaloid, which relaxes the body, has a positive effect on the cognitive abilities and even improves the mood. Only if your body isn't exhausted by endless sleepless nights and doesn't need a quality rest. Otherwise, you are very likely to want to sleep.
Some experts say that if exactly 20 minutes after a cup of coffee to drink a glass of water, you can neutralize this effect by restoring the water-salt balance.
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WHY does a train back up before moving forward?
If the driver of a heavy freight train tries to move it sharply forward, the train may not move at all, because the total frictional force of the railroad tracks acting on the wheels of the cars will exceed the sliding force of the locomotive's driving wheels.
Frequently, the driver must first reverse in order to loosen the couplings. And only then drive forward, propelling the cars one by one.
If the driver of a heavy freight train tries to move it sharply forward, the train may not move at all, because the total frictional force of the railroad tracks acting on the wheels of the cars will exceed the sliding force of the locomotive's driving wheels.
Frequently, the driver must first reverse in order to loosen the couplings. And only then drive forward, propelling the cars one by one.
Why can't you create a folder named 'con' in Windows?
In Windows, you cannot normally create a folder named 'con'. Numerous web sites claim that it is the personal wish of Bill Gates, who was teased with this word as a child (which supposedly means "nerd").
In fact, it's much simpler than that. It turns out that when Bill was designing MS-DOS, he had prescribed folders in the file system that can only be created once and they are used for the needs of the system itself. So, besides the CON folder you can't write many other names like PRN, NUL, AUX, LPT0, LPT1, COM1, COM2 and so on.
In Windows, you cannot normally create a folder named 'con'. Numerous web sites claim that it is the personal wish of Bill Gates, who was teased with this word as a child (which supposedly means "nerd").
In fact, it's much simpler than that. It turns out that when Bill was designing MS-DOS, he had prescribed folders in the file system that can only be created once and they are used for the needs of the system itself. So, besides the CON folder you can't write many other names like PRN, NUL, AUX, LPT0, LPT1, COM1, COM2 and so on.
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