Why is the defibrillator roughed up before use?
The reason is to improve the conduction of electricity through the skin. Dry skin is a poor conductor of electricity, and the electrical impulse must be passed through the heart. Also, dry skin gets too hot to conduct electricity and can burn the patient's chest.
The defibrillator's working surfaces are lubricated with a special gel or moistened with water.
The reason is to improve the conduction of electricity through the skin. Dry skin is a poor conductor of electricity, and the electrical impulse must be passed through the heart. Also, dry skin gets too hot to conduct electricity and can burn the patient's chest.
The defibrillator's working surfaces are lubricated with a special gel or moistened with water.
Why do we cry from happiness?
Our autonomic nervous system consists of sympathetic and parasympathetic. One part is responsible for "fighting" and the other for "relaxing" respectively. It's the sympathetic nervous system that kicks in during stress, such as by increasing heart rate. And the parasympathetic system, with its calming function, is directly connected with the lacrimal glands.
When we experience intense happiness, our heart rate increases. And the emotion is so strong that our body cannot recognize it. So our rapid heartbeat activates the parasympathetic system, sending a signal to the lacrimal glands, and we start crying.
That is, the body simply can't tell the difference between a strong positive emotion and a negative one.
Our autonomic nervous system consists of sympathetic and parasympathetic. One part is responsible for "fighting" and the other for "relaxing" respectively. It's the sympathetic nervous system that kicks in during stress, such as by increasing heart rate. And the parasympathetic system, with its calming function, is directly connected with the lacrimal glands.
When we experience intense happiness, our heart rate increases. And the emotion is so strong that our body cannot recognize it. So our rapid heartbeat activates the parasympathetic system, sending a signal to the lacrimal glands, and we start crying.
That is, the body simply can't tell the difference between a strong positive emotion and a negative one.
Why do lightning bolts vary in color?
Cause of the air they pass through.
The channel of lightning heats up to 30,000 degrees Celsius during a flash. The air at that temperature has a bluish-purple glow to it. That's the color of lightning that occurs close to the observer. However, the air disperses the blue, cyan, and violet colors more strongly, so the lightning turns white and then yellow as you move away. Fine dust raised in the atmosphere makes lightning appear yellow-orange, and water droplets in the path of light can make it turn red.
Cause of the air they pass through.
The channel of lightning heats up to 30,000 degrees Celsius during a flash. The air at that temperature has a bluish-purple glow to it. That's the color of lightning that occurs close to the observer. However, the air disperses the blue, cyan, and violet colors more strongly, so the lightning turns white and then yellow as you move away. Fine dust raised in the atmosphere makes lightning appear yellow-orange, and water droplets in the path of light can make it turn red.
Why do men grow beards and mustaches?
Hair follicles are sensitive to testosterone.
Human hair follicles (bulbs) are located all over the skin except on the palms of the hands and feet. Their function is strongly influenced by the male sex hormones - testosterone and its derivatives. At "male" (high) concentrations of these hormones, stiff hair grows out of the most sensitive follicles; at "female" (low) concentrations, soft fuzz grows out.
Hair follicles are sensitive to testosterone.
Human hair follicles (bulbs) are located all over the skin except on the palms of the hands and feet. Their function is strongly influenced by the male sex hormones - testosterone and its derivatives. At "male" (high) concentrations of these hormones, stiff hair grows out of the most sensitive follicles; at "female" (low) concentrations, soft fuzz grows out.
Why do rats and squirrels run in a wheel?
In nature, squirrels, hamsters, rats and other rodents move around large open spaces in search of food. Prolonged movement has become a need in itself for them. Putting a wheel in the cage allows it to be satisfied.
A similar behavior is observed in other animals whose way of life involves long journeys: many of us have probably seen a wolf trotting for hours in its cage.
In contrast, animals not prone to constant movements (e.g. rabbits) sit quietly in captivity as well.
In nature, squirrels, hamsters, rats and other rodents move around large open spaces in search of food. Prolonged movement has become a need in itself for them. Putting a wheel in the cage allows it to be satisfied.
A similar behavior is observed in other animals whose way of life involves long journeys: many of us have probably seen a wolf trotting for hours in its cage.
In contrast, animals not prone to constant movements (e.g. rabbits) sit quietly in captivity as well.
Why is business class located in the front of the plane if it's safer in the back?
The probability of surviving in the front of the plane is only a few percent higher than in the tail. Considering that plane crashes are extremely rare, that's akin to a statistical margin of error.
Nevertheless, engine noise is barely audible at the front of the plane, and the view from the porthole is not blocked by the wings.
The probability of surviving in the front of the plane is only a few percent higher than in the tail. Considering that plane crashes are extremely rare, that's akin to a statistical margin of error.
Nevertheless, engine noise is barely audible at the front of the plane, and the view from the porthole is not blocked by the wings.
Why is a light with a higher color temperature cooler than that with a lower one, and vice versa?
Perhaps someone has noticed that the higher the color temperature in Kelvin, the cooler the light. So, a light bulb with a color temperature of 1800 K would have a light similar to candlelight. And at 5,000 K, it is white, similar to daylight.
That's due to the fact that the color temperature of the light is created correspondingly to the heating of the substance. So, if you heat metal to 1300 K (1027 ° C), it will emit a bright red glow. And the higher the temperature, the "whiter" the glow will be.
Perhaps someone has noticed that the higher the color temperature in Kelvin, the cooler the light. So, a light bulb with a color temperature of 1800 K would have a light similar to candlelight. And at 5,000 K, it is white, similar to daylight.
That's due to the fact that the color temperature of the light is created correspondingly to the heating of the substance. So, if you heat metal to 1300 K (1027 ° C), it will emit a bright red glow. And the higher the temperature, the "whiter" the glow will be.
Is it true that a piece of paper can only be folded seven times?
Yeah, if we're talking about an A4 sheet of office paper.
An A4 sheet of paper has an area of 600 cm² and a thickness of 0.01 cm. Each time it is folded, the thickness doubles and the area is halved, even a little more. With seven folds, the area and thickness will change about 128 times.
At the seventh stage, you will have to make a considerable effort to bend in half a stack almost a centimeter thick and measuring 2 × 4 cm. In this case a 2x2x2 cm cube is formed and its further folding simply makes no sense.
Yeah, if we're talking about an A4 sheet of office paper.
An A4 sheet of paper has an area of 600 cm² and a thickness of 0.01 cm. Each time it is folded, the thickness doubles and the area is halved, even a little more. With seven folds, the area and thickness will change about 128 times.
At the seventh stage, you will have to make a considerable effort to bend in half a stack almost a centimeter thick and measuring 2 × 4 cm. In this case a 2x2x2 cm cube is formed and its further folding simply makes no sense.
How far does a laser pointer shine?
It all depends on the conditions.
Thus, in the daytime already after 10 meters its trace on the wall will not be visible. At night, the laser light can disappear on a wall at 80 to 100 meters.
However, if you shine it in the direction of a man, at night he could notice the light even from 10 km away.
And in space conditions, if no interference is present, the laser will be visible even through hundreds of thousands of kilometers.
It all depends on the conditions.
Thus, in the daytime already after 10 meters its trace on the wall will not be visible. At night, the laser light can disappear on a wall at 80 to 100 meters.
However, if you shine it in the direction of a man, at night he could notice the light even from 10 km away.
And in space conditions, if no interference is present, the laser will be visible even through hundreds of thousands of kilometers.
The python swallows the animal whole - surely the gastric juice can dissolve the skeleton?
Calcium phosphate and other salts form the mineral basis of the bones. They are insoluble in water, but dissolve in hydrochloric acid, which is present in a fairly high concentration in gastric juice.
However, in the bones the salts are bound to proteins and are not so easily attacked by acid. Yet, digestion in large snakes can last for weeks. Bones under the influence of acid are deprived of calcium, and the remaining protein "armature" is destroyed by digestive enzymes.
Calcium phosphate and other salts form the mineral basis of the bones. They are insoluble in water, but dissolve in hydrochloric acid, which is present in a fairly high concentration in gastric juice.
However, in the bones the salts are bound to proteins and are not so easily attacked by acid. Yet, digestion in large snakes can last for weeks. Bones under the influence of acid are deprived of calcium, and the remaining protein "armature" is destroyed by digestive enzymes.
Which star is the largest one found?
Betelgeuse is a red supergiant.
One of the largest stars known to astronomers: according to various estimates, if placed in the place of the sun, it would reach as far as Mars and possibly Jupiter.
Betelgeuse is less dense than the sun. This giant is exceptionally "loose," only 13 to 17 times heavier than the Sun, so its brightness drops quite smoothly toward the edges, making it hard to accurately estimate its size.
Why is it the largest? Betelgeuse is constantly shrinking: over the past couple of decades, the star's diameter has shrunk by almost 20 percent.
Betelgeuse is a red supergiant.
One of the largest stars known to astronomers: according to various estimates, if placed in the place of the sun, it would reach as far as Mars and possibly Jupiter.
Betelgeuse is less dense than the sun. This giant is exceptionally "loose," only 13 to 17 times heavier than the Sun, so its brightness drops quite smoothly toward the edges, making it hard to accurately estimate its size.
Why is it the largest? Betelgeuse is constantly shrinking: over the past couple of decades, the star's diameter has shrunk by almost 20 percent.
How old is the oldest tree?
The oldest tree on Earth (a lodgepole pine in the White Mountains in California) had been growing for 1,000 years by the time the last mammoth died, although no one knows when it even died, but it sounds lovely.
It grows in the White Mountains, California. Its age is 5067 years.
The oldest tree on Earth (a lodgepole pine in the White Mountains in California) had been growing for 1,000 years by the time the last mammoth died, although no one knows when it even died, but it sounds lovely.
It grows in the White Mountains, California. Its age is 5067 years.
Why is the inscription on the ambulance backwards?
If these words were written as ordinary, they would become unreadable in mirrors, so they are initially applied mirrored.
When driving, with an ambulance behind you, the inscription on the hood will no longer be reversed for you, but mirrored in your rearview mirror.
If these words were written as ordinary, they would become unreadable in mirrors, so they are initially applied mirrored.
When driving, with an ambulance behind you, the inscription on the hood will no longer be reversed for you, but mirrored in your rearview mirror.
Why are there so many cats in Turkey?
Street cats had a longstanding place in the ecosystem of Turkish port cities, where rodents have always been plentiful.
In the 8th century, tireless hunters saved Istanbul from the plague by exterminating the hordes of rats that swarmed the port docks and streets.
To this day, cats still control the population of mice and rats in the cities.
Street cats had a longstanding place in the ecosystem of Turkish port cities, where rodents have always been plentiful.
In the 8th century, tireless hunters saved Istanbul from the plague by exterminating the hordes of rats that swarmed the port docks and streets.
To this day, cats still control the population of mice and rats in the cities.
Why does every flower produce a unique scent?
It is the scent that attracts insects. And some of those insects have "their own" pollinators. Plants benefit by letting pollinators visit one of them and fly to another of their kind.
Then the flowers will get pollen of their own kind, not someone else's. To that end, flowers have features that help insects recognize them: shape, coloration, and, of course, smell. It can include aromatic oils that are attractive to the "right" pollinators.
It is the scent that attracts insects. And some of those insects have "their own" pollinators. Plants benefit by letting pollinators visit one of them and fly to another of their kind.
Then the flowers will get pollen of their own kind, not someone else's. To that end, flowers have features that help insects recognize them: shape, coloration, and, of course, smell. It can include aromatic oils that are attractive to the "right" pollinators.
Why do the instructions for medicines require you to drink water with your pills?
Other drinks may contain substances that react with the contents of the pill or affect its physiological effects.
Even carbonated water without syrup changes the effect of some medicines by speeding up their absorption.
Other drinks may contain substances that react with the contents of the pill or affect its physiological effects.
Even carbonated water without syrup changes the effect of some medicines by speeding up their absorption.
Why doesn't a person in a sauna or bathhouse start to boil?
Indeed, at temperatures above 40 degrees, proteins do break down and "boil". However, a living person responds adaptively by sweating.
When a person perspires, the sweat evaporates and takes up body heat. That's how our body cools down. Yet this adaptive mechanism is not infinite and sooner or later the tissues of the body will overheat.
Indeed, at temperatures above 40 degrees, proteins do break down and "boil". However, a living person responds adaptively by sweating.
When a person perspires, the sweat evaporates and takes up body heat. That's how our body cools down. Yet this adaptive mechanism is not infinite and sooner or later the tissues of the body will overheat.
What makes the peacock unique?
Peacocks are omnivores, eating anything their stomachs can digest: plants, fruits, cereals, insects, mammals and even small snakes.
Peacocks can "talk" to each other by means of infrasonic signals produced by the moving of their tail feathers. The human ear cannot perceive them.
Peacocks are omnivores, eating anything their stomachs can digest: plants, fruits, cereals, insects, mammals and even small snakes.
Peacocks can "talk" to each other by means of infrasonic signals produced by the moving of their tail feathers. The human ear cannot perceive them.
Why do crab sticks have nothing to do with crabs?
Ever heard that crab sticks have little to do with crabs? The recipe for this favorite salad ingredient of domestic housewives originated in 1973 in Japan and hasn't changed much since then. When crabs became scarce, the Japanese considered about how to replace one of the key ingredients in traditional dishes.
They based it on a dish called Kamaboko, using cod fish fillets. Cod fillets are crushed and then ground, resulting in surimi meat. Potatoes, soy sauce, starch, egg powder and flavorings are added. Then the mixture is made into oblong sticks and evaporated to get rid of the fat.
Ever heard that crab sticks have little to do with crabs? The recipe for this favorite salad ingredient of domestic housewives originated in 1973 in Japan and hasn't changed much since then. When crabs became scarce, the Japanese considered about how to replace one of the key ingredients in traditional dishes.
They based it on a dish called Kamaboko, using cod fish fillets. Cod fillets are crushed and then ground, resulting in surimi meat. Potatoes, soy sauce, starch, egg powder and flavorings are added. Then the mixture is made into oblong sticks and evaporated to get rid of the fat.