Children's questions that even adults do not know the answer to. And we know
Countless questions have plagued us since childhood. Why can't our hair have a natural blue color or why do cats' eyes glow so devilishly in the dark? Many of the things that interest us are still shrouded in mystery, but by no means all.
The editors found answers to questions that worried everyone at least once in their lives.
1. Why do we like to stretch after sleep
Muscles after a long period of immobility need a soft but strong tension, which prepares them for a mode of activity.
The easiest way - sipping - is rewarded with pleasant sensations, because this movement is necessary for the body, and all that our body needs usually excites pleasure centers in the brain.
2. Why insects fly into the light
The flight of insects to the light is a paradoxical phenomenon: having noticed a source of light, the insect tends to it, and approaching, loses orientation.
Moreover, these creatures need light, because without it they are unable to distinguish surrounding objects, therefore, as a rule, they do not fly in the dark.
Science has not yet been able to answer this question with 100% accuracy.
3. Why are 365 days a year
In fact, the number of days in a year is approximately 365,256 days. To get this amount, you need to divide the time of the Earth's rotation around the Sun by the time of rotation around its own axis.
By the way, scientists believe that the duration of the calendar year is reduced: the study of fossil corals allowed them to assume that 380 million years ago in the year there were about 400 days.
4. Why do ducklings walk in single file
Ducks often build nests far from the water, and to get to the reservoir, they need to travel a long distance.
If the duckling is lost along the way, it is simply doomed to death.
Therefore, birds are forced to follow one another in the wake: only this can guarantee that the entire brood will reach the place intact.
The “leader” is chosen very simply: when the chicks hatch, they begin the so-called sensitive period.
At this time, the duckling remembers his mother or the one who is next to him (therefore, ducks can walk, for example, for a person).
5. Why hair can not be green or blue
Hair color depends on the ratio of two "dyes" based on the natural pigment melanin - eumelanin (black or brown) and pheomelanin (yellow or red).
The final color depends on their ratio.
Blue, like green, cannot come out of these shades.
6. Why are the pigeon chicks not visible on the street
Pigeon chicks spend a long time in the nests and leave them as adults.
The look of a simple person is unable to distinguish between an adult and a young individual, so all the pigeons seem to be approximately the same in age.
Nests are usually located in places inaccessible to humans: in attics, cornices, in secluded corners on the roofs.
7. Why trees do not freeze in winter
Frosts are best tolerated by those trees that accumulate enough sugars in their tissues: dissolved in cell sap, they protect cells from water loss and, as a result, from coagulation of protein.
If there is not enough sugar in the tissues, the cells will begin to freeze and crystallize. The protein will curl in this case, and the tree will die.
8. Why does a hammerhead shark have such a shape?
The hammerhead shark feeds on stingrays that have poisonous spikes on their tails.
They are not afraid of injections, since sharks have innate immunity to neurotoxins, but to lose their eyes for this predator would mean certain death.
Over time, evolution has adjusted the position of the organs of vision so that the spikes of the rays can not reach them.
In addition, such an arrangement of the eyes allows predators to notice more dangerous individuals in advance and thereby remain alive.
9. Why does a person tremble if he is cold
One of the most amazing functions of self-preservation, which are actively used by the human body, is to increase muscle activity.
When we freeze, our body tries to warm itself on its own due to frequent muscle contraction, and this is exactly what we used to call trembling.
10. Why do cats glow in the dark
In many animals, including cats, the eyes are able to capture and make the most of even the weakest light radiation, which is reflected from the back of the eyeballs.
Outwardly, it looks like a devilish glow, but in reality it only allows animals to see better in the dark.
11. Why do aristocrats have “blue blood”
For centuries, aristocrats have married close relatives, which was fraught with the development of the so-called incest diseases, such as blood cancer.
And in this case, the expression "blue blood" meant that this blood is not bright red, but reddish, devoid of a healthy color.
According to another theory, aristocrats had more transparent skin through which blue veins could be seen, so it was customary for the common people to believe that the color of their blood was blue. Pallor, in turn, appeared due to a lack of tan and a lack of vitamin D.
12. Why does a spider not stick to its web
There are two types of threads in the web - smooth radial and adhesive concentric.
A spider always moves only along radial threads, therefore it does not stick.
13. Why is the sky blue
When the sun's rays reach the Earth’s atmosphere, they collide with air molecules and scatter.
At the same time, sunlight has a wide range of colors: red, orange, yellow, green, blue, purple.
It is blue that dissipates faster and more than anyone else, so we see the sky painted in this color.
Accordingly, at night the sky becomes dark, because the light from the Sun does not reach us, and therefore does not scatter.
14. Why are stars visible only at night
In fact, the stars shine both night and day.
Only in the daytime the sun's rays “block” their light, and at night, when they are not there, nothing prevents us from seeing the stars.
15. Why are the “buttocks” of cucumbers bitter
The "ancestors" of modern cucumber grew in the shade of tropical forests and were sweetish in taste.
In the northern latitudes, the cucumber, being in the bright sun, "protests" and produces the substance cucurbitacin, which makes it bitter.
In other words, the more sun, the more bitterness in the cucumber.
16. Why does a person have 5 fingers
It is believed that the five-fingered limb is the inheritance of the ancestors of all vertebrate creatures on the planet.
Reducing the number of fingers or even their complete loss was possible only in those species to whom fingers for some reason began to interfere, becoming "superfluous."
For example, this happened with horses: the middle finger turned into a hoof, and the rest were reduced, since they were an obstacle to the development of the hoof.