# Questions From Readers (Part 6)

How bees produce honey, why you can't yawn without opening your mouth, why some people have curly hair, while others have direct and other questions from our readers.

#### What criteria can be used to determine the volume of a person's brain during his lifetime, and is it possible?

Konstantin Voronov, Yekaterinburg

Despite the fact that in general the size of the skull, of course, determines the size of the brain placed in it, it will not be possible to accurately determine its volume only by external parameters, individual variations are too strong. Typically, the brain occupies 91-95% of the volume of the skull, although its size can vary quite widely, from less than 1000 to over 2000 cubic meters. cm.

If that's not enough for you, then put the fists of both hands together: each hemisphere is about 1.5 times the size of a fist - and together they will give an idea of ​​the full volume of your brain. You can also calculate the weight: in men, the brain is about 2% of the body weight, in women - 2.5%.

It is not superfluous to add that neither his abilities nor skills depend on the individual size of the human brain. The genius Dante was known for a surprisingly small head, and the owner of the largest brain known in medicine suffered from mental retardation.

#### Is it possible to see through a telescope a video of the movement of celestial bodies, such as stars and galaxies, or can astronomers receive only frozen pictures?

Irina K., Stavropol

It is impossible to "see" the movement of the stars directly. This parameter is measured by analyzing the spectrum of their radiation: it is known that the spectral peaks of helium correspond to certain wavelengths, and that they can shift in one direction or another depending on the speed of the source relative to us. By measuring spectral displacements with high precision, you can establish this speed - modern methods allow you to achieve accuracy of the order of centimeters per second.

In observational astronomy, there is even a separate direction - astrometry - which deals with the "cartography of the cosmos", establishing the exact positions and speeds of movement of celestial bodies, including stars.

#### How do bees produce honey?

Elena Proshkina, Karaganda

The main material for the "production" of honey in the hive is flower nectar, and its processing begins as soon as the bee collects it. The secret of the insect's internal glands breaks down the sucrose of the nectar to glucose and fructose, saturates it with viscous dextrins. This process continues after the honey is placed in the honeycomb container. At the same time, in the warm and dry atmosphere of the hive, excess moisture evaporates from it - in ten days it will be possible to use ready-made honey.

#### Why can't you yawn without opening your mouth?

Because yawning is a breathing act: a long deep breath and a quick exhalation. In this case, of course, it is required to open the pharynx, and sometimes the glottis, which creates a special sound that often accompanies a yawn. At the same time, it is convenient to open the mouth, but it is not necessary, by controlling the jaws and lips, you can refrain from this.

#### What does the symbol of a snake biting its tail mean, and what are the origins of this symbol?

Angelina Yudina, Lipetsk

The serpent biting its own tail - in Greek Ouroboros - is one of the most ancient and universal symbols in human culture. It is not possible to establish exactly its origin: their "uroboros" are found in ancient Egypt and China, India and Scandinavia.

Most often it is interpreted as a representation of eternity, the cyclical nature of time, the alternation of periods of creation and destruction, life and death.

#### What is the reason for the fact that some people have curly hair, while others have straight?

Igor Laptev, Moscow

This is due to a random combination of genes derived from ancestors that determine the shape of follicles - "pouches" under the surface of the skin, which contain hair follicles. From a round follicle, hair grows that is more round in cross section and straight. From the oval follicle, the hair is flattened, curly and sometimes even curly.

#### Why does a person hiccup and after what does it happen? I heard, for example, that this happens if you eat spicy sweet food

Hiccups are involuntary, repetitive, harsh breaths. Like any breath, they are formed by the work of the intercostal muscles and the diaphragm, which separates the lungs from the abdominal cavity. When, for some reason, the diaphragm begins to contract convulsively - this can be caused by cold, stretching of the stomach after a particularly plentiful meal, etc. - we begin to have episodic hiccups.

There are many popular ways to calm the diaphragm - from calm counting aloud to holding your breath - and many of them really work. In any case, deep calm breathing and a few sips of warm liquid will help.

#### Why are the organs in humans and higher animals usually paired: two arms, two legs, two eyes, etc.?

Camilla M., St. Petersburg

Such a pairing of organs and structures in biology is called bilateral symmetry: the two halves of many organisms located on the sides of the median axis are largely mirror images of each other. Bilateral symmetry is characteristic of animals, but not plants or fungi, and the more actively the animal moves, the brighter it appears. Therefore, it is believed that its appearance is associated precisely with movement: it inevitably leads to the appearance of the front and back, upper and lower, right and left sides of the body.

#### Is it true that cats only use meows to communicate with humans?

Sergey L., Novosibirsk

This is absolutely not so - which should be known to everyone who has ever heard the March fights of desperately screaming cats or the plaintive meow of a hungry cat. Hearing in cats is excellent, and the voice is for them the main means of communication with each other. They also have vocal data: they are able to communicate in the ultrasonic range that is elusive for our ear.

However, there is a special meow - what is called meow in English, but does not have a special name in Russian - which is demonstrated only by domestic adult cats, begging for food or other "bonuses" from the owners. It is believed that it is an example of infantilization: with such a meow, kittens turn to their mother, but if in the wild they soon lose this tone, living next to a person, they found benefit from it in adulthood.

#### Why does the vegetation on the islands often take on gigantic proportions relative to the same species on the continent?

Mikhail I., Voronezh

Some islands are isolated from the rest of the world by hundreds or even thousands of kilometers of sea water, which is an almost insurmountable obstacle for all land inhabitants. Once the ancestors of the inhabitants of the islands could have got here by accident, due to a different sea level or landscape of the coastline. Since then, they can live on their own for tens, or even hundreds of thousands of years.

However, variability and selection continue to operate in these isolated corners of nature, and native species continue to evolve in the local environment. As a result, they can acquire traits that noticeably distinguish them from their ancestors on the mainland - this can be giganticization, and dwarfism, and a variety of other "deviations".

#### What evidence of the written language of mankind is considered the most ancient at the moment?

Alexey Lukin, Rostov-on-Don

It is believed that originally our ancestors practiced writing numbers - more precisely, sticks - for keeping score. Symbols such as those sometimes scratched by prisoners to count the days have been found on rocks dating back 40,000 years ago.As for the writing of words, she was born in Mesopotamia around 3200 BC. and - independently of it - later, in about 600 BC, in Mesoamerica (some believe that the writing systems of Ancient Egypt and China also have an independent origin). The oldest known literary texts also belong to Mesopotamia - these are records of Sumerian epics, dated to about 2600 BC. And the first famous writer by name was a woman, Akkadian priestess of the Moon and princess En-henu-Ana, who signed her "Hymns to Inanna".