For the inhabitants of the Earth, the constant change of day and night is a common occurrence. All life on the planet is subject to the rhythmic alternation of dark and daylight hours. However, this does not happen on all planets. For example, on Venus, which rotates very slowly around its axis, the year lasts less than two Venusian days. Jupiter rotates on its axis in about five Earth hours, and Saturn in ten.

The Earth makes a full rotation around its axis in 23 hours 56 minutes 4.1 seconds, the day during this time is replaced by night - a sidereal day passes. A sidereal day is understood as the time of a complete revolution of our planet around an axis relative to the stars, considering them infinitely distant.

The alternation of day and night creates favorable conditions for all life on Earth. As you know, the Earth has the shape of a ball, and the axis of its rotation is constantly inclined to the plane of the orbit at an angle of 66 ° 33 "22". Because of this, the sun's rays illuminate different parts of the earth's surface differently, and therefore the length of day and night is different everywhere. It depends on geographic latitude and time of year.

Only twice a year - on the days of the spring and autumn equinoxes (March 20-21 and September 23 - approx.), The length of day and night is the same at all latitudes of the Earth and is equal to 12 hours. The sun at this time is at its zenith above the equator, and the terminator - the line separating light and shadow on the planet's surface - passes through the poles, coinciding with the direction of the meridians. The sun's rays fall on the equator these days at an angle of 90 °, and the Northern and Southern hemispheres are heated evenly.

On the days of the summer and winter solstices (June 22 and December 22 - approx. from the site), the planet has the longest night and the shortest day. For example, on June 22, the Sun is at its zenith over the Tropic of the North (23°07"N). In the Northern Hemisphere on this day at all latitudes, the day is longer than the night. North of the Arctic Circle (66°33"N. ) the polar day is established - the Sun does not set below the horizon for days. In the Arctic Circle, the polar day lasts a day, and at the poles - up to six months. The southern hemisphere on June 22 is less illuminated than the northern one. Here, at all latitudes, the day is shorter than the night, and the polar night sets in in the southern polar region.

The earth moves around the sun, but the tilt of the planet's axis of rotation remains constant. Gradually, the height of the Sun above the horizon in the Northern Hemisphere decreases, the days become shorter and the nights longer. Finally, September 23 comes - the day of the autumn equinox, when the length of day and night is equal at all latitudes. From this point on, the Sun begins to illuminate the Southern Hemisphere more. On December 22, on the day of the winter solstice, the hemispheres seem to change places. On this day in the Southern Hemisphere at all latitudes, the day is longer than the night, and there is a polar day beyond the Antarctic Circle. At the same time, polar night reigns in the northern polar regions.

To the south and north of the polar circles in both hemispheres, white nights come. At this time, evening twilight turns into morning, and darkness does not come. Beyond the Arctic Circle, white nights precede the polar day - note .. At different latitudes, white nights differ in duration: for example, in St. Petersburg they last from June 11 to July 2, and in Arkhangelsk - from May 13 to July 30.

The satellite of our planet, the Moon, rotates around its axis at such a speed that when moving around the Earth, it is constantly turned to it with one side. If the Earth moved around the Sun like the Moon and was constantly turned to it on one side, the natural conditions on the planet would change tremendously. One hemisphere of the Earth would be illuminated all year round, while the other would be constantly in the shade. The illuminated hemisphere would heat up to a temperature of more than 100 ° C, which means that all rivers, seas and oceans would evaporate. On the dark side of the planet, the temperature would be below -100 ° C, here all the water would turn into ice. Hurricanes, earthquakes and volcanic eruptions would rage on the border of light and shadow due to large temperature differences.

TOPIC MESSAGE

"The change of night and day"

pupils of the 4th "G" class of secondary school No. 24

Angelica

Angelica Gennadievna

Simferopol

2015

A day is a cycle of time during which the sun, rising from the east, passes through the sky and sets in the west, then, when night falls on our half of the earth, the sun passes a revolution from another part of the planet and rises again from the east.

A day is exactly 24 hours long. Each hour consists of 60 minutes. Every minute out of 60 seconds.

How does day and night change on earth?

As a result of its rotation around its axis, the Earth is turned to the Sun by one side or the other. Consequently, the sun's rays fall either on one or the other side of the earth's surface. On the side facing the Sun we have day, on the opposite side we have night. So there is a change of day and night.

Conventionally, the time of day is divided into several parts:

• Morning - begins with the dawn of the sky in its eastern part and the sunrise from behind the horizon.
• Day - the movement of the sun across the sky from east to west.
• Evening - sunset in the west of the sky and gradually fading colors of the sunset.
• Night - Night time. At this time, the sun passes on the other side of the globe relative to us.

Since the Earth consists of continents located on both sides of the globe, the time of day in each part of the Earth is different. So if it is still night in New York, then in London it is already morning, in Moscow it is midday, and in Petropavlovsk-Kamchatsky it is already evening.

Changing the time of day

A lot of photographers tried to capture the change of day and night. By taking many pictures in a row from one position, one could trace the smooth movement of the sun across the sky, see the movement of the stars, and get beautiful video clips of sunrise and sunset. Features of time-lapse photography is when the camera is mounted on a tripod in a stationary position for a long period of time takes a series of photographs at certain intervals.

If the duration of the day is constant, then the duration of the constituent parts of the time of day varies depending on the time of year. This is due to the tilt of the earth and the movement around the sun in an ellipsoidal trajectory. So in the summer daylight hours last longer than the night, and in winter, on the contrary, the night is longer than the day.

At the same time, in different parts of the globe, the length of day and night is different. For example, in the Crimea it gets dark quickly in the summer, the night is dark, and in St. Petersburg June is famous for "white nights", the sun does not set far below the horizon line and therefore the nights seem bright.

Different times of the day look and feel differently. This is also connected with the biological (internal) clock by which a person is used to living (day - wakefulness, night - sleep) and with a variety of color contrast, as well as with mood. In the morning, strength is added, the day passes in study, business, work, and in the evening fatigue, a gradual departure from the department, rest and sleep.

Twice a year, the Earth is in such a position relative to the Sun that its surface facing it is illuminated completely from the north to the south pole. Twice a year, the Earth is in such a position relative to the Sun that its surface facing it is illuminated completely from the north to the south pole. At this time, all over the globe, day equals night. These are the days of the spring (March 21) and autumn (September 23) equinoxes. This time on the entire globe, day is equal to night. These are the days of the spring (March 21) and autumn (September 23) equinoxes.

Humanity for a long time puzzled over how the change of day and night occurs. It is hard to believe, but a few centuries ago, no one living on earth could imagine exactly how this complex process works. So, in times of uncertainty, people simply figured out how the sun hides, depriving everyone and everything around of its cozy light, and from where a lonely moon comes out in its place. Today we will try to talk about the most interesting fairy tale explanations for the change of day and night, many of which are really hard to believe.

Hindu interpretation

The legend of the worshipers of the god Krishna says that from the very beginning there was always a bright day on earth and there was never darkness. The very first inhabitants on the planet were Yami and Yama, a brother and sister who loved each other very much. One day, Yami died and his sister was inconsolable. She wept continuously until Krishna took pity on her and created the night. God did this not by chance, but so that during oblivion, that is, sleep, Yama would let go of her grief and gradually come to her senses. By the way, in India they still remember this legend and tell it to their children to explain the natural phenomenon of the change of day and night in a fabulous form.

Interpretation of American Apaches

The ancient Indians of the Mayan tribe, distinguished by their clairvoyance and ability to predict the future, were sure that the sun swallowed some huge creature living beyond the mountains during the night. With the onset of early morning, this monster spits it out, and the world is again filled with light and warmth. By the way, this fabulous explanation of the change of night and day is very reminiscent of the story of the luminary, which was swallowed by the famous crocodile Korney Chukovsky.

Egyptian theory

The ancient Egyptians were considered one of the most developed civilizations on the planet, otherwise how to explain their truly divine buildings? So they, being pagans, believed that the wise Ra descends into the darkness at night and wins the right to a new day there every time. At the same time, he fights to the death with sinister monsters and monsters with his terrible sword.

Another fabulous explanation of the change of day and night refutes the presence of two luminaries in the system of the universe. It implies that only the sun lives in the sky, which during the daytime rides around the planet on white horses, and at night harnesses black horses to its triple. By the way, in many children's fairy tales of the world, a similar allegory is used.

Russian truth

In Russia, they adhered to the theory regarding family ties. No matter how strange it may sound, but our ancestors reduced the fabulous explanation of the change of day and night to family relationships between brother and sister, who were in a centuries-old quarrel with each other. They thought that the sister is the day and the personification of life, and the brother was considered the night and the product of death. None of them wanted to meet, so seeing from afar the outlines of a relative, the other immediately hurried to leave. In Russian folk tales and riddles, this fact is confirmed.

Perhaps these are all the most interesting fairy-tale explanations for the change of day and night, which they could only come up with in antiquity, because now everyone knows how their alternation takes place.

Outline of the lesson on the world around in accordance with the requirements of GEF Grade 2

Topic:"The change of night and day."
Target:
- explain the change of day and night with the rotation of the earth around its axis, the sequence of events during the day.
Equipment: Table "Solar system", 2 drawings
depicting day and night, tellurium, globe, dunno, plates -
yesterday, today, tomorrow, 24 hours a day.

1. Organization of children for work:
We continue to explore the world around us.
Today we will talk about an amazing phenomenon on our planet that you observe every day. More precisely, at the beginning of the day and at its end.
We will observe these phenomena on all planets of the solar system and even on the Moon.
DON'T KNOW
Our friend Dunno depicted this phenomenon in two drawings:

Who guessed what he was drawing?
Today we must find out what happens in our life and nature during the day, and what happens at night?
We must find out why there is a change of day and night?

Since in the lesson we will talk about many objects of nature and objects around us, we must REMEMBER with you! very important rules and laws of their life.
!Check of knowledge. Table "Solar system"

What celestial bodies are depicted on it? (sun, planets)
Who knows what the science of celestial or cosmic bodies is called? (astronomy)
What are scientists who study celestial bodies called? (astronomers)

Now I will find out if you know the names of all these bodies and objects.

Task from Lena and Misha:
Lena and Misha, who are fond of astronomy, sent me an envelope with the task by mail:
- With the help of what device does Lena study the bodies of the solar system? (telescope)

- What bodies are included in the solar system? (the sun, planets, these include stars and the moon)

QUIZ:
GUESS THE HEAVENLY BODY BY ITS DESCRIPTION!
I will read out a description of a celestial body, and you guys answer by raising your hand.
1. They themselves glow and illuminate the planets. They are very large celestial bodies, planets move around them. They have the shape of a ball. (Stars)

2. This is a star. It glows and illuminates the planets. (Sun)

3. They themselves do not glow, but are illuminated by the sun and another star. They are large and move
Around the stars and the sun. They have the shape of a ball. (Planets)

4. The planet is illuminated by the sun. When it's day on one side, it's night on the other. (Earth)

5. Satellite of the Earth moving around it. (Moon)

TRAIN

Now imagine a train. We got on the train and looked out the window.
What did we see?
That all objects around are moving. In fact, the train is moving. That's why it seems to us that houses, trees, fields, meadows, etc. are moving. This is an optical illusion.
PTOLEMEY

He developed his own system of the world, in the center of which he placed the Earth.
Around the motionless spherical Earth, according to Ptolemy, move: the Moon, the Sun and 5 planets, as well as the sphere of fixed stars.
He, like us sitting on the train, saw the Sun moving (it rises in the morning, sets in the evening), the Moon and stars move.
In fact, the Earth itself moves, along with the Moon, around the Sun.
Objects around our train move in the same way.
COPERNICUS

Nicolaus Copernicus created a correct picture of the world around us. He placed the Sun in the center, around which the Earth and other planets move.
Let's remember two celestial bodies:
SUN - illuminating our planet during the day
MOON - illuminating our planet at night

How are they similar? (illuminate the Earth)
- What light does the moon shine with? (reflected sunlight)
- What is the Sun? (a star that glows and illuminates the planets)
- What is the Moon? (It is a natural satellite of the Earth)
- Guys, tell me what I will list for you now: Ursa Major, Ursa Minor, Cancer, Cygnus ??? (these are constellations)

THE GLOBE

What shape does our planet Earth have?
- How does it spin? (around the sun)
- How else? (around its own axis)
You and I walk on the earth's surface, why don't we fall into outer space?
What force keeps us on the surface?
THIS IS THE POWER OF EARTH'S GRAVATION.
ISAAC NEWTON discovered the law of universal gravitation.

The earth attracts us, therefore we walk, move, do certain work.
If you do not get off the ground and fly into space. The force of gravity ceases to act and a state of weightlessness arises.
Astronauts experience weightlessness during several hours of flight.

They use special devices while in zero gravity. Light clothing, food in special tubes, all small items with laces.
SOLAR SYSTEM TABLE

Guys, what big body holds our planet close to it? (Sun)
- What force does not allow our planet to fly into outer space? (the force of solar attraction)
The rotation of our planet around the Sun leads to a change of day and night.

LEARNING NEW MATERIAL:
What do you know about these periods of the day?
-Our friend dunno again confused in the words-today, tomorrow, yesterday.
-What do they mean?
-What is the difference between day and night? -What colors can be used to depict them?
THE STORY BY TELURIUS

Our Earth, like all planets, revolves in outer space.
The Earth revolves not only around the Sun, but also around an imaginary axis.
The rays of the sun bring us warmth and light.
When the Earth turns to the Sun by the side where we live, it seems to us that
The sun rises in the sky, rises. The sun's rays illuminate our planet from one side and we have a DAY at this time. The Earth continues to rotate further and we see that the Sun passes through the sky and begins to descend, and then hides behind the horizon. It is the Earth that turns away from the sun's rays during its rotation. The sun goes down, it gets dark, it's NIGHT. And on the other side of the globe day.
It takes 24 hours, i.e. DAYS, for the Earth to complete a full rotation around its axis.
And 24 hours pass from one dawn to another.
FIXING:
- Show on the table how the Earth revolves around the Sun?
(counterclock-wise)
What other movement does she make?
(around its own axis)
- What is the time of complete rotation around an axis called?
(day)
- What are the days?
(24 hours)
- What does the proverb mean? "DAY AND NIGHT, DAY OFF."
(A day includes both day and night.)
What axis does the earth rotate around? Real or imagined?
How many revolutions does the earth make in a day?
(one)
- So why do we have a change of day and night on our planet?
Results:
- Guys, what new and interesting things did you learn today from our conversation?
- What is an Earth day? And what is this time-day???
HOMEWORK: November 17, 2016

Various ancient peoples, be it the Egyptians, Greeks or Romans, tried to explain all the phenomena occurring around them, so a fabulous explanation of the change of day and night has come down to our times. Legends of different nationalities are generally similar.

Change of day and night: a fabulous explanation

With the words "the sun has risen" or "the sun has set" we begin or end another day in life. Our ancestors endowed sunrises and sunsets with great power. These phenomena had a sacred meaning for our ancestors.

Indeed, during sunsets and dawns, various rituals and ceremonies, both church and magical, were performed. From here a fabulous explanation of the change of day and night “grew up”. Each user of social networks has a photo of sunset or dawn. Today, modern man does not understand these phenomena and does not know the sacred meaning.

ancient greek myth

The ancient Greeks have a fabulous explanation for the change of day and night. The titan Hyperion had three children: Selena, Eos and Helios. Shining with a cold light, Selene was the goddess of the moon. On her head was a sickle-moon. On the night road she rides in a chariot drawn by bulls. Selena leaves this road when her child stars fade and the marble columns turn pink.

Eos - the goddess of the morning dawn, announces the dawn of a new day. Following Eos, their brother Helios rushes from the east in a shining golden chariot. The Greeks revered him no less than the powerful and supreme Zeus. The rays of Helios penetrated into the most distant and dark corners through black clouds. Their warm light awakened all life. Thanks to the rays, trees and fruits grew. Helios is the storm of all criminals. The rays of this god blind them. Even the gods cannot hide from such rays.

Helios knows everything about the divine "affairs". It was he who suggested to Demeter that her daughter Persephone was kidnapped by Hades into his gloomy realm of shadows. But noon comes when Helios reaches the west. By evening, the horses of Helios and he himself get tired and blush. God goes to his palace for rest, where the divine retinue also rests, and Selena's chariot leaves for the road ... Such is the Greek change of day and night. Their fabulous explanation is similar to the Slavic myth.

Related videos

Slavic vision of day and night

The ideas about the world among the ancient pagan Slavs were very complex and confusing. The sun and sunlight were different concepts for them. For each season, the Slavs had a separate "sun" - Yarilo, Kupailo, Svetovit and Kolyada. They called the sun itself Horos. By the way, this word meant "circle". This is where the word round dance comes from.

Like the Greeks, the Slavic fairytale explanation of the change of day and night is simple - Dazhdbog (the sun - the giving god) rode a golden chariot across the daytime sky, harnessed by fiery winged horses. Morning and evening dawns were considered sisters. Moreover, the dawn was the wife of the sun. On the day of the summer solstice, the Slavs celebrated their wedding. Like the Greeks, the Sun is an all-seeing eye that watched everything and everyone. Because the criminals operate at night to this day.

Ancient Indian idea of ​​the emergence of a new day

A distinctive Indian legend about the change of day and night. The fabulous explanation says that there was no night. She appeared thanks to one tragic incident. There was a brother Yama and a sister Yami. The brother died, and the lonely sister had no choice but to endlessly mourn the unfortunate brother. To all requests and exhortations to calm down and stop shedding tears, Yami only exclaimed: “But he died today!” The gods saw the truth: in order for the girl to calm down, a night is needed, only in this way will a new day come. They made the night. Morning came, Yami forgot about grief. And the Indians began to say "the sequence of day and night."

Conclusion

For many years our ancestors believed in these myths and legends about the creation of day and night, right up to the Middle Ages. Religion and mystical ideas were replaced by science. Nicolaus Copernicus 500 years ago wrote a book about how our planet rotates on its axis, orbiting around the star Sun. So, according to Copernicus, there was a change of day and night.

The fairytale explanation was destroyed. And the scientist's book was banned by the Pope, as it contradicted the Christian religion. Copernicus became famous as the creator of the heliocentric system. The name of this system comes from the name of the sun god Helios, so, according to the theory of Copernicus, the Sun is located in the center of the universe. The Polish astronomer died of a stroke on May 24, 1543, at the age of 73.