Monthly sunset. Today the daylight hours are getting longer.

MOSCOW, December 24 - RIA Novosti. After winter solstice The sun can rise even later than before, and the length of the day gradually increases from evening due to more high speed movement of the earth around the sun. This was told to RIA Novosti by the head of the Department of Astrometry and Time Service of the Sternberg Astronomical Institute of Moscow State University (GAISh), Doctor of Science Konstantin Kuimov.

From the point of view of astronomers, the winter solstice is the moment when the Sun reaches its minimum declination, that is, it is at the lowest angular height above the horizon. The solstice took place on December 21 at 23.28 UT, on December 22 at 02.38 Moscow time.

According to Kuimov, after the solstice, daylight hours begin to increase, but this does not happen evenly, and not from "both sides" - first, the moment of sunset is pushed back in time.

"If you look at the table of sunrises and sunsets, you will see that despite the fact that the duration daylight hours increases, sunrise is a little later for the first few days, and sunset is also a little later. They say that the day is added from the evening," the astronomer said.

So, on Friday the Sun in Moscow rose at 08.58, and will set at 15.59, and on Saturday already at 08.59 and 15.59, respectively. Over the next few days, sunset will move about a minute a day, and sunrise will "stand still" at 08:59.

"This happens because the Earth rotates around its axis at a certain speed, but in winter it is close to the Sun and moves in orbit a little faster than in summer. The annual movement of the Sun across the sky is somewhat faster than in summer, and, combined with daily movement, this and gives such an effect," Kuimov explained.

The Earth's orbit, although very close to circular, has a noticeable eccentricity (the degree of elongation of the ellipse), it has a point as close as possible to the Sun - perihelion, and as far as possible - aphelion. According to Kepler's laws, a body moving in an elliptical orbit has great speed at points close to the central body.

"Therefore, it turns out that in winter the Sun moves across the sky a little faster, and in summer a little slower," the source said.

According to him, the Earth is at perihelion around January 3rd, and at aphelion around July 3rd. The date can change by a day or two, because the movement of the moon also affects the distance, the scientist added.

Kuimov noted that the ellipticity of the earth's orbit affects the climate: when in the northern hemisphere winter - the Earth is closer to the Sun, and in summer - further, which somewhat softens the difference between the seasons in the northern hemisphere and somewhat increases - in the southern.

Because of the perturbations of the planets in 100 thousand years, the situation will be reversed. The perihelion point makes about one revolution every 200 thousand years.

"The difference in distances in winter and summer between the Earth and the Sun is 0.3% -0.4%. The illumination decreases with the square of the distance, and the difference can already reach 6%, and this is already a noticeable value. After about 100 thousand years, these 6% could cause noticeable climate change," the astronomer said.

According to him, some experts believe that this is one of the reasons for regular glaciations, although only this astronomical reason should change the climate in different hemispheres in different directions.

in the northern hemisphere the day begins to increase - December 21-22. This is due to the fact that at this time the tilt of the Earth's axis of rotation relative to the Sun is the greatest, and the Northern Hemisphere is illuminated the least.

Accordingly, in the summer of June 20 or 21, the Earth's axis again assumes the greatest inclination, but at this moment the Northern Hemisphere is illuminated most fully - the summer solstice, the longest day.

In the southern hemisphere, respectively, the opposite is illuminated: June 20-21 is the winter solstice, December 21-22 is the summer solstice.

Exact date or not?

It is customary to consider the date when the day begins to increase, December 22. In all calendars, it is celebrated as the Winter Solstice. But to be absolutely precise and take into account all modern research astronomers and physicists, we will have to state this fact. The position of the solar luminary for several days before the solstice and after does not change its inclination at all. And only 2-3 days after the solstice, it can be stated that the time has come when daylight begins to increase.

So if you follow scientific research, then the answer to the question of when the day will begin to increase will be this - December 24-25. It is from this period that the nights become a little shorter, and the daylight hours become longer and longer. But at the household level, information has firmly settled that the time when daylight begins to increase falls on December 22.

Longitude of the day

The length of the day depends on the geographical latitude of the place and on the declination of the Sun. At the earth's equator, it is approximately constant and is usually a little more than 12 hours; deviations from the exact value are due to the very definition of sunrise and sunset, since sunrise and sunset are traditionally considered the moment the upper edge of the solar disk crosses the visible horizon, and not the moment the center of the Sun crosses the true horizon. In addition, refraction also affects the length of the day. sun rays, and the inclination of the earth's axis to the plane of the ecliptic determines fluctuations in the longitude of the day, including at the equator. In the Northern Hemisphere of the Earth, the longitude of the day is more than 12 hours from the end of March to the end of September, and less than 12 hours from the end of September to the end of March, in the Southern - on the contrary.

The longest day is on the day of the summer solstice (about June 22 in the Northern Hemisphere, about December 22 in southern hemisphere), and the smallest - on the day of the winter solstice (about December 22 in the Northern Hemisphere, about June 22 in the Southern Hemisphere).

On the days of the equinoxes (around March 21 and around September 23) everywhere on Earth the day is somewhat longer than the night, for the same reason that the day at the equator is longer than 12 hours.

Within the polar circles, the longitude of the day in summer can exceed 24 hours (polar day), and at the poles the day lasts half a year plus a correction for the reason mentioned twice above.

Between the pole and the line of the Arctic Circle, the longitude of day / night varies according to a non-linear relationship, however, at polar degrees, the dependence breaks down, the difference is slightly noticeable due to the almost always unstable state upper layers atmosphere and, as a result, its oscillating refraction - therefore, it is possible to accurately determine the pole by visual observations alone in the region of the light solstice (summer in the Arctic and winter in the Antarctic) only with a significant error.

Maximum day length on other planets

In this case, the units of Earth time are used:

• Mercury - about 60 days
• Venus - 243 days
• Mars - 24 hours 39 minutes 35.24409 seconds (Martian "sol")
• Jupiter - 9 hours
• Saturn - about 10 hours
• Uranus - about 13 hours
• Neptune - about 15 hours

Since June 22, every day has been waning - the nights are getting longer and the days are getting shorter. The maximum, when we observe the longest night and the shortest day, is reached on December 22. It is from this date that the period begins when the day begins to increase and the night shortens.

The longest night

If you want to get enough sleep, then December 22 will be the most successful for you. Astronomers have noticed that in the Northern Hemisphere it is on this day that the most long night. And the next day, when it starts to add time, it will become more and more.

On December 22, the sun rises to its lowest point above the horizon. There is a fairly simple scientific explanation for this. has an ellipsoid shape. The Earth at this time is at the farthest point of the orbit. Therefore, the Sun in the Northern Hemisphere in December rises above the horizon by minimum height, and the peak of this minimum falls on December 22.

Exact date or not?

It is customary to consider the date when the day begins to increase, December 22. In all calendars, it is celebrated as a Day. But to be absolutely accurate and take into account all the modern studies of astronomers and physicists, we will have to state such a fact. The position of the solar luminary for several days before the solstice and after does not change its inclination at all. And only 2-3 days after the solstice, it can be stated that the time has come when daylight begins to increase.

So if you follow scientific research, then the answer to the question of when the day will begin to increase will be this - December 24-25. It is from this period that the nights become a little shorter, and the daylight hours become longer and longer. But at the household level, information has firmly settled that the time when daylight begins to increase falls on December 22.

Such inaccuracy is forgiven by scientists. After all, sometimes folk omens, based on centuries of observations, are much more tenacious than the latest modern research.

Golden for important news

The Slavs not only celebrated December 22 as the date when the day begins to increase in winter, but also carefully watched what the weather was like during these days, how birds and animals behaved.

It is on December 22 that the folk proverb "The sun - for the summer, winter - for the frost" is attributed. If frost fell on the trees that day, it was considered a good omen. So, to be a rich harvest of grain.

Interestingly, in the 16th century in Russia, the bell ringer of the Moscow Cathedral himself went to the tsar with "important" information. He reported that the Sun would burn brighter, that the nights would henceforth be shorter, and the days would become longer. In general, he did not let the king forget the date when the day was added. The importance of such a report can be judged by the fact that the king always rewarded the headman with a gold coin. After all, the news was joyful - winter is waning. And although there were still cold January snowfalls and severe February frosts ahead of the inhabitants of Russia, the very fact that day beats night was optimistic.

Glory to next spring

Why was such attention paid to the Winter Solstice in ancient times? After all, they remember him very rarely, and even more so they do not mark the date when daylight hours begin to increase. Unless they mention it in the news in a short line, that's all. But our ancestors, whose life depended entirely on the Sun and heat, celebrated this date widely and massively.

Huge bonfires were lit on the streets, both adults and children jumped over them. The girls danced round dances, and the guys competed who would show strength and ingenuity. On the ancient Russia celebrated joyfully and loudly. But Europe was not far behind.

Sun wheel on ancient monuments

In Europe, immediately after the Winter Solstice, pagan holidays began, which lasted exactly 12 days, according to the number of months. People had fun, went to visit, praised nature and rejoiced at the beginning of a new life.

There was an interesting custom in Scotland. An ordinary barrel was smeared with melted resin, then it was set on fire and rolled down the street. It was the so-called sun wheel, or otherwise - the solstice. The burning wheel resembled the Sun, it seemed to people that they could control the heavenly body. Such a solstice was made both in ancient Russia and in other European countries.

Interestingly, archaeologists find an image of the sun wheel in the most different countries: in India and Mexico, in Egypt and Gaul, in Scandinavia and Such rock paintings are also in in large numbers found in Buddhist monasteries. By the way, among other names, the Buddha is also called the "King of Wheels". I really wanted to control the Sun.

Male force of nature

Massively celebrated the date when the day is added, and in France, where people held costumed festivals and gave real balls. Accompanied by musicians, the people on December 22 walked through the streets, as if to a demonstration. In the days of the Gauls, it was believed that it was imperative to pick a branch of mistletoe on this day, which would bring happiness to the house.

But in ancient China At this time, the season of mass holidays began. It was believed that along with the energy of the Sun, masculine power awakens in nature. A new one starts life cycle that promises happiness. Everyone celebrated this date - both nobles and commoners. And so that work does not interfere with fun, almost everyone, from the emperor to handymen, went on vacation. Shops closed, people went to visit, gave gifts and made sacrifices.

Today, the tradition of celebrating the Winter Solstice has practically disappeared. Modern man does not look at the sky too often and believes that he does not really depend on the Sun. But a completely erroneous opinion. The Sun is the source of all life on earth.

A day is the length of time between sunrise and sunset when the sun is visible above the horizon. Light day can have different longitudes, depending on the geographical latitude of the place and on the angle of declination of the star.

Instruction

The length of the day depends on the daily rotation of the Earth around its axis and orbital rotation around the Sun. Due to the rotation of the Earth in its orbit, the solar disk makes an annual visible bypass of the celestial sphere, moving along the ecliptic. In this regard, its declination changes and affects the length of the day differently at different geographical latitudes.

At the earth's equator, the length of daylight hours is approximately constant and is about 12 hours. In the northern hemisphere of the Earth from March to September, daylight hours are more than 12 hours, and from the end of September to the end of March - less. In the Southern Hemisphere, everything is exactly the opposite. At the Arctic Circle in summer, daylight hours can be longer than 24 hours. This phenomenon is called polar day. At the poles, the length of the day is six months.

The shortest and longest daylight hours occur during the winter and summer solstices. In the northern hemisphere, the winter solstice falls on December 21 or 22 (depending on the time zone), and the summer solstice falls on June 21 or 22 (depending on the time zone). leap year may occur June 20). On the other side of the equator - in the Southern Hemisphere - the December solstice occurs in the summer, and the June solstice occurs in the winter.

During the winter solstice, day length is only 5 hours 53 minutes. - This is the shortest day of the year and, accordingly, the longest night. The summer solstice makes it possible to live the longest day - 17 hours 33 minutes. Having reached its maximum duration, from this moment the daylight hours begin to decrease until the winter solstice again comes, and it again begins to grow.

For a long time, in the traditions of many nations, the custom of celebrating the days of the winter and summer solstices has been preserved. So, in Russia, for example, most short day a holiday called "Kolyada" is dedicated to the year.

Historians claim that the ancient Egyptians knew about the solstice. There is a version that they built the majestic pyramids in such a way that on the day of the summer solstice the sun would set between them. You can verify this phenomenon by looking at the pyramids from the side of the Sphinx.

A lot of mysteries and secrets are fraught with the famous British Stonehenge, located 130 km from London. Some scholars call it an ancient observatory and also associate it with summer solstice. Because it is on this day that the Sun rises over the Hillstone stone, located somewhat separate from the main structure.

It seems to many that all winter nights are equally long. But this is not true, the shortest day of the year falls on the twentieth of December, or rather, on the 21st or 22nd, depending on the year and time zone. Until that day, the nights lengthen and the days shorten. But after the winter solstice, the short daylight hours begin to gradually increase.

Few people know, but the length of the longest night differs depending on the time zone. The closer to the equator, the shorter it is. But, for example, in the Arctic, the length of the night is measured not in hours, but in days. At the same time, how many days it lasts will also depend on the specific location. At the northernmost point of the planet, at a latitude of 90 degrees, its duration is 176 days.

In many countries, including Russia, the winter solstice was considered the holiday of the birth of the sun. In order to follow the ancient traditions and celebrate this day as it was supposed to be many centuries ago, you first need to find out what date the winter solstice is in 2015. According to the calculations of astronomers, the center of the sun will move to the farthest point from the equator of the celestial sphere at 04:48 on December 22, universal time. But it is important to consider that Moscow time will be 08:03.

Since ancient times, it was believed that the winter solstice is a turning point for this star, therefore, in many nations, the concept of the rebirth of the gods was developed (it was believed that they die, but then reappear). Moreover, in many cultures, cyclic calendars were tied to this event.

The day of the winter solstice among the Slavs is the so-called Kolyada or Svyatki. The roots of these festivities go back to pagan times, but later it was timed to coincide with Christmas, and so they began to call the period after Christmas and before Epiphany. Moreover, earlier December 20 was considered the last day of autumn, and from the 21 winter month and the beginning of the next new year. Note that on the same day the birth of Kolyada, one of the incarnations of Dazhdbog, who was the embodiment of the Sun, was also celebrated.

Nobody wanted the longest night to last so it was filled with fun. The day before, they prepared kolivo (a special porridge seasoned with honey and raisins) and socheviki (pies stuffed with cottage cheese or jam). But this was not the main attribute of the holiday. People gathered in the streets and lit bonfires, rolled lighted wheels - this is how they helped the new sun to be born.

And the tradition of going from house to house to sing carols at Christmas has come from those pagan times. In addition, local priests sacrificed a domestic animal (it could be a pig, a duck, or some other animal). It was a common ritual, which, by the way, is still observed today. After all, many New Year's table you can find baked meat. The tradition of laying chic tables has survived to our times, because since then the belief has remained: as you meet the year, so it will pass.

The days of Christmas time among the Slavs were considered magical. Fortune-telling was especially common, people tried to find out whether there would be a war, whether a family was waiting for a wedding, they found out the future harvest. It was also customary to commemorate departed relatives. It is clear to many that most of these traditions have been preserved, only the date of the holidays has shifted. At the same time, most of the rites were transferred to Christmas and the period of Christmas time that follows this holiday.