Why nights happen white, and days - black? The First half of summer I like to spend
at home because I madly love that time when in my city there come the white nights. On the South it is possible to go also in August when the period of the white nights already ends.
Having read the first lines, someone will think that the author lives in the city of St. Petersburg, the white nights are associated with this city. It is a merit of our literature - exactly thanks to literary traditions many are ready to consider the white nights as sight only of our northern capital. However it not so. The white nights are both in Kazan, and in Kirov, and in Arkhangelsk, and in Pskov, and in Samara, and in Syktyvkar where there lives the author.
The southern border of a zone of the white nights passes at the width of 49 º. From the equator to this parallel of the white nights never happens - exactly here and only here day always white, and night - black. At the width of 49 º (at this width there are the Volgograd region, the North of the Rostov region, etc.) there is one white night in a year - on June 22. To the North from this width the white nights become lighter, more long and brighter.
Then that can admire the white nights and Muscovites, however in the capital of night are not so light, as in St. Petersburg. In Syktyvkar the white nights are even longer and brighter, than in St. Petersburg. And in Arkhangelsk nights are more white, than in Syktyvkar. The closer to the North, the period of the white nights lasts longer: in St. Petersburg during the summer there are 23 white nights, in Petrozavodsk - 52, and in Arkhangelsk - 77 nights. Near the bay Tiksi that in Yakutia, the Sun does not plunge under the horizon from May 12 to August 1. Imagine - more than two months the round-the-clock day!
Often I hear from the people who for the first time arrived in the summer to Syktyvkar, what surprise they tested, having found out that in Syktyvkar the white nights - white. “ How so? We sacredly believed that the white nights happen only in St. Petersburg “. And I sometimes want to answer them: “ Means, you read fiction - it is good! But it was necessary still the textbook on astronomy to esteem “.
Why night happens white? As we remember from lessons of natural study, geography and astronomy, the axis of Earth is inclined therefore the Sun differently lights our planet - it turns out that in the winter sunshine practically do not get on our North, and in the summer, on the contrary, the Sun shines with almost day and night.
Experts call time of the white nights civil twilight. Civil twilight in astronomy is the period from calling for the horizon of the upper edge of a solar disk until, so far immersion of the Sun under the horizon does not exceed 6 - 7 º. In the summer in the north immersion of the Sun for the horizon even at midnight happens so small that evening civil twilight passes in morning without night darkness.
In other words, the white night is a merge of evening and morning twilight. Alexander Sergeyevich Pushkin in the preface to the poem “ Bronze Horseman “ sang the white night in Pyotr`s city. At the same time it truly defined essence of this astronomical phenomenon:
And, without starting up darkness of night
One dawn Hurries to replace other
With gold heaven,
, having given to night half an hour.
At the width of 65 º and to the north it is possible to observe continuous day, the kingdom of the midnight Sun exactly here begins. You had not to see it? And it was necessary to me. Imagine: at half past twelve in the night the cheerful company goes out for a walk, to drive by boats. On the street birdies sing, the sun brightly shines, smells of the blossoming plants, and there is such feeling that it not midnight, but midday time. Feelings are inexpressible.
The people who got used that in the summer at night light-as in the afternoon, practically do not pay attention to it. It is remembered, somehow in the summer to us on a visit there arrived the mother`s relative from Krasnodar Krai. So he, poor, could not sleep in any way - its organism which got used that it is necessary to sleep when on the street it is already dark, did not want to fall asleep in any way because it was not dark neither at night, nor in the afternoon. However the relative liked this phenomenon - the white nights. He declared that if they also had same nights white, as in the north in the summer, then Krasnodar Krai the Krasnodar Paradise would be called.
Very much it is pleasant to me that we have a period of the white nights in the north - it the phenomenon positively affects on my internal, a state of mind. There is a wish to love, to sing, create, write verses and in general to live! But this fine astronomical phenomenon has a medal back - the country of the white nights turns into the country of rainy days in the winter. Where in the summer the sun only for a while hides for the horizon, there in the winter it is almost not shown.
Once I told the relative living in the south about one ridiculous case which occurred at us in the house on December 30 and between times mentioned that light at me in the apartment already burned - there was a half the day before yesterday. I saw how eyes of my listener widely revealed. I understood not at once what in my story was her surprising. And later, having understood, explained to her that at us in December completely dawns only to 10 o`clock in the morning, and begins to darken after 14 hours. I not really love this period - all - people, as well as plants, reach for heat and light. And when day and night darkly, the person wants to lie down in hibernation.
Between 67 and 83 º in December there is a multidaily night: the sun during a row of days does not ascend at all, morning and evening twilight merges, only not in midnight any more as in the summer, and in midday. There comes polar night - so call part of year when the sun does not rise over the horizon. Polar night is in Vorkuta, Naryan - to Mara, Murmansk. In Murmansk during polar night even schools are closed for vacation.
On other side of the equator, in the southern hemisphere, at the corresponding geographic latitudes the same phenomena are observed. However at the latitudes answering in the southern hemisphere to the latitude of Arkhangelsk, Syktyvkar, St. Petersburg the infinite ocean stretches therefore there to admire the white nights and rainy days only seafarers can.
Since the childhood of people acquires representation about “ correct “ to change of day and night on Earth: at night - it is dark, in the afternoon - light-. However actually change of light and darkness on our planet is more various than children`s ideas of it. Our world is difficult and mysterious, but at the same time is madly beautiful!