Why is dark at night, a scientific explanation

At any point in time the land is the light and the time when it is dark. This is due primarily to our main luminary – sun. It moves across the sky, changing light levels. Simply put, the night is dark, because the sun is on the horizon.
Why is dark at night, a scientific explanation
Interesting view of old people
In ancient times, people assumed that it revolves around the sun and our planet lies beyond the horizon. No long time could not even assume that our planet revolves in a large space around the star. The same applies to the moon. Sun and Moon were given divine origin: they worshiped brought gifts, sang the songs and ceremonies. But the era of science that proved that everything is still just the opposite. Earth – not the center of the universe, and it is only a tiny part, and why the night is dark, not associated with any divine manifestations.
Why is dark at night, a scientific explanation

What is the Earth’s rotation and it affects
There are two simultaneous movements and movements of planets in space, moving in orbit around the Sun and around its axis, like a child broomrape. That is, at the same time when the planet is flying in space, it revolves around itself, and combination of these factors is the reason why the night is dark and day – light. Moving in its orbit in space complete with the fact that Earth’s axis is tilted to the same orbit at an angle of about 66 degrees – is the reason for the change of seasons and their “unequal”.
Why is dark at night, a scientific explanation in different parts of the Earth, depending on the heat rays of light in their time changing autumn, winter, spring and summer. Thus, the mid-latitudes often attend all four seasons, in varying degrees of intensity (eg Italy summer as winter much warmer than in Moscow). At the equator, which is mostly under direct sunlight during midday close to the angle of 90 degrees, the day is a little longer part of 12 hours.

The poles why cold day although there six months?
At the poles, the picture is very special way – the sun’s rays fall so that they slide and is almost entirely reflected from the surface, without stopping and not leaving it warm, though day and night lasts almost six months each. Why north and south pole – the coldest regions of our planet.
Varying the length of day and night
The rotation of the planets around the sun, the main star for us, sets the change of seasons and day and night. The spherical shape of the planet and heterogeneity of the surface property of light rays reflected complement and make the climate varied by location in such areas. But there are days when all latitudes to the polar zone coming days, with the same allocation of time between clear and dark part of the day – the days of spring and autumn equinox. At this time, the equator is any object will slightest shadow, as the sun let its rays at 90 degrees to the surface.

In principle, why the night is dark, everything is clear. But it is interesting that it is dark for a long time, and sometimes a bit. For our typical Northern Hemisphere reducing the duration of the night of 21 March (vernal equinox) to September 23 (autumnal equinox), and vice versa – there are long nights in winter. In the southern hemisphere, on the contrary.
And how to explain this to children?
Explain to children the phenomenon that is dark at night, because the sun shines not, it is not true. After all, in fact, the sun shines forever. It does not turn off and not by someone’s decision as a desk lamp. But talk about the position of the Earth in space, the angles of incidence of rays and other zaumnostyah that can be understood by children of school age are not required. To do this, parents best be smart and show clearly how this happens. In order to explain why the night is dark, it is necessary to familiarize the child with two concepts: what is the sun and a planet Earth. Make it pretty simple: draw two balls – one yellow and rays (actually the Sun), and the other – blue outline of the image of the continent. Furthermore, without going into the complicated terminology to talk about shape and demonstrate with a model of the solar system. Suffice to yellow balls and a small globe, and if possible, better to buy a complete model or make yourself such, even with the child.
Why is dark at night, a scientific explanation Show that the sun stands still, and we spin why its rays on different parts of the globe not always fall. Then the child will be clear that the night is dark, because at that time we turn away from it, to substitute the sun, so to speak back. For complete clarity, you can at night to demonstrate this phenomenon using the same globe flashlight, which acts as the sun.