Day follows night, and night is day. We got used to it and not think about it, where is hidden the sun at night. It seems to us that it moves across the sky - rises in the morning and in the evening descends over the horizon, why on the planet there is a change of day and night. But actually the Sun is motionless, it is our planet continuously rotates on its axis, turning to the Sun of one side, then the other. On the side that lights the Sun, the day comes, on the opposite of the night. Fills the Earth the sun the other side - and on the night side of the coming day, and the day night is falling.