Under natural conditions the rarefied air meets only in highlands. In such air because of big height there are not enough molecules of oxygen and nitrogen that considerably complicates breath.

The pole star received the name because of nearness to the North Pole of Earth. Its orientation on the North does it by a convenient reference point for all who were left without compass. To orient in space, it is necessary only to find a Pole star.

Population in translation from Latin means "population", "people". Population dynamics is the movement of population, its development, movement. The connected with a concept of ecology, population dynamics is characterized by the certain factors creating changes in the nature and the area. Each population has the leading fitness to various environmental conditions of dwelling.

The pole star belongs to the constellation Little Dipper. It is at distance of 431 light years from Earth and represents a threefold star system which consists of the giant Polar And yes a small star of Ab and also remote from them Polar Century.