On account of the obliquity of the earth’s axis, for six month i.e., from March 21 to Sept. 23 the north pole is inclined towards the Sun and is always in the light. During this period the South pole is inclined away from the Sun and is throughout in the dark. Hence it is day for six months at the north pole and night at the south pole. But from September 23 to March 21st the case is just the opposite. The north pole is inclined away from the Sun and is in the dark while the south pole is inclined, towards the Sun and is in the light.
