The Axis Of Earths Rotation
Due to friction caused by the tides and stray space particles, the Earth’s rotation is very gradually slowing down. Estimates indicate that every century, the Earth takes about one five-hundredth of a second longer to rotate once. Around the beginning of the Earth’s formation, a day lasted about 13 or 14 hours, instead of today’s 24. The Earth’s slowing rotation is the reason we add one leap second once every few years.
Why do we have day and night?
The Earth experiences days and nights as a result of the planet spinning on its axis. As the planet spins, the part that is facing the sun experiences day, while it is night for the part facing away from the sun.