Though perennially in dual motion, the Earth has a deceptive appearance of being stationary. The concept of a calendar day consisting of 24 hours, split into daytime and night-time, can be attributed to the phenomenon of Earth’s rotation around its axis. Besides, the Earth is continuously orbiting the Sun at an average speed of 29.78 km per second. Aboard, we fearlessly crisscross diverse seasons–winter, summer, spring, autumn–while gravity keeps us from falling off into space.
The duration of a 360° rotation of the earth around its axis, which is gauged with allusion to a distant star, is 23 hours and 56 minutes. The orbital process, however, prolongs the average length of a solar day–adopted as a calendar day of 24 hours. Due to the elliptical path the earth traverses, its distance from the Sun keeps varying. Notwithstanding the concomitant variance in orbital speed, the average length of a solar day remains 24 hours.
Every dawn is the harbinger of a new day, and every sunset augurs the onset of the night. The alternating frequency of dawn and sunset has configured the pattern of our lives. We sleep during the night and remain active during the daytime, notwithstanding unusual exceptions. Though the next calendar date begins at midnight (00:00 hours), practically a new day dawns with sunrise. The world becomes alive at the crack of dawn. The human race has become accustomed to the template of calendar day. Compartmentalisation of time into days, months, and years, enables us to observe anniversaries and birthdays.
Daily chores beckon us to abandon our beds at daybreak. Practice of bathing, brushing our teeth, cleaning of premises, washing clothes, and so many other activities, have become daily habits. The twin movements of the earth have shaped inexorably the lives of human beings. The common denominator of all its inhabitants is the Earth itself.
Traversing space together aboard Planet Earth, all its inhabitants are bound in a terrestrial affiliation which is more primeval than bonds forged by parochial identities. An alien from another planet will identify any inhabitant of the earth as a terrestrial creature only, oblivious to the divisions of nationality, religion, ethnicity and race. The Earth unites all its proud inhabitants in an inalienable affinity.