Why We Have Day and Night?

From the beginning, human being has been wondering over the interchanging arrangement of day and night. A number of questions arise in mind, why there is day and night.

We experience day and night because the earth continuously spins around its axis, an imaginary line passing through the North and the South Pole of the earth. Being a star, the sun, with reference to its satellite, the planets, doesn’t change its place, while the planets, including our earth, do revolve around it.

Day Night Why We Have Day and Night?

For an ordinary observer not familiar with the earth’s rotation round its axis, the sun moves from the East to the West, but actually it is the Earth that takes round about its axis while maintaining a certain distance from the sun such that its horizontal plan comes in juxtaposition with reference to sun experiencing a greater moment of revolve, i.e. greater the distance from poles downward the globe, the greater will be the turning effect experienced. So the zones that are away from poles experience a full scale day and night.

Over the course of this spinning, half of the earth remains sunk in the dark (the façade of earth not facing the sun at a given moment) while the other half facing the sun experiences the day and the two halves gradually alternate their position over the course of the movement.

The earth takes about 24 hours to complete its rotation around its axis. A living organism can not experience the turning effect of earth because it is moving at a constant constantly speed smoothly — no acceleration. Another theory that can be propounded in support of this effect is that as long as an object is remains within the precincts of the frame of reference of its gigantic host, harboring the tiny object, the external factors, such as displacement w.r.t. objects external to the system. Viewed from above the North Pole, the earth is found revolving anti-clock wise and consequently the day light zones follow from the East to the West.

In a common sense, the term “day” designates the period of sunlight from dawn to dusk, in sheer contrast with “night”. The span of daylight remains constant if we travel within the same latitude whereas vice-e-versa situation is encountered if we move up or down the longitude. For example, during summer at poles the day reaches a maximum length of 24 hours, popularly referred to as “the midnight sun”.

Likewise, other planets of the solar system also rotate about their axis, but with certain variations and accordingly receive their share of light from the sun, thereby exhibiting different lengths of days and nights in commensuration with their respective sizes and rotational speeds.

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