Question

What divides the Earth into eastern and western hemispheres?

Answer 1

Hint: The hemispheres are the two equal halves of planet earth. For e.g. The northern and the southern hemispheres are two hemispheres of the earth that are divided by the 0-degree latitude called the Equator.

Complete answer:
The earth is divided into the eastern and western hemisphere by an imaginary line which is denoted as the zero-degree longitude and is called the Prime Meridian.

It passes through the Royal Observatory, Greenwich in London, Great Britain. This line for geographical reference and navigation was established by Sir George Airy (a British mathematician and astronomer) in the year 1851. This became an extremely popular means for navigation and was found marked on literally every map in the world.

In the year 1884, an International Meridian Conference has held in which 41 delegates from 25 nations met at Washington D.C. and selected this meridian passing through Greenwich as the Prime Meridian. It was due to the popularity that it had earned in a very short span of time.

Presently, the Prime Meridian passes through The United Kingdom, France, Spain, Algeria, Mali, Burkina Faso, Togo, Ghana and Antarctica. Countries that lie on this have the same time, which is known as the ‘Greenwich Mean Time’ (GMT). Countries lying towards its west are a few hours behind the GMT depending on their distance from the Prime Meridian. Similarly, the countries lying to its east are a few hours ahead of the GMT.

Thus, the Prime Meridian divides the Earth into eastern and western hemispheres.

Note: India’s standard time is +05:30 GMT. The + indicates that India is ahead of the Prime Meridian, as it is located to the East of it. Similarly, the standard time in New York would be -04:00 GMT, with the – indicating that it is in the West. The U.S is spread across a large area and crosses many longitudes. Hence, it has 4 different standard times. India is a comparatively smaller nation with a smaller longitudinal span. Hence, it requires only one standard time.