Success Samrat

The word Geography is the combination of two Greek words-GEO- EARTH and GRAPHOS-DESCRIPTION. Eratosthenes (276-194 BCE) first coined the term “GEOGRAPHY” in 234 BCE. The geography is primarily concerned with the study of the earth’s surface where all forms of life including human life and its activities which takes place on the earth are studied.

VARIOUS DEFINITIONS OF GEOGRAPHY

• By L. D Slamp– “ The description of earth as the abode of human beings.”
• By Richard Hartshorne-” Geography is concerned with the description and explanation of areal differentiation of the earth’s surface.”
• By Alfred Hettner– ” Geography studies the difference of phenomena causally related in parts of the earth’s surface.”

BRANCHES OF GEOGRAPHY

Ptolemy And The Geocentric Concept Of The Universe– Claudius Ptolemy, the great roman astronomer proposed the Geo Centric Concept Of the Universe. According to it, ” the earth was at the centre and all other celestial bodies were moving around it.”

Copernicus And The Heliocentric Concept Of The Universe– In 1543, Copernicus proposed the Heliocentric Concept Of The Universe. According to it,” the sun was at the centre and all other celestial bodies were moving around it.”

The heliocentric concept remained in vogue for a very long time. Until in 1805, a British astronomer, William Herschel while studying the universe through his telescope found that our solar system was merely part of a galaxy. There are many more galaxies. In 1925, Edwin Hubble, an American astronomer stated that the diameter of the universe is 2.5 billion light-years.

THE THEORIES REGARDING THE ORIGIN OF THE UNIVERSE

The Big Bang Theory– In 1960-70, a Belgian astronomer, E. George Lamaitre proposed the Big Bang Theory. According to this theory,” about 10-15 billion years ago there was a big heavenly body, made up of heavy matters. Due to the explosion in the body, normal matters came out of it and many celestial bodies were formed as a result of the aggregation of the matter. Later there was an increase in the size of the body as normal matter accumulated around it. By this process, the galaxies were formed. Stars were formed due to re-explosion in these galaxies. Later on, planets were too formed by this process.”

The Steady-State Theory Of The Universe– The theory was proposed by a trio of Thomas Gold, Hermann Bondi and Fred Hoyle. The theory suggests that” the number of galaxies in the observable universe is constant. It means new galaxies are created and they fill the gap that has been created by a galaxy that has moved beyond the boundary of the observable universe. Therefore the overall size of the observable universe is constant.”

The Pulsating Universe Theory– The Pulsating Universe theory is a corollary to the Big Bang Theory. The theory was proposed by DR. Allen Sundes. The theory states that “the universe expands and contracts alternately. Currently, our universe is expanding. It will expand to a certain limit after that it will start contracting under the gravitational pull. After contracting to a certain limit it will explode again and start expanding. This alternate expansion and contraction give our universe a pulsating nature.