Cosmology is made from the Greek word ‘cosmologia’ and ‘logos’. Cosmology is defined as the science of studying the origin and fate of the universe. Even though it is closely knit with the fields of astrophysics and astronomy, cosmology has gained a deeper insight through particle physics. The basic understanding of modern cosmology comes when we connect the behaviour of the largest structures found in the universe (like the sun, planets, stars, galaxy etc) with the smallest ones found in the universe (i.e. the fundamental particles).
HISTORY OF COSMOLOGY
Cosmology is one the oldest forms of the study. During ancient times, humans looked up in the sky to ask questions like from where did we come here, are we alone in the universe, what are the shiny things present in the universe etc. the questions were always there but the answers varied. The geocentric model of universe was found to understand more about stars.
Nicolaus Copernicus in 1543, gave evidence for an heliocentric model of the solar system. This refuted the earlier claim of Earth being the centre of the universe. Copernican Principle basically changed the assumption of Earth having a priveledged position in the cosmos. Isaac Newton combines all the discoveries together for explaining the planetary motions. He gave gravity, calculus and three laws of motion.
GENERAL RELATIVITY AND THE BIG BANG
With Albert Einstein’s general relativity theory, the concept of gravity shifted. Gravity was now understood as the bending of a four dimensional space-time in response to presence of any massive object like the galaxy, planet or a star.
But problem arose when it was discovered that space-time wasn’t in equilibrium. Einstein then introduced a cosmological constant into his theory which then counteracted the expansion and contraction of the universe. Einstein later removed the cosmological constant.
Big bang theory states the original or how the entire universe came around. Alan Guth in 1980 gave inflation theory which stated that the fluctuation in our planet is less.
FEW MYSTERIES OF MODERN COSMOLOGY
Dark matter and dark energy remain the two unsolved puzzles left in the field of science. They account for explaining the expansion of universe.
Cosmology is said to be one of the earliest fields in the history that gave results contradictory to the traditional religious worldview. The modern time is also known as the golden ago of cosmology. Cosmic inflation is the modification of big bang theory.