Study of the Cosmos, at best, is considered
a semi-scientific discipline, primarily because the la-boratory for carrying
out measurements and tests of theories (the Cosmos) has been largely
inac-cessible for centuries. The cosmic vista into the yonder, however,
continued to fascinate humankind due to its inherent beauty and sheer
curiosity. The invention of the optical telescope more than five centuries
back, however, led to the opening of observational cosmology as a scientific
discipline with firm experimental basis. However, the investigations based on
visible light posed obvious limitations for the range of such observational
cosmology. The advent of the radio telescope in the first half of the 20th
century marked a fundamental new step in the progress of this branch of
science. There has been no looking back in the march of knowledge in the
discipline since then. A whole new vista was laid bare as a result of this
development, leading to the discovery of altogether new celestial objects, such
as quasars and pulsars and still newer galaxies. The parallel progress of the
physics of fundamental constituents of the material world and their interactions
led to an interesting merger of these two branches of physical sciences,
yielding absolutely astounding knowledge of the nature and evolution of the
Universe. New concepts of dark energy and dark matter thought to constitute the
dominant share of the Universe were brought to light as a result of these new
observations and theoretical ideas. This brief article aims to provide an
overview of these exciting developments in the field of cosmology and the
associated physics.
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