Being oneself as well a part of surroundings and universe, human is always curious to know in detail about not only about his inner self but all about its relationship with outer world extended to astronomy and cosmology. Knowledge about astronomy and cosmology along with its application for the wellbeing of mankind has been the basis of mythology all over the world in general and Hindu mythology in particular as the oldest philosophy of life.

Our ancient knowledge of astronomy and cosmology however, remained constrained verbally and fewexamples of written text to a particular section of society and thus lost its acceptance with time. At present when Indian knowledge and application of astronomy and cosmology concepts in day to day life has become as a laughing stock, advanced countries with strong footing of research in these exciting areas of science have progressed very much ahead of us.Need is to popularize the teaching of these so called difficult and irrelevant topics of science and technology to younger generation.Technological development has made it possible to observe the astronomical and cosmological concepts and events with ease which were though not more than some natural phenomena some time back.

Why we are interested in studying the Astronomy, Astrophysics and cosmologyand solving the mysteries of our Universe?

• It is the same curiosity that human kind have since its early existence to explore the environment where we are.  Initially, we are limited to ourselves, our surrounding (earth) and then think of our solar system and universe to universes that how and why we are entangled together. Thus, knowing and understanding the stage on which our life is being played is crucial for any existence to have real meaning.
• We, humans, are curious to learn about the formation and evolution of the world we see. It is not that our curiosity and leaning about ourselves, our immediate surroundings and our life processes have come to an end but continuing the same, we are also interested to learn about our entanglement with astronomy and cosmology.
• Nowadays, we have technical resources to explore even far away into the space leading our knowledge about astronomy and cosmology.
• We want to know the mysteries of our space (solar system as well as universes).
• Though astronomy and cosmology is not my field but as a Physics student the topic is always very dear to my heart. Similarly, most of the people are naturally interested is space, how big it is, what is out there simply because it is so different from what we experience every day.
• However, to unleash the secrets of universe together, is the only goal in most of the people's life.
• Humans are driven to extend the boundaries of our scientific and technical limits, explore the space, discover new worlds, and then push even further.
• Information about space, the solar system, dark matter, galaxies, black holes or any one of a range of different topics of astronomy and cosmology have become very common to people nowadays.

Modern pursuits in understanding astronomy and cosmology

It started with the theory of relativity given by Albert Einstein in 1905. The Nobel Prize in Physics 1921 was awarded to Albert Einstein "for his services to Theoretical Physics, and especially for his discovery of the law of the photoelectric effect."  At 26, the famous physicist explained the science behind consequences of relativistic motion as well as today's solar energy revolution.

Theory of Relativity

The theory explains the behaviour of objects in space and time, and it can be used to predict everything from the existence of black holes, to light bending due to gravity, to the behavior of the planet Mercury in its orbit.

Einstein’s theory of relativity is divided into two parts:

1. Special theory of relativity- dealing with inertial frames of references
2. General theory of relativity- dealing with non-inertial frames of references

• >Many interesting theoretical consequences of special theory of relativity which were and are still experimentally being proved came into light:
• -Length contraction

• -Time dilation (Twin paradox)
• -Velocity addition
• -Variation of mass
• -Energy-mass relationship
• -Dark Energy
• -Doppler’s effect & red shift
• -Relativistic gyroscopes

• >Similarly, understanding of general theory of relativity is also proving a milestone in exploring the mysteries of space. The implications of Einstein's most famous theory are profound. The theory explains the behaviour of objects in space and time, and it can be used to predict everything from the existence of black holes, to light bending due to gravity, to the behaviour of the planet Mercury in its orbit. 

A New Window onto the Universe

The last six decades have witnessed a great revolution in astronomy, driven by improvements in observing capabilities across the electromagnetic spectrum: very large optical telescopes, radio antennas and arrays, a host of satellites to explore the infrared, X-ray, and gamma-ray parts of the spectrum, and the development of key new technologies (CCDs, adaptive optics).Each new window of observation has brought new surprises that have dramatically changed our understanding of the universe.

• -the relic cosmic microwave background radiation which has become our primary tool for exploring the Big Bang
• -the fact that quasi-stellar objects are at cosmological distances which has developed into the understanding that they are powered by supermassive black holes
• -pulsars which opened up the study of neutron stars and illuminated one endpoint for stellar evolution
• -X-ray binary systems which now enable us to make detailed studies of black holes and neutron stars
• -gamma-ray bursts coming from immense distances which are not fully explained even today
• -the fact that the expansion of the universe is accelerating which has led to the hunt for the nature of dark energy.
• -There is keen interest in observing gravitational waves directly, in order to test Einstein’s theory of general relativity and to observe some of the most exotic objects in nature, particularly black holes.

Scientists are still trying to explore all mysteries of space with the help of scientific knowledge and technology in the field of astronomy, cosmology and space science as well as trying to imbibe the applications of relativity in daily life. Still there is a long way to go ahead to understand, explain and make to understand following mysteries of space.

• -Grand unified theory
• -Alien life
• -Dark Matter
• -Dark Energy
• -Quantum Entanglement
• -Antimatter
• -The Fermi Paradox
• -Black Holes
• -Space Roar
• -Cosmic Rays
• -Fate of the universe (Big bang & big crunch), Age, Cosmological constant, The Multiverse
• -Gravity (The Great Attractor), gravitational waves, Gravitational constant
• -The Giant Void
• -Astronomical objects: comets, meteoroids, meteors, exoplanets &dwarf planets, Kuiper belt objects, planetary systems, star clusters, nebulae, and galaxies, asteroids, moons, planets, and stars

Milestones of numerical solving

Numerical solving is a thousand-year-old art, which developed into modern numerical analysis several decades ago with the advent of modern computers and supercomputers. It is impossible to summarize all the important work on the subject but for a compelling account of the early history of numerical analysis and computing in the field of astronomy, cosmology and space science.  There is a long list of numerically solving results leading towards the prediction and our better understanding of astronomy, cosmology and space.

Einstein's Relativity in Everyday Life

When Einstein finalized his theory of gravity and curved space-time in November 1915, ending a quest which he began with his 1905 special relativity, he had little concern for practical or observable consequences. He was unimpressed when measurements of the bending of starlight in 1919 confirmed his theory. Even today, general relativity plays its main role in the astronomical domain, with its black holes, gravity waves and cosmic big bangs, or in the domain of the ultra-small, where theorists look to unify general relativity with the other interactions, using exotic concepts such as strings and branes.