Imagine a Concentric circle, the outer being the Universe, in it the Milky way galaxy and then our Solar System. Is it not so simple?
The larger picture is far more complex and yet inconclusive.
Evolution of Universe from the Big Bang singularity, where in , the Universe was infinitely small mass of particle and over time due to expansion(inflation) it became larger and larger such that certain particles with higher dense mass region due to the gravitational force of attraction got contratcted giving rise to milky way galaxies, stars and human beings.
The one such structure which is of particular importance is black hole, unlike star, it has a massive gravitational force of attraction, anything inside it, even its own light, would not escape its boundary, the event horizon.
The second law of Thermodynamics, which measures the disorder, entropy, in a system, is related to the black hole event, if black hole should collapse any particle in it then it should increase it’s mass and thereby the area of its boundary, event horizon, but as further probe began it was proved that if there is a change in system, (here the area of the black hole boundary), there should be disorder and subsequently it should emit radiation, and if we could measure the radiation we could find the black hole, the problem? it pulls its own light, so how could it reach the observer at earth for this to be seen.
The law gave rise to another aspect of evolution of Universe, what if the Universe contracts , from disorder to order will we be able to go back in time , but that would cause entropy, disorder, of the system to decrease, and in any changing sytem entropy never goes down, then it was agreed that the contraction did not require to be necessarily the time reverse of expansion.
So, what is the origin of Universe. Can there be a unified theory of everything? The possibilities are:
- Someday we might discover it.
- There is no ultimate theory of the universe, just an infinite sequence of theories that describes universe more and more accurately, from big bang, theory of relativity to uncertainty principle of quantum theory.
- There is no theory of the universe as events cannot be predicted beyond a certain extent and occur randomly and arbitrarily.
Personally, the book offers a good start to know much more about the Universe and improve ones scientific temper.
ABOUT THE AUTHOR: STEPHEN W. HAWKING
PUBLISHER: JAICO PUBLISHING HOUSE(SPECIAL ANNIVERSARY EDITION)