Is the Universe the way we think it to be?
When we talk of the Universe creation we hear the famous tale "Once upon a time out of nothing we had a big bang creating the space, time, matter and energy the way we perceive them today."
When we here it a common curiosity upsurges about what lead to the most famous Bang of cosmology? What was there before the "Big Bang "? How the hell so much of mass and energy was compressed into a ball of almost no dimension? The classical cosmologist including the legendary Stephen Hawkings have a logical but still a incomplete reply to the above in-questions. In fact we still are miles from the theory of everything which is supposed to give the answers of all our curiosity about the Universe.
Lets move billions of years back in time, to the time when it all began. As per the existing and widely accepted theory, it all began out of The Big Bang, explosion releasing energy far beyond we can imagine and the Universe started expanding since then. And with the explosion the Universe was created having huge energy, matter and anti matter, which in random motion collided with one another thus annihilating each other which further lead to the another fire work all across the Universe, leading to a tempature of few millions oC. And we were lucky that the amount of matter was slightly more than that of anti matter which lead to the Universe containing matter only as all anti matter were annihilated. With course of time, the universe cooled down and the remaining matter came closer to form atoms basically Hydrogen. The hydrogen gas gradually came closer to form dense hydrogen clouds, and some of them became so dense that the temperature and the pressure at the core forced the hydrogen atoms to fuse and form Helium and in turn releasing immense energy in form of heat light and other radiations, and this was how the stars came into existence.This happened all over the universe creating billions of stars. In the bigger stars where the temperature was even higher the helium atoms also fused to form beryllium, and many such other cross fusion lead to the the generation of different elements in star's core. But the fusion beyond Iron was not feasible in the core leading to a stop call to the generation of elements with higher atomic number. But as stars grew old and with depleting atomic fuel signalling their death, the stars starts expanding leading to formation of Red Giant(something to which our Sun will turn after 5 billions of years). The stars expands to millions of time of their size ,to visualize:- When our sun will turn into a red Giant it will engulf all the inner planets including the Earth. After the Red giant phase the fate of the stars lies on its size and mass . The stars which are the size of Sun will form white dwarf (the core part containing carbon in diamond phase) And the larger ones explode releasing the energy that would had been enough for humans since existence. And these tremendous explosions are termed as The SUPER NOVA and the more violent explosions The HYPER NOVA. And the energy released in the explosions forces the elements to fuse further forming elements with higher atomic number. The super nova releases huge amount of matter along with energy into the Universe and what is left behind forms what we call it Black holes, which have mighty gravitational power which doesn't even allow the light to escape. The matter released comes together to form Nebulae out of which other stars and planets and formed.
And this way the Universe reached the state we see it today and still it is expanding and the process of formation and destruction of stars and planets is going on.........For further reference "Brief History of time" by Stephen Hawkinkgs may be concerned or any book on cosmology,..
Now lets think on the time before the Big Bang was it really there nothing or what are the possibilities. A new upsurging theory THE STRING THEORY which considers everything to be made of tiny strings of Energy has a interesting view point on the Universe the way it is. It talks of Parallel Universes and says there are many of them existing parallel to ours and big bang is nothing but the result of collision of the two parallel universes(see video) thus saying that there might have been more than on big bangs in our universe history and it existed even before the bang and such big bangs are possible in future, A still another theory says that our universe might be inside a black hole of a higher universe and some of biggest black holes of our universe might to have Universes inside them. But we could find the exact answer if some day we can unify the in the present two independent theories the gravitational theory with quantum physics theory. Because it will be then we can understand the core of the black holes and the state of Universe before the big bang!