Why big bang is not repeating?

There are new theories which propose that the current era of the universe we are living in after the Big Bang is only one of the many possible eras after other possible Big Bangs. The universe undergoes Big Bangs and expansion eras and later on contract to a big crunch resulting in another big bang. This is called the cyclic model, originally proposed by Richard C. Tolman, but was not accepted due to some theoretical difficulties. Newest theories of the cyclic models are based on brane-world scenario and uses string theoretical ideas. So far these theories have not been substantiated or refuted.

For details see the discussion below:

Cyclic model:

In the 1930s, theoretical physicists including, Richard C. Tolman, proposed cyclic model for the universe as an alternative to the Big Bang. But their theories could not explain the decrease of entropy due to contraction of the universe as, according to the second law of thermodynamics, entropy should never decrease, as a whole for the universe.

Paul Steinhardt (Princeton) and Neil Turok (Cambridge) have recently proposed a model for the cyclic universe, in which space and time exist forever. The big bang is not the beginning of time. Rather, it is a bridge to a pre-existing contracting era. The Universe undergoes an endless sequence of cycles in which it contracts in a big crunch and re-emerges in an expanding big bang, with trillions of years of evolution in between. The temperature and density of the universe do not become infinite at any point in the cycle; indeed, they never exceed a finite bound (about a trillion - trillion degrees).

There is no inflationary era in the new cyclic model after the most recent big bang. The current homogeneity and flatness were created by events that occurred before the most recent big bang. The seeds for galaxy formation were created by instabilities arising as the Universe was collapsing towards a big crunch, prior to our big bang.The transition from big bang to big crunch is explained by recent developments in superstring theory that suggest that the cosmic singularity is otherwise.

Cheers.

How do we know it has not happened? The string theorists say there are 11 or 12 dimensions. Other bangs may have occurred in the 7 or 8 dimensions we do not see. Universes within Universes. The other possibility is that only some Universes survive and the chance of that is small as their fine structure constants, gravity values, etc do not lead to stability. They collapse immediately and maybe add a few photons to our Universe, though possibly not. If these are fairly infrequent they would be undetectable.

Some say the net energy of our Universe is zero. That means the net mass is zero too. Other Universes with zero net mass could appear and decay "right in front of us" and we might never know.

I don't think anyone can explain. Yet.

Big Bang's are responsible for the formation of our galaxy, comets, suns, planets and many more celestial bodies which are not sighted yet.

According to this theory, there was a gigantic, enormus mass(energy) that blasted and all the other things formed. Now the thing have been prooved that there is a form of energy(you can call that gravity) that has been expanding our universe and due to this the distance between two celestial objects increasing(don't go with earth and sun, it is due to sun's gravity).

If this same expanding energy begins to contract, all the celestial things will collid each other and the same mass is formed which was responsible for the big bang.

This means that for every big bang, big crunch is requirred and for a big crunch, the expanding gravity has to turn to contracting gravity.

Hence big bang can not be repeated at all the time, if so how can evolution be possible?

Though I don't understand a lot about the universe, I fiound this explanation of the Big Bang theory very interesting. Maybe it will shed some light on your question (my memory's not so good) ...

The Awesome Universe--Where Did It Come From? :

- The BIG Bang

- Questions the Big Bang Does Not Answer

- The Light-Year--A Cosmic Yardstick

- "We Are Missing Some Fundamental Element"

http://watchtower.org/e/19960122/article_01.htm

If the Big Bang is real I see it as a bouncing ball (think of a super ball). On the first bounce (the original BIG BANG) the ball bounces high (expands) and then comes back down (contrasts). When it reaches its original place in time it bounces (expands) again with less energy and contrasts many times with less energy after each cycle until it comes to rest. We could be in the first bounce or the last bounce...who knows.

I also believe that because space is infinite that many Big Bangs happen every day or every second for the past billion even trillion years. I can't imagaine, if the Big Bang is real, that something beginning smaller than the size of an atom in infinite space (even by chance) could not be happening every day. We just can't see it becasue it is beyond our event horizon...space is too vast (infinite) for it to just happen HERE or once every billions of years. In infinte space our entire Universe looks many many many times smaller than an atom...inifnitely smaller.

First let the universe die as it is going to in some billion years.For big bang to occur,there has to be nothing first.The big bang itself is not a proven theory and it is used to fill the gap of unknown,that is the creation of universe.As far as you going wrong is concerned,relax,nobody can go wrong on something which is not established.But yes,you are wrong when you say that it might have occured many times as the time duration measurement is done on many parameters from big bang start and we can now know about every small happenings in universe like supernova etc.

Big Bang is a...bluff theory...

To evaluate the size of the universe with respect to the time and space, one must assume the starting cause of this fantastic universe. Do you agree (practically) that anything which were holding the mass exploded and scattered atoms all around in the vacuum (what was there before...any empty space..? Or that atom itself had the total universe within it?), thereafter, gravitational pool started building up, organised everything in patterns of Galaxies or whatever, increased the mass of all atoms and became stars and planets...though claiming the Universe is constantly accelerating since then....!!! How wonderful...!!!

It is hypothesised that the 'Big bang' event caused our universe to come into existence. It also means that, we & all that we see and feel around us are the resultants of 'Big Bang'. Now can another 'Big Bang' occur within what was created by a 'Big Bang'? I do not think that it is possible. If it is possible, then the first one can not be called a 'big bang'.

Another 'Big bang' is possible, if the existing Universe becomes the victim of a 'Big Crunch'.

Who says it hasn't happened? The universe, to put it simply, is big, really big. We have probably only discovered 1 tenth of 1 percent of everything that is out there.

String theory states that there are many other dimensions we do not see with our eyes. It is quite possible that it has happened and we have not seen it.

big bang was the result of uncontrollable division taking place in a molecule. due this high amount of energy was released and therefore there was bang all particles moved away from each other.for repearting the big bang we need the same conditions which is immposible in near future and can happen later