Big Problems with the Big Bang..., page 1

Originally posted by Evolution Cruncher
about 20 billions years ago, all the matter in the universe was gathered and compressed into a region, no bigger than the period at teh end of this sentence.
and then it spun faster and faster. then one day, it exploded.

I think that you've already been given some papers on inflation and the big bang.

4.6 billions years ago, the earth was formed

This has nothing to do with the big bang or inflation and is an entirely different subject.

im just looking for all of the other versions.

There aren't other 'versions' strictly. There are some variations on inflation and the like, but they are different, as far as I know, in rather technical details. The description presented above is a very standardized, non-technical-language description. A very 'hand waving' version at that too.

Generally, textbooks are good for teaching the basics of these kinds of things. If a person wants to really research and question these things, textbooks aren't useful for that purpose, they weren't designed for it. Its like reading a set of instructions to build a model airplane, you can be really good at it, but that doesn't mean one is an aircraft engineer or pilot. So be wary of textbooks if you aren't being tested on the subject in school.

This set of pages looks like a good set of explanations and discussions on it. Here's a somewhat garbeled selection:

The Big Bang Model rests on two theoretical pillars: [...]A key concept of General Relativity is that gravity is no longer described by a gravitational "field" but rather it is supposed to be a distortion of space and time itself[...]That is, the matter in the universe is homogeneous and isotropic when averaged over very large scales. This is called the Cosmological Principle.[...]Given a law of gravity and an assumption about how the matter is distributed, the next step is to work out the dynamics of the universe - how space and the matter in it evolves with time. The details depend on some further information about the matter in the universe, namely its density (mass per unit volume) and its pressure (force it exerts per unit area), but the generic picture that emerges is that the universe started from a very small volume, an event later dubbed the Big Bang, with an initial expansion rate.

Interestingly, the page has these cautions:

Please avoid the following common misconceptions about the Big Bang and expansion:

The Big Bang did not occur at a single point in space as an "explosion." [...]That region of space that is within our present horizon was indeed no bigger than a point in the past. Nevertheless, if all of space both inside and outside our horizon is infinite now, it was born infinite. If it is closed and finite, then it was born with zero volume and grew from that. In neither case is there a "center of expansion" - a point from which the universe is expanding away from.

It is beyond the realm of the Big Bang Model to say what gave rise to the Big Bang. There are a number of speculative theories about this topic, but none of them make realistically testable predictions as of yet.

Here is another page on it:

When Einstein formulated the general theory of relativity, he found that it was incompatible with a static universe; the equations predicted that the universe must either be expanding or shrinking. [...]Extrapolating this expansion backwards, we find that at a specific time in the past the universe would have been infinitely dense[...]The big bang model has been extremely successful at explaining known aspects of the universe and correctly predicting new observations. Nonetheless, there are certain problems with the model. There are several features of our current universe that seem to emerge as strange coincidences in big bang theory. Even worse, there are some predictions of the theory that are in contradiction with observation. These problems have motivated people to look for ways to extend or modify the theory without losing all of the successful predictions it has made. In 1980 a theory was developed that solved many of the problems plaguing the big bang model while leaving intact its basic structure. More specifically, this new theory modified our picture of what happened in the first fraction of a second of the universe's expansion. This change in our view of that first fraction of a second has proven to have profound influences on our view of the universe and the big bang itself. This new theory is called inflation.[...]
An element is defined by the number of protons in a nucleus—one for hydrogen, two for helium, and so on. For roughly three minutes after the big bang the temperature of the universe was so high that protons and neutrons couldn't bind together into nuclei; the particles all had so much energy that the forces that hold nuclei together were too weak to make them stick to each other. Thus for those first three minutes the only element in the universe was hydrogen, i.e. single protons not bound to anything else. (A neutron with no proton is not considered an element.) As the universe expanded and cooled it eventually reached a temperature where the protons and neutrons could bind together, and different elements were formed. The formation of these nuclei from their constituent particles (i.e. protons and neutrons) is known as nucleosynthesis. Nuclear theory is well tested and understood. By applying it to a homogeneous, expanding medium at high temperature we can predict what relative abundances of different elements should have emerged when these nuclei were formed in the early universe. It turns out that only the three lightest elements, hydrogen, helium, and lithium, would have been able to form at that time. All of the heavier elements were formed much later in stars, and currently make up a tiny percentage of the matter we see in the universe. The predictions of the relative abundances of these light elements accurately match the observational data. This match is particularly important because it strongly suggests that the big bang model is an accurate description of the universe at least as far back as nucleosynthesis, i.e. three minutes after the predicted moment of the big bang. All of the other evidence for the theory, such as the microwave background and the motions of distant galaxies, relate to the universe at much later times, so we have no direct evidence for the accuracy of the big bang model before nucleosynthesis.

Haven't read the whole of that paper, but it looks like its a good description so fars anyway.

Also, here is a neat little slide presentation on some of these subjects.

And here is an interseting consideration of the physics of the big bang and some of its philosophical implications