Posted 10 December 2006 - 10:00 PM
Although I am only a freshman in college and a physics major, I know enough to realize that a lot of what is being said here is done with little prior knowledge to the Big Bang Theory and the Inflationary model. I recently posted about it, but I will give a detailed description of what the theory states.
Keep also in mind that this is a VERY young theory. And it also is to describe the entire history of the universe. Meaning that research in this field is still very preliminary but I will explain why it is such a strong theory, though there are many loopholes that are exploited frequently by creationists.
The Big Bang Theory first does not state how the universe started, for the Big Bang is STILL CONTINUING! The universe is still expanding, and as observations are the expansion is accelerating. The theory states that at one point the universe (after T = 10^-43 seconds) went into an extreme inflationary state. But this was not done by that matter moving. Matter moves at a very slow rate compared to the expansion of the universe on large scales. By General Relativity, space is considered an actor, which is warped by the mass density within it. Space can expand greater than the speed of light, with matter embedded in it in a sense. It is as if you have raisens in bread, and the bread expands, the raisens did not move through the bread, but expanded evenly.
At the early part of the universe, energy was very dense and the temperatures were high (common in thermodynamic systems). As things in relative equilibrium expand they cool down. At about T = 300,000 years, the universe had reached a temperature in which the particles in the universe (protons, neutrons and electrons) were at a low enough energy to combine for the first time (called recombination). This then released a vast amount of high energy photons (now seen as the Cosmic Microwave Background). Before this, if any type of atom tried to form, then it would be obliterated and scattered by other high energy particles. The expansion continues and gravity builds an effect, combining clouds of mostly hydrogen to form stars, which then forums the other elements due to Fusion in the core of stars. Stars explode which creates the other elements seen the universe. Gravity continues and forums into planets as heavier elements are "more' abundant (yet still a small portion of the overall matter).
The proof for this expansion is in the continued redshifts of the galaxies in all directions. THIS DOES NOT MEAN WE ARE IN THE CENTER! If you take any sheet of dots, and then increase the scale factor of those dots, the universe will look like it is expanding from each dots perspective. All galaxies that are not gravitaitonally bound (for us that is outside of our local cluster) are expanding away from us, and us from them.
The proof for a hot dense early history of the universe comes in the relative abundances seen in the elements. It can be predicted that by mass 75% of the universe was hydrogen early on, about 24.99999% as helium, and less than one percent other material. This calculation is done using energy combination probabilities that are quantum mechanically understood (I learn some of that next year). Scientists predicted what the relative abundances would be if this type of universe were true and THEN AFTERWARDS compared them to the period table abundances (observed abundances) and they match up with an impressively low (in physics that means practically not even worth mentioning) % of error.
Also another prediction from the theory was made before discovered, The Cosmic Microwave Background. This is the light seen at about 300,000 years after T=0, and was predicted to be around 2 degrees kelvin and nearly completely isotropic and homogeneous in nature. This was discovered a short time later to be almost perfectly isotropic and homogeneous in 1 part in 10^8 (very small almost completely perfect in all directions).
No Creation Scientist discovers these things. They only take what scientists know and try to take on a creator to it. Very little value in that (no new science!).
And before I get any more "WHERE DID THE MATTER COME FROM" posts. Where did your god come from? Until you can answer me that question, I think it is fine that scientists have not figured out with a good amount of certainty how the energy got there in the first place.
Also at this moment in history it is impossible to know how to probe that which is not matter. Science can not send highly energetic particles to collect data in cosmology. We can only do things in indirect manners (which so far has gotten us cars, computers, etc!).