Wednesday, June 13, 2012

Big Bang Cosmology- How Far Back?

The current scientific consensus is that the universe came into being following an event known as the ‘Big Bang’. Matter expanded rapidly from an extremely hot, extremely dense state, having transmuted from pure energy. Matter and energy then sprang forth to form the universe as we know it. This conclusion is drawn by interpreting certain observed information, notably two phenomena, the cosmic microwave background and the red shift of distant objects. 

The Big Bang is a generic expression for theories of this general nature but which may differ in the understanding of details. The prevailing detailed theory is the Lambda CDM model.

On the face of it there is reasonable evidence for some sort of Big Bang scenario. However as we probe into very early cosmological time, and try to evaluate what happened when matter first came into existence, we find there is little theory or consensus. There is an initial time, called the Planck Epoch, before which it is impossible, according to current understanding of fundamental physics, to probe. There are no firm ideas on what ‘seeded’ the Big Bang.  There is no understanding of what came before the Big Bang, or indeed whether there was a 'before'.

We are caught in the flow of time. Richard Feynman sets this out for those who have never considered it in his excellent book 'The Character of Physical Law'. When considering long gone events, we are left with our imagination and our ability to extrapolate backwards to form a view of the past. When we do this we rely on the assumption that there are no sudden changes or unexpected factors, other than the ones we already know about or have inferred. We often make many large jumps of conjecture. We assume we have all the information, all the relevant laws, all the correct theories, all the variables, all the significant factors. These are big assumptions.

It is certainly possible that God could have used a process similar to the Big Bang to create the Universe. The theory does have some widely acknowledged problems, such as the matter/anti-matter balance, and the dark matter/dark energy hypothesis/mystery. 

What the Big Bang Theory certainly does not do is rigorously explain how everything came from nothing. The prevailing lambda CDM model for cosmological origins requires the sudden appearance of expanding space-time. It does not tell us where space-time came from. It also requires immense radiation energy, again without rigorously explaining where it came from. It requires the background conceptual fabric of mathematics. Does that have an existence independent of any physical reality. If so, why?

If scientists are going to see scientific reductionism as a complete explanation of beginnings, to rid themselves of that word 'creation', then we will have to get beyond this point. I do not believe there are currently any meaningful leads on this one. 

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