Friday, March 17, 2006

The pointless search for the POINT singularity

Came across an interesting news article about observing the universe when it was a trillionth of a second old. '' I got to tell you I have always had a problem with the concept of a finite universe. I am really an ignorant layman when it comes to theoretical physics. I do not keep up with the latest Astrophysics rags, and probably would have a hard time doing so. However I am familiar with Hubble's law, redshift, microwave background radiation, and how it relates to the "Big Bang" theory. I also am familiar with special relativity, time dilation and the repulsive forces between atoms. I have never really been able to conceptually reconcile the two theories. How is it possible to measure the age of something when the actual concept of what you are measuring (time) is strongly effected by the density of the entity you are measuring.

Just take the universe out of it for a second and consider a large cloud of interstellar gas. After a thousand years, the cloud divides into two parts the first stays a constant density, the second collapses into a singularity (infinite density?). After another thousand years in the uncollapsed part, time proceeds at a "normal" pace relative to the rest of the universe (whatever that means). In the singularity time essentially stops. What is the age of the singularity? If you ask an observer in the cloud you would say two-thousand years. In the singularity you would say on thousand. What is the right answer? Its even possible that there is another observer outside the cloud to which time passes faster. So consider that for a second, then take away the cloud and everything else but the singularity and instead of collapsing it expands. To me that's the nature of the big bang. Going from a point of infinite density and stopped time to infinite space and variable time. How is it possible to measure something of which you are very much a part of and the thing you are measuring is also affected by your frame of reference? It seems impossible to extrapolate a beginning of the universe.

In a related article I read that 'before the big bang (the universe) all there was space with infitesimal variations of temperature' Along similar lines, how can there be something else other than or outside the universe? It seems to me that even empty space and background radiation constitute something. In my limited understanding of string theory even empty space is 'composed of' strings.

So basically I still don't get it and I am not sure even those people studying it get it either. The steady state theory, cyclical and slowing expansion theory are still around but are currently somewhat discredited by recent observations. I recall reading a paper describing the cyclical universe by I think Wheeler a long time ago. One of the things that struck me about it was that whether or not the universe was expanding or contracting, it would still seem to be expanding because the very nature of time would be affecting any observations made from within the universe. And since it is silly or perhaps impossible to conceive of something outside the universe the whole question of the end or the beginning of the universe seems a little ridiculous.


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