Big Bang: Discovering the Reasons Behind Its Occurrence

[finiter]

When the dark matter first condensed, yes, it started to clump.
It wasn't until the protons and electrons became neutral atoms that the normal matter started to become clumpy.

Can becoming clumpy be regarded as becoming cold? In that case, the entropy should decrease; so it would appear that the approved model of the black hole goes against what is expected.

 

[Chalnoth]

Can becoming clumpy be regarded as becoming cold? In that case, the entropy should decrease; so it would appear that the approved model of the black hole goes against what is expected.

Well, it gets a bit complicated there. Becoming clumpy does relate to a loss of energy, but the way that gravity works, things that become more clumpy tend to have higher temperatures. This is a statement that the specific heat of gravitational systems is negative. So, for instance, as a cloud of gas collapses into a star, it loses total energy, but ends up getting hotter as the gas falls lower and lower into the potential well.

One thing to bear in mind is that the way entropy interacts with gravitating systems is not simple, and cannot be directly related to the usual thermodynamic concepts we're used to. In fact, except in very special circumstances, we don't even know how to calculate the entropy of a gravitating system.

 

[finiter]

In fact, except in very special circumstances, we don't even know how to calculate the entropy of a gravitating system.

That means the 'entropy of a gravitating system' is a grey area, and one can try some unexplored ideas to relate heat, gravity and entropy.

 

[Chalnoth]

That means the 'entropy of a gravitating system' is a grey area, and one can try some unexplored ideas to relate heat, gravity and entropy.

Well, it's not terribly difficult to at least get a handle of when a gravitational system increases in entropy. If you take some gravitational system, and let it be, then whatever happens will be an increase in entropy. This typically means an emission of particles such as photons which leads to a reduction in energy of the system, which causes it to collapse inward, which causes the temperature to increase.

We don't currently know how to precisely define the value of the entropy in such a situation, but we can be very confident it increases.

 

[budrap]

Higher-resolution observations (e.g. from the HST) show that there is no reason to believe these are anything but chance correlations, and that there isn't actually any interaction. The information is available on the Internet if you're willing to look for it. Just pick a specific observation and go hunting.

I am not interested in beliefs - yours or mine, I prefer empirical data. The chance correlations argument is statistical in nature and disingenuous when applied to individual observations. For any statistical argument to have merit it needs to be applied to a statistically significant set of high redshift/low redshift pairs. The one man who bothered to make a survey of such pairs was Halton Arp and he was denied telescope time for the attempt.

You can't trust the behavior of the result in the vicinity of any singularities in the coordinate system (which would be at t=0), but other than that it doesn't mess anything up...

We should obviously be careful not to extrapolate it too far beyond our cosmological horizon, or too close to t=0. And we certainly wouldn't want to use these coordinates to attempt to describe behavior too close to overdense/underdense regions. But other than that it isn't a concern.

So the argument seems to be that the Big Bang model gets the right answers (after proper adjustments for predictive failures) except for those areas where it yields illogically absurd results which we are to ignore as inconvenient and thus we can consider the model a great and scientifically sound success. "We get the right answers except when we don't" is nothing but a scientifically unjustifiable evasion.

The nature of my criticism can be summarized as follows:

1) The observed cosmos either comprises a singular entity or it does not.

2) Scientists have assumed the first option without ever properly vetting either.

The problem with your posts is that you seem incapable of even grasping the conceptual distinction between the two possibilities. All of your responses consist of retreating into the shelter of your preferred model, pointing out its successes and discounting its failures and inconsistencies. But discounting inconvenient results is a mathematical strategy only, one that should have no place in science.

The big bang model is not expected to be complete. General Relativity itself is the problem here: GR predicts that there will be a singularity in the finite past, almost no matter what sort of physical model we use. We expect that a correct theory of quantum gravity will correct this flaw in GR.

No, GR is not the problem here it is the imposition on the cosmos of a conceptual "Universe" that causes GR to spit out absurd results - the very concept itself being antithetical to GR.

The very idea of a universal reference frame is one that if you are within a perfectly-insulated, closed container, you can tell how fast you are moving. Picking a particular coordinate system within which to do calculations doesn't change the fact that we can't do this. In the FRW universe, we would still have to look outside to see the CMB, for instance. There would be no way to determine our motion without looking outside.

You are conflating a Universal SpaceTime Reference Frame with the long discarded concept of the Aether, which is a USTRF with a pervasive physical component. They are not one and the same. Relativity theory dispensed with the need for any form of USTRF not just the Aether. The Big Bang model however, by treating the "universe" as a singular entity, inherently assumes the existence of a USTRF albeit one without a pervasive physical component.

 

[Chalnoth]

I am not interested in beliefs - yours or mine, I prefer empirical data. The chance correlations argument is statistical in nature and disingenuous when applied to individual observations. For any statistical argument to have merit it needs to be applied to a statistically significant set of high redshift/low redshift pairs. The one man who bothered to make a survey of such pairs was Halton Arp and he was denied telescope time for the attempt.

I wasn't talking about beliefs. I was talking about observations. I'm saying that the observations that Arp made where he claimed there was some interaction between a low redshift galaxy and a high-redshift quasar were shown to be misleading: higher-resolution observations by Hubble of these same galaxies show no interaction whatsoever.