Models and theories about the origins of the universe or greater cosmos.

[JimL]

Jim, I'm not following you. Are you suggesting that if our universe was not expanding that our sun, or stars in general, would burn forever? And if all our stars eventually burn out where is the useable energy?

What I am trying to explain is that entropy in a non expanding volume has a limit which we call equalibrium. In such a case the second law would no longer apply. If that same universe magically began to expand, then the second law would come into effect again, the entropy would begin to increase once again. The reason entropy reaches a maximum is due to the volume of the system.
Put it this way, imagine our universe is not expanding and is filled with nothing but gas. No sun, no stars, planets, nothing. How can the entropy increase? Can you explain in what sense the entropy increases in such a case?

[shunyadragon]

That is completely false Shuny and you know it. The inflation theory is the theory, not only for individual universes, but for the multiverse as a whole. And as Vilenkin makes clear there is no model for an eternal past. And as I quoted, it is possible, as least mathematically, to have an eternal future. And once again - an open system is one that can gather energy from outside of itself, if the multiverse is an open system from where comes this extra energy?

Descriptive reference to an ancient Hindu model does not reflect the current view of cosmology. If your going to take this Hindu view as a whole accepted by Vilenkin, then the multiverse is eternal, as he described in the citation.

Again for the readers:

http://now.tufts.edu/articles/beginning-was-beginning

No model answers the question of an eternal past or not. The enrgy comes from the matrix of the multiverse, ie dark energy and dark matter. If you look at the evidence in our universe. The galaxies are expanding, but the matrix of the dark energy and matter is not.

So it is clear to anyone without a bias that the multiverse as a whole can not have an eternal past.

No it is not clear, it is unknown.

I already explained myself Shuny - you haven't. There is no model for an eternal past. What energy source is feeding your open system? And the multiverse theory is only a theory of mathematics at this point - unlike with the Quantum World there is no direct, observable evidence multiverse. No matter how much you pout and hold you breath...

I already explained myself with references. The multiverse is a non-equilibrium open system. There is no evidence in any model that would conclusively determine that the multiverse is infinite nor finite, nor have a beginning or not.

[seer]

What I am trying to explain is that entropy in a non expanding volume has a limit which we call equalibrium. In such a case the second law would no longer apply. If that same universe magically began to expand, then the second law would come into effect again, the entropy would begin to increase once again. The reason entropy reaches a maximum is due to the volume of the system.
Put it this way, imagine our universe is not expanding and is filled with nothing but gas. No sun, no stars, planets, nothing. How can the entropy increase? Can you explain in what sense the entropy increases in such a case?

Jim there is a difference between useable energy and energy that is not useable. If all the stars burnt out (which they will do some day) that energy is not lost. That would be a heat death for the universe - they energy is still within the boundaries of the universe but it is unusable. It doesn't do anything, it does create anything. So in your greater universe wouldn't this also apply? What is generating these new smaller universes within it?

[shunyadragon]

Jim there is a difference between useable energy and energy that is not useable. If all the stars burnt out (which they will do some day) that energy is not lost. That would be a heat death for the universe - they energy is still within the boundaries of the universe but it is unusable. It doesn't do anything, it does create anything. So in your greater universe wouldn't this also apply? What is generating these new smaller universes within it?

Only in a closed equilibrium entropy system would the energy be considered not usable.

[JimL]

Jim there is a difference between useable energy and energy that is not useable. If all the stars burnt out (which they will do some day) that energy is not lost. That would be a heat death for the universe - they energy is still within the boundaries of the universe but it is unusable. It doesn't do anything, it does create anything. So in your greater universe wouldn't this also apply? What is generating these new smaller universes within it?

Well, now you are changing the subject, or shall i say returning to my original idea, so I guess i got my point across. There is a limit to entropy increase within an infinite or non expanding volume.
Now to your question, I gave my personal understanding of that as well. The uncertainty principle, quantum fluctuations in the energy field can turn the second law on its head causing patches of spacetime to inflate. You see the same change of effect with gravity which normally we see as an attractive force but under the right conditions becomes a repulsive force and in this case it is repulsive gravity which is the driving force of inflation. I might add as food for thought, the energy of the universe regardless of its increasing volume due to expansion remains constant throughout space. Every cubic centimeter of space has a certain percentage of energy that never diminishes regardless of the increasing volume due to expansion.

[seer]

Well, now you are changing the subject, or shall i say returning to my original idea, so I guess i got my point across. There is a limit to entropy increase within an infinite or non expanding volume.
Now to your question, I gave my personal understanding of that as well. The uncertainty principle, quantum fluctuations in the energy field can turn the second law on its head causing patches of spacetime to inflate. You see the same change of effect with gravity which normally we see as an attractive force but under the right conditions becomes a repulsive force and in this case it is repulsive gravity which is the driving force of inflation. I might add as food for thought, the energy of the universe regardless of its increasing volume due to expansion remains constant throughout space. Every cubic centimeter of space has a certain percentage of energy that never diminishes regardless of the increasing volume due to expansion.

Funny, the live debate tonight touches on just about all these question. I will you with that:https://www.youtube.com/watch?v=FifVgGL_cIY

[shunyadragon]

Funny, the live debate tonight touches on just about all these question. I will you with that:https://www.youtube.com/watch?v=FifVgGL_cIY

It may 'touch' on these issues, but a doubt we will see more then a superficial coverage.

I am very pleased with Dr. Sean Carroll's response, and yes it went far beyond the superficial argument.

The main problem is that Craig is out of his element. He has no competence in arguing 'Physics and Cosmology' to justify an argument for the existence of God, from the argument for 'beginnings,' 2nd Law of Thermodynamics, nor the Teleological argument. His selective parsing of quotes out of context by scientists glaringly reflects this problem. He is still arguing a fudged Newtonian Physics.

Craig repeated himself too much. Repeating over and over and over again does not help unsound arguments.

'Pop into being from nothing?????' This is ridiculous from any scientific perspective.