An Infinite Past?

[seer]

I think we could even grant more than this, by saying that there's weak indirect physical evidence. Something is weak if its already predicted to be true by other theories. For example one weak prediction of inflationary cosmology is the virtual non-existence of magnetic monopoles, or that the General Theory of Relativity is true. However none of this can establish it, yet it if any of it was shown to be false you might have ruled out those models.

But yes, basically there's no significant evidential support.

Yes, but even weak physical evidence would be physical evidence. Jim L was speaking of math equations, and I think that is the evidence that Tass and Shuny would point to also. But those equations, I think, would have to make predictions in the physical world, would have to be confirmed by reality. A while back I was watching a science program with Physicist Brian Greene (I know it is layman stuff for the masses). He pointed to a number of different string theories (6 or 7 if I remember) and they all were perfectly elegant and they all contradicted each other. So math, no matter how elegant, needs confirmation in the physical world.

[Sea of red]

Thank you for writing a post that doesn't invite fragmentation Sea of Red.

No problem, I've always respected your ability to hold your own.

You're wrong to call the BGV theorem speculation, it simple establishes a problem in all eternal inflationary models that have an average Hubble constant larger than zero. Namely that you get ultraviolet runaway problems as you go backwards in time. This isn't speculation, it mathematically proves that this problem will occur in almost all space-times.

I think you missed my point. Inflation to begin with is a framework that has yet to be confirmed in experiment, ask the folks at BICEP2. This whole idea is a very speculative theory that at times looks more like an ideology I'm sad to say. He'll we had people saying that inflation could work even if we don't find the predicted gravity wave patterns, which has more to do with anthropic crap than anything else.

Secondly, I do avoid the use of infinities for various reasons, and since a closed spacetime is more elegant and easier to treat when it comes to boundary conditions it looks favorable for those reasons alone. Ignoring here all philosophical problems with infinities. I don't like the mysticism you seem to throw towards the paradoxes that emerge from infinities in mathematics. I am aware of those, and its things like them that you'd typically use to argue that infinite extensive properties don't exist in the universe.

Sometimes what's elegant isn't reality. Even still, so what if we can currently understand the fundamental nature of space-time. It's no excuse to go and hand over the problem to religion. I'm not accusing you of that and I understand your reasoning for using arguments to double as illustrations.

Thirdly, I wouldn't call it speculation that the best supported list of models is the one where time has a definite beginning. Even if quantum gravity models come about there's nothing that really indicates that they would have an infinite past either. It would be an argument from ignorance that because there's stuff out there we don't know about, we don't have evidence that the past is finite. From physics alone, this seems like the only and best option.

Now this is just going to far. Even the authors of this theorem have stated that it does not prove an absolute beginning of time and frankly, I don't know where you got that from. The main point of BGV was to show that inflation is not geodesically complete, and thus other physics would be required to explain the beginning of time. This has been suspected for years as Borde and Vilenkin have wrote many independent papers on that subject, and the theorem proved to be more of an exercise in differential geometry than anything else. I can provide you with those old papers if you like.

And what's with the "not even understanding the barebones essentials of these topics"? Do you mean to say that the theologians discussing these things don't understand General Relativity, or do you mean that things like quantum gravity isn't understood well enough yet to warrant a discussion?

These are complicated issues that take years of heavy training in the mathematics and physics to understand these subjects. For Bill Craig to simply jump in and start talking about papers that I he can't even understand the equations of is just plain ignorant.

The former is clearly false in some circumstances, the latter is false as well since we do have some tentative models of what a successful quantum gravity would look like and it doesn't appear that it will change the outcome ultimately. This will be assertion on my part until I get home. The weekend after this one I'll be there.

We're getting into some very technical territory here. My issues with the anthropic principle, inflation, multiverse concepts, and string theory are numerous and so if you're up for it we can chat about it in another thread if you'd like.

You're tone got a wee bit patronising with these statements.

That was not my intention.

James

[shunyadragon]

Thirdly, I wouldn't call it speculation that the best supported list of models is the one where time has a definite beginning. Even if quantum gravity models come about there's nothing that really indicates that they would have an infinite past either. It would be an argument from ignorance that because there's stuff out there we don't know about, we don't have evidence that the past is finite. From physics alone, this seems like the only and best option.

None of these theorems or models, like BVG, come close to proposing a beginning of everything physical, as the Kalam argument, and other theist arguments would propose that would require another 'Source,' like a Creator. These theorems and models propose 'beginnings,' i. e. our universe from a singularity with in a greater context of the cosmos.

The same problem arises as to what is referred to as 'nothing' in science, and 'nothing' in theology, as in beginnings from nothing. In physics and cosmology this nothing is in reality something, the Quantum World of Quantum gravity, and Quantum zero point, from which things arise and beginnings happen.

[seer]

These theorems and models propose 'beginnings,' i. e. our universe from a singularity with in a greater context of the cosmos.

That is just false Shuny, Vilenkin himself says that Eternal Inflation/multiverse needs a beginning. https://www.youtube.com/watch?v=NXCQelhKJ7A

[shunyadragon]

That is just false Shuny, Vilenkin himself says that Eternal Inflation/multiverse needs a beginning. https://www.youtube.com/watch?v=NXCQelhKJ7A

False seer, Absolutely nowhere did Vilenkin propose that this was an absolute beginning of everything, To propose the possibility (this only a model and not in any way conclusive) of a beginning of a multiverse does not eliminate the possibility that there are infinite multiverses. IF you can cite Vilenkin as proposing absolute beginnings, please do. You do not accept the evidence for existence of multiverses anyway, so 'Where are you coming from with this meaningless assertion?' You jump around from theorem to theorem cherry picking things that agree with your religious agenda. It is possible that multiverse exist within an infinite Quantum world. Still waiting . . .

[seer]

False seer, Absolutely nowhere did Vilenkin propose that this was an absolute beginning of everything, To propose the possibility (this only a model and not in any way conclusive) of a beginning of a multiverse does not eliminate the possibility that there are infinite multiverses. IF you can cite Vilenkin as proposing absolute beginnings, please do. You do not accept the evidence for existence of multiverses anyway, so 'Where are you coming from with this meaningless assertion?' You jump around from theorem to theorem cherry picking things that agree with your religious agenda. It is possible that multiverse exist within an infinite Quantum world. Still waiting . . .

What are you talking about. Vilenkin makes it clear that his theory does require a beginning for the multiverse. It is in the link, he himself, uses the term beginning. He doesn't address infinite multiverses - whatever that means. I mean do you have a credible theory that leads to an eternal past? What is it?

[shunyadragon]

What are you talking about. Vilenkin makes it clear that his theory does require a beginning for the multiverse. It is in the link, he himself, uses the term beginning. He doesn't address infinite multiverses - whatever that means. I mean do you have a credible theory that leads to an eternal past? What is it?

False seer, Absolutely nowhere did Vilenkin propose that this was an absolute beginning of everything, To propose the possibility (this only a model and not in any way conclusive) of a beginning of a multiverse does not eliminate the possibility that there are infinite multiverses. IF you can cite Vilenkin as proposing absolute beginnings, please do. You do not accept the evidence for existence of multiverses anyway, so 'Where are you coming from with this meaningless assertion?' You jump around from theorem to theorem cherry picking things that agree with your religious agenda. It is possible that multiverse exist within an infinite Quantum world. Still waiting . . .

I mean do you have a credible theory that leads to an eternal past? What is it?

You have cited the following one!

Source: http://arxiv.org/abs/astro-ph/0204479

The Cyclic Universe: An Informal Introduction

Paul J. Steinhardt, Neil Turok

(Submitted on 29 Apr 2002)

The Cyclic Model is a radical, new cosmological scenario which proposes that the Universe undergoes an endless sequence of epochs which begin with a `big bang' and end in a `big crunch.' When the Universe bounces from contraction to re-expansion, the temperature and density remain finite. The model does not include a period of rapid inflation, yet it reproduces all of the successful predictions of standard big bang and inflationary cosmology. We point out numerous novel elements that have not been used previously which may open the door to further alternative cosmologies. Although the model is motivated by M-theory, branes and extra-dimensions, here we show that the scenario can be described almost entirely in terms of conventional 4d field theory and 4d cosmology.

© Copyright Original Source

By the way Guth proposes that the universe might be infinite - https://www.youtube.com/watch?v=rfeJhzPq3jQ

[Tassman]

That is just false Shuny, Vilenkin himself says that Eternal Inflation/multiverse needs a beginning. https://www.youtube.com/watch?v=NXCQelhKJ7A

Well, this is really what the thread is all about isn't it? Vilenkin certainly uses the word “beginning” but he doesn't mean by it what you and some others around here seem to think he means – as several of us have tried to point out.

As SoR, in his usual concise way, states: “Even the authors of the [BGV] theorem have stated that it does not prove an absolute beginning of time…The main point of BGV was to show that inflation is not geodesically complete, and thus other physics would be required to explain the beginning of time. This has been suspected for years as Borde and Vilenkin have written many independent papers on that subject, and the theorem proved to be more of an exercise in differential geometry than anything else”.

This is a relatively new field of investigation and physicists have a way to go before the fundamental nature of space/time is well understood by them - let alone by opportunistic apologists like WL Craig.

[seer]

False seer, Absolutely nowhere did Vilenkin propose that this was an absolute beginning of everything, To propose the possibility (this only a model and not in any way conclusive) of a beginning of a multiverse does not eliminate the possibility that there are infinite multiverses. IF you can cite Vilenkin as proposing absolute beginnings, please do. You do not accept the evidence for existence of multiverses anyway, so 'Where are you coming from with this meaningless assertion?' You jump around from theorem to theorem cherry picking things that agree with your religious agenda. It is possible that multiverse exist within an infinite Quantum world. Still waiting . . .

Again Shuny, you are nuts. I never claimed that any possibility was eliminated. Or that Vilenkin didn't have other "ideas." Only that his multiverse theory required a beginning. And that you can find in the link I posted. So again, if you have any actual evidence for an infinite past please enlighten us all.

You have cited the following one!

Yes I agree, that is a nice idea. But where is the evidence? Like Dr. Carroll mentioned in the debate with Bill Craig there are a number of different models out there that may lead to an infinite past but they all have serious problems.

[seer]

Well, this is really what the thread is all about isn't it? Vilenkin certainly uses the word “beginning” but he doesn't mean by it what you and some others around here seem to think he means – as several of us have tried to point out.

As SoR, in his usual concise way, states: “Even the authors of the [BGV] theorem have stated that it does not prove an absolute beginning of time…The main point of BGV was to show that inflation is not geodesically complete, and thus other physics would be required to explain the beginning of time. This has been suspected for years as Borde and Vilenkin have written many independent papers on that subject, and the theorem proved to be more of an exercise in differential geometry than anything else”.

This is a relatively new field of investigation and physicists have a way to go before the fundamental nature of space/time is well understood by them - let alone by opportunistic apologists like WL Craig.

I have no idea what you are saying Tass. First, Vilenkin certainly did mean begin like we use begin. The man is not that sloppy, and that was proved in his exchange of e-mails with Craig where Vilenkin made it clear that Craig did not misquote him. The fact is his theory does not get us to an eternal past - period. No matter what language you care to use. And Tass, you are free to keep "believing" in an eternal physical past even without a lick of actual physical evidence. Like I always say - never let it be said that I would deny a man his faith.

[shunyadragon]

Again Shuny, you are nuts. I never claimed that any possibility was eliminated. Or that Vilenkin didn't have other "ideas." Only that his multiverse theory required a beginning. And that you can find in the link I posted. So again, if you have any actual evidence for an infinite past please enlighten us all.

Again, and again and again, you are selectively citing physicists and cosmologists to support your religious agenda. The beginnings described in these theorems and models never described anything that is close to the absolute beginning required for theist arguments like Kalam. It is a contradiction to misrepresent Vilenkin concerning the multiverse having a beginning and then assert that his multiverse model supports your claim of a beginning of our physical existence,

Yes I agree, that is a nice idea. But where is the evidence? Like Dr. Carroll mentioned in the debate with Bill Craig there are a number of different models out there that may lead to an infinite past but they all have serious problems.

Please cite Dr. Carroll specifically and completely. I do not believe he said this in his debate with Craig. He did say there were a number of different models that describe the cosmos as infinite, and the one I referred does that. ALL models have unresolved problems, and cannot be used selectively misuse one aspect of a model to support a religious agenda. IF you do not believe these models are supported by the evidence, don't cite them as evidence for your religious agenda.

Actually none of the models and theorems concerning our cosmos can be ethically cited in an argument to conclusively support an infinite and eternal nor finite and temporal cosmos. The ultimate nature of our cosmos is unknown.

[seer]

Again, and again and again, you are selectively citing physicists and cosmologists to support your religious agenda. The beginnings described in these theorems and models never described anything that is close to the absolute beginning required for theist arguments like Kalam. It is a contradiction to misrepresent Vilenkin concerning the multiverse having a beginning and then assert that his multiverse model supports your claim of a beginning of our physical existence.

Where did I ever, ever say that any physicists supported my beliefs? I did say that we have NO EVIDENCE for an eternal physical past. And the fact that Vilenkin's model does not get us there - period.

[shunyadragon]

Where did I ever, ever say that any physicists supported my beliefs? I did say that we have NO EVIDENCE for an eternal physical past. And the fact that Vilenkin's model does not get us there - period.

You cherry pick theorems and models from different scientists to support your religious agenda. If you genuinely believe there is no evidence it is unethical to do this.

If it is not to support your religious agenda, why do it?

[shunyadragon]

I have no idea what you are saying Tass. First, Vilenkin certainly did mean begin like we use begin.

No he did not!

The fact is his theory does not get us to an eternal past - period. No matter what language you care to use. And Tass, you are free to keep "believing" in an eternal physical past even without a lick of actual physical evidence. Like I always say - never let it be said that I would deny a man his faith.

This only shows that his theorem indicated a beginning, and not an absolute beginning, and as he admits there are other theorems that show an eternal past. He admits that his theorem cannot give us an eternal past, but that of course only applies to his theorem. Guth one of his partners states that our physical existence could be infinite.

[seer]

No he did not!

Prove that Vilenkin used beginning in an uncommon way. It really is perfectly clear in the You Tube link.

This only shows that his theorem indicated a beginning, and not an absolute beginning, and as he admits there are other theorems that show an eternal past. He admits that his theorem cannot give us an eternal past, but that of course only applies to his theorem. Guth one of his partners states that our physical existence could be infinite.

Again Shuny, Guth or anyone else can assert an infinite past, the problem is there is zero physical evidence for such a theory. And what exactly is the difference beginning and absolute beginning? If something begins to exist it begins to exist - period.

You cherry pick theorems and models from different scientists to support your religious agenda. If you genuinely believe there is no evidence it is unethical to do this.

If it is not to support your religious agenda, why do it?

You are lying again, I never cherry pick anything - my point has always been, that there is zero physical evidence for an infinite past. And yes, I am a Christian who believes that God created this universe - so? You certainly have no evidence to the contrary.