Vilenkin, 2012 at Hakwing´s birthday event: "Did the universe have a beginning? my answer is probably yes,.., there are no models, at this time, that provide a satisfactory answer for a universe with out a beginning..."
I'm about halfway through this, and regardless of conclusions, thank you for pointing me to it. It's great.
It is, however, beside my actual point, which is that Craig wants to have his cake and eat it too.
Your Welcome.
You said Carroll talked real science:
Fact:
Carroll mislead others in his debate with Craig, at least, in relevance to Boltzman´s brains (as Aguirre clearly states to Carroll´s face, in front of virtually every other recognized physicists, of the moment).
Carroll himself, states on one of the reference videos I posted: "So, you can get a universe,that just looks like our very early universe, from a very simple starting point, and since then, there´s been no better model that has come along" , even though, he argued different in the debate (based on unproven theoretical models, the one´s he refers as no better than the one starting from a very simple point, in the previous quote). So, in fact he mislead others, in more than just Boltzman´s brains respect.
I hope, you take pause before stating the same again.
You said Vilenkin did not agree the Universe had a beginning:
Fact:
Vilenkin made the most comprehensive study of the types of theoretical models available, at the moment, and, concluded that probably the Universe had a beginning. And, states and defends it in front of the most distinguished panel possible.
I hope, you take pause before stating the same again.
All the rest (Carroll used as support for his arguments) are "Feynman´s" guesses (hypothesis) that might turn out to be validated by observation or not.
If "Craig wants or not his cake and eat it too", I couldn´t care less, I am interested in the support for the premises of his, or other´s arguments.
Onto, I can’t see your videos but since Aguiire is the one main defenders of the idea that we do live in a multiverse and he also suggests that multiverse is eternal into the past I find it unlikely that Agguirre would side with Craig. Aguirre recently wrote a piece on this in Sky and Telescope. I suggest you read it:
1. scipp.ucsc.edu/~aguirre/.../Where-Did-It-All-Come-From%3F.pdf
In fact it appears to me that it’s Craig that did the misrepresenting about Boltzmann brains. If you have an infinite multiverse ( as Guth and Vilenkin suggest) then Boltzmann brains and universes like ours both occur an infinite amount of time and so neither is more likely than the other. Unless that is, you pick a preferred measure of probability and picking that measure can determine properties of the multivere. This is what Carroll says and that’s with Guth and Vilenkin says here:
http://arxiv.org/abs/0808.3778
“In an eternally inflating multiverse,
The numbers of normal observers and Boltzmann brains
Produced over the course of eternal inflation are both infinite.
They can be meaningfully compared only after
One adopts some prescription to regulate the infinities.”
Vilenkin has argued the universe had a beginning, but he argues it happened naturally without a cause. I find it amazing that Craig can stand on a stage and quote Vielnkin to back up premise 2 and then says no one would suggest a violation of premise 1. How does he have the nerve to do this?
Vilenkin review is not very comprehensive. He's analysed only three models (in the paper Criag quotes in 2012)1 eternal inflation and other cosmologists disagree with him on that; see Nomuira and Aguirre and Susskind for example. He also analysed the Ekpyrotic models and the emergent universe models. These models aren’t that popular in the literature anyway. I think more popular models are non singular bounce models and Vilenkin admitted that these models do violate his theorem. Bottom line is Vilenkin's opinion is not that relevant, what is relevant, is the consensus in the scientific literature. I would say Carroll has it right, there is no consensus. More importantly still is there is no empirical test of any of these theorems.
It was Craig that does the misleading.
Here are two more example I can think off the top of my head. Firstly he said quoted Aguirre tot ry and prove premise 2 but Aguire think the universe is past eternal , he’s well known for this. He specifically attacked (in an intellectual way of course) vilenkin for saying it wasn’t. What Aguire was saying was that the emergent universe is not past eternal but that’s irrelevant as Aguirre doesn’t think the reason for an eternal past is based upon an emergent universe.
Craig said Wall’s theorem proves a quantum gravity era has a beginning. It does not, Walls theorem is based upon semi classical gravity. Attempts at analysing the big bang using actual quantum gravity theories often predict only a short period of quantum gravity anyway and then a contracting universe prior to that so its irrelevant if the quantum gravity period is not eternal. There are plenty of papers out there that argue the universe is eternal and others that argue that it’s finite. What Craig does is pick the ones out that agree with him and says it’s been shown wit some degree of confidence . Please, nothing about the quantum origins of our universe has been shown with any confidence. Carroll pointed out that out and so he was the one that was being honest.
