(December 6, 2015 at 11:52 am)Quantum Wrote: The big bang theory as it is understood by cosmologists today, most emphatically, does not state that the universe began in a single point marking the beginning of time or any such thing.

It posits that the universe was very dense and hot, with a certain structure to its flictuations. That is sufficient to explain the creation of matter and subsequent evolution. Anything beyond that is speculation. A nontrivial mechanism such as inflation is required in the early phase in order to explain flatness  homogeneity and the roughly scale invariant perturbation spectrum. What happens before inflation and how it gets started, is even more speculative.

This is the thinking today? Could you provide a link or two to articles that discuss this change of thought? Apparently, I have some catching up to do.  

Thanks!

@athrock

A careful reading on the Wiki article on "big bang" will do for a start.

(November 30, 2015 at 2:41 pm)jcvamp Wrote: I responded to a thread on Facebook about atheist morality. I expressed that I believe that religious people's belief reflects their morality and not the other way around. I gave Christians as an example, citing biblical teachings that modern Christians don't follow, and a Christian responded by arguing that everything needs a creator.

They said, 'Classic logic can bring one to the conclusion of a single God.  We humans are contingent beings, that is, my parents had to make me, your parents had to make you, so on and so forth up the line.  If any of that changed, I wouldn't be the same, or you wouldn't be the same.  Going back and back it's not as if there can be some loop where two or hundreds or thousands are equally contingent upon each other, it must come back to one being who is not contingent upon any other being. That would be God.  Now going from deism to a specific religion requires faith, but monotheistic deism is the logical way.'

This was my response, 'My parents made me using a natural biological process, and yes, their parents in turn made them. However, your logic falls apart at the point when you assume that this means a god must have initiated the process.

You postulate that everything must have a creator, then break your own postulate by saying that the first creator didn't have a creator. If your premise is that all things had a creator, who created god? You can't posit that everything requires a creator, but then say that your line of logic only works if that rule is broken. This leaves us with the postulate that some things require a creator and others do not.

If we follow this line of reasoning, my parents created me, and this extends back to a point where something came about without the need for a creator. Why can't that be the formation of organic chemicals (proteins, amino acids, RNA, and DNA) from inorganic material by chemical processes that we know to exist, and have reproduced in the lab?'

What's your take on this? What would you have responded? Do you agree or disagree with my argument?

I would have dealt with their "classic logic" only after putting them back on track for the original discussion by pointing out how they had moved the goalposts from the facts on how humans create their religions, forcing them to chew on that for awhile.

On their "classic logic", I would give them this answer: everything does have a creator, and life began when a chemical chain reaction was created according to the laws of physics, which are still not very well understood. We don't know this for sure, but it is the most likely answer for what can be observed and honestly discussed. Questions on things not well understood require an honest "I don't know" answer, not a dishonestly gnostic one.

(December 6, 2015 at 4:31 pm)Quantum Wrote: @athrock

A careful reading on the Wiki article on "big bang" will do for a start.

Also maybe the article on inflation, not because inflation must be true, but because it provides reasons why the simplest extrapolation to the earliest possible point is unlikely to be viable. The article should also make clear that the numerous correct predictions of bbt do not rely or involve an extrapolation to a singularity, but merely require (and are supported by strong evidence for) a hot dense state.

The important point is also that the extrapolation beyond scales at which we know the laws of physics are speculative, and that general relativity would break down anyways because of quantum gravity before a real mathematical singularity.

Ah, Matt Strassler explains it nicely:

http://profmattstrassler.com/2014/03/21/...ngularity/

From the text:

M. Strassler Wrote:Yet all over the media and all over the web, we can find articles, including ones published just after this week’s cosmic announcement of new evidence in favor of inflation, that state with great confidence that in the Big Bang Theory the universe started from a singularity. So I’m honestly very confused. Who is still telling the media and the public that the universe really started with a singularity, or that the modern Big Bang Theory says that it does? I’ve never heard an expert physicist say that.

Matt himself has done important work in gravity and string theory and knows what he is talking about.

(December 6, 2015 at 11:52 am)Quantum Wrote: The big bang theory as it is understood by cosmologists today, most emphatically, does not state that the universe began in a single point marking the beginning of time or any such thing.

It posits that the universe was very dense and hot, with a certain structure to its flictuations. That is sufficient to explain the creation of matter and subsequent evolution. Anything beyond that is speculation. A nontrivial mechanism such as inflation is required in the early phase in order to explain flatness  homogeneity and the roughly scale invariant perturbation spectrum. What happens before inflation and how it gets started, is even more speculative.

After reading the salient points of the Wiki article, let me ask: Are you then saying that the universe did not begin from "nothing" but from a very hot, very dense "something"?

(December 6, 2015 at 9:57 pm)athrock Wrote:

(December 6, 2015 at 11:52 am)Quantum Wrote: The big bang theory as it is understood by cosmologists today, most emphatically, does not state that the universe began in a single point marking the beginning of time or any such thing.

It posits that the universe was very dense and hot, with a certain structure to its flictuations. That is sufficient to explain the creation of matter and subsequent evolution. Anything beyond that is speculation. A nontrivial mechanism such as inflation is required in the early phase in order to explain flatness  homogeneity and the roughly scale invariant perturbation spectrum. What happens before inflation and how it gets started, is even more speculative.

After reading the salient points of the Wiki article, let me ask: Are you then saying that the universe did not begin from "nothing" but from a very hot, very dense "something"?

I would say

1. we can say with very high degree of certainty that the universe was once very hot and dense about 13.7 billion years ago and we have a very good grasp on its expansion history ever since

2. Before that, it probably underwent inflation or something equivalent, but the details are foggy because of lack of data and much theory work to do

3. What came before is unclear and speculation. We cannot talk about it with any degree of certainty

4. The notion of time and space coming from *** is semantic nonsense.
4b. Our naive notion of a linear continuous time probably breaks down here, and with them naive intuitions about causality.

I am not saying anything definite about where it came from, because I cannot say anything secure about it.

A comment concerning 4,

When quantizing spacetime, it becomes apparent that at the shortest scales, time becomes, if not discrete which would probably be an oversimplification, at least fuzzy and convoluted. It seems very unlikely that it remains - at the shortest scales and highest energies - this apparently smooth and linear thing we have constructed for ourselves. Anyone who tries to argue about causes and caused causes and uncaused causes and god being infinite or finite, or the universe having a beginning, and what was before the beginning, and all that, is not merely barking up the wrong tree, but barking up a shadow of the wrong tree, if you will. All philosophizing concerning these topics by people who don't know modern physics really really well is probably just noise, and the philosophizing from those who do, is basically shooting in the dark.

The situation is made worse by the fact that causality is already a shaky concept within our universe - it is far from clear whether the world doesn't contain true randomness in form of quantum uncertainty.

Also, the arrow of time (which distinguishes past from future) is a purely statistical phenomenon - the future is in the direction of complexity, as illustrated by the increase in entropy - and it could well be that near the origin, time simply connects to another branch that goes into the future again entropy-wise as we go "further back".
A friend has written a paper on this idea recently which got quite a bit of attention. This is their money plot



While their model is a bit of an oversimplification (to say the least) and has been criticized for overselling the novelty of their results a bit, it nicely illustrates a fascinating possibility. Even if we are able to keep a linear timeline through the big bang for some reason, time could be going forward in both directions away from the origin, and what we call causality is reversed accordingly on the other side. (again, of course this is speculation, but viable speculation). Where is your infinite regress of causes of causes if time goes into the future in both directions? Exactly Who knows, maybe time is a star of several lines going into the future from a common point of low entropy. And this is the level of weirdness you can get if you still assume a smooth continuous timeline!

My point is though, not that this must be the correct picture, or even is particularly likely to be the correct picture, but that the rabbit hole goes really deep, and any discussions of causality and time and all those arguments pertaining to the origin of the universe based on notions of linear time and causality, as you find them from apologists and old philosophers, can be safely discarded as uninformed and too naive. Ordinary language of before and after, cause and effect, past and future, moved and unmoved movers, does not capture the potential complexity of the situation even remotely. Likewise, physicists who make confident pronouncements about what happens "before" the big bang, are overselling what is known, because there is just so little data that can be used. Even inflationary models have barely a handful of known parameters that can be measured from the fluctuations in the CMB and extrapolated back, and before that we have nucleosynthesis which afaik doesn't tell us much about quantum gravity, and before that? Since the gravitational fluctuations claimed to be seen by BICEP2, which Matt Strassler alludes to in my quote above, turned out to be a misinterpretation of the data, it doesn't look like we will get a much clearer picture of those things any time soon.

(December 6, 2015 at 9:22 am)Crossless1 Wrote:

(December 6, 2015 at 3:11 am)orangebox21 Wrote: Addressed and answered by athrock in post #80.

Yes, but the problem with that answer is that step 2 in the chain of reasoning doesn't take into account that we can only say with confidence that the universe in its present observable state came into being at a certain time, which does not necessarily imply creation from "nothing".  A singularity, after all, is not nothing.  We simply don't have the tools or conceptual framework to describe what the state of the universe was "prior" to the Big Bang.  But that doesn't justify the leap to an intelligent creator outside space/time acting as an eternally existing first cause, a.k.a. "God".  Any honest answer to the question "what caused the universe" must end with an admission of ignorance.  Theists who invoke the cosmological argument wish to give the impression that they have answered the question, when all they have really done is given a sort of name to their ignorance as if that answers anything.

I'm not defending the cosmological argument as a whole, just the question of why or why not God would require a creator.

(December 7, 2015 at 11:54 am)orangebox21 Wrote:

(December 6, 2015 at 9:22 am)Crossless1 Wrote: Yes, but the problem with that answer is that step 2 in the chain of reasoning doesn't take into account that we can only say with confidence that the universe in its present observable state came into being at a certain time, which does not necessarily imply creation from "nothing".  A singularity, after all, is not nothing.  We simply don't have the tools or conceptual framework to describe what the state of the universe was "prior" to the Big Bang.  But that doesn't justify the leap to an intelligent creator outside space/time acting as an eternally existing first cause, a.k.a. "God".  Any honest answer to the question "what caused the universe" must end with an admission of ignorance.  Theists who invoke the cosmological argument wish to give the impression that they have answered the question, when all they have really done is given a sort of name to their ignorance as if that answers anything.

I'm not defending the cosmological argument as a whole, just the question of why or why not God would require a creator.

Whether "God" does or does not require a creator is just a question of word play. Since we don't have a good shred of evidence that such a being exists, the "answer" comes down to how it is fancifully defined and whether all persons in the conversation subscribe to the same language game. Nothing more, nothing less.