[Halc]

By 'eternal', do you mean 'for all of time' (the cosmos being contained in unbounded time),

No! Eternity is not time.  The cosmos is not contained in anything.

Good.  Just checking.

If the former, you're on your own, because it demotes cosmos to an object within a larger thing.

I would be interested to see the process by which you reach that conclusion.

Everyone uses language for objects (the only things we know) to describe things which are not in the category of objects.  Objects are 'created' and usually have a finite span of time and space in which they exist.  So to pick one (me), there are points in time which are not simultaneous with any event at which I am present.  Thus I am not not eternal (by the first definition, which you're not using).  I can use tensed language with reference to myself: Before me, during me, after me. 'I have always existed' is false regardless of the selected 'present' moment with which such syntax relates.
Objects are members of a set, but the set is not a member of the set. Objects are thus 'contained' by the set.  They're existing members of it. Thus it makes no sense to use such syntax to non-objects like 'cosmos'.  To use such language implies its membership in a larger set, one with the cosmos as a member, even if the only member.

Hence I have a real problem with statements like 'the cosmos exists' because that language implies membership of 'cosmos' in a larger set of things that exist.  This paradox vanishes if 'exists' is a relation (between object and set) instead of a property.  My mailbox thus doesn't have the property of existence.  What is has is the relation of existence with the cosmos.  The cosmos contains my mailbox.  Almost everything is a relation to me.  It seems free of contradictions, even if it isn't entirely intuitive.  I had to discard what turned out to be several basic biases I held, some of which I still believe despite knowing them to be false. Proof that the rational side of me is not in charge I guess.

[Bill S]

Are you a physicist? 

https://www.thenakedscientists.com/forum/index.php?topic=65009.msg475694#msg475694      #5

[Halc]

Are you a physicist? 

Well, my answer is not absolutely right, since it's philosophy, not physics, being discussed. You've been asking philosophical questions in this thread. Those sorts of answers are consistent or not, but they're not right or wrong.

If you find my post totally useless, just say so and I'll be on my way.

[Bill S]

If you find my post totally useless, just say so and I'll be on my way.

On the contrary; I find your answers interesting and informative.  I really appreciate the time and effort you devote to addressing my foibles.  In the same way that one might pass a humorous remark to/about a friend, that one would not pass about a relative stranger; I would not have made a joke about someone whose input I didn’t value.  I look forward to returning to more points from your contributions, and hope I have not put you off responding.

[Halc]

I liked the joke.

My reply was not totally in jest.  While some of the fallacies in thinking were pointed out, in the end the answer I gave is merely one I find consistent and relatively lacking in problems (like something coming from nothing).  But it was meant as a real disclaimer: I lay no claim that there are not other very different answers to the problems. I've just never found any others that worked as well.

[Bill S]

Well, my answer is not absolutely right, since it's philosophy, not physics, being discussed. You've been asking philosophical questions in this thread. Those sorts of answers are consistent or not, but they're not right or wrong.

You have a knack of putting a finger on problems.  Most people seem to regard this type of discussion as philosophical, and often dismiss it, as a result. (Thanks for not doing that). However, I have to wonder if looking for the possible origin of the Universe is, actually, philosophy.  Consider two questions.
 
1. Why is there something, rather than nothing?

2.  How can there be something, rather than nothing?

Sean Carroll asked Q1, and attempted a “physical” answer; but I would consider this to be philosophy.

Q2, on the other hand, asks for a “mechanism that would explain the obvious existence of “something”.  Surely, this is physics.

[RobC]

Sidney Morgenbesser, his professor at Columbia, said to Jim Holt "even if there was nothing you still would not be satisfied".

[Halc]

I have to wonder if looking for the possible origin of the Universe is, actually, philosophy.  Consider two questions.
 
1. Why is there something, rather than nothing?

2.  How can there be something, rather than nothing?

Sean Carroll asked Q1, and attempted a “physical” answer; but I would consider this to be philosophy.

Q2, on the other hand, asks for a “mechanism that would explain the obvious existence of “something”.  Surely, this is physics.

Your two question seem like the same thing to me.  Maybe I parse it differently.
I'd like to see Carroll's response to it if you have a link.  He usually does more of the physics answer: the mechanism behind what prompted the big bang. I have very little understanding of the various theories involved, and without a unified field theory, no real guidance as to which of them actually makes sense.  The all seem to have in common some greater field out of which separate bubbles of spacetime emerge, our own (that which started at the big bang) being one of them.

All these theories aside, none of them address the question of how/why there is something in the first place. It's a realist question, and a serious fault in realism because there never seems to be a satisfactory answer to it. Positing a god doesn't help at all since no god can create the cosmos, since the cosmos is everything, including the god. The deity answer is a realist one, and suffers the same problem as any realist position. For this reason, I abandoned realism some time back.

[Bill S]

Why answers questions about reason. How answers questions about mechanism/method.

Consider: "How are cars built?" and "Why are cars built?"

Link to Sean's article:

 https://www.preposterousuniverse.com/blog/2018/02/08/why-is-there-something-rather-than-nothing-2/

[Halc]

Why answers questions about reason. How answers questions about mechanism/method.

Consider: "How are cars built?" and "Why are cars built?"

Link to Sean's article:

 https://www.preposterousuniverse.com/blog/2018/02/08/why-is-there-something-rather-than-nothing-2/

He answers the physics question of the mechanism of the origin of the big bang, and only to say there is one, and to say it is a metaphysical mistake to use language that assumes a defined arrow of time when speaking of the physics outside our spacetime.

I see zero comments in that article that address the title.  He discusses the 'origin' of our universe, but not of what you're calling the cosmos.  He says it is a mistake to take our local experience of an arrow of time (what he calls 'metaphysical baggage') into the realm from which the big bang emerged, so there is no meaningful direction that is towards the 'beginning' of it, hence no obvious cause-effect relationship between two states, and hence no obvious first event that lacks a cause.  I agree with all that.  But none of it explains the existence of the structure in the first place vs the lack of its existence.  That's the part I think we're discussing.

[alancalverd]

"Why" presumes, or at least looks for, an ulterior motive or primary driver outside of the action being observed. When that action is "everything we can observe", you clearly aren't going to find a cause.

However everything we can observe, i.e. the Observable Universe, is not necessarily everything there is. Schwarzchild places a limit on the radius of the observable part of the universe, but not on everything that might exist.

Now we have two competing gravitational phenomena. At shortish distances, stuff tends to coalesce into galaxies and so forth, but if the universe is actually infinite, the stuff outside our observable radius is pulling the fringes outwards whilst the stuff inside is condensing into discrete chunks. So whilst the OU in its present form of accreting masses may well have begun with a big bang, that itself may have been caused by the coalescence of a previous OU into a black hole that was unstable in the gravitational field of everything else, or collided with another giant black hole.

So here's a difference between science and religion. I'm pretty sure there is stuff out there that I can't observe, but has played a part in my history and will play a part in my future, but I don't ascribe any motives to it, only a presumption that it behaves pretty much in the same way as the stuff I can see until proven otherwise. That's science, and in this case it suggests "how". 

[Bill S]

He says it is a mistake to take our local experience of an arrow of time (what he calls 'metaphysical baggage') into the realm from which the big bang emerged,

I’m not comfortable with calling our experience of time “metaphysical baggage” but “who am I to blow against the wind?”  However, extrapolating it to argue that there was time before the BB can lead to problems.

  so there is no meaningful direction that is towards the 'beginning' of it, hence no obvious cause-effect relationship between two states, and hence no obvious first event that lacks a cause.

 I, too, agree with that; but it needs some qualifying if it is to explain the existence of the Universe. 

[Halc]

I’m not comfortable with calling our experience of time “metaphysical baggage” but “who am I to blow against the wind?”  However, extrapolating it to argue that there was time before the BB can lead to problems.

You cannot use comfortable terms to describe something that completely different than the environment in which we find ourselves.  Yes, there is time of sorts (possibly more than one dimension of it) outside the BB, but it isn't 'ordered' like it is here, so there is no 'before' and 'after' relation between events, and asking how it 'started' implies an ordering that is not there, and also a bound that has no reason to be there either.

I lay no claim to knowledge about that realm since such knowledge doesn't help answer the main problem I see.  My thinking is simpler than that.

but it needs some qualifying if it is to explain the existence of the Universe.

That answer isn't found in there, which is why I've not explored it in depth.  Carroll did not answer the question in his title.  He just said there wasn't an obvious 'first cause' way over at one end that needs to be explained.  The whole thing needs to be explained, and he's right about that.  But he didn't actually address the question.

I reduced the question to 'why is the <cosmos> real?', and found no answer anywhere.  I thus abandoned my realist philosophy that I had held for quite some time. There are better alternatives.

[Bill S]

That's science, and in this case it suggests "how".

Agreed.  How would you be with extending that to saying that studying the contents/structure of the OU, in an attempt to adduce its provenance, would be “science”?

[Halc]

... studying the contents/structure of the OU, in an attempt to adduce its provenance

That part is figured out.  The BB represents said provenance of said OU, and plenty more that's not observable.

I'm pretty sure there is stuff out there that I can't observe, but has played a part in my history and will play a part in my future, but I don't ascribe any motives to it, only a presumption that it behaves pretty much in the same way as the stuff I can see until proven otherwise.

This is true for stuff too distant to observe.  Were you to observe it, it would appear/behave pretty much like it does here.  There is little to no reason this should be true outside our bubble of spacetime.

[Bill S]

“There is nothing new to be discovered in physics now.”  Attributed (possibly apocryphally) to Lord Kelvin.

“.........the laws of physics underlying everyday life are completely understood.”  Sean Carroll.

“That part is figured out.”  Halc.

Eat your heart out, Nostradamus! 
 

[Bill S]

Seriously, though: the laws of physics take us back to a fraction of a second after the BB; maths provides us with our best tool for understanding these laws; but, unless I’ve missed something vital, neither actually tells us how we could we can be here.

[alancalverd]

The presumption, as Halc says, is that the unobservable part of the universe (i.e. pretty much all of it) behaves the same as the observable part. Then by any reasonable definition of "infinite", the Big Bang and all its trivial and evanescent consequences (including us) was just one inevitable incident in a conservative continuum.

Or to put it simply, we're here because we are.

[Bill S]

Then by any reasonable definition of "infinite", the Big Bang and all its trivial and evanescent consequences (including us) was just one inevitable incident in a conservative continuum.

That’s fine, but it doesn’t address the question of how the “continuum” could exist. 

Is there a law of physics that says: there must always have been “something?
If so, is there a law that says it must be a continuum?
If so, is there a law that deals, effectively, with infinite regression?

Or to put it simply, we're here because we are.

Straightforward statement of the Anthropomorphic Principle, but still misses the main point.

Stay with me, Alan (& Halc), there could be light on the horizon.

That’s not detracting from the valuable input of others, but Halc & Alan look like staying the course.  Brave!

[alancalverd]

The laws of physics are simply the mathematical relationships we discover that rationalise what we know and predict what we might see. I don't see any disjoint between an infinite and fundamentally unchanging universe with occasional hiccups, and the laws that we have invented to describe our present hiccup.

"We're here because we are" is surely the diametric opposite of the anthropic principle, which states that everything else is there in order for us to be here. Seeing the universe, or even this tiny corner of it,  as constructed for Man, is vanity. Seeing  Man as a transient blip in the universe, is science. Remember that Goldilocks invaded  the Three Bears' house, which was actually built for the bears, not G-lox.