Big Bang not an instance of something from nothing?

[scherado]

On 7/28/2017 at 10:19 AM, Airbrush said:

Are there any theories in cosmology about "nothing"?  What exactly is nothing?

"I feel your pain"; I usually use: "Nothing, == no things."--which is precisely the problem some seem to have when they play with flimsy referents. There are, apparently, many people with Letters trailing their names who play with flimsy referents and get a paycheck to boot.

[Strange]

3 minutes ago, scherado said:

"I feel your pain"; I usually use: "Nothing, == no things."

That just moves the problem to defining what is meant by "thing" so this flimsy definition doesn't really help. 

[StringJunky]

'Nothing' means 'We have no idea'.

[Mordred]

The expression "Nothing is impossible" definetely applies in this instance hehe

 

 

[beecee]

13 hours ago, Dubbelosix said:

Maybe. My picture really is no more clear cut than other peoples. I think this struggle about the universe from nothing, is a common one.

Ignoring the non scientific myths re creation and deities, is there really any other conclusion re a universe from basically nothing? Other then some infinite model that has always existed? I see the question as analogous to asking about how life came to be...Abiogenisis even without evidence, seems the only scientific answer.

8 hours ago, StringJunky said:

'Nothing' means 'We have no idea'.

Well, at least we have no evidence to support any particular concept. 

8 hours ago, Mordred said:

The expression "Nothing is impossible" definetely applies in this instance hehe

I prefer the question "what is nothing" which may actually support what your expression conveys.  

Edited September 29, 2017 by beecee

[StringJunky]

20 minutes ago, beecee said:

Ignoring the non scientific myths re creation and deities, is there really any other conclusion re a universe from basically nothing? Other then some infinite model that has always existed?

If time emerged with the BB maybe it makes no sense to talk about 'before' and things occurred or proceeded in some sequence or manner not amenable to our temporal and spatial sense prior to the emergence of time and space.

 

Edited September 29, 2017 by StringJunky

[beecee]

1 minute ago, StringJunky said:

If time emerged with the BB maybe it makes no sense to talk about 'before' and things occurred proceeded in some sequence or manner not amenable to our temporal sense prior to the emergence of time and space.

 

I actually like that scenario: Let me say rightly or wrongly, I have a problem accepting "infinity" could be just a mental block or just my stubborness.  

[StringJunky]

5 minutes ago, beecee said:

I actually like that scenario: Let me say rightly or wrongly, I have a problem accepting "infinity" could be just a mental block or just my stubborness.  

It eliminates infinity because it is not contingent upon it. I think it's important not to transpose our sense of time and space into a pre-BB scenario if they aren't modelled to be there, difficult though that is.

Edited September 29, 2017 by StringJunky

[Dubbelosix]

7 hours ago, beecee said:

Ignoring the non scientific myths re creation and deities, is there really any other conclusion re a universe from basically nothing? Other then some infinite model that has always existed? I see the question as analogous to asking about how life came to be...Abiogenisis even without evidence, seems the only scientific answer.

 

I don't believe there will ever be the kind of evidence we need to falsify questions about scenario's that does seem, unfortunately, beyond experimental means. I don't think we will ever show that a universe can come from nothing, unless we manage to make a universe in the lab. 

 

 

 

6 hours ago, StringJunky said:

If time emerged with the BB maybe it makes no sense to talk about 'before' ....

 

 

You could go one step further and say that cause and effect may break down at the big bang, so it doesn't make sense to talk about a before. 

Edited September 30, 2017 by Dubbelosix

[StringJunky]

6 minutes ago, Dubbelosix said:

You could go one step further and say that cause and effect may break down at the big bang, so it doesn't make sense to talk about a before. 

Yes, that's what I suggested earlier

Quote

....things occurred or proceeded in some sequence or manner not amenable to our temporal and spatial sense...

Assuming GR's out of the equation because space and time have yet to emerge, could quantum effects still work and proceed without them in the light of current quantum physics?

[Dubbelosix]

Not that I am aware of, because Planck space seems to be the space in which physics makes sense. Below it, even for point like dynamics, the physics seems to be... nonsensical.  If you want you could say it requires a new physics, but not the kind we associate to quantum effects as we know them. 

[StringJunky]

3 minutes ago, Dubbelosix said:

Not that I am aware of, because Planck space seems to be the space in which physics makes sense. Below it, even for point like dynamics, the physics seems to be... nonsensical.  If you want you could say it requires a new physics, but not the kind we associate to quantum effects as we know them. 

Right.

[Mordred]

1 hour ago, Dubbelosix said:

Not that I am aware of, because Planck space seems to be the space in which physics makes sense. Below it, even for point like dynamics, the physics seems to be... nonsensical.  If you want you could say it requires a new physics, but not the kind we associate to quantum effects as we know them. 

accurate descriptive, however how one defines a singularity depends upon the metrics defining the system and system states involved. Those metrics can often be defined as per a particular observer. Some singularities that show up in the pertaining metric system, may be resolved by a coordinate, metric or observer change. There is often artifacts of a metric to be recognized within the applicable bounds provided by the numerous function cutoffs of a metric. In both GR and particle physics in terms of path integrals of the Feyman scattering diagrams etc. The cutoff treatments of applicability is a prevention of the metric affinities arising. Some examples being a wicks rotation, or Wilson loop. QFT corresponds to displacement via the Hamiltons of action under field treatments. In particular A Quanta of action"

[Dubbelosix]

yes valid point.

[Mordred]

The aforementioned treatments will be described by its killing vectors, just an aside note any field treatment will involve killing vectors.

Edited September 30, 2017 by Mordred