Did the big bang singularity not have a history?

[consuli]

Hello!

Hawking has written, that the physical mechanics and the time before the big bang singularity cannot be measured, as time in this big bang singularity has been bent indefinitly and therefore has just started with the big bang.

Questions:
1. Does Hawking mean, there has not been any time before the big bang, thus the big bang does not have history?
2. Or does Hawking mean, the time before the big bang is not of the scale of our time, like the imaginary numbers are not of the scale of conventional rational numbers?

Consuli

 

[Dale]

It doesn’t really matter. Nobody expects that our current models are valid at or near the singularity. Anything we say about it is just a wild guess

 

[PAllen]

Hawking was a proponent of the “no boundary hypothesis”, which he originated. Topologically, this makes the Big Bang origin similar to the south pole of a sphere. Thus, ther is no singularity, nor is it in any way meaningful to ask about before the Big Bang from the point of view of a surface dweller. The surface of the sphere is analogous to our whole universe. Behind analogies, was much real math based QFT in curved spacetime and Wick rotations.

 

[consuli]

It doesn’t really matter. Nobody expects that our current models are valid at or near the singularity. Anything we say about it is just a wild guess

Well, I think the assumption wether there is (otherwise scaled) time before the big bang singularity may have large implications.

In the inflationary universe theory the value of the cosmological constant is very narrow. Following Hawking the universe would have collapsed again, if it was part of a million smaller; on the contrary the universe would be pretty empty now, if the cosmological was a part of a million smaller. From a statistical point of view that means, that the appropriate cosmological constant is not a divine addition to physical laws, but the probability is high, that the theory has NOT covered all relevant effects (or relationships), given the assumption, that alternative neighboured parameter realisations (in this case alternative relasations of the cosmological constant) are comparably probable. Following, a less restrictive theory of the expanding of the universe regarding its parameters, thus allowing for alternative realisation of our universe, would be much more probable.

Further huge massed black holes in our universe are cold and little black holes are hot. This might lead to the conclusion, that the very huge massed big bang singularity could not have been like a black hole in our universe.

If there would have been another type of time before the big bang singularity, maybe the proper search for a unified theory is not integrating the physics law we already know to one, but the explanation of a quantum transformation of materia within the big bang singularity (and maybe shortly before and shortly after it).

Consuli

 

[PeroK]

Well, I think the assumption wether there is (otherwise scaled) time before the big bang singularity may have large implications.

If there would have been another type of time before the big bang singularity, maybe the proper search for a unified theory is not integrating the physics law we already know to one, but the explanation of a quantum transformation of materia within the big bang singularity (and maybe shortly before and shortly after it).

Consuli

... and that is your wild guess!

 

[Dale]

Well, I think the assumption wether there is (otherwise scaled) time before the big bang singularity may have large implications

None of the currently accepted mathematical models allow us to predict the implications. So it is purely a guess that the implications are large, or what they are.

If there would have been another type of time before the big bang singularity, maybe the proper search for a unified theory is not integrating the physics law we already know to one, but the explanation of a quantum transformation of materia within the big bang singularity (and maybe shortly before and shortly after it).

Please cite a peer reviewed reference that supports this speculation or any other speculation that you might choose to make.

 

[consuli]

A physical closed theory of the explanation of the universe - as any closed scientific theory - has to provide a comprehensible explanation for any state of the system in the theory, which in case of the expansion of the universe, from my point of view, does include the question of the the source of the intial big bang singularity, regardless of time and measurement problems. Otherwise the theory would not be logical closed.

However, I will not actively drive this question further for the practical reason, that there are no observations and especially no data from a potential history before the big bang to model up from.

Instead, I want to ask a new, from a statistical point of view more interesting question:
What is the deviation in the expansion of the universe exactly quantified, when I would assume general relativity and calculate it backwards?

Consuli

 

[Dale]

Otherwise the theory would not be logical closed.

The Big Bang theory is not logically closed in that sense. It only describes the evolution of the universe from an assumed initial hot dense state until now.

 

[martinbn]

A physical closed theory of the explanation of the universe - as any closed scientific theory - has to provide a comprehensible explanation for any state of the system in the theory, which in case of the expansion of the universe, from my point of view, does include the question of the the source of the intial big bang singularity, regardless of time and measurement problems. Otherwise the theory would not be logical closed.

I don't understand this part? Why is it logically not closed? Say you study the properties of a class of functions defined on the open interval $(0,\infty)$, is there a logical problem in this purely mathematical case? I would say no. Then why do you have a problem with a theory in which the spacetime manifold is $\mathbb R^3\times\mathbb R_{>0}$?