I've split off much of the discussion into another thread, since it was going pretty far off-topic.
From which reference frame?time traveller d said:what existed before the big bang?
the mainstream about the quantum beginnings of expansion is MANY STREAMS. it is too early to try to sum up and say that there is a consensus. I suggest you SAMPLE one of the quantum bang theories.CosmologyHobbyist said:Hi everyone! I have 3 questions :
If the big bang was a quantum event (as suggested by some entries in this thread) - doesn't that require quantum field to exist before the big bang? Wouldn't this make it likely that quantum field exists "outside" the big bang universe? My question 1 : Does anybody have more information on the topic of quantum field before and outside of big bang universe?
The only other big bang origin I have heard of is from singularity - Question 2 : Is there a mainstream big bang theory that creates the quantum field out of the big bang?
Question 3 : Are there other mainstream theories on relationship of big bang and quantum field?
Thanks for putting up with my ignorance! :)
In the braneworlds picture, branes bump together repeatedlyCosmologyHobbyist said:Thanks very much for your answer, Marcus. I did read the Ashketar paper before I posted (I'll read it again now!); I suppose I was trying to find a synopsis of current views.
You might be interested in this.marcus said:In the braneworlds picture, branes bump together repeatedly
search arxiv.org for author name Steinhardt
braneworld cosmology is very different from loop quantum gravity cosmology. (and there are other attempts too, Hawking had a quantum cosmology back in the 1980s which no one works on much but which he has popularized)
I do not know of a synopsis that harmonizes the diverse ideas.
Yes! I knew of that paper! it is a strange offbeat paper because it USES the cushioning effect of LQG repulsive gravity (which I personally tend to think as having a good chance of being real) tohellfire said:You might be interested in this.
What else than an ever existing swinging " Infinity-verse" ?time traveller d said:i all ways wonder this. what existed before the big bang?
To me N.Z.E.U.M. preserves incomprehensibility. Symmetry is elegant and beautiful, but isn't like throwing away the baby and the bathwater? Is N.Z.E.U.M. the only way (if it really is?) to preserve causality?Chronos said:I am prejudiced in favor of the net zero energy universe model - it preserves causality, IMO.
To me belief seems like a 'well' adapted boundary/frontier. Interest in what is behind or beyond seems to stop there. I don't want to live in such a prison.Chronos said:I admit believing NZE is necessary to preserve causality in an FRW universe.
My understanding is that experts like Hawking describe three posible scenarios. 1) The big bang singularity, whatever its cause, or lack thereof, began as a unique event with "creation of everything out of nothing" which jibbed well with othrodox Christians because of the the book of Hebrews says something akin to "it is by faith that we believe God created everything that is seen from what is not seen" and was interpreted by orthodox theologians as meaning creation 'ex nihilo' (out of nothing)time traveller d said:i just came up with a theory. another universe. maybe when a
universe ends it explodes in a big bang and creates another universe. what do you guys think?