Understanding through Discussion


Welcome! You are not logged in. [ Login ]
EvC Forum active members: 86 (8945 total)
261 online now:
DrJones*, Faith, jar, JonF, PaulK, xongsmith (6 members, 255 visitors)
Newest Member: ski zawaski
Upcoming Birthdays: ONESOlivia, perfect
Post Volume: Total: 865,570 Year: 20,606/19,786 Month: 1,003/2,023 Week: 511/392 Day: 55/72 Hour: 0/2


Thread  Details

Email This Thread
Newer Topic | Older Topic
  
Author Topic:   questions about the origin of singularity = nothing
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 16 of 38 (218388)
06-21-2005 11:13 AM
Reply to: Message 15 by Sylas
06-21-2005 10:41 AM


though of course as you point out this presumes a quantum foam and a multiverse in which many such events may occur, and so just pushes the "ultimate origin" question to a new domain.

It's a good stalling tactic, but never ultimately satisfying :-)

Or it could be totally different... the universe may fit the nice smooth zero-boundary Stephen Hawking notion with no larger meta-universe in which you can speak of our universe as a thing coming into existence at all.

Exactly. I think this model should be understood before trying to looking at more esoteric theories. Once you've got the essence of no-boundary, it all becomes much more clear. If you can grasp that, you can grasp anything that string theory throws your way! There are very few pictures I have ever seen that are more satisfying than no-boundary in a closed FRW universe.


This message is a reply to:
 Message 15 by Sylas, posted 06-21-2005 10:41 AM Sylas has not yet responded

Replies to this message:
 Message 21 by Primordial Egg, posted 08-21-2005 6:10 AM cavediver has responded

  
Thugpreacha
Member
Posts: 13187
From: Denver,Colorado USA
Joined: 12-30-2003
Member Rating: 1.1


Message 17 of 38 (235058)
08-20-2005 6:45 PM
Reply to: Message 11 by cavediver
06-21-2005 9:34 AM


Truly pantheistic (and incorrect) thinking!

This message is a reply to:
 Message 11 by cavediver, posted 06-21-2005 9:34 AM cavediver has responded

Replies to this message:
 Message 18 by cavediver, posted 08-20-2005 7:11 PM Thugpreacha has responded

  
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 18 of 38 (235065)
08-20-2005 7:11 PM
Reply to: Message 17 by Thugpreacha
08-20-2005 6:45 PM


Huh? I can only assume you are objecting to my anthropomorphising of the universe... it's a literary technique used for effect and emphasis.

Just in case you're objecting to the science, it's called General Relativity, and it's just the way it is... sorry.


This message is a reply to:
 Message 17 by Thugpreacha, posted 08-20-2005 6:45 PM Thugpreacha has responded

Replies to this message:
 Message 19 by Thugpreacha, posted 08-21-2005 2:36 AM cavediver has responded

  
Thugpreacha
Member
Posts: 13187
From: Denver,Colorado USA
Joined: 12-30-2003
Member Rating: 1.1


Message 19 of 38 (235187)
08-21-2005 2:36 AM
Reply to: Message 18 by cavediver
08-20-2005 7:11 PM


The error of your method is that the human mind is not the origin of creation. We can imagine, however, so at best your scenario is an imaginary hypothesis. The universe can no more "think" than we can be eternal.

This message is a reply to:
 Message 18 by cavediver, posted 08-20-2005 7:11 PM cavediver has responded

Replies to this message:
 Message 20 by cavediver, posted 08-21-2005 4:16 AM Thugpreacha has not yet responded

  
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 20 of 38 (235192)
08-21-2005 4:16 AM
Reply to: Message 19 by Thugpreacha
08-21-2005 2:36 AM


The error of your method is that the human mind is not the origin of creation.

Where I did I suggest it was?

We can imagine, however, so at best your scenario is an imaginary hypothesis.

We can do science, however, so at worst my scenario is a scientific hypothesis.

The universe can no more "think" than we can be eternal.

I did not think I was implying either...


This message is a reply to:
 Message 19 by Thugpreacha, posted 08-21-2005 2:36 AM Thugpreacha has not yet responded

  
Primordial Egg
Inactive Member


Message 21 of 38 (235203)
08-21-2005 6:10 AM
Reply to: Message 16 by cavediver
06-21-2005 11:13 AM


Exactly. I think this model should be understood before trying to looking at more esoteric theories. Once you've got the essence of no-boundary, it all becomes much more clear. If you can grasp that, you can grasp anything that string theory throws your way! There are very few pictures I have ever seen that are more satisfying than no-boundary in a closed FRW universe.

Does the no-boundary proposal require a closed universe as a starting assumption? I was under the impression that all the observational evidence pointed towards an open universe?

PE


This message is a reply to:
 Message 16 by cavediver, posted 06-21-2005 11:13 AM cavediver has responded

Replies to this message:
 Message 22 by cavediver, posted 08-21-2005 8:38 AM Primordial Egg has responded

  
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 22 of 38 (235211)
08-21-2005 8:38 AM
Reply to: Message 21 by Primordial Egg
08-21-2005 6:10 AM


Yes, "no boundary" works with a closed universe. Observational evidence points to a flat universe, with W=1. If it is truly flat, then this is an infinite universe like the open universe. However, one of the benefits of inflation is that it explains this flatness as a product of the inflation. You can start with any value of W and inflation pushes it close to 1. So the universe is quite possibly closed. The observed acceleration does not change this. We are beyond the original three scenarios of the FRW universe now.

This message is a reply to:
 Message 21 by Primordial Egg, posted 08-21-2005 6:10 AM Primordial Egg has responded

Replies to this message:
 Message 23 by Primordial Egg, posted 08-21-2005 9:03 AM cavediver has responded

  
Primordial Egg
Inactive Member


Message 23 of 38 (235214)
08-21-2005 9:03 AM
Reply to: Message 22 by cavediver
08-21-2005 8:38 AM


Confused. How can W < 1 in a Universe where the expansion is accelerating? Can W change with time (could we be undergoing another inflationary period)?

PE


This message is a reply to:
 Message 22 by cavediver, posted 08-21-2005 8:38 AM cavediver has responded

Replies to this message:
 Message 24 by cavediver, posted 08-21-2005 9:20 AM Primordial Egg has responded

  
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 24 of 38 (235218)
08-21-2005 9:20 AM
Reply to: Message 23 by Primordial Egg
08-21-2005 9:03 AM


Sorry, I'm being a little loose with my definitions. I'm talking about W distinct from the accelerative factor (cosmological constant, quintessence, whatever). We can have a closed universe that has accelerative expansion... this is just like de Sitter space. And yes, this is like the inflationary period, just much much much less dramatic! Don't think of W changing, but whatever it is that is causing the expansion.

This message is a reply to:
 Message 23 by Primordial Egg, posted 08-21-2005 9:03 AM Primordial Egg has responded

Replies to this message:
 Message 25 by Primordial Egg, posted 08-21-2005 11:09 AM cavediver has responded

  
Primordial Egg
Inactive Member


Message 25 of 38 (235231)
08-21-2005 11:09 AM
Reply to: Message 24 by cavediver
08-21-2005 9:20 AM


Thanks cavediver, I appreciate you taking the time out to answer these.

That doesn't mean I understood you by the way, I always understood closed and Big Crunch to be pretty much synonymous. I guess you're telling me they aren't. What does a closed Universe mean in this context?

Incidentally, doing a bit of digging on the web and I found this interview with Neil Turok (do you know him?):

Part I
Part II

Part II discusses how Hawking and Turok came up with a no-boundary proposal for open universes. It posits something called an instanton, which contains a much "nicer" singularity than the traditional Big Bang singularity. According to the Cambridge Quantum Gravity site this should be testable in the next few years when MAX and the Planck Surveyor are launched. I'd never heard of any of this and I thought I was reasonably up to date.

PE


This message is a reply to:
 Message 24 by cavediver, posted 08-21-2005 9:20 AM cavediver has responded

Replies to this message:
 Message 26 by cavediver, posted 08-21-2005 11:38 AM Primordial Egg has not yet responded

  
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 26 of 38 (235238)
08-21-2005 11:38 AM
Reply to: Message 25 by Primordial Egg
08-21-2005 11:09 AM


Closed and big crunch are synonymous in a classic FRW universe, which is what we used to believe in (no cosmological constant, no quintessence) That is why you (and most of us) still put the two concepts together. But add a cosmological constant type device and everything changes...

I'd forgotten the Turok thing. It post-dates my time in the field. I've only spoken with him a couple of times. Seemed a nice guy. He joined the department not long after I left. Don't worry, when you look at the number of papers published in this field, you only ever hear of a fraction of a percent of the stuff that goes on. Check out the daily lists of hep-th and gr-qc at xxx.lanl.gov.


This message is a reply to:
 Message 25 by Primordial Egg, posted 08-21-2005 11:09 AM Primordial Egg has not yet responded

  
Glory2God
Inactive Member


Message 27 of 38 (285785)
02-11-2006 12:15 AM
Reply to: Message 15 by Sylas
06-21-2005 10:41 AM


The theory of relativity predicts an ABSOLUTE beginning. The first law of thermodynamics can not allow for such a beginning. Nevertheless, that there was a beginning is without question. Therefore a naturalistic cosmology is neither feasible nor logical. The only other alternative MUST by needs be supernatural. To stay within the bounds of both the theory of relativity and the first law of thermodynamics there MUST be an original cause. The only KNOWN logical explanation from history is in fact:

Ge 1:1 ¶ In the beginning God created the heaven and the earth.

Here we have an absolute beginning, WITH a supernatural CAUSE. It fits perfectly with ALL laws of thermodynamics and satisfies all the requirements of relativity.

Heb 11:3 Through faith we understand that the worlds were framed by the word of God, so that things which are seen were not made of things which do appear.

http://www.newtestamentchurch.org/html/Christian_Evidence/Science_in_the_Bible.htm

http://www.inplainsite.org/html/scientific_facts_in_the_bible.html

http://logosresourcepages.org/Believers/science.htm

Sorry, I do not know how to use code to make active links.


This message is a reply to:
 Message 15 by Sylas, posted 06-21-2005 10:41 AM Sylas has not yet responded

Replies to this message:
 Message 28 by Son Goku, posted 02-11-2006 7:53 AM Glory2God has not yet responded
 Message 30 by cavediver, posted 02-11-2006 8:57 AM Glory2God has not yet responded
 Message 31 by Chiroptera, posted 02-11-2006 2:13 PM Glory2God has not yet responded

  
Son Goku
Member
Posts: 1153
From: Ireland
Joined: 07-16-2005


Message 28 of 38 (285808)
02-11-2006 7:53 AM
Reply to: Message 27 by Glory2God
02-11-2006 12:15 AM


Slow down there sparky!
The theory of relativity predicts an ABSOLUTE beginning. The first law of thermodynamics can not allow for such a beginning.

I'm going to assume you mean the second law of thermodynamics, because the first law barely rules out anything.
(In fact the origin of the second law was the inadequacy of the first)

The second law definitely allows for such a beginning and in no way contradicts relativity.
(In fact if you get into the issue of Weyl curvature they're supportive of each other)


This message is a reply to:
 Message 27 by Glory2God, posted 02-11-2006 12:15 AM Glory2God has not yet responded

Replies to this message:
 Message 29 by cavediver, posted 02-11-2006 8:50 AM Son Goku has not yet responded

  
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 29 of 38 (285813)
02-11-2006 8:50 AM
Reply to: Message 28 by Son Goku
02-11-2006 7:53 AM


Re: Slow down there sparky!
In fact if you get into the issue of Weyl curvature they're supportive of each other

That's right SG, start with the basics :laugh:


This message is a reply to:
 Message 28 by Son Goku, posted 02-11-2006 7:53 AM Son Goku has not yet responded

  
cavediver
Member (Idle past 1959 days)
Posts: 4129
From: UK
Joined: 06-16-2005


Message 30 of 38 (285816)
02-11-2006 8:57 AM
Reply to: Message 27 by Glory2God
02-11-2006 12:15 AM


SG has alreay covered this, but just to emphasise: thermodynamics is very much secondary to Relativity. In its usual guise it is merely a probablistic statement, applies locally, and has no application to considerations of the universe as a whole.

When time is simply an internal aspect of the universe, the beginning of time does not imply a beginning of the universe. If the universe is created (and as a Christian I believe it is) then that creation not only involves the beginning of time, but its middle and end.


This message is a reply to:
 Message 27 by Glory2God, posted 02-11-2006 12:15 AM Glory2God has not yet responded

  
Newer Topic | Older Topic
Jump to:


Copyright 2001-2018 by EvC Forum, All Rights Reserved

™ Version 4.0 Beta
Innovative software from Qwixotic © 2019