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Cosmological Constant and "Big Bang" Momentum

Posted: Wed Aug 24, 2005 11:17 am
by gutdoc
Hi!

I just joined the forum to ask the following question; nonetheless, I am looking forward to following the discussions here.

I am in a small group that is reading Hugh Ross' The Creator and the Cosmos. Today, several of the group (non-scientists) were asking why the "stretchiness" of the space-time fabric was not momentum from the Big Bang rather than an intrinsic property of space. The biologist (me) and the two engineers in the group did not know the answer. Is there one? I've not been able to find a specific answer to this question but most of what I've read argues that the cosmological constant is an intrinsic property and not simple momentum.

Can anyone help me out?

Thanks in advance!
Randy

Posted: Wed Aug 24, 2005 12:36 pm
by ray
I think you need, for my case especially, more explantion. I really don't understand what you are asking ie, explain what you mean by 'stretchiness'. One comment I can make is that you seem to assume 'the big bang' is a fact and that is how the universe came into being. Maybe a different assumption could explain things better, ie, God made the universe.

Ray

Posted: Wed Aug 24, 2005 1:32 pm
by AttentionKMartShoppers
The Big Bang does fit with Christianity actually (and fits with no naturalistic or pantheistic frame). That's one of the things Hugh Ross talks about I believe (haven't read his books yet). "Let there be light"...one of the particles in the Big Bang was the photon :-p


But, with stretchiness, not sure what you're asking asking. All I know with the cosmological constant is that it is small and positive, which means that as distance increases between galaxies, acceleration of expansion increases, and that at any other constant, the universe would explode or implode or rip apart or something nasty like that.

Re: Cosmological Constant and "Big Bang" Momentum

Posted: Wed Aug 24, 2005 5:39 pm
by Kurieuo
gutdoc wrote:I am in a small group that is reading Hugh Ross' The Creator and the Cosmos. Today, several of the group (non-scientists) were asking why the "stretchiness" of the space-time fabric was not momentum from the Big Bang rather than an intrinsic property of space. The biologist (me) and the two engineers in the group did not know the answer. Is there one? I've not been able to find a specific answer to this question but most of what I've read argues that the cosmological constant is an intrinsic property and not simple momentum.

Can anyone help me out?
Welcome gutdoc,

I think is pretty straight forward that if you follow the stretching backwards, is naturally leads to an infinitely small point—the singularity which I believe is God's point of contact that spawned everything into being. Penrose and Hawking proved in a series of theorums that a big bang singularity is inevitable as long as gravity remains an attractive force.

There are also other things supporting the big bang such as the cosmic background radiation. The universe bathes in a temperature which as I understand it sits about three degrees above absolute zero. This radiation is something we would expect from a scenario such as the big bang wherein everything in the universe was once tightly compact and extremely hot. The temperature is like a fading glow from the hot birth of the cosmos. It is hard to understand how such a radiation bath could have arisen otherwise. This is also something that put a nail into the coffin of the the steady state theory.

Anyway, I hope this helps. I'd perhaps also recommend getting a hold of The Mind of God wherein Paul Davies (although a secular author) explains things very well.

Kurieuo.

Cosmological Constant/Big Bang/Stretchiness & God

Posted: Wed Aug 24, 2005 5:47 pm
by gutdoc
Folks:

Hugh Ross does use the very convincing evidence of the Big Bang and other aspects of modern cosmology to argue very convincingly of the action of God as creator/designer of a very precisely balanced, well-designed for life universe. As stated, the Big Bang is very suggestive of God as creator -- much more supportive of Creation than it is any naturalistic explanation, the odds are just against it IMHO.

In trying to answer my question, I found this site: http://www.godandscience.org/apologetic ... stant.html

This article led to my posing the question on this forum since it seemed to be frequented by folks with a background in the sciences. As I understand it, the cosmological constant is an intrinsic property of expanding space & time such that the universe stretches farther and faster as two bodies get farther apart. Hence the observed phenomenon that galaxies farther away from us are universally moving away from us faster. What I could not do in my small group was to explain adequately why this "stretchiness" (as Ross and others describe it) was not left-over momentum from the Big Bang. I was hoping someone with a better background in physics (maybe even the author of the article) could help me help my friends understand.

Randy

Re: Cosmological Constant/Big Bang/Stretchiness & God

Posted: Wed Aug 24, 2005 5:59 pm
by Kurieuo
gutdoc wrote:What I could not do in my small group was to explain adequately why this "stretchiness" (as Ross and others describe it) was not left-over momentum from the Big Bang.
Ahh, phrased that way makes better sense (the 'not' in your original question was quite confusing). I'm sure many believe it is as you say, left-over momentum from the cosmic outburst. Infact this is one thing favouring the big bang scenario over other theories. Does Ross state otherwise (which page in his book so I can look it up)? Does it ultimately matter whether it is left over momentum from the beginning?

Kurieuo.

Posted: Wed Aug 24, 2005 6:00 pm
by Prodigal Son

Posted: Wed Aug 24, 2005 6:04 pm
by AttentionKMartShoppers
Someone define stretchiness, I'm confused

Posted: Wed Aug 24, 2005 6:09 pm
by Prodigal Son
expansion?

Posted: Wed Aug 24, 2005 6:09 pm
by gutdoc
Does Ross state otherwise (which page in his book so I can look it up)?
pages 45-46. He doesn't outright state one way or the other, but I think he implies it is an intrinsic property apart from inertia
Does it ultimately matter whether it is left over momentum from the beginning
No, not really. I just wanted to be sure I had a proper understanding of the concept.

RP

Posted: Wed Aug 24, 2005 6:33 pm
by Kurieuo
AttentionKMartShoppers wrote:Someone define stretchiness, I'm confused
The heavens are literally stretching out at several times the speed of light. Galaxies move further and futher apart. This is the strechiness being spoken of.
gutdoc wrote:pages 45-46. He doesn't outright state one way or the other, but I think he implies it is an intrinsic property apart from inertia
It is interesting going back and reading what he says, and understanding it much easier this time around. I'm not a scientist, but I have spent much time trying to grasp these issues over the years.

What is interesting is that the stretching continues to grow faster and faster. If only gravity was at work, then we would expect the stretching from the initial outburst to be slowing down, and perhaps eventually contract. Yet, this isn't the case (the stretching is speeding up), which means there is another factor at work (the cosmological constant) that that increases the rate of expansion.

So back to your question, an expansion is something we would expect from the big bang scenario (as you were asked), however we would expect such an expansion to be slowing down is only gravity was at play. I just didn't make this connection in my last post. Since it isn't slowing down, but rather speeding up, I believe you are correct to assume there is another factor that is an intrinsic property—the cosmological constant.

Kurieuo.

Posted: Wed Aug 24, 2005 6:44 pm
by August
So for little ignorant me, is that acceleration linear so as to arrive at a constant? If it is, how do we know it's linear since we are not in the middle of the universe, and would therefore observe objects moving at different speeds relative to our position?

Posted: Wed Aug 24, 2005 6:49 pm
by August
http://pancake.uchicago.edu/~carroll/encyc/

I understand some of that....and some not, but explains it a bit.

Posted: Wed Aug 24, 2005 7:50 pm
by Prodigal Son
:shock: dang, august, we ain't that bored!

Posted: Wed Aug 24, 2005 8:00 pm
by Prodigal Son
um, maybe i am...linear.