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Re: Infinite universe?

Posted: Tue Dec 25, 2007 6:25 pm
by Kurieuo
tommyboy605182 wrote:
KrisW wrote:
tommyboy605182 wrote:
my question is, is there any true PROOF against an ageless universe?
Yes...it's called the Big Bang Theory, which says the Universe came into being at a past time via an 'external causal agent'.

The 2K background radiation predicted by the Big Bang Theory was confirmed in the early 1990's.
yes, i understand the big bang theory. the problem is that the big bang theory proves that OUR universe had a beginning, it does not prove an absolute beginning. well, for me it does, but for a stubborn atheist who refuses to "let a divine foot in the door," it doesn't; there could have been millions of universes before ours came into being, or perhaps a multiverse. what im trying to show this guy on facebook is that infinity simply does not exist within our universe. ever since hubble's discovery of the expanding universe, scientists have been trying to find a way around the "creation event," a way to somehow show that the universe did not have an absolute beginning.
That is correct tommy. I think sometimes Christians jump the gun a bit. A beginning to our universe does not mean a beginning, and Christians will often retort back that it is irrational or mere speculation to assume there is anything before our "universe" especially since it can't be scientifically tested. Another is that those who follow multiple universe theories disregard Occam's razor by introducing infinitely vast complexities to explain just one universe (ours). I think these are very good argument against those who take a multiple universe way out. However, there is still the possibility multiple universes could be the case, so I guess many who proclaim themselves Atheists are content with this "way out" even if there is no observing these "other universes".

A more sophisticated argument can be made however. For example, each universe within an infinite universe theory requires something. They require physical laws by which they work and run. As the Naturalist philosopher Paul Davies noted in his book The Mind of God: "Plausible world-ensemble theories still require a measure of explanation, such as the law-like character of the universes and why there exists a world-ensemble in the first place." Davies here raises two dilemmas for those who opt for multiple universe theories. The first is that such theories fail to explain how the many-universe possibilities could have existed in the first place. And second, while an infinite universe theory may provide a selection of different alternative universes, such theories cannot explain the laws by which they run that are responsible for producing an infinite amount of universes.

Some like Lee Smolin postulate theories that allow for small variations in the actual physical laws of new universes, however the laws linking such universes together can not be explained. Thus, I think not only is it grasping for straws to postulate multiple universe theories, but even if one allows them into their beliefs they still end up at dead end explanations. To me it is 1) much simpler, 2) more consistent, 3) has greater explanatory power, and 4) more obvious based on our own experiences in the world we live to infer that laws are put in place by an intelligent law-maker and as such the laws by which our universe works.

Re: Infinite universe?

Posted: Tue Dec 25, 2007 9:06 pm
by KrisW
Kurieuo wrote:
tommyboy605182 wrote:
KrisW wrote:
tommyboy605182 wrote:
yes, i understand the big bang theory. the problem is that the big bang theory proves that OUR universe had a beginning, it does not prove an absolute beginning.

It certainly doesn't disprove it either. In fact, it proves that EVERYTHING we see with our natural senses has a discrete begining.

Re: Infinite universe?

Posted: Wed Jan 02, 2008 6:02 pm
by Seraph
my question is, is there any true PROOF against an ageless universe? i have been involved in a debate with an atheist on facebook (i have a lot of free time, lol) and he consistently argues that although the universe as we know it had a beginning, the energy it contains is timeless. he cites the laws of thermodynamics, stating that it is impossible for energy to have an end or a beginning. i have been able to shoot down his arguments for a cyclic universe and a multiverse, however i can't seem to find any sources that acknowledge this particular belief (that energy is timeless).
The way I see it, doesn't Christianity support the idea of energy being timeless? After all, to my understanding God contains limitless energy, and God is timeless. Perhaps the energy in our universe always did exist before the big bang in God. It doesn't mean that there is an infinite amount of randomly generated universes.

Re: Infinite universe?

Posted: Fri May 16, 2008 2:29 am
by angel
Hi guys
It is ages that I am not around (and honestly I don't think I will be around for a long time this time either).

I just wish to point out (and I am quite informed in the field) that:
1) Big Bang theory is a model in general relativity (GR).
So according to GR our universe necessarily started in a singularity about 13 BYago.
The epoch is computed fitting the theoretical model against red shift data observed.

(Just so that you know it, a singularity is a state of spacetime in which spacetime curvature, matter density, matter temperature and so on are actual infinite quantities!
Whatever, it means that is what you are talking about.
No physicist I know (and I know a number of them) is ready to accept this kind of states are realistic.
They have been fighting them to prove that they are not there or that we could never see them, for about 70 years now.)

2) There is no observed data closer to big bang more than about 400 KY. So nothing like a direct evidence that Big bang really happened.
And no evidence at all (direct or indirect) of what happened closer to some time (the Planck time) which is very small but finite positive time.
The only thing that we know for sure is that the universe expanded as predicted by Big Bang model from 400KY after big bang to about 5BY ago.
In the last 5 BY or so, Big Bang model is not able to fit observed data anymore and to force it to work one is forced to INVENT dark energy and dark matter.
There is no clue about what they are, nor if they really exist as particle we will sooner or later be able to see directly in colliders.
These dark components of the universe amount to 96% (!) of the content of the universe.
Apparently, God created light as well as some dark stuff; apparently quite focusing on the latter.

3) If you knew any physicist you could ask him or her to confirm what I claimed. And they would confirm that the current attitude among ANY theoretician working in GR is the expectation that GR must be modified to account for quantum physics; each of them expects the quantum corrections to PREVENT singularities to happen.
We still do not have a satisfactory quantum theory of gravity to replace GR at a fundamental level.
But avoiding singularities is routinely the first test a proposal has to pass in order to be considered.

4) Today there are a number of candidates being considering as possible quantum gravity theories. The two most popular (string theory and loop quantum gravity) both seem to point to a removal of the Big Bang as a singularity and to the fact that the universe existed before and it was undergoing a contraction phase, even though the particular dynamics of the crunch and bang washed out the memory of pre-Big Bang states so that we probably will never be able to observe the detail of the process.
I repeat, these are only candidates being considered to describe the process, but it is all we have today.

In view of these FACTS, it is simply ridiculous to state that today we know for sure that the universe begun in the big bang. Actually quite the opposite, if you accept current speculations. If instead you want to keep stuck to what we know for sure and ignore speculations (something which I would appreciate) well, you cannot conclude anything different from:

WE DO NOT KNOW HOW IT BEGUN, NOR IF IT BEGUN. yet.

According to my past experience on this forum, you will not believe to me (nor you are supposed to) and most of you will avoid to check it on independent sources (and you should be supposed to).
Just want to add that Kur and the site keepers are not a reliable source in cosmology.
:amen: :clap: :clap:

Take care
Lorenzo / Angel / Ipazia

PS: BTW as far as we know the total energy of the universe is zero. The matter contribute for a positive quantity and gravity contribute for a negative quantities.
Using classical GR many researchers agree that the total is exactly zero. So the fact it is eternal does not say anything about the possibility that universe was created.

Re: Infinite universe?

Posted: Fri May 16, 2008 4:56 am
by Canuckster1127
Angel,

Thanks for your input and it is fine to disagree with me or any of the other moderators.

I do disagree with much of what you've put up here. I think if you were serious about your assertions you could post some sources instead of appealing to unnamed authorities and asserting positions that frankly, I know not to be true in terms of the consensus of the field in approaching the singularity.

You're quite correct that there is a lot here that is theory that has yet to be proved and there's been a lot of new information found even in recent times. Some of it has been predicted and some of it has impacted current theory. Dark matter is a strong case in point.

I think you're attempting to make more of what is unknown that building on what is known and where there is consensus. That's a common tactic among YEC supporters.

It's your responsibility to support your assertions and frankly all you've done here is attempt to cast doubts while not supporting your assertions.

Blessings,

Bart

Re: Infinite universe?

Posted: Fri May 16, 2008 5:54 am
by angel
I do disagree with much of what you've put up here. I think if you were serious about your assertions you could post some sources instead of appealing to unnamed authorities and asserting positions that frankly, I know not to be true in terms of the consensus of the field in approaching the singularity.
Well... My suggestion is simply: get informed. Ask people, possibly working in the field.
Anyway, I was just reporting experience, not calling on authority.

Any student in physics can tell you that the general attitude is that quantum corrections will remove singularities.
I am not saying that we KNOW that they do. But the whole thread is certainly misleadingly pretending that
we already KNOW that our universe begun at BIg Bang.
This story is not new and it dates back to well before you joined this forum.

Anyway, you were asking about references. Here they are.
Just the beginning... I can provide quotations from basically anyone (including Hawking)
confirming exactly the attitute I reported.

You may disagree with it, but it is certainly a fact in physics community.




http://en.wikipedia.org/wiki/Black_hole
According to general relativity, a black hole's mass is entirely compressed into a region
with zero volume, which means its density and gravitational pull are infinite, and so is
the curvature of space-time that it causes. These infinite values cause most physical equations,
including those of general relativity, to stop working at the center of a black hole.

So physicists call the zero-volume, infinitely dense region at the center of a black hole
a singularity.
The singularity in a non-rotating black hole is a point, in other words it has zero length,
width, and height. The singularity of a rotating black hole is smeared out to form a ring
shape lying in the plane of rotation. The ring still has no thickness and hence no volume.
The appearance of singularities in general relativity is commonly perceived as signaling
the breakdown of the theory. This breakdown is not unexpected, as it occurs in a situation
where quantum mechanical effects should become important, since densities are high and
particle interactions should thus play a role.


Unfortunately, till date it has not been possible to combine quantum and gravitation
effects in a single theory. It is however quite generally expected that a theory of
quantum gravity will feature black holes without singularities.
BTW I am not the author of this! :ewink:

About singularity removal in quantum gravity:
http://www.citebase.org/abstract?id=oai ... %2F0509078

About singularity removal in Big Bang
http://www.gravity.psu.edu/outreach/art ... vaynet.pdf
http://arXiv.org/pdf/gr-qc/0601085

Same in string theory
http://arxiv.org/abs/hep-th/0111275
http://www.nordita.dk/conference/cosmo2005/
http://adsabs.harvard.edu/abs/1997gr.qc.....8018J

Want more?

Re: Infinite universe?

Posted: Fri May 16, 2008 7:11 am
by Canuckster1127
angel wrote:
I do disagree with much of what you've put up here. I think if you were serious about your assertions you could post some sources instead of appealing to unnamed authorities and asserting positions that frankly, I know not to be true in terms of the consensus of the field in approaching the singularity.
Well... My suggestion is simply: get informed. Ask people, possibly working in the field.
Anyway, I was just reporting experience, not calling on authority.

Any student in physics can tell you that the general attitude is that quantum corrections will remove singularities.
I am not saying that we KNOW that they do. But the whole thread is certainly misleadingly pretending that
we already KNOW that our universe begun at BIg Bang.
This story is not new and it dates back to well before you joined this forum.

Anyway, you were asking about references. Here they are.
Just the beginning... I can provide quotations from basically anyone (including Hawking)
confirming exactly the attitute I reported.

You may disagree with it, but it is certainly a fact in physics community.




http://en.wikipedia.org/wiki/Black_hole
According to general relativity, a black hole's mass is entirely compressed into a region
with zero volume, which means its density and gravitational pull are infinite, and so is
the curvature of space-time that it causes. These infinite values cause most physical equations,
including those of general relativity, to stop working at the center of a black hole.

So physicists call the zero-volume, infinitely dense region at the center of a black hole
a singularity.
The singularity in a non-rotating black hole is a point, in other words it has zero length,
width, and height. The singularity of a rotating black hole is smeared out to form a ring
shape lying in the plane of rotation. The ring still has no thickness and hence no volume.
The appearance of singularities in general relativity is commonly perceived as signaling
the breakdown of the theory. This breakdown is not unexpected, as it occurs in a situation
where quantum mechanical effects should become important, since densities are high and
particle interactions should thus play a role.

Unfortunately, till date it has not been possible to combine quantum and gravitation
effects in a single theory. It is however quite generally expected that a theory of
quantum gravity will feature black holes without singularities.

About singularity removal in quantum gravity:
http://www.citebase.org/abstract?id=oai ... %2F0509078

About singularity removal in Big Bang
http://www.gravity.psu.edu/outreach/art ... vaynet.pdf
http://arXiv.org/pdf/gr-qc/0601085

Same in string theory
http://arxiv.org/abs/hep-th/0111275
http://www.nordita.dk/conference/cosmo2005/
http://adsabs.harvard.edu/abs/1997gr.qc.....8018J

Want more?
Nope. Thanks. I'll work to digest some of these and see if you're quoting them accurately in terms of your earlier comments.

Re: Infinite universe?

Posted: Fri May 16, 2008 11:10 am
by angel
"Be on guard against giving interpretations of Scripture that are farfetched or opposed to science, and so exposing the Word of God to the ridicule of unbelievers." St. Augustine
I like this. And agree I do. :wave:

Re: Infinite universe?

Posted: Mon May 19, 2008 1:46 pm
by BGoodForGoodSake
I would have to agree with Angel in that a singularity is interpreted as a breakdown in GA. Thus the push for a unified theory.
When the math breaks down it is generally assumed that it no longer can be used as a model of the physical universe.

Re: Infinite universe?

Posted: Thu May 29, 2008 7:21 pm
by chizum
Well I'm not married to the Big Bang or anything, but, angel, don't you think Hubble's Law and the PREDICTED cosmic background radiation are pretty solid beams of support? Contrary to what you said of "no direct evidence."

I also have to disagree with your statements that most astrophysicists doubt the Big Bang. I know Wikipedia isn't always a reliable source, but it claims "very few researchers now doubt the Big Bang occurred."

Wikipedia further goes on to say, "The core ideas of the Big Bang—the expansion, the early hot state, the formation of helium, the formation of galaxies—are derived from many independent observations including Big Bang nucleosynthesis, the cosmic microwave background, large scale structure and Type Ia supernovae, and can hardly be doubted as important and real features of our universe."

Man, it's times like this when I really wish I could take some astronomy/physics courses. Unfortunately, I blew my first two years of undergrad by switching majors constantly so I pretty much have to spend my remaining 2 years on stuff for my major (psychology). :\ I've always been lacking in my astrophysics knowledge, it frustrates me, lol.