Compacting universe before big bang?

[Whitney]

The Big Bang describes how the Universe began as a single point 13.7 billion years ago, and has been expanding ever since, but it doesn't explain what happened before that. Researchers from Penn State University believe that there should be traces of evidence in our current universe that could used to look back before the Big Bang. According to their research, there was a contracting universe with similar space-time geometry to our expanding universe. The universe collapsed and then "bounced" as the Big Bang.

Full article: http://www.universetoday.com/am/publish ... _bang.html

I don't understand what exactly this would mean in relation to the fate of our own universe. I tried googling loop quantum gravity, but didn't find much in the way of how it applies to whether this universe is open or closed. If it is true that prior to the BB a contracting universe existed which bounced back into what we have now, does that mean that this universe could also face the same fate of contraction even though it is currently accelerating outward?

I found this article while trying to find current theories related to the idea that our current universe is the result of infinate expansions and contractions. But I couldn't remember what that theory was called.

Anyway, although it is pretty much impossible at this point to definately say how the universe came to be and what it will become, what is everyone else's pet theory?
_________________
“Generally speaking, the errors in religion are dangerous; those in philosophy only ridiculous” - David Hume

[Squid]

The big bounce is part of the LQG theory. Here's a wiki article on the big bounce:

http://en.wikipedia.org/wiki/Big_Bounce

Lee Smolin talks about loop quantum gravity:

http://www.edge.org/3rd_culture/smolin0 ... index.html

Wikipedia article:

http://en.wikipedia.org/wiki/Loop_quantum_gravity

Smolin also had an article in the January 2004 issue of Scientific American:

http://www.sciamdigital.com/index.cfm?f ... 1F85536798

[Whitney]

thanks for the links...very helpful.

[Squid]

No problemo.

[Asmodean Prime]

well, since you asked

(not sure if i'm gonna get my ears chewed off by you for posting my beliefs in this section instead of the preaching forum, but since you asked it in this section, here goes.

look around you, at all the trees, hills, dirt, planets, stars - billions and billions of them, containing soooooo much matter we cant even begin to grasp how much -  how can you believe this sprang into being, by ITSELF, out of nothing, with no creator?  after all, its here, and its BIG.  could you not allow yourself the possibility of considering that maybe it was CREATED?  it makes at least as much sense as the big bang theory from an infinitely SMALL dot of infinite density.  my viewpoint makes more sense, i believe.

dont you ever look up at the stars, etc, with a sense of awe, and just wonder?
or, as i suspect, do you struggle really hard to go out of your way to find an alternative explanation because maybe you dont WANT to accept things as being created?   i mean, your belief requires at least as much faith as mine.

[TwistOfCain]

Our belief doesn't really require as much faith as yours. We have compelling evidence to back ours up. And I do look at the stars with a sense of wonder. When I see then, I think "I wonder what's out there, and will I ever get to see it?"

[Asmodean Prime]

but, twist of cain, how can you say you have compelling evidence? as the original posting said,

"Anyway, although it is pretty much impossible at this point to definately say how the universe came to be and what it will become, what is everyone else's pet theory?"

where is the evidence, or is it just pet theories?

[TwistOfCain]

Compelling evidence is not absolute proof. I have compelling evidence for my theories. I recognize that I could be wrong. My evidence for my hypothesis (admittedly untestable) is the current state of the universe. It can be shown that the universe is expanding. If the universe is finite, which I believe it is, then it makes sense that it would contract at some point. Given physical laws that state that matter cannot be created or destroyed, this implies that matter has always existed. Therefore, the universe always existed. That's my evidence. But, again, I'm no scientist.

[MikeyV]

how can you believe this sprang into being, by ITSELF, out of nothing, with no creator?

I ask you the same question about your god. You bleevers always say creation ex nihilo is impossible, but you beleive your god was created ex nihilo.

If your comeback to that is, god has always existed, how do you know matter hasn't always existed?

where is the evidence, or is it just pet theories?

I really wish that they would ban bibles in jail, and only allow science or other usefull books. That way, when you get out of the pen, you can be a usefull member of society instead of a godbot.

Insted of asking this question here, why don't you pull your nose out of your musty tome of fairy tales, and read something else? Learn something new. It won't kill you, I promise.

[Jassman]

Insted of asking this question here, why don't you pull your nose out of your musty tome of fairy tales, and read something else? Learn something new. It won't kill you, I promise.

You've gotta give him credit for trying. He's just learning why we think how we do. It's hard for a Christian to step out of their own worldview, even for a few seconds. I think he's asking some great questions which will enable him to learn a lot of stuff he otherwise would have overlooked.

[Asmodean Prime]

as a matter for the record, i've studied in depth all kinds of scientific theories over a number of years, including evolution, particle physics, string theory, black holes.  im not coming from a totally uninformed position, you may know.

as a matter of interest, current theories on subatomic particles seem strongly to suggest something of what you would call metaphysics to explain what scientists are observing, not hard and fast science after all.

[McQ]

as a matter for the record, i've studied in depth all kinds of scientific theories over a number of years, including evolution, particle physics, string theory, black holes.  im not coming from a totally uninformed position, you may know.

as a matter of interest, current theories on subatomic particles seem strongly to suggest something of what you would call metaphysics to explain what scientists are observing, not hard and fast science after all.

Well that's good to know. As an amateur astronomer I've been studying and teaching astronomy for about 25 years. I also have a BS in Biology and a great interest in evolutionary biology. We might have a lot to discuss.

However, I'd be interested to know what theories on subatomic particles you speak of that go into "metaphysics". I doubt that they are current accepted theory.

While we're at it, let's differentiate between the words "theory" and "hypothesis". They seem to get people into trouble as scientists tend to have different definitions than lay folks and, especially, creationists and intelligent design folks.

A theory isn't something that is just an idea. Here is a brief definition from the American Museum of Natural History:

"In everyday use, the word "theory" often means an untested hunch, or a guess without supporting evidence. But for scientists, a theory has nearly the opposite meaning. A theory is a well-substantiated explanation of an aspect of the natural world that can incorporate laws, hypotheses and facts. The theory of gravitation, for instance, explains why apples fall from trees and astronauts float in space."

So that will hopefully keep us out of trouble when we start discussing theories. They aren't guesses, or hypotheses.

[Whitney]

but, twist of cain, how can you say you have compelling evidence? as the original posting said,

"Anyway, although it is pretty much impossible at this point to definately say how the universe came to be and what it will become, what is everyone else's pet theory?"

where is the evidence, or is it just pet theories?

by "pet theory" I was actually referring to origins prior to the big bang.  Although the big bang is a theory it is also backed up by quite a bit of evidence, so it is logical to think that something like the BB happened.  However there are numerous BB based theories which try to further make sense of the universe.

My current idea is that matter may have just always existed in some form or another.  Something existing could just be the natural state of things.  Theists think god always existed...so why can't that idea just apply to matter and cut out the middle man.  I think the big difference you'll find between atheists and theists is that atheists are willing to change their beliefs in light of new evidence.  Theism, esp of the religious variety, doesn't give that much room for changing beliefs without altering core beliefs.  Right now we have the question "why is a universe here rather than nothing?"  The real answer is we don't know right now but have some theories that seem promising.  Theists use god to replace "we don't know" (often called god of gaps) atheists are generally content with admitting to not have the answer yet.

[Amor Fati]

as a matter of interest, current theories on subatomic particles seem strongly to suggest something of what you would call metaphysics to explain what scientists are observing, not hard and fast science after all.

Yes, Metaphysics is traditionally a branch of philosophy that studies the nature of the universe and reality.  However, physicist studying sub-atomic structures and particles are performing metaphysical studies, only using the empirical methods of scientific inquiry.  This is what makes it hard science.  
Just so we're clear, empiricism was, and is, also a branch of epistemology, the study of the nature of knowledge in philosophy.  Science cannot ask questions about the nature or value of empricism, since it takes this as a basic assumption.  Within philosophy, hardly any other idea is more solid than empiricism as a method for attaining true knowledge about the world.

[McQ]

but, twist of cain, how can you say you have compelling evidence? as the original posting said,

"Anyway, although it is pretty much impossible at this point to definately say how the universe came to be and what it will become, what is everyone else's pet theory?"

where is the evidence, or is it just pet theories?

by "pet theory" I was actually referring to origins prior to the big bang.  Although the big bang is a theory it is also backed up by quite a bit of evidence, so it is logical to think that something like the BB happened.  However there are numerous BB based theories which try to further make sense of the universe.

My current idea is that matter may have just always existed in some form or another.  Something existing could just be the natural state of things.  Theists think god always existed...so why can't that idea just apply to matter and cut out the middle man.  I think the big difference you'll find between atheists and theists is that atheists are willing to change their beliefs in light of new evidence.  Theism, esp of the religious variety, doesn't give that much room for changing beliefs without altering core beliefs.  Right now we have the question "why is a universe here rather than nothing?"  The real answer is we don't know right now but have some theories that seem promising.  Theists use god to replace "we don't know" (often called god of gaps) atheists are generally content with admitting to not have the answer yet.

Well, technically, the statement that matter cannot be created or destroyed is wrong. Therefore, saying that matter has always existed in some form or another is tenous. It has to be better defined. Matter, isn't always well-defined either. If you're talking about "everyday" matter, the fermionic kind, then your talking about the stuff we're familiar with. But that excludes electromagnetic energy and certain types of field energy.

Anyway, the point is that matter is not conserved, especially in Special Relativity, according to the common definition of matter. The Law of Conservation of Matter does not propose that matter cannot be created or destroyed. Even though it states that matter is not destroyed in a reaction, it doesn't prevent matter from changing form, which is what happens.

And besides, none of this is relevant to the universe prior to the Big Bang. Neither does the Big Bang address, or need to address, what came before. It is an accepted theory for what happened from the time of singularity, through inflation, and just after. The predictions made by BB theory have been borne out by experiment and observation. It's a pretty damn solid theory. It does not try to account for more than that.  There are other hypotheses out there trying to do that now.

I've rambled now, and even managed to lose my own train of thought, so I'll quit here! LOL!
(damn, I hate it when I do that!)