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astromark
2008-Sep-16, 10:39 AM
In the thread about the eventual fate of matter in the universe I, just as a added thought asked would it be possible that this expanding universe might come across another also expanding universe... Now this idea is not what I would call factual, or mainstream. We know of no other universe. I am not going down that road of other universes. I just asked a question; Could it be like this? I have opened this thread only to stop this discussion spoiling the OP I mentioned. As I said there this universe is according to mainstream science expanding. If a universe might be not the only one... then the answer must be yes. As we may never actually be able to know the truth here... I will bow to the wisdom of my piers... and conclude with a 'probably not'. maybe... and I can not say.:)Could I see a show of ideas? opinions?

Fiery Phoenix
2008-Sep-16, 11:35 AM
I don't think so. Assuming there are other universes, in theory, they are parallel. So, if two things are parallel to each other, and both are expanding, they probably won't come across one another whatsoever - if that's what you're asking.

On more note, I often think of this possibility; that our universe is merely part of a larger scale. And that molecules, which are incredibly small, have their own universes within them. As irrelevant and far-fetched as it may sound, I like to think of it.

Jeff Root
2008-Sep-16, 11:53 AM
Mark,

I actually started to reply in the other thread, then decided not to bother.
What I started to say was that max8166's objection is just semantic --
in this case, the meaning of the term "universe". There's no reason stuff
couldn't exist which never had any connection with the Big Bang. Such
stuff as dreams are made on... Oop, sorry, I mean, Such stuff might have
been created in a different, separate Big Bang from the one that made
everything we can see. There's no obvious reason such a separate
universe couldn't subsequently come into contact with ours. Do we then
say that the region of overlap is part of our universe, not a separate
universe? If you marry someone, does that person become part of your
family? Do you become part of that person's family? Are the two families
identical?

While we can probably never know whether other universes actually exist,
the semantic problem here is a trivial one. Similar to but not nearly as
bad as the one in another thread regarding the term "species".

-- Jeff, in Minneapolis

astromark
2008-Sep-16, 07:18 PM
"On more note, I often think of this possibility; that our universe is merely part of a larger scale. And that molecules, which are incredibly small, have their own universes within them. As irrelevant and far-fetched as it may sound, I like to think of it." end quote. FP;

I can tell you that on a sub-atomic level that is wrong...BUT, it is a good way of imagining the structures of galaxies, and there components... Not so for the universe. I agree with your expanding in parallel thought, but can not find proof.


" Such stuff as deams are made on..." end quote. Jeff;

Here's the r and of... But thanks for this, which is as I thought.

If we can see or detect it, then it is part of 'our' universe.
I might need a stronger coffee... because now I am thinking that if such other universes were to be expanding as this one is, then it would not be visible to us as its light image could not be ahead of a faster than C expanding mass... space.
I shall think slower....:)

speedfreek
2008-Sep-16, 08:12 PM
Hmmm. In order for this expanding universe to come across another expanding universe, the implication is that they would have to overlap each other. This would require the said universes to have edges, would it not?

How is that going to work if we assume that everywhere in this universe would think of itself as the centre of expansion, and although it may seem like distant galaxies are receding faster than light, all clusters of galaxies can be considered to be at rest in relation to the Hubble flow?

Jeff Root
2008-Sep-16, 08:28 PM
Hmmm. In order for this expanding universe to come across another
expanding universe, the implication is that they would have to overlap
each other. This would require the said universes to have edges,
would it not?
That would be one way. Another would be for a Bang to occur in a
place where a universe already exists, from an earlier Bang. We had
a really, REALLY BIG Big Bang. I'd expect smaller Bangs to be more
common and more frequent.



How is that going to work if we assume that everywhere in this
universe would think of itself as the centre of expansion,
It won't. So let's not assume that.

-- Jeff, in Minneapolis

sohh_fly
2008-Sep-16, 08:46 PM
what if there was other expanding universe's in a overlap with ours.
what if our universe with the others has no edges.(just a thought)
can it be like a free flow?
maybe trading energies ?
maybe fusing at distances to far to detect, not like big bangs, but more something like mixing two paints very slowly?

if there is multiverses, maybe they have their own secret handshake

Jeff Root
2008-Sep-16, 08:56 PM
That isn't what speedfreek meant by "edge". He didn't mean any kind of
membrane or force or matter preventing one from going beyond a certain
point -- he just meant a place where there is universe on one side of you
but no universe on the other side of you. Descriptions of the Universe's
geometry generally say that there is no such edge. I'm not convinced.
However, nobody can deny that the Universe is very, very, VERY BIG!
So it's hard to tell whether there's an edge or not.

-- Jeff, in Minneapolis

Fiery Phoenix
2008-Sep-16, 08:57 PM
I agree with your expanding in parallel thought, but can not find proof.

And you won't, simply because it's my own personal opinion. Glad to hear you agree, though.

speedfreek
2008-Sep-16, 09:42 PM
That would be one way. Another would be for a Bang to occur in a place where a universe already exists, from an earlier Bang. We had a really, REALLY BIG Big Bang. I'd expect smaller Bangs to be more common and more frequent.
-- Jeff, in Minneapolis

Interesting.. another universe appearing somewhere within our universe with a small bang! The more I think about this one, the more my mind simply boggles, it is like my brain wants to look the other way and ignore the problem and I can't drag it back! (What would it look like? If we can't view our own universe "from the outside", how about this new small one?)

astromark
2008-Sep-17, 06:06 AM
The problem; as well pointed out already, is this. Space outside this universe is not there yet... could that be wrong..

Jeff Root
2008-Sep-17, 09:04 AM
Mark,

Even after you posted the letter 'r' for me to fix my typo (thank you!),
I didn't understand what you were talking about, because I didn't notice
the typo until just now. I thought you were just acknowledging that
you recognized the quote.

I'm going to take the 'r' you gave me and insert it where it belongs.

I haven't been able to tell whether all the missing letters in my typing
are due to my mentally skipping past those letters, or the keys on the
keyboard sometimes not registering when I hit them.

The word 'on' is the correct final word in that quote.

-- Jeff, in Minneapolis

astromark
2008-Sep-17, 09:33 AM
Will I require medical attention...:)
Yes, the on is fine. I just assumed you meant ' The stuff dreams are made of ' Being not so correct myself is not the fault of my key board... Its me. But I except it might not be you... for I have witnessed the key bourd phantom myself.

I have carried this idea of this expanding finite universe possibly coming across some other reality as it does so. I also see it as a ATM idea. I asked the question only to test my own reasoning... and now am happy to conclude this with a ' Maybe.'
No, I will not be engulfed by a senseless passion to prove the unprovable. Thank you all.
--- Mark.

Cougar
2008-Sep-17, 05:18 PM
...would it be possible that this expanding universe might come across another also expanding universe...

Certainly not if Alex Vilenkin's eternal inflation (http://cosmicvariance.com/2006/09/09/alex-vilenkin-many-worlds-in-one/) model is correct. IIRC, this model states that "this expanding universe," that is, "our" universe, is the decay product - a low-energy bubble - in a (much) larger universe that continues to undergo exponential inflation. It is conjectured that there are many, many other bubbles that have decayed (the first instant of decay is their "big bang"), but their vacuum and physical constants and dimensions may be different than ours. But no bubble will ever meet another since the exponentially inflating "space" between them is expanding faster than light.

astromark
2008-Sep-17, 07:15 PM
" Certainly not if Alex Vilenkin's eternal inflation model is correct. " Quote, Couger;

and it might be. Just as it might not be. A model, theory, explanation. A well educated persons point of view and sense of reasoning is difficult to just refute or ignore. I am not going there. My understanding is that because of the inflation of the universe we will never know. Mr Vilenkins explanation sounds good for me... I only asked. Questioning my own resolve not yours. As a amature astronomer I just wanted a better understanding. Which I now have. This train of thought is not a compulsory doctrine norr am I asking anybody else to take on board my stance.
Now I think you should take back that ' Certainly not ' Because that is not so. Probability is not certainty.

Cougar
2008-Sep-19, 08:18 PM
Well, that "certainly not" was connected to a pretty big "if." But with over 150 publications, Alex Vilenkin (http://en.wikipedia.org/wiki/Alex_Vilenkin) is certainly no slouch nor wild speculator. Remarkably, he outlines an observational test that could support or disprove his concept. Unfortunately, we may not have the technology to conduct such a test for another 50 or 100 years....

astromark
2008-Sep-20, 05:17 AM
The point being that if we accept that this is a thing called a universe that we are part of... and I would dare to say that it is true. Then we can say that this universe has parameters of physics that make the rules the same anywhere across this universe. The atomic structure of atoms and then molecules of elements and the way they interact with each other. The enormity of the complexity and size is a struggle to comprehend. I still maintain that of one set of circumstance deemed it possible for this great expansion and matter as we now know it. It would most likely have happened more than just the one time. The idea of just the one reality, this universe is now becoming unacceptable as the mainstream idea. That not to long ago, I would have being arguing with this. The weight of the argument has swayed me. Its logical.
I will not go so far as to say there must be multi universes with every connotation imaginable of every possible reality infanitum... But it would seem that just this one universe is verging on a religious belief that is based on some thing other than the truth.

max8166
2008-Sep-20, 10:48 AM
Ok, I know it was me. A sweeping statement of certainty in a very uncertain world.

I expressed what seemed like a fact, but in reality was only an opinion, as fact. Sorry.

I believe that what I said was true though, This universe and all it's co-ordinate points within can never impact on another universe if they did exist, due to the fact that if the other universe had cardinal points within this universe it would have to be integral to our universe and therefore a part of our universe and so within the whole, making the second (impacting) universe a figment within the whole. Maybe that is semantic.

sirius0
2008-Sep-20, 12:21 PM
Ok, I know it was me. A sweeping statement of certainty in a very uncertain world.

I expressed what seemed like a fact, but in reality was only an opinion, as fact. Sorry.

I believe that what I said was true though, This universe and all it's co-ordinate points within can never impact on another universe if they did exist, due to the fact that if the other universe had cardinal points within this universe it would have to be integral to our universe and therefore a part of our universe and so within the whole, making the second (impacting) universe a figment within the whole. Maybe that is semantic.
I like the logic of what you are saying about the whole. But it turns my mind to that suggestion that dark matter might be galaxies of another universe that happen to gravitationally bond to ours. Inferring that we look like dark matter to them. But Okam's razor doesn't like this sort of overly grand explanation. Still I wonder sometimes if it is not impossible to have a complete and proven explanation of something and then miss another just as complete explanation that seems totally different but is, due to limits in our understanding, completely equivalent.

RussT
2008-Sep-21, 11:01 AM
But it would seem that just this one universe is verging on a religious belief that is based on some thing other than the truth.

:clap::clap:

Very good astromark! Based on many of your other posts I wasn't sure that you had this conceptualization available.

I meant to post something about an additional "Multi-verse" concept in young Mr Spratley's thread, and will copy this there if/when he returns.

'Parallel Universes', 'many worlds', and the "Inflationary" expanding/contracting 'baby universes' have all been covered...to death...

There is another though that continually seems to be missed.

First though, I will repost this, as it has always seemed the most fitting to me...

http://www.bautforum.com/showpost.php?p=648294&postcount=66

This is Tim Thompson's answer to this question. Anyone can read all the responses, but here is part...



Personally, I find multiple universes far easier to understand, and I see that as the direction in which cosmology seems to be inexorably moving. The point is that any theory which includes one and only one universe, has still to explain how & why this universe comes to be in its "fine tuned" state, which allows for us to exist & see it. We are delicate creatures, and it's easy to imagine some small variation on the constants of nature, such that there would be no chance of us, or anything like us, ever existing. It's the old anthropic principle problem.

But, suppose (just suppose) that there is a population of universes, each of which has its own set of fundamental constants, like unto ours. You can create a probability distribution for each of the fundamental constants, based on the frequency of occurance of each value of that constant, in the population of universes. Of course, we can't do that observationally, because we can't see any of the universes. But if we had a theory that explains how universes "bang" into existence, we could use that theory to produce the desired probability distribution. That will in turn explain why our universe is the way it is, without invoking any sense of 'fine tuning', because our universe simply becomes one of the elements in the probability distribution. All you need is a theory which does not make our universe improbable. String theory, for instance, seems to work quite well along those lines.

and the one I have quoted often...


But there is one more point. It is not true that there is no evidence for multiple universes. Dark matter & dark energy are not observed, but are rather assumed to exist, as a consequence of observation. But how do we know that dark matter & dark energy are the most suitable interpretations? What if the other universes are not so "unobservable" after all? What if we have misinterpreted the observations, and the force we interpret as "dark matter" is really gravity leaking out of the other universes, and into ours? I can readily imagine a multi-universe theory, which includes such an effect, and therefore is not simply "consistent" with observation, but actually predicts the observed effects we call dark matter & dark energy, as consequences of the communication of information between universes.

Now, as I said above there is another Multi-Verse that is called Fractal Universes.

That simply works like this...

Fractal Universes says that there are Universe levels above and below our Universe.

That is, that there is a whole Universe one level above Ours, and a Whole Universe one level below Ours, and that those whole Universe levels 'could' be Infinite all the way up AND all the way down.

Now, obviously we can Never know how many levels up or down there are, OR how or where the "First" one started [That is how God Will always stay in the picture, for those that need or want that:)], BUT I truely think that Tim has an excellent point.

In Mr Sprately's thread, the "Communication", as usual, was putting the 'human' into the equation, and rather than a spaceship, the communication (Between universes) was consiousness.

That is NOT the "Communication" that Tim is talking about.

Enjoy