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#25867 05/01/08 12:12 PM
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most of you are probably already aware of the idea of time dilation...
time dilation; the faster you move, or the greater your proximity to large masses: the rate of time will proportionally decrease(with respect to a datum position in space/time)

so the 'edge of the universe' seems more plausible; lets pretend that you had a 'perfect' space suit: if you were to approach the edge of the universe, statistically there would be fewer masses floating around and in this sense, the closer you get to the edge than the slower time would pass; and eventually you would reach a state where the rate of time(again with respect to the datum) would reach a lower limit, where it exists only because of your own mass. (so you could never physically cross over the edge; to the claustrophobic: this means we are trapped!! haha)


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bfp: "if you were to approach the edge of the universe, statistically there would be fewer masses floating around"

Two questions:

What makes you think the universe has an edge?

Why do you think there would fewer masses floating around? Is it because you suppose that you would be on the brink of a 'nothingness' beyond the universe?

(Sorry, that's three questions smile )

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Hello everyone,

Answer me a question(s). What is the shape of the universe? Is it round? Is it a cube? A sphere? Is it shaped like an hour glass as 2 universes connected by a black hole? When you get to the edge-how does it stop, and what is "stop"? You can't fall off the edge like the sailors feared before Columbus.

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Hi bfp, and Hi odin1.

Difficult to discuss without some rambling preamble, so let's ramble a bit.

Let's recap on some theory:

In the beginning was a point. The point was spacetime and all the energy thereof. Without the point there was neither spacetime, nor energy. Spacetime inflated and expanded. As it did so, it cooled. As it cooled, fundamental particles were formed. From the fundamental particles, the lightest elements were formed. From the lightest elements, stars were formed. From the stars, galaxies were formed. While that was happening, and ever thereafter, space continued to expand (or stretch, if you prefer). Such has been the rate of expansion that most of the universe now lies beyond the observable limit of 13.7 billion light years. There's an observable limit because it all began about 13.7 billion years ago, so light has had time to travel only 13.7 billion light-years - in a billion years from now, an observer would be able to see for 14.7 billion light years.

So, how much of the universe can we not see?

"The universe is at least 156 billion light-years wide." 24 May 2004
http://www.space.com/scienceastronomy/mystery_monday_040524.html

The mentioned limit of observation is often referred to as the 'edge' of the universe, but obviously it's not. Whilst our observable universe is necessarily spherical, we don't know about unobservable part. We don't even know if the physical laws are the same. We can try to deduce, extrapolate, speculate or whatever, but we cannot know.

I would be very interested to see what anyone can find on the net about this subject. Beware though: there's a high percentage of conflicting information, mis-reporting and plain nonsense out there, so it's well worth at least checking the sources before taking an article seriously.

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Originally Posted By: redewenur
bfp: "if you were to approach the edge of the universe, statistically there would be fewer masses floating around"

Two questions:

What makes you think the universe has an edge?

Why do you think there would fewer masses floating around? Is it because you suppose that you would be on the brink of a 'nothingness' beyond the universe?

(Sorry, that's three questions smile )


It is known that the universe has an edge because in the hubble telescope other universes can be clearly seen beyond our own.

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Originally Posted By: Rallem
It is known that the universe has an edge because in the hubble telescope other universes can be clearly seen beyond our own.

You're mistaken, Rallem. If you can provide a link to the source of your info, I'm sure we'll be able to find out why.

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I'll have to get you a url for this info when I get home, because I am at work and the site is blocked.

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BFP, et al, I presume that all of you know that you are dialoguing about what I mean when I use the anagram, GØD?

If my question is meaningless to you, we can always dialogue, in fun and good faith, about it, okay? laugh

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G~O~D--Now & ForeverIS:Nature, Nurture & PNEUMA-ture, Thanks to Warren Farr&ME AT www.unitheist.org
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I cannot find right now where I got this information redewenur, but it would appear that you are right about me being mistaken because if other universes have been detected it was not by the Hubble Space Telescope. I did see a show on NASA television where someone whom I don't know or can't remember was talking about space flight in our Universe and he pointed out that there were other Universes and demonstrated how far they were from our own universe. The man was asked whether it was possible for us to get to these other Universes and his short answer was no, because he said that we had no idea what was between our own Universe and even the nearest other Universe and he said that even if we could tackle that problem we would have no idea on what form of physical laws that Universe follows until we get there and then would be a bad time to find out that in another Universe its time runs backwards, or even that in that universe magic was the predominate force of physical law and not actually physics. I will try to find this out for you redewenur, but I will warn you that this is all from my memory which has been less than dependable lately.

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Hi Rallem.

There are a few distinctly different scientifically legitimate hypotheses regarding the 'multiverse' that aren't necessarily mutually exclusive. Wiki contains quite a good outline of these:

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

The only edge I can perceive within these hypotheses is that of the kind of boundary represented by the hypothetical wormhole, or by an event such as the Big Bang. Theorists seem generally convinced that our spacetime continuum is either infinite, and therefore boundless, or finite and unbounded, meaning that if you go 'straight' for long enough, you wind up back where you started. Currently, I think the situation is that there's no evidence for either.


"Time is what prevents everything from happening at once" - John Wheeler
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I'm a little confused. In reference to another universe. How do you know when the one we live in ends? What governs the "next" universe? I was under the impression "another universe" would have to be in another dimension.
definition of universe:

"The Universe is most commonly defined as everything that physically exists: the entirety of space and time, all forms of matter, energy and momentum, and the physical laws and constants that govern them."

I am referring to the gentleman that works with NASA Rallem was talking about.

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"Answer me a question(s). What is the shape of the universe? Is it round? Is it a cube? A sphere? Is it shaped like an hour glass as 2 universes connected by a black hole?"

we cannot be certain; every possibility sounds plausible; even the one with the 'edge' which i talked about

"When you get to the edge-how does it stop, and what is "stop"? You can't fall off the edge like the sailors feared before Columbus."

this is what i was trying to explain with 'time dilation' we need not fear falling off the edge because it is impossible to get close enough to do so.

a lot of the things we're talking about here is just pure speculation, what gives us the idea that the universe has a shape at all? or that there are other universes? i don't think that one can argue one idea to be more plausible than another


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Hi odin1

Firstly, we should remind ourselves that while some eminent scientists insist that, logically, other universes must exist, there is no proof.

Re the definition of universe: We can define universe in two ways: either as including any other universes as part of it, irrespective of their accessibility, or by considering each as a separate universe. Scientists appear to prefer to differentiate between the 'universe', as commonly understood, and 'multiverse', for the purpose of communicating these ideas unambiguously.

"I'm a little confused. In reference to another universe. How do you know when the one we live in ends?"

Confused? You’re not alone.

This universe has no end in the conventional sense of a connecting point with something beyond it, unless we consider the possiblity of inter-universe wormholes (Schwarzschild wormholes). Metaphorically (and reducing the spatial dimensions from three to two for the sake of understanding the concept) it's described as being either like a flat sheet that extends to infinity in all directions or, alternatively, like the surface of a balloon upon which an ant might crawl indefinitely without finding an end.

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But if this Univers has no end then how do we know it is expanding faster every day? Would the galaxies we see separating further apart every day be enough to to base a theory upon if the Universe were infinate as well as the posible galaxies we cannot see? If this Universe were not finite wouldn't a theory or hypothesis of an expanding Universe be sort of like a flat Earth Theory?

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Hello everyone,

Boy, this is a complicated subject! You know, I think this is one of these things you can't just visualize in your head, it can only be understood with numbers.

The problem I have with this subject is if the universe is expanding what is it expanding in to? For example, if you blow up a ballon it expands, but it has the "space" for the expansion and we understand what that "space" is. But when you talk universe which is defined as everything that physically exist even momentum as defined-what else is there? I believe in some way our psyche must be involved in the equation or our awareness
of the universe we live in . I believe in some way black holes
connect these different universes. I also believe our perception of a 3D universe "tricks" us and we are aware of only what we can comprehend. I said in an earlier post on another thread I really don't believe we know what space is. We explain it in distance and vacum. I believe there is more to it that that.

I am ready for the attacks, so go ahead.

best regards,
odin1


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Do you think there is a difference between black holes and worm holes?

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Hello Rallem,

Yes, with my limited knowledge I believe they are. I beleive a wormhole is just a short cut from point A to point B through the fabric of time and space.

A black hole I believe is the "power source" and glue that maintains order in the universe. Let me be a little bit clearer if it is possible for me. I said in another post that I thought black holes were present in each galaxy at the center. All the matter in that galaxy rotates around the center, which is a black hole. I think it takes about 2X10 8th years for our galaxy to make a complete rotation. Imagine if there were no black holes in the center of the galaxies, what would fuel the rotation? Now, we have orderly little galaxies floating around in space instead of solar systems drifting aimlessly in the universal expanse. Perhaps, and probably there would not even be star systems with planets without blackholes.

Something to consider.

Also, I think this could possible have something to do with time travel, but is not of concern in this thread.

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odin1


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Rallem: "Would the galaxies we see separating further apart every day be enough to base a theory upon if the Universe were infinite as well as the possible galaxies we cannot see? If this Universe were not finite wouldn't a theory or hypothesis of an expanding Universe be sort of like a flat Earth Theory?"

The general assumption is that what's happening in the observable universe is also happening in the unobservable part, and that the known laws of physics also apply beyond that part; but it's not provable. There’s no way can ever know the characteristics of the unobservable universe. Philosophy, reason etc, we can have aplenty, but no proof.

odin1: "The problem I have with this subject is if the universe is expanding what is it expanding in to?"

It's a problem everyone has, I guess. I do. Here's a long answer from Prof David Kornreich:

http://curious.astro.cornell.edu/question.php?number=274

And here's a short answer from Prof Michio Kaku:

"Then it is clear now that the universe is expanding in hyperspace, and that the original Big Bang took place in hyperspace. If we cannot visualize hyperspace, it is only because we spend our time in the third dimension."

odin1: "I said in an earlier post on another thread I really don't believe we know what space is. We explain it in distance and vacuum. I believe there is more to it that that."

People working at the LHC, CERN agree with you, and hope to be able to tell us more in the next few years.

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I am glad Dr. Kaku agrees with my thoughts on the 3D world we live in.

I read an article one time on dimensions. An analogy used the article was this:

If you were in your house and decided to walk outside, but you could not look up--you could only look straight ahead of where you were going. And once you got outside, you see a shadow gliding on the ground in front of you, unaware that a cloud was passing over the sun above. So, you don't know what the shadow is. You have no explanation for it because you are missing part of the information you need to determine what it is.

I believe we are slave to this scenerio all the time in questions looming over us about the universe.

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odin1


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by the way rendewenur,

I read the link you posted and it was very informing. I appreciate it, I would encourage anyone else that is interested in this thread to read it.

Thanks,
odin1


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So the universe is like raisin bread. I just knew I tasted it from somewhere before but couldn't place it.

I feel that while worm holes and black holes are both cosmic singularities I don't think they have anything else in common, but I am not at all certain that there is a worm hole and think it may just be a plot device to a science fiction show because I have seen no hard evidence of the later. If worm holes are real thogh, I wonder if there is any connection to black holes and if so what?

I wonder if that article is the writings of a hypothesis or if this is is an actual theory because the author seems very sure about his answer, but I wonder how he can be if other scientists still discuss the possibilities of other universes outside our own.

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Hello Rallem,

I believe worm holes can be created. Maybe, they don't exist in nature without an external power source, and may I reinerate I am speaking from limited knowledge that may not be worth the time to read, but everyone has opinions. Again, I think the true nature or makeup of "space" is the defining factor in this discussion.

Like I said earlier, this is a very complicated subject. I had never heard it explained as the way this author explained it. I am assuming this is 1 theory on the table. As for "other universes", I was under the impression they exhisted but in another dimension completely void of our own. This is a relatively new subject and perhaps the "language" or words used in explaining are not making it clear.

You know, it could be that the universe needs no end, perhap it is irrelivant for an end. Something else to think about. I am sure one day the great minds will have an answer for all of us.

keep on thinking,
odin1


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Hello everyone,

Rallem said:

"But if this Univers has no end then how do we know it is expanding faster every day? Would the galaxies we see separating further apart every day be enough to to base a theory upon if the Universe were infinate as well as the posible galaxies we cannot see? If this Universe were not finite wouldn't a theory or hypothesis of an expanding Universe be sort of like a flat Earth Theory?"

Rallem, do you think the galaxies are moving away from each other or moving relative to each other? What I am getting at is this- if galaxy X is moving away from galaxy Y what causes the difference in speed? Assuming the same forces are acting on each galaxy? I understand there could be a difference in mass, but that shouldn't be a factor. Also, galaxies have collided, that has been talked about in another thread, and I would assume that if the speed is relative and they are moving from a central location this should not occur.

odin1




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odin1, re your question (above) to Rallem:

Your question suggests that you think the galaxies are moving away from each other 'through' space. That isn't the case. The Big Bang wasn't an explosion in the ordinary sense, in which material is ejected through space. When our universe originated as a point, that point was the whole of our spacetime continuum, the whole of our universe. Our universe was comprised of nothing other - no space 'outside' of it into which the energy could be radiated. Space itself stretched, and has continued to stretch.***

There are two relevant consequences of that:

(1) The Big Bang did not occur at one place to the exclusion of all other places. It occurred everywhere, because the point was 'everywhere'; so the concept of the 'central location', that you mentioned, is false.

(2) The relative motions of the galaxies result from the uniform - and currently accelerating - stretching of space, except to the extent that they are acted upon by mutual gravitational attraction. The expansion of space is carrying the galaxies with it. Hence the analogy of raisin bread rising in an oven.

*** There was (theoretically, of course), for a fraction of a second, a period of 'inflation'. There are many versions of the theory. Typically, you’ll be informed that during the period of inflation lasting 10-32 of a second, a volume of just a few cubic centimetres expanded to a volume roughly equal to that of the currently observable universe.

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Originally Posted By: odin1
Hello everyone,

Rallem said:

"But if this Univers has no end then how do we know it is expanding faster every day? Would the galaxies we see separating further apart every day be enough to to base a theory upon if the Universe were infinate as well as the posible galaxies we cannot see? If this Universe were not finite wouldn't a theory or hypothesis of an expanding Universe be sort of like a flat Earth Theory?"

Rallem, do you think the galaxies are moving away from each other or moving relative to each other? What I am getting at is this- if galaxy X is moving away from galaxy Y what causes the difference in speed? Assuming the same forces are acting on each galaxy? I understand there could be a difference in mass, but that shouldn't be a factor. Also, galaxies have collided, that has been talked about in another thread, and I would assume that if the speed is relative and they are moving from a central location this should not occur.

odin1




Yes, but my point is that if our Universe is boundless and infinite and that our telescopes can only detect galaxies from up to a certain distance of that infinite space then shouldn't we also assume that the number of galaxies inside the universe is almost infinite in itself and all those other possible galaxies we cannot detect might be doing something other than expanding away. Heck like you pointed out many of the galaxies we can detect aren't separating and I think one is about to collide with us in the next few billion years.

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Hello redewener,

My question is if the fabric of space is stretching then how does a galaxy collide with another. Assuming everything started from an epicenter what is the reason for the flunctuation in velocity of the galaxies-assuming of course the fabric of space is expanding and pulling the galaxies along like the raisin bread stretching. The raisins don't move, the dough moves, do you see my point? I am getting to something, I just want to see what you think.

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odin1


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Odin I think you and I are asking a similar question and my problem is that I am not that articulate.

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Hello Rallem,

You do real well, I should have read your question closer before I asked mine.

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Originally Posted By: odin1
My question is if the fabric of space is stretching then how does a galaxy collide with another. Assuming everything started from an epicenter what is the reason for the flunctuation in velocity of the galaxies-assuming of course the fabric of space is expanding and pulling the galaxies along like the raisin bread stretching. The raisins don't move, the dough moves, do you see my point? I am getting to something, I just want to see what you think.

The galaxies are observed to be in groups, clusters, superclusters and supercluster complexes. On the largest scales, this gives the matter in the universe a foam-like structure. As space expands, this structure expands - but the gravity of galaxies that are comparatively close together counters the separating factor of the expansion, causing them either to separate at a slower rate, or be drawn together.

There was no epicentre, as there would have been if the Big Bang had been an explosion at some point in space. Expansion occurred everywhere at once. The Big Bang happened everywhere.
______________

Link to a page about the large scale structure of the universe http://www.mpa-garching.mpg.de/galform/millennium/

"The cold dark matter model has become the leading theoretical paradigm for the formation of structure in the Universe. Together with the theory of cosmic inflation, this model makes a clear prediction for the initial conditions for structure formation and predicts that structures grow hierarchically through gravitational instability."

And there's an absolutely brilliant movie:

"A 3-dimensional visualization of the Millennium Simulation. The movie shows a journey through the simulated universe. On the way, we visit a rich cluster of galaxies and fly around it. During the two minutes of the movie, we travel a distance for which light would need more than 2.4 billion years."

Beware - it's 120MB: http://www.mpa-garching.mpg.de/galform/data_vis/millennium_flythru.avi

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Hello rendewenur,

The question that is nagging at me is this. The galaxies don't move. It is the stretching of space that moves the galaxies, so the movement is relative to space. According to this article, the galaxies stay the same distance apart. If they stay the same distance apart (relative to the stretching of space)how can ones gravity capture another?

Let me put it like this, and I am using hypothetical numbers to make a point. If 5 billion years ago we had a big bang. The universe started stretching and moved along for another 2 billion years, in all that time "space" stretched and the galaxies stayed stationary relative to space. But, something happens, galaxy A gets captured by galaxy B's gravity. This overwhelms the forces that are expanding space and these two galaxies collide. What is present when they collide that wasn'nt present when the big bang occured 5 billion years ago?
Or why didn't it happen 1 billion years after the big bang?

You got me straight on the epicenter, I stand corrected.

Thanks,
odin1

Last edited by odin1; 05/06/08 12:31 AM.

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Ok, here I am about to make a total arse of myself by asking retarded questions after giving a little history to my reasoning. Shortly after the theory of the Big Bang was developed another theory called the Big Crunch was developed where it was predicted that gravity from the Universe would overtake the force of the expansion and the Universe would collapse in on itself. The Theory of the Big Crunch was later proven defunct though when it was determined that after several billions of years that not only is our Universe not expanding at slower rate, but it is growing faster every day. (Sorry for the possibly bad word choices) Now there is a theory that some day the Universe will be so big that the Galaxies and everything in them will be unable to hold themselves together and everything in the Universe will fall apart at the molecular level. Now back to the beginning, where shortly after the Big Bang pure energy had turned into matter somehow. We know this must have happened because of the vast amounts of matter which surrounds us. To the present, there are pictures from the Hubble Telescope showing a nursery for new born stars, so there must still be matter being made from the energy of the Universe, and here are my questions. How do we know that the Big Crunch is defunct? Can't this so called dark energy which is pushing our Universe ever so larger be converted into matter over time and be the actual source for our collapse in the future as it is the source for our expansion now? Couldn't the several billions of years our Universe has been around be anything but a blink in the eye beyond our scope and our Universe is still quite young and that is why we are expanding so quickly?

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Hello Rallem,

I think we should remember this is "theory" as you mentioned. But, we have to start somewhere. I have seen some articles debunking the big bang theory, so it is safe to assume that if there were no big bang, there will probably be no big crunch.

I really think, and this is my humble opinion, that we need to know what space is before we can measure it's "tensile strenght".
As of right now, we don't even know what gravity is. There are some theories, but no absolute proof.

And, you are not making an "arse" of yourself asking questions. If that were so, I would be on display in a state fair now.

Hopefully, redewenur will give some input to your question. He is pretty sharp at this.

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Hi, odin1

I could quite easily have misunderstood your question, so bear with me if I have.

"The question that is nagging at me is this. The galaxies don't move. It is the stretching of space that moves the galaxies, so the movement is relative to space."

The movement isn't actually relative to space. The galaxies are stationary relative to space, unless acted upon by gravity of other galaxies.

"According to this article, the galaxies stay the same distance apart"

The article has misled you. The galaxies don't stay the same distance apart. The distance between them is increasing (unless they are acted upon by the gravity of other galaxies).

"If they stay the same distance apart (relative to the stretching of space) how can ones gravity capture another?"

The first galaxies are said to have formed more than 12 billion years ago. The youngest galaxy yet discovered, called I Zwicky 18, is thought to be less than 1 billion years old. As the galaxies condense at different times, there arise new gravitational sources. So, the galaxies have not been in a stable gravitational environment. It's been changing steadily over time, because of the gravitational instability. It's this gravitational instability that has caused the universe to have it's current, foamy large scale structure.

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Hello redewenur,

I see now that the space between the galaxies is stretching and they are getting further apart. I went back and read the article again. It is a good article, but like you said it can be a little misleading, and sometimes I have a tendency to speed read and miss a little something.

Do you thing that black holes may have anything to do with the collision of two galaxies?

P.S. I was reading a blog called "The Angry Astronmer" while ago about the big bang. It was pretty interesting, if you would like to read some of it I will send you a link.

thanks,
odin1


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odin1


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Hi, Rallem.

"Ok, here I am about to make a total arse of myself by asking retarded questions"

Your questions are good. Not always easy to answer, but good.

"there are pictures from the Hubble Telescope showing a nursery for new born stars, so there must still be matter being made from the energy of the Universe"

Stars have there origins in two different ways.

(1) First generation stars. They are formed from the primordial matter that formed subatomic particles soon after the Big Bang, i.e., mainly hydrogen, some helium, and a little lithium.

(2) Second generation stars - or any generation after the first - are formed from the debris of supernovae (possibly with a little left over primordial gas, but I don't know about that). These are the stars that the Hubble telescope shows us.

So, no new matter is needed. It's old matter, recycled. Although there are new elements manufactured in stars, and then dispersed into space by supernovae. Hence the existence of our Earth.

"How do we know that the Big Crunch is defunct?"

We don't know for sure. It just looks a very unlikely scenario in view of the current accelerating expansion.

"Can't this so called dark energy which is pushing our Universe ever so larger be converted into matter over time and be the actual source for our collapse in the future as it is the source for our expansion now?"

Since no one yet knows what dark energy is, I would say that you could be right. There's just no evidence.

"Couldn't the several billions of years our Universe has been around be anything but a blink in the eye beyond our scope and our Universe is still quite young and that is why we are expanding so quickly?"

I don't see a possible connection between its age and its expansion rate, except for the period of inflation at the start, and the current observed acceleration. Do you?

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Hello everyone,

here is the blog site if you want to check it out.

best regards,
odin1
http://angryastronomer.blogspot.com/2006/07/big-bang-common-misconceptions.html


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Hi, odin1

"Do you think that black holes may have anything to do with the collision of two galaxies?"

I take it you're asking if I think they might be a cause of the collisions (as opposed to asking if they might be a result of the collisions).

Since the collision occurs as a result of mutual gravitational attraction between the total masses of the galaxies, whether or not that mass is partly within the black holes is unimportant.

Thanks for the link (angryastronomer). Jon Voisey has it right. Worth reading.

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Originally Posted By: odin1
Hello Rallem,

I think we should remember this is "theory" as you mentioned. But, we have to start somewhere. I have seen some articles debunking the big bang theory, so it is safe to assume that if there were no big bang, there will probably be no big crunch.

I really think, and this is my humble opinion, that we need to know what space is before we can measure it's "tensile strenght".
As of right now, we don't even know what gravity is. There are some theories, but no absolute proof.

And, you are not making an "arse" of yourself asking questions. If that were so, I would be on display in a state fair now.

Hopefully, redewenur will give some input to your question. He is pretty sharp at this.

best regards,
odin1



I would like to point out that this is not "just a theory," and while it is not a law of physics and it never can be one because of its complexity, as it mentions somewhere on this site in an article, a theory is not something to be taken lightly because a theory means that more than one Scientist subscribes to this theory and while parts of the theory can be altered when new information is provided it is difficult to debunk a whole theory.

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The accepted analogy for the expansion of the Universe, is the expansion of a balloon being blown up,
or better, the currants within a cake that is being baked.
The Galaxys, or currants separate from each other as the cake expands during baking.

While this analogy is true, my personal opinion is that our Universe may not be expanding consistantly in every direction.
Its shape might not be like an expanding rubber balloon, but more like a rubber glove complete with fingers.
The reason I think this is due to the large Galaxy Andromeda, that is fast approaching our own MilkyWay galaxy, and will eventually merge with us.
Just this single merging of two large galaxies, must spoil the accepted "nice even" spherical picture we believe the expanding Universe shows us. Plus there are a multitude more Galaxies out there that will eventually collide and merge, inspite of this constant expansion.
The Red shifts that we see now, will not change, but remember there are also a few blue shifts.
All in all this suggests to me that our Universe is not such an even expanding sphere as we might believe?
Protruding fingers of matter, even depressions, probably exist all around us?
Yet another question for Astronomers to prove or disprove?



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Mike: "Yet another question for Astronomers to prove or disprove?"

It's disproven already. The Cosmic Microwave Background Radiation has been observed to be isotropic. The irregularities of red/blue shift are accounted for by motion due to gravity that counters, adds to or subtracts from the rate of mutual recession.

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Originally Posted By: redewenur
Mike: "Yet another question for Astronomers to prove or disprove?"

It's disproven already. The Cosmic Microwave Background Radiation has been observed to be isotropic. The irregularities of red/blue shift are accounted for by motion due to gravity that counters, adds to or subtracts from the rate of mutual recession.


Originally Posted By: Mike Kremer

Hi Redewenur,
Forgive me but I was'nt refering to the Cosmic Microwave Background, but to the Universes Constant Expansion.
I didnt explain myself very well when I said the Red Shifts won't change, but there might be 'fingers of protruding matter', or even depressions.....we just could'nt prove their existence,
since we assume that equal Red shifts of equal brightness means equal distances from us. which is further strengthened by the assumption that Dark Matter, thats causing our expansion is in (constant?} production, everywhere?
However put another way.....similar Galaxy distances don't always produce similar Red Shifts.
'Tired' light that is coming out from an 'above average' higher gravitational Galaxy than normal, or light that has travelled further than we suspect due to its gravitational bending on its way to us, are just two cases in point. Or even light that has travelled thru a dusty environment.

The fact is there is no guarantee that similar Red Shifts of similar brightness, are all equidistant Galaxies.
Without a distance guarantee, there is no speed guarantee, making for further complications.

Or to put it yet another way....it could mean that there is no proof that Dark Matter is produced uniformly throughout our 'spherical' Universe.
Therefore since true 'far galaxy' distances cannot be proven, then the known universe cannot be proven to be a true spherical shape.
Which , as I stated previously, is what I believe.

Its an interesting discussion, but I dont believe either of us will come to any conclusion, due to the unproven variables concerned.
http://www.iop.org/EJ/abstract/0264-9381/15/8/016





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Mike: "my personal opinion is that our Universe may not be expanding consistantly in every direction"

Me: "The Cosmic Microwave Background Radiation has been observed to be isotropic"

Mike: "Forgive me but I was'nt refering to the Cosmic Microwave Background, but to the Universes Constant Expansion."

- CMBR isotropy implies that space is expanding at the same rate everywhere. If it were not, one would expect to find a related anistropy, but such differences in temperature have proven non-existant. The rate of expansion has been shown to be uniform in space, and accelerating in time.

Mike: "which is further strengthened by the assumption that Dark Matter, thats causing our expansion is in (constant?} production, everywhere?"

- I think you mean Dark Energy. If so, can you point me to some info regarding its constant production, as this is news to me.

Mike: "'Tired' light that is coming out from an 'above average' higher gravitational Galaxy than normal..."

- Modern day tired light proponents not only fail to take account of all the evidence, but also apply faulty reasoning. Here's one example:

"Regardless of your beliefs as to how the Universe started, one piece of experimental observation has to be explained - that is, in redshift, the photons of light have a longer wavelength on arrival at the Earth, than when they set off from the distant galaxy. This means that photons of light have less energy on arrival than when they set off.
Where did this energy go?"

- which fails to note that since the energy is stretched in space, it is also stretched in time, i.e., it takes a little longer for the same amount of energy to arrive. No energy if lost.

The tired light theory is defunct,

http://www.astro.ucla.edu/~wright/tiredlit.htm (Note, also, the reasoning associated with CMB)
http://curious.astro.cornell.edu/question.php?number=444

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Originally Posted By: redewenur
Mike: "my personal opinion is that our Universe may not be expanding consistantly in every direction"

Me: "The Cosmic Microwave Background Radiation has been observed to be isotropic"

Mike: "Forgive me but I was'nt refering to the Cosmic Microwave Background, but to the Universes Constant Expansion."

.....................>


Mike: "'Tired' light that is coming out from an 'above average' higher gravitational Galaxy than normal..."

redewenur
- Modern day tired light proponents not only fail to take account of all the evidence, but also apply faulty reasoning. Here's one example:

"Regardless of your beliefs as to how the Universe started, one piece of experimental observation has to be explained - that is, in redshift, the photons of light have a longer wavelength on arrival at the Earth, than when they set off from the distant galaxy. This means that photons of light have less energy on arrival than when they set off.
Where did this energy go?"

- which fails to note that since the energy is stretched in space, it is also stretched in time, i.e., it takes a little longer for the same amount of energy to arrive. No energy if lost.

The tired light theory is defunct,

http://www.astro.ucla.edu/~wright/tiredlit.htm (Note, also, the reasoning associated with CMB)
http://curious.astro.cornell.edu/question.php?number=444


Originally Posted By: Mike Kremer


Many, many, thanks for the above 'tired light' URL's, Redenur.

I will keep them and study them with great interest.
For they do show me how far behind I am, with the latest facts in Cosmological thinking.




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"You will never find a real Human being - Even in a mirror." ....Mike Kremer.


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