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I keep trying to refine this idea. As I get it more organized I repost it. I am just about ready to send it to 20 or 30 professional astronomers and see what they think about it. If you see something particularly stupid here please let me know before they do.

Bud



When I look at “The Expansion of the Universe”, I see a massive dichotomy.

Everyone basically agrees that the universe is expanding and the galaxies are moving away from each other. The farther away they are the faster they are moving apart. Every new astronomy student hears the expanding Universe described as being comparable to a balloon or to a cake with raisins stirred into it. As the cake raises, the raisins move apart. If two raisins are half an inch apart and the cake doubles in size they will then be one inch apart. However, if they start at two inches apart and the cake doubles they will be four inches apart. The farther apart they are the faster they recede from each other. But, they always move away from each other at some rate of speed. The raisins are used to symbolize galaxies.

But, everyone also knows that in the world of real galaxies; everywhere we look, within say a few billion years; everything is coming together into super mega-clusters and walls. All of those billions of galaxies! They are not moving away from each other they are moving toward each other! In the real universe, the raisins are forming into clumps, and clusters, and super clusters and walls. The cake explanation does not conform at all to what we see in the Universe.

A long time ago, galaxies were expanding from each other very rapidly: almost at the speed of light. That was plus or minus fifteen billion years ago. What has happened to that expansion today? We just don’t know! We have absolutely no idea of what is happening fifteen billion light years from us, at this instant. The only things we know about the present, is what we can see within a few light years. Astronomers are historians, not news reporters. Astronomy deals almost exclusively with “old news”.

Cosmologists generally agree that if there is enough matter in the Universe it will expand for awhile and then contract. This is the closed universe model. Gravity will slowly gain control of all matter. When it has, the universe will start to contract. How could we tell if it started to contract? How would we know it was contracting rather than expanding.

Most people tell me the Hubble Constant is the proof it is still expanding. We can see that the farther away we look, the faster space is expanding. The red shift lets us know it is still expanding. The problem with that is; the light that is red shifted left its source fifteen billion years ago. Even I agree it was expanding back then. But that gives us no clue as to what is happening now.


So, how would we know if The Universe were contracting?

This contraction would first be noticed in the home galaxy. Then the local group would start to move together. In the beginning of the Local Group’s contraction the cluster would still be expanding, though at a reduced rate.

In another few million years or so, the Cluster would start to move together, but the Super-Cluster would still be expanding, though at a reduced rate. Of course in real time the entire Universe would stop concurrently (or thereabouts), but because of the look back into time we can only observe the contraction within the number of light years since the contraction began. Before that time, it was still expanding.

In other words if the universe came to dead stop say one billion years ago, what would we see now? Well, we should see our own Galaxy perhaps having a slight contraction. Our local group should be generally trending toward blue shift, though the proper motions of the bodies would ameliorate this to some degree. Our cluster would be a trifle into the blue. Our super-cluster would be red shifted but decreasingly so.

These are exactly the conditions we find today. Our home galaxy is stable. In our local group: the Magellanic clouds are in the process of merging into the Milky Way, as are Sagittarius, and Canis Major among a number of others. The Andromeda Galaxy is closing on us, while also merging with M32, M33, and M110 amongst others. The entire local group is moving toward the Virgo Cluster. Which is moving toward the Virgo Super-Cluster.

This meets all of the conditions for contraction of the closed model of the Universe. Why then would we still think that the universe is continuing to expand? It seems to me the reason for this is that it is less than 100 years since we found out there was an expansion. It was quite a discovery since everyone at that time thought the universe was static, even Hubble!

Since we were not around when the Milky Way was expanding, we didn’t notice it stopping. The same applies to the local group! We didn’t see it expanding so we think it was always gravity bound. We have never really dealt with the question of "Why isn’t space expanding between us and the other galaxies in the local cluster?" We just say they are gravity bound and let it go at that. GRAVITY BOUND LOCAL AREAS IS ONE OF THE FIRST CHARACTERISTICS OF A CONTRACTING UNIVERSE!


The Hubble constant says that in the distant past the Universe was expanding very rapidly. The closer we get to the present the slower the Universe is expanding. We generally hear the constant used to describe what happens to light shift based on how far away galaxies are from the Earth. The farther away the galaxies, the faster they are receding and the higher their red-shift. But the constant doesn't really deal with distance; it deals with time. The farther in the past, the more expansion.

If we see a galaxy that is red-shifted, is it necessarily moving away from us? Of course not! It just means it was once moving away. What is happening to galaxies ten billion light years away from us at this moment? We have no idea what is happening to them. We really know very little about what is happening in the universe at present.

The blue-shifted light we see from Andromeda left there over two million years ago. All we know is that it was moving toward us two million years ago; not what it is doing today! Hubble deals with what was happening in the past, not with what is happening now.

The farther that we go into the past the faster the universe was expanding and the closer that we get to the present, the slower the universe is expanding. This is not theory; this is what we observe.

Occam’s razor say’s the simplest explanation that fits all of the facts is probably the correct one. The simplest explanation for the data is that the expansion of the universe has stopped.

If I am correct, we should be able to find a roughly spherical horizon around Earth inside of which most bodies are being drawn together and outside of which they are expanding from each other. Those at the horizon being generally stable. Proper motion will cause some problems in finding this horizon, but should not prevent its being found.


If you think some of the data or conclusions presented here are incorrect, please contact Bud Camp. The humility might do me some good. If you agree with them also please let me know.

bud.camp@verizon.net

Nearly every piece of information I've read about the expansion of the universe fails to mention whether the acceleration is occurring now, real-time, or whether it's only an observation of what was happening 5-10 billion years ago. I have found one site that does acknowledge that the acceleration being observed is in the past. These are the experts too, high energy astronomers at NASA.

http://imagine.gsfc.nasa.gov/docs/ask_astro/answers/980119a.html

According to them, if we could take a snapshot of the entire universe right now, the expansion would be constant, not accelerating. Of course, I agree with Bud that according to observations made within a 75-100 million light year range, galaxies are moving toward each other. We don't know what's happening right now 10 billion light years away, as of 50-100 million years ago galaxies in our local super cluster were moving towards each other or towards the great attractor anyway. And as recent as 2 million years ago, galaxies within our local group were moving towards each other. At least, that's how I've interpreted what I've read.

Here's a nice link that gives some perspective to scale of local groups, super clusters, etc. (Thanks Al)

http://www.csm.ornl.gov/~geist/WheresAl/localgroup.html

The universe is expanding from what we know, but not at a constantly faster rate. Based on the laws of physics, everything exerts a gravitational force, and because of that force, it doesn't matter how far away things get, they will always be decelerating towards one another until they stop. Then they will start pulling themselves back together. Once that happens in a few billion years or so, we will be headed back to another Big Crunch and the stone age again.

Well, I've resisted posting to your threads for some time now, mostly because I'm a fully indoctrinated physicist and I have alot of faith in the way the scientific community arrives at a widely accepted theoretical hypothesis. If more cosmologists still had questions such as yours even after they have reviewed all of the data and all of the alternative proposed theories regarding expansion, then I imagine that there would be a number of competing theories that were also widely accepted within the community according to their merit. Since I've heard of no popular competing theories which would try to fit the currently accepted observational data to a contracting universe model, I must conclude that such an exercise has a) not proven possible, b) has not occurred to anyone to try, or c) the correct model has yet to be discovered. I think a) is fairly likely, b) is fairly unlikely, and if c) is the case, then you have a PhD dissertation with your name on it... if you can come up with the right model.

So, this is why I have not given too much thought to your posts before now, though I have read every one. But since you appear to be really stuck on this point, and you are putting some serious energy into your search for answers, I feel that the least I can do is try to provide you with some more things to consider while you search.

First and foremost, the model is the key. If it can be shown conclusively that a certain model fits the observed universe and you have no competing model to offer, then the existing model is probably fairly accurate and your contrary assertions are not helping the scientific discussion. If, on the other hand, the theory in question has not been rigorously established (which is the case here, since cosmology is still a moving target), then you really need a good competing model to get some serious discussion started. Any reasonable model must at least satisfy general relativity or give very persuasive arguments for why it does not apply.

So, what are some of the things that might be "not quite correct" (notice I didn't say wrong) about the current models? What assumptions might you be able to challenge and posibly propose alternative (and reasonably plausible) explanations?

Well, one possibility is that I don't think that the mechanism of expansion is understood very well. In the early models after Hubble's original discovery, it was thought that everything was thrown out from some central point. Unfortunately, attempts to discover the location of that central point was impossible since every galaxy is moving away from every other galaxy. Then, the model that led to the big bang theory proposed that all matter and energy in the universe started out at a point singularity. Something happened and all of this stuff was kicked out into the universe with alot of kinetic energy. The original closed model universe was based on the assumption that all of this kinetic energy would eventually be converted to gravitational potential energy, and then the universe would begin to collapse in on itself again. I think this is also where you can make the calculations, based on momentum arguments alone, that the universe is still expanding.

Well, apparently, this model proved to be too simple to explain all of the observational data. That is the rate of the expansion of the universe has not been steadly decreasing in a manner consistent with this model. So the model was ammended with the notion that perhaps it was the very fabric of space-time itself that was thought to be expanding. That is the actual space in between galaxies was growing of its own accord. This idea has been with us for a while now, however the fundamental physical processes responsible for space-time expansion are still unknown. Enter here all of the recently proposed "dark matter/energy" models. I think that until someone actually produces or observes dark matter or energy in a laboratory (or comes up with a good reason why we can't do this) I will continue to be skeptical of any model based on the assumption of its existence. As it stands now, I see dark matter/energy as a tweakable parameter which cosmologists use to make their otherwise consistent theories match up with observational data.

Well, this is just one possible avenue that you might want to explore. If I think of anything else, I'll let you know. If you are going to approach some professional astronomers/astrophysicists about your concerns, I would first ask them how it is that they came to be comfortable with the idea that the universe is still expanding even though we can't see it. Then ask them if they know of anyone proposing credible alternative models which might contradict the assumption of expansion. Good Luck.

Well, I certainly don't have the credentials to declare that the leading cosmologists are wrong and I'm not trying to. I would like to know where there is more information about what we currently observe about the motion of our galaxy with respect to our local group of galaxies, the Virgo super cluster of galaxies, and those 1 billion or more years away. As Bud mentioned and the last I read as well, was that the galaxies in our local group were moving closer to each other and would eventually merge. Also, our galaxy is moving towards then center of the Virgo super cluster of galaxies. I admit that these observations don't prove contraction in the universe as a whole, but it seems to support contraction within a 50 million light year radius of the Virgo super cluster. I realize that is small on the scale of the known universe. In order to support accelerating expansion though, the closer the objects are to us, the faster they should be moving away from us, correct? And I'm talking about what we can actually see, not the theoretical real-time snapshot. If this is this case, how far away are these objects that we see moving away from us? Have we observed this in our local group? Virgo super cluster? How far away are these observations and where are we observing them in relation to the known universe? I don't how many or how far away the galaxies are that are moving away from us. Anyone know a link to this information? If only a few galaxies have been observed moving away from us, I don't consider that proof. Two rivers can be flowing away from each other at some point, but they can both still empty into the same sea. My point is, perhaps we're observing galaxies that are moving away from us, but merging into a huge thread like structure and that structure may ultimately merge with the thread we're in. I don't have a PhD and can never prove (or disprove) this or even present it to people who could. I just enjoy the debate and I would like to find more information on the web that supports any of the views given.

Bud,

4 things:

1-
Over the past twenty years, many measurements have been taken and put into models, in order to calculate the average density of the known Universe. It is my understanding that all recent calculations show that (according to the models) the density of the Universe is too small to allow the Universe as a whole to contract via gravity.

2-
You keep refering to what is happening in far-away galaxies *NOW*, as opposed to our ability to see only what happened to them long ago. Please be aware that the Theory of Special Relativity warns us to be careful when using the word 'NOW'. What is happening to another galaxy right now depends crucially on what moving frame of reference we are in at the time.

Many will argue that it really doesn't make much sense to ask what is happening to a far-away galaxy now, since that depends entirely on what reference frame you are in at the time you ask.

However, I admit that you might consider this point to be nit-picking, as it is not crucial to your point. We can, instead, realize that the far-away galaxy we see has a future, and ask what happens to it in that future.

3-
I have not seen evidence that our local group is contracting. But, even if it were, it could very well be a local effect. Every cluster of mass in the Universe, from comets to mega-clusters of galaxies, is the local result of gravity. Yet the Universe as a whole may still expand. Remember, we are talking about space-time expanding/contracting. If our local group is losing energy, then it is contracting. It is not correct to see masses coalesce and then conclude that this is an indication that the whole Universe might be contracting. The local coalescing of mass, by itself, gives us no information as the the expansion of the Universe.

4-
Just to get on the wild side . . .
Some cosmologists, physicists and philosophers have hypothesized that if the Universe were contracting, then entropy would be decreasing, therefore the direction of time would be backwards, and our experience would therefore be to see the Universe as expanding. So we would see the Universe as expanding whether it is expanding or contracting.

alana

If you think there is no such thing as "Now", don't try stepping in front of a truck. The theory of special relativity will not apply, and you will become two-dimensional.


Look around and you will find that there is general agreement that our local group is contracting into itself. But more to the point, so are the other local groups that we have observed throughout the universe.

Bud

As usual you come up with great answers. I only have two comments on it at this time. (One) it seems to me to be a contridiction in terms to have "faith in science".

(two) There is already a model for what I am discussing, it is called the closed universe. If omega is more than one this is what we have. All I am talking about is how do we know if it is one, less that one or more than one?

That PHD does sound good though!

Bud

Of course there is such a concept as "Now". But what is happening "Now" at a place other than where you are depends on your state of motion.

BTW, if two events happen at the same place, everyone, regardless of his state of motion, will agree an which event happened first, or whether they happened simultaneously. So, if I happen to be at a plave simultanwous with a truck, everyone will agree that one of my 26 dimensions will collapse : (




Ok, I'm not arguing the point. I simply haven't seem the reports.

alana

Bud,



Was this msg directed at me?

If so, I don't remember mentioning "faith in science". Scientific faith is quite different than religious faith.

The value of Omega is one of the great unknowns in physics.

I don't have a Phd, but I did attend graduate school in physics for one year.

alana

p.s. I am sorry if I am answering a msg directed to someone else.

Sorry for the confusion Alana. It was addressed to PhysBrain.

Bud

I just love pictures. Here's another good link to give some visual perspective on this topic...

http://www.anzwers.org/free/universe/superc.html

Well, I'm glad you enjoy my posts. I enjoy posting them because it makes me think about things that I wouldn't otherwise have cause to go into much detailed thought about. I hope that I can provide at least some insights about the universe, or at the very least about how I think about the universe. I have a number of thoughts and hunches about the way I think the universe works, but they don't even qualify as theories since I do not have anything other than intuition to back them up. In general, I try to draw a pretty clear distinction between my ideas and those that I have actually read elsewhere (as noted by some of my discaimers). I also try to post links to, what I consider, reliable sources whenever I can.

WARNING: Philosophical rant follows. You may skip to the next post without missing anything important.

Now, on its surface, a comment like "I have faith in science (and/or the scientific method)" would seem to be a contradiction in terms. Faith is typically reserved for describing one's beliefs in things, concepts, or ideals that cannot be objectively experienced or proven. However, from an epistmological perspective, both religion and science are belief systems. The only significant difference is how we have come to obtain the knowledge in each. In fact, I would go so far as to say that the two are not mutually exclusive, and when viewed with the proper perspective, they are actually complimentary. Religious faith is typically placed in some underlying assumptions about our own existence, meaning and purpose. Scientific faith is based in the belief, or assumption, that given enough time and careful consideration of the right questions, there is no (physical) phenomenon in the universe that cannot be understood. Disagreement usually occurs over things in which the two overlap, or one or the other tries to make predictions or judgements about things that they should probably not be offering opinions.

That being said, scientists are quite dependent upon the scientific method as a means of acquiring new knowledge. We implicitly accept the fundamental requirement that theories should be experimentally verifiable and experimental results should be reproducable. This is the primary criteria which we use to judge the value of newly proposed ideas. It helps us to distinguish good science from bad and sound theoretical advances from crackpot theories.

So, when I say "... I have alot of faith in the way the scientific community arrives at a widely accepted theoretical hypothesis.", I mean that I will accept certain theories as more or less true, or at the very least the most accurate articulation of those ideas to date. Despite not having any direct experience with the observations or derivations used to arrive at their conclusions, I will accept them because believe that there are people out there who will validate the work of their peers before endorsing their theories and widely publicizing them. This is the way it must be. Scientists have always "stood on the shoulders of giants". They accept the current theories about the universe as essentially true so that they can go on and discover new things. The only time one really need to question, and perhaps experimentally verify, those presumptions are when one encounters something that cannot be completely explained with the existing models.

As for the models of the universe, well there are several. Here is a website with a very good introductory level tutorial of the current state of cosmology.

http://map.gsfc.nasa.gov/m_uni.html

From the looks of it, in the last five years or so, there have been several reductions of different kinds of observational data, and they are all in agreement that the universe is not only expanding, but accellerating. They also describe the shape of the universe as essentially flat; meaning that the density of matter in the universe is insufficient for a closed universe and is too great for the universe to be open. The difference in these universal models can be summed up by looking at what happens to two beams of light that are emitted parallel to one another. In the absence of any other distorting effects, in a closed universe, the two beams would eventually cross and possibly even return to their origin; in an open universe, the two beams would diverge; and in a flat universe, the beams would remain effectively parallel.

While I didn't see anything at this site that would explain the motion of the local groups, I tend to agree with alana on point #3. The net motion of the local group towards the "great attractor" is most likely a local phenomenon. It would appear that the rate of expansion of the universe is not contradicting the influence of gravity at such relatively close distances.

omg! and they say that we've only explored 10% of the entire universe!