What?
Do you deny that highly similar spiral galaxes seen face-on are roughly similar in star-count?
Do you deny the observation that there are highly similar spiral galaxies that occupy very different angular diameters on the sky?
Do you deny the observation that spiral galaxies with lower angular diameters have higher redshifts? And that the redshifts squeeze the entire emissions spectrum from such galaxies?
Do you deny the Lyman-alpha forest?
These are all observations that someone with a decent back-yard observatory could make on his or her own.
So what observations do you want to throw out? Parallax? The observation that stars within our galaxy and M31 differ on average only in the spectral redshifting from stars in the smaller-angular-diameter set that Vesto Slipher identified in 1914? Again, this is the sort of astronomy[1] you could do in a reasonably dark field near your home.
> It is an attempt to get a handle on understanding the universe around us.
Sure, that's what science is. And a viable theory is one that does not conflict with observations to date. Theories that are viable today can become inviable tomorrow; all it takes is a new observation. There are literally tens of thousands of theory-challenging astronomical observations made in any 24-hour period in 2017, and theorists get very excited by even the slightest inconsistency with the standard cosmology. Unfortunately such inconsistent observations are extremely rare, and tend to vanish under repeated observations (by the same and by other observatories).
> At this point, none of the models seems to cover enough bases to make it the most likely scenario
What exactly have you read about "the models" and the "bases"? Serious question. Is it anything more than mathless popsci articles or comments in technology-focused Internet discussion forums?
> gravity to give rise to "Black Holes" and yet has not stopped the "Big Bang" from happening
Go back and re-read the comment you replied to. The thrust of it is that galaxies exist even though in the past they were much closer together. Why haven't they collapsed gravitationally into something much denser? There are a variety of possible answers, but (paraphrasing myself), the most attractive one is that there is a component of the action of galaxies that acts against their mutual gravitational interactions. With suitable coordinate conditions, that can be seen as a fifth force, and with other coordinate conditions, that can be seen as a simple feature of the vacuum, and with other coordinate conditions, that can be seen as a fine balance between inertia and gravitation, and so forth. But unless you want to argue that the cosmological frame is an improper choice and defend that position, you're stuck with the reality that in that frame it is most natural to identify the action component with an energy density.
Put more simply, yes indeed, the crucial question is why hasn't all the visible matter collapsed into a big black hole?
Since you identified that question yourself, you're on the cusp of understanding, yet you reject the most obvious answer: there is something at work preventing the gravitational collapse of galaxies. The only additional step is that in certain frames of reference, preventing two massive objects from eventually moving closer together under their mutual gravitational interaction requires work to be done.
(Maybe there is an intermediate step: why don't galaxies individually collapse into giant black holes? Or why haven't the planets crashed into the sun? In both cases there is a lot of angular momentum that would have to be radiated away from the orbiting objects in order that they can get close enough for the gravitational interaction to produce a collision. That takes a long time. Gödel proposed that the entire universe is rotating around a central axis[2] so therefore there is a lot of angular momentum keeping distant galaxies in an orbit rather than colliding with nearby (to us) galaxies. Rotating metrics have been studied (thanks in large part to Gödel) and they produce very different observables of distant galaxies than the ones we have.)
> the supposed science into religion and religion is considered anathema amongst certain groups within the science communities
Georges Lemaître -- referenced in [1] below -- sure was religious! Nobody doubted his astrophysics chops. There are plenty of working cosmologists today who hold to some faith or other (they're certainly not all Christians! or even monotheists!). They go to where observations, experiments and other types of material evidence take them. As long as one does that, nobody will care what she or he believes about spirituality or even the presently extremely hard to observe early universe.
But you, who does not seriously challenge the observations or evidence, refuse to entertain their implications, and do not offer up anything to explain why other than that you argue (wrongly) that others' collaborative efforts to rigorously and formally follow those implications are "religious" because inter alia (a) incompleteness of models means the whole model is entirely wrong (b) General Relativity is self-inconsistent (it sure isn't!) (c) General Relativity is not a successful tool at the relevant length scales (d) strong gravity is in play at length scales in which one can observe galaxies at all.
Your argument is plainly based on ignorance and personal incredulity. It is easy to fix the ignorance part: there is a lot you can read; you might start with something like Carroll's textbook[3] working your way to Chapter 8. Wanting to reject the standard cosmology just because it doesn't sit right with your intuition is a character trait you'll just have to wrestle with, like any good scientist has to from time to time. But when your intuition isn't even informed and you insist that the standard cosmology (which you do not understand) is wrong, well, people will form adverse opinions.
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[1] https://arxiv.org/abs/1108.4864
[2] https://www.wikiwand.com/en/G%C3%B6del_metric#/Cosmological_...
[3] https://www.goodreads.com/book/show/259680.Spacetime_and_Geo...
Don't put the horse before the cart please. Observations are first, not theories. The development of theories is dependent on the observations and the predictions those theories give rise to experiments to test the veracity of the theory in question.
Your comments about my response regarding "black holes" and "big bang" miss the anomaly between the two concepts. You are replying in a theoretical sense not in any actual experimental sense.
What I find interesting is that you ask the question of why the universe hasn't collapsed, when it should be why did singularity from the theory ever explode?
Yes, what is it that holds the universe as it is? Your obvious answer is a continuation of the "big bang" model, but is that model actually valid? I don't believe it is, nor do I believe that gravity is the prevailing force that the model suggests. The reason for not thinking so is related to the underlying basis for the model that the universe is electrically neutral. Since that is incorrect, too many plasmas occurring all over the place, we must look at including electromagnetic effects within the models we develop. If we ignore these effects, which is what occurs in the prevailing theory, then additional other entities must be added to explain the actual observations made.
You ask the question of why don't galaxies collapse into black holes. Well, the simple answer may be that there are no "black holes" because the theoretical entity cannot exist in the universe. Does that in turn mean that there are no large gravitational bodies? No, but it does mean that what people are calling "black holes" are, in fact, not "black holes" but some other body for which our models have not yet found an effective theoretical base. Remember that "black holes" have very specific properties in theory, one of them being a singularity and the other an event horizon at which time has stopped as seen from outside the event horizon.
You miss the religious reference. I am not referring to men and women who believe in God, a god or gods and accept the theory or model. But I am referring to those who have turned science itself into a religion, or more the point, have turned the belief in the theory/model into a religion. That is a major concern and should be addressed.
Why would I challenge the observations? What I am challenging, if you like, is the interpretation of those observations. The observations stand and fall by precision by which they are made.
The simple point is that too many of the observations indicate that the basis for the model theory is not only incomplete but wrong. As I said above, the theory depends on an electrically neutral universe so that the only force of any consequence is gravity. The universe is too big for the time since the "big bang" so a unknown, unknowable process called inflation has had to be incorporated, movements with a galaxy are doing things that are not according to what the theory says they should so then "dark matter" had to be incorporated into the model, and then movement between galaxies wasn't occurring in the manner predicted, so "dark energy" was added.
Now for the last twenty years or so, no experiment devised to find "dark matter" or "dark energy" has found either of those entities. Hence, there is a significant possibility that they don't exist.
Mayhaps, the model is wrong and there needs to be a revisiting of the observations to see if some alternate theory might have more success. Is this occurring? Not that I can see. If anything, it appears that those who believe in the theory are doubling down and doing everything to justify their theory.
This is supposed to be science, you know, that process by which we systematically observe the universe around and try to develop viable theories that help us understand what we are seeing. If a model doesn't work, we are allowed to throw it out, you know. If we can't do that and look for better explanations, then what are we doing?
I have been wrong about many things during my lifetime and when I have been shown that, I give up the old and take up the new. This was a fundamental part of my science and engineering education.
Let me put something to you, I am not hung up on any particular model as being the "right" model. If the theory/model in question has problems explaining some observations, it just means that there is a better explanation, we just haven't worked it out yet.
My personal belief is that God (personal Christian Trinity) created the universe and that He takes great delight in us learning about His creation and how it works. It works according to the rules He has put in place and it is up to us to investigate and find out those rules, laws, etc.
What you believe is up to you. If you don't believe that there is a creator then you also have to come up with a reason for why the rules are precisely as they are.
Irrespective of the cause of the universe and what you believe about that, we need to be capable of modifying and/or dropping theories that no longer match what we see.
You can consider me ignorant if you wish, but I think I have a greater wonder about the universe than you do. It is for exploring and there are ever more complexities than our simplistic theories will ever uncover. That is the fun part.
The article is about the metric expansion of space, or if you're really really really stubborn about that (you appear to be) the redshift-distance relation sans mechanism.
That relation is an empirical fact and has been known for more than a century. Indeed, the discovery of that relation both predated the discovery of galaxy clusters and enabled the discovery that galaxies are collections of billions to hundreds of trillions of stars.
> experiment
You are being way too fussy about this. Sure, you can take an ultra-Popperian attitude towards cosmology, but that would make you an extremist rather than a scientist; science generally doesn't work that way. You'll be hard pressed to find any scientist who advocates ignoring observational evidence simply because local direct testing is infeasible with current technology. Heck, we still can only demonstrate the inverse square law for gravitation down to micrometer scales in laboratory settings, and there was no experimental value for the gravitational constant until the start of 19th century. Yet there Neptune is.
At any rate, you do not really seem interested in learning about the theoretical underpinnings of dark energy in any way, and if you're as uninterested as you appear to be in advancing your own understanding of the standard cosmological model and the many observations and experimentally well-validated theories that it wholly captures (notably the Standard Model of Particle Physics and General Relativity), then it seems wasteful to continue this thread. I have no need or desire to "convert" you, and am uninterested in your personal beliefs or what you believe I believe or why I believe it. Honestly, I hope my withdrawing from the conversation will make you feel better.
Try to remember that a model is only a model and a theory is only a theory that is one possible explanation of the reality we observe.
It is an attempt to get a handle on understanding the universe around us. When you and others go off and start proclaiming the actual existence of these theoretical entities without at least the experimental confirmation of such, then you are setting yourself to be considered in the same light as attendees at the local ufo conventions.
It annoys me when theoretical entities are declared as existing when the evidence is only slightly in their direction or the only evidence is that they need to exist based on the current mathematical models being used.
When said and done, dark energy and dark matter are mathematical entities required by the prevailing theory. The prevailing theory is only one of a number of possible models. Which one you subscribe to is up to you and your view of how the current evidence stacks up.
At this point, none of the models seems to cover enough bases to make it the most likely scenario. So, for me, this is still an open question. The current prevalent model has at it basis, some, from my point of view, untenable inconsistencies.
The first and foremost is that gravity (whatever model you might ascribe to) is the majority controlling force. The inconsistency is that model uses gravity to give rise to "Black Holes" and yet has not stopped the "Big Bang" from happening. When you start to play around with reconciling both entities, it becomes a bit of a problem. You then add time dilation effects due to gravity (as per the various models in use) and you get other strange quirks/inconsistencies appearing.
The upshot of this is that people should be careful to not declare the actual existence of theoretical entities from incomplete models just based on belief. This just turns the supposed science into religion and religion is considered anathema amongst certain groups within the science communities.
The theories and models are supposed to be helpful working explanations that can change or be thrown out based on new evidence. They have a particular usage profile and range of applicability. If you go outside of that usability or applicability range then the theory/model will start to fail. As we were taught in undergraduate engineering all those decades, you use the applicable model/theory for the specific circumstances being investigated.