Cosmological expansion vs. stretching

[Neuroglider]

Cosmological expansion vs. "stretching"

From a relativistic point of view, how can we tell the difference between a universe that’s expanding (outward) from a singularity versus one that is being sucked INTO a singularity? In the case of the latter, it seems that those objects closer (than us) to the singularity would be accelerating more rapidly and thus be red-shifted. Also, we would be accelerating more rapidly toward the singularity than those that are farther from it, so those would appear to be red-shifted too.

The physicists from whom I’ve been able to elicit a response counter with, “This can’t be true because the universe has no center.” I understand that that the universe has no three-dimensional center. But I don’t see why a singularity of DESTINY is different from a singularity of ORIGIN. In other words, if the conventionally accepted singularity (the origin) doesn’t represent a 3D center of the universe then why would the one we’re (putatively) falling INTO have to represent a 3D center?

In such a scenario, my uses of “closer,” “farther,” “toward,” and “away” refer not to 3D space but to some higher order construct where at least one other dimension (e.g., time) obfuscates the “position” of the singularity. In fact, one might even consider that, relativistically speaking, “expansion” is not a meaningful term; the universe is, more correctly, experiencing STRETCH; whether that is an outward stretch or an inward stretch would seem difficult to determine. The expansion of the 2D surface of a balloon is often used as an analogy for the 3D expansion of the universe. I envision instead the 2D surface of a vortex, whereby the direction representing “down” (e.g., down into a whirlpool) represents a 4th (or higher) dimension not perceived by us as “space.”

Notably, the stretching apart of galaxies as they accelerate into this putative singularity would account for the new data that appear to indicate acceleration of the universal “expansion,” right? And, if we apply Occam’s razor to this data, the current explanation doesn't hold much water. The “dark energy” required to fuel such an acceleration seems much more contrived and convoluted than would a descent into a singularity, especially in the lack of any (other) evidence for this energy.

 

[Chalnoth]

From a relativistic point of view, how can we tell the difference between a universe that’s expanding (outward) from a singularity versus one that is being sucked INTO a singularity? In the case of the latter, it seems that those objects closer (than us) to the singularity would be accelerating more rapidly and thus be red-shifted. Also, we would be accelerating more rapidly toward the singularity than those that are farther from it, so those would appear to be red-shifted too.

A collapsing universe would have further objects being blue-shifted, not red-shifted.

 

[Neuroglider]

A collapsing universe would have further objects being blue-shifted, not red-shifted.

Yes, but I wasn't asking about a collapsing universe. Hence, the word "stretching." Please read the post again.

Perhaps it would be best to scale things down to the vicinity of a black hole as an analogy. Imagine your spaceship has been captured by the gravitational field of a black hole without the requisite velocity/trajectory to remain in a stable orbit or escape. As the ship accelerates in toward the black hole, objects farther away would appear to be red-shifted because your point of reference is receding from them.

Suppose there is a gargantuan singularity capable of casting a gravitational field across the visible universe. This is where my mathematical understanding of the current models breaks down. Is the asymptotic flatness derived from equations that contain an assumption or two? Or does it fit real observation? And if so, how does one explain the "peculiar motion" of the Milky Way? Indeed, how does one explain the Shapley supercluster?! Don't answer that-- I know it's explainable. But it's also VERY intriguing! We don't really know what's going on there, do we...?

 

[Chalnoth]

Yes, but I wasn't asking about a collapsing universe. Hence, the word "stretching." Please read the post again.

Then you're not talking sense. The visible universe is smooth and uniform as far as we can see (which is quite far). You can't get a significant redshift from local objects like black holes that looks like a cosmological redshift in such a universe.

 

[Neuroglider]

The visible universe is smooth and uniform as far as we can see (which is quite far).

That's not strictly true, is it? The red shift is not uniform. And there are whole superclusters of galaxies that appear to be aggregating rather than moving apart. How do we know that this is due to a local effect such as gravity rather than aberrations in the fabric of the expansion? And even if it is gravity, we have no idea what's responsible for it, right? It seems to differ from black holes quantitatively enough to seem like a qualitatively different phenomenon.

And as for "(which is quite far)," what about the Zone of Avoidance? How can we know what's going on behind that curtain?

You can't get a significant redshift from local objects like black holes.

I don't envision anything "local"; or even an "object," really. I've seen erudite and confident statements on this forum asserting that a singularity is not necessarily a black hole. What I'm trying to wrap my imagination around is a distortion of space-time that, for whatever reason, we don't perceive spatially. Going back to the tried-but-true balloon analogy, imagine the balloon is tied off and no more gas is going into expand it. Now imagine a pencil is being shoved into the balloon (eraser first, of course!). The disks attached to the balloon in that vicinity are moving farther apart because the balloon's material surface is stretching.* Sure, that indentation doesn't look flat from our vantage point; but it's my understanding that the two dimensions of the balloon's surface are held to be analogous to the three dimensions of what we perceive to be space, such that the third dimension of balloondom-- that through which we see its curvature-- is time. Or do I have that wrong? If not, I suppose a Flatlander living on the surface of the balloon would not really see its curvature, including the curvature of the indentation caused by the pencil.

*Disks attached to the opposite side of the balloon are moving apart because that part of the surface is actually expanding as the insertion into what was previously a sphere displaces the gas inside. But I think we can pretend that doesn't happen with regard to the universe. Suppose that instead of being a closed system, the space and matter disappearing into the singularity are escaping our universe altogether-- transiting into another universer, perhaps. (Besides, an observer in the indentation wouldn't be able to see the other side of the balloon anyway.)

 

[rbj]

From a relativistic point of view, how can we tell the difference between a universe that’s expanding (outward) from a singularity versus one that is being sucked INTO a singularity? In the case of the latter, it seems that those objects closer (than us) to the singularity would be accelerating more rapidly and thus be red-shifted. Also, we would be accelerating more rapidly toward the singularity than those that are farther from it, so those would appear to be red-shifted too.

A collapsing universe would have further objects being blue-shifted, not red-shifted.

Chalnoth, my understanding of how the question is posed is like there is some singularity (with a lotta mass) out at the point of infinity. sort of like saying the complex function

[tex] f(z) = \frac{1}{z} [/tex]

has a "zero" at [itex]z=\infty[/itex].

from a Euclidian POV, that's a lotta different z's. so, instead of saying that 1/z has a singularity at z=0, is the OP saying that [itex]f(z)=z[/itex] has a singularity out there at infinity? so as galaxies get closer to that, they accelerate faster toward it?

i can't visualize it either and i don't know that I'm guessing at the OP's point correctly.

 

[Chalnoth]

That's not strictly true, is it? The red shift is not uniform.

Redshift certainly is uniformly related to distance, which is the picture of a universe which is the same everywhere and in all directions but expanding. Having some singularity out there would produce a preferred direction (towards the singularity), and no such preferred direction exists.

 

[Drakkith]

This sure seems like wild speculation to me...

 

[Neuroglider]

Redshift certainly is uniformly related to distance.

Distance AND direction of travel, you mean. Because there are most certainly galaxies that are blue-shifted with respect to the Milky Way and other galaxies. So to say that the red-shift is uniform suggests "uniform after correction for peculiar motion." But it would seem that such correction is only possible for objects whose motion can be validated by some means other than red shift (otherwise would be begging the question). So I suppose it only holds for galaxies close enough that their motion can be confirmed by parallax or line-of-sight observation. Sure, there's Tully-Fisher, but that's subject to pretty big error, right? Like as much as 50%?

Now, I recognize that a blue-shifted galaxy in a field of other galaxies that are shifted as predicted can be considered an anomaly-- a case of peculiar motion-- regardless of distance or independent confirmation of the peculiarity. But when one considers a whole supercluster that is SUPER-red-shifted, does it not give one pause?

 

[Neuroglider]

This sure seems like wild speculation to me...

Well, yeah-- touche'. But its undeniably helpful to think outside the box now and again.

 

[Mark M]

We know this scenario can't be true because of the cosmic microwave background. The CMB is the radiation left from the recombination. The recombination was the point 380,000 years after the big bang when the universe reached a specific, cool, temperature of 3000 degrees Kelvin. Prior to this, the universe was too hot for electrons to be held into atoms. Their kinetic energy was far too high to be held in orbit by the electromagnetic force. Since these elections weren't bound by atomic nuclei, they were free to run around and do their own thing. More precisely, they scattered photons. So, no light could be released. The entire universe was an opaque plasma, and we can not see farther than this point. When the electrons were captured by atoms at the recombination to form hydrogen, photons were free to be emitted.

So, we have a prediction of the big bang model as compared to yours. The big bang model predicts that we will observe this radiation today - as being homogenous everywhere, having a very high redshift (because of Hubble's law. Since this radiation is reaching us from far away, it will have a higher redshift), having a blackbody spectrum, having certain polarizations for the photons that compose it, and having slight anisotropies that would be evenly distributed, to give us the even distribution of galaxies we see.

We observe this through BOOMERanG, COBE and WMAP, with all of these characteristics.

On top of that, your scenario doesn't predict a homogenous distribution of galaxies as the big bang model does. We do observe such a distribution.

 

[Chalnoth]

Distance AND direction of travel, you mean. Because there are most certainly galaxies that are blue-shifted with respect to the Milky Way and other galaxies.

This is only true of a small number of nearby galaxies. Basically, there is an overall effect (the expansion), plus small local random motions. To give a sense of scale, typical galaxy motions top out at around 1000km/s, while the current Hubble rate is around 70km/s per Megaparsec, meaning that beyond about 14 Megaparsecs (about 47 million light years), the recession velocity always wins out. Most of the universe that we can observe is more than a hundred times further than that, so that it is perfectly reasonable to ignore the local velocities most of the time we're talking about the expansion. Local velocities are important for understanding the errors in our estimates of the expansion and other parameters, but don't account for much otherwise.

So yes, effectively the redshift is uniform with distance, once you go out beyond a few million light years.

 

[Mark M]

To add to what Chalnoth said, the only galaxies that are blue-shifted are some within our galactic cluster. Because the galaxies are sufficiently close together, the mutual gravitation of the galaxies is enough to counter the effect of expansion.

 

[Neuroglider]

the only galaxies that are blue-shifted are some within our galactic cluster. Because the galaxies are sufficiently close together, the mutual gravitation of the galaxies is enough to counter the effect of expansion.

Well, if you mean "blue-shifted" in an absolute sense, yes. But one can also consider "blue-shifted relative to the expected red shift." In other words, wavelengths that are longer than they'd be in a static universe but still shorter than those from galaxies at an equal distance. And I believe there are plenty of those outside of our cluster.

And it's my impression that "mutual gravitation" is not the only thing that makes the Milky Way's motion peculiar. We are moving relative to the CMB in a way that is not consistent with the center of gravity of our local cluster, right? Isn't it the case that we appear to be moving generally toward the Great Attractor and the Shapley supercluster beyond that? In fact, the Dark Flow seems to indicate a very large portion of the visible universe is sashaying its way nonchalantly in that general direction (Kashlinsky et al., 2008). It's my understanding that the visible mass-- and its attendant mutual gravity-- of those peculiar clusters is insufficient to account for the Dark Flow, though that appears to be a subject of ongoing debate.

So, there seems to be agreement that there is red shift and that it follows Hubble's Law, but... that it is not uniform. This is essentially what a vortex model would predict, no? The anomalies seem subtle relative to the distance-magnified, exponential rate of the Hubble effect; but that also seems to fit a vortex model.

 

[Neuroglider]

So yes, effectively the redshift is uniform with distance, once you go out beyond a few million light years.

But that's only because the peculiar motion of those very distant galaxies gets proportionally dwarfed by the Hubble effect. That doesn't make the red shift uniform-- it just makes anomalies more difficult to detect/appreciate. Right?

 

[Drakkith]

Well, yeah-- touche'. But its undeniably helpful to think outside the box now and again.

To think outside the box, one must first understand what's inside the box. As an example, your claim that certain galaxies are blue shifted is true, but those galaxies are very very close to us on a cosmological scale. Everything past a hundred million light years or so is completely red shifted.

 

[Drakkith]

But that's only because the peculiar motion of those very distant galaxies gets proportionally dwarfed by the Hubble effect. That doesn't make the red shift uniform-- it just makes anomalies more difficult to detect/appreciate. Right?

The redshift isn't 100% uniform, as galaxies orbit around each other, just like anything else in space does. This results in some moving away slightly faster or slower than the average due to their velocities through space. On average the redshift is uniform with distance.

 

[Neuroglider]

certain galaxies are blue shifted is true, but those galaxies are very very close to us on a cosmological scale. Everything past a hundred million light years or so is completely red shifted.

Perhaps this post crossed in the ether with the one where I explained that I was talking about RELATIVE blue shifts rather than ABSOLUTE blue shifts. Check that, then hit me back, please.

 

[Neuroglider]

The redshift isn't 100% uniform, as galaxies orbit around each other, just like anything else in space does. This results in some moving away slightly faster or slower than the average due to their velocities through space. On average the redshift is uniform with distance.

Yeah, I know about local clusters and local gravitational effects. That's not what I'm talking about. And I think Kashlinsky would quibble with you about the "average redshift" being uniform.

For those of you who keep harping on uniformity, I would be sincerely interested in your take on the following refs:

A. Kashlinsky, F. Atrio-Barandela, D. Kocevski, and H. Ebeling (2008). "A measurement of large-scale peculiar velocities of clusters of galaxies: results and cosmological implications". Astrophys. J. 686: 49–52.

A. Kashlinsky, F. Atrio-Barandela, D. Kocevski, and H. Ebeling (2009). "A measurement of large-scale peculiar velocities of clusters of galaxies: technical details". Astrophys. J. 691: 1479–1493.

 

[Drakkith]

Perhaps this post crossed in the ether with the one where I explained that I was talking about RELATIVE blue shifts rather than ABSOLUTE blue shifts. Check that, then hit me back, please.

Yeah that's pretty much what we are saying. Galaxies don't fit the redshift curve exactly but are spread around it. I don't know much about this vortex model you mentioned though, so I can't comment on it.

 

[Drakkith]

Yeah, I know about local clusters and local gravitational effects. That's not what I'm talking about.

Then what are you talking about?

 

[Mark M]

Have you not read my above post? The CMB falsifies your proposal. Because of the CMB, we know the early universe was hot and dense, as in the big bang model. Your model doesn't predict that the universe was hot and dense. It's as simple as that. How do you explain the blackbody spectrum of the CMB?

On top of that, there are many ways we have been able to identify the age of the universe as 13.7 billion years. How could your model account for this?

What about the abundance of light elements? That's a unique feature of the big bang model. In fact, the agreement between the prediction that the BBM makes about the abundance of specific elements and the ratios we observe is one of the best agreements between theory and data. How does your model explain that?

Also, your model isn't consistent with general relativity, which predicts an expanding universe. How do you resolve that issue?

Next, why would acceleration only begin 7 billion years ago? If you were correct, the acceleration should have been around for much longer than that.

Finally, this model doesn't allow expansion to be uniform. Galaxies in certain directions would have significantly less redshift, if not blueshift.

So, the point I am making is that your model can't explain any other data. When you propose a replacement for a theory, you must account for all other data already explained by the existing model.

In short, the 'collapsing universe' proposal is wrong.

 

[Neuroglider]

We know this scenario can't be true because of the cosmic microwave background. ... The recombination was the point 380,000 years after the big bang when the universe reached a specific, cool, temperature of 3000 degrees Kelvin. Prior to this, the universe was too hot for electrons to be held into atoms. ... Since these electrons [corrected] weren't bound by atomic nuclei, they were free to run around and do their own thing. ...

But that's all theory that derives from circular reasoning, no? Isn't it, in some sense, speculation contrived to explain the CMB? And even if there was a hot Big Bang, can we really deduce a priori what the temps would be? Isn't that derived from backwards extrapolation? Feel free to correct me if I'm wrong-- I'll freely admit that I don't know how the model of the Big Bang was derived down to the detailed level of degrees K.

So, we have a prediction of the big bang model as compared to yours. The big bang model predicts that we will observe this radiation today - as being homogenous everywhere, having a very high redshift.

Well, no-- I wasn't making predictions. But I don't see anything about my idea that precludes homogeneous distribution, necessarily.

I also wasn't making assumptions. And that's what "having a very high redshift" seems to be. How do we know that the CMB isn't coming from an sphere of dark energy surrounding our solar system just a few thousand light years away, emitted initially at microwave frequencies? Yeah, that's a bit silly, bordering on facetious; chalk it up as polemic. But, f' real-- how do we really know the degree to which the CMB is red shifted? We can't unless we know its source, and I have trouble believing that primordial photons released from their electron matrix is any better explanation than some partial component of this dark energy I keep hearing about (but never detecting ).

Regarding the blackbody spectrum, polarizations for the photons composing the CMB, and the slightness of the anisotropies... well, you got me there. I'll admit I don't know about that stuff. But I really can't imagine they have only one explanation. Maybe only one explanation (Big Bang) that fits Occam's razor. But Occam wasn't half the sculptor that Gaudi was.

 

[marcus]

Yeah, I know about local clusters and local gravitational effects. That's not what I'm talking about. And I think Kashlinsky would quibble with you about the "average redshift" being uniform.
...

The 2008 "dark flow" paper. Finding a slight deviation from uniformity that was, as I recall, met with mild skepticism or ignored. Whether or not the "dark flow" is real doesn't seem to make much difference to the overall uniformity of the expansion pattern.
I haven't noticed much in the way of a followup.

The promotional term Kashlinsky used, "dark flow" made the alleged statistical drift seem a lot more mysterious and exciting than it actually was, in down to Earth km-per-second terms.

 

[Mark M]

As I also mentioned I my second post, you can't account for the abundance of light elements either.

 

[Mark M]

But that's all theory that derives from circular reasoning, no? Isn't it, in some sense, speculation contrived to explain the CMB? And even if there was a hot Big Bang, can we really deduce a priori what the temps would be? Isn't that derived from backwards extrapolation? Feel free to correct me if I'm wrong-- I'll freely admit that I don't know how the model of the Big Bang was derived down to the detailed level of degrees K.

No. George Gamow predicted the CMB before it was observed.

Well, no-- I wasn't making predictions. But I don't see anything about my idea that precludes homogeneous distribution, necessarily.

The tidal effect, for one. Galaxies that were left or right of ours would be pulled towards us.

 

[Chalnoth]

But that's only because the peculiar motion of those very distant galaxies gets proportionally dwarfed by the Hubble effect. That doesn't make the red shift uniform-- it just makes anomalies more difficult to detect/appreciate. Right?

What it means is that the peculiar motions are irrelevant when attempting to understand the behavior of the universe as a whole (provided what you're interested in isn't the typical peculiar motions...which does provide some interesting signal).

 

[Chalnoth]

Yeah, I know about local clusters and local gravitational effects. That's not what I'm talking about. And I think Kashlinsky would quibble with you about the "average redshift" being uniform.

For those of you who keep harping on uniformity, I would be sincerely interested in your take on the following refs:

A. Kashlinsky, F. Atrio-Barandela, D. Kocevski, and H. Ebeling (2008). "A measurement of large-scale peculiar velocities of clusters of galaxies: results and cosmological implications". Astrophys. J. 686: 49–52.

A. Kashlinsky, F. Atrio-Barandela, D. Kocevski, and H. Ebeling (2009). "A measurement of large-scale peculiar velocities of clusters of galaxies: technical details". Astrophys. J. 691: 1479–1493.

These papers have been pretty thoroughly debunked. Basically, they misunderstood the statistics of the CMB pretty egregiously.

 

[Neuroglider]

First things first:

In short, the 'collapsing universe' proposal is wrong.

The very first response to my original posting assumed that I was describing collapse. I tried to correct that in my reply. It is NOT collapse that I am imagining.

So, the point I am making is that your model can't explain any other data. When you propose a replacement for a theory, you must account for all other data already explained by the existing model.

Yeah, I know it's nascent (perhaps even infantile ). If I was ready to propose a replacement of the Big Bang theory, I don't think my first move would be to post on PhysicsForums.com.

Besides, I'd have to be choked up to the gills on hubris to think that I had the GUF in my noggin'. Truly, I'm just tossing ideas out there so that I can learn from you guys. Call it the inverse-Socratic method.

Your citation of General Relativity as a point for the Big Bang team is salient. Because the genesis of all of this, for me, is relativity. I began with the simplistic notion of relative motion; you know, like a train that appears to be moving down its tracks westward when really the Earth is just spinning out from 'neath it. And it made me wonder if there's not some way in which the other galaxies appear to be receding when really it's our vantage point that's doing the receding-- sliding away into some other dimension. At first, I supposed that this other dimension would not be perceived by us as 3-D space (thus obviating the need for non-uniformity in the spatial distribution of galaxies). But then my reading took me to the Great Attractor... the Norma cluster... the Shapley supercluster, and... DARK FLOW! Intriguing stuff.

Ultimately, my message is: Free your minds. Open up just a little. Current theory-- General Relativity, Big Bang, Etc., Etc.-- is not the be-all/end-all, obviously. Otherwise, we wouldn't still be waiting for GUFman.

 

[Neuroglider]

These papers have been pretty thoroughly debunked. Basically, they misunderstood the statistics of the CMB pretty egregiously.

OK, good to know... good to know. (Another cool person in the armor of the peer review process, huh?)

Thanks.

 

[Drakkith]

Your citation of General Relativity as a point for the Big Bang team is salient. Because the genesis of all of this, for me, is relativity. I began with the simplistic notion of relative motion; you know, like a train that appears to be moving down its tracks westward when really the Earth is just spinning out from 'neath it. And it made me wonder if there's not some way in which the other galaxies appear to be receding when really it's our vantage point that's doing the receding-- sliding away into some other dimension.

But that's the beauty of GR. This recession IS a result of our galaxy receding from every other galaxy. Just like every other galaxy is receding from us.

Ultimately, my message is: Free your minds. Open up just a little. Current theory-- General Relativity, Big Bang, Etc., Etc.-- is not the be-all/end-all, obviously. Otherwise, we wouldn't still be waiting for GUFman.

Why do you think our minds are closed? The problem is that so many people THINK scientists minds are closed when it's usually the opposite. The only difference is that most scientists require that new things fit into the current laws of physics, as we have observe the universe to work that way. The average person doesn't think this way.

 

[marcus]

... know the degree to which the CMB is red shifted? We can't unless we know its source, and I have trouble believing that primordial photons released from their electron matrix is any better explanation than some partial component of this dark energy I keep hearing about (but never detecting ).
..Maybe only one explanation (Big Bang) that fits Occam's razor. But Occam wasn't half the sculptor that Gaudi was.

"Dark energy" is an unnecessary elaboration. At the classical GR level we just need to observe that two gravitational constants naturally occur in the GR equation naturally. Not only G but also Lambda (are allowed by the symmetries of the theory).

http://arxiv.org/abs/1002.3966/
"Why all these prejudices against a constant?"

Calling Lambda an "energy" is a dubious speculation which gets attention and creates a sense of importance. But so far there is no evidence that it is anything but a naturally occurring constant, comparable to Newton's G (which also occurs in the GR equation.)

There is no evidence for "dark energy" qua energy. Only that a certain constant in the currently accepted law of gravity is non-zero.

By contrast, the release of the CMB at about 3000 Kelvin is something that can be verified empirically. One can heat hydrogen gas to 3000 Kelvin and MEASURE the degree of ionization and calculate the mean free path of photons, at a given density. One can determine empirically how opaque or how transparent the hot glowing gas would be.

So this is familiar conventional physics, not at all comparable to the imaginative speculations about "dark energy".

I agree with your characterization of one of your comments as RHETORICAL. That's also how this comparison of CMB and "dark energy" looks.

Speaking of rhetoric, I like your ornamental flourish of comparing Occam with the great Barcelona architect Gaudi! Gaudi creates a strange Catalonian dreamland by putting every oddity on his buildings, whose lines waver as in a mirage.

Modern cosmology, by contrast, is remarkably simple and straightforward if properly understood. And in excellent overall agreement with data. More Nervi than Gaudi.
http://www.google.com/search?q=pier...QXzqfSyDw&sqi=2&ved=0CFUQsAQ&biw=1115&bih=627
(google images for "pier nervi")

 

[Chalnoth]

OK, good to know... good to know. (Another cool person in the armor of the peer review process, huh?)

Thanks.

Huh? No. It's just that the initial peer review that papers go through to get published is the beginning of peer review, not the end. Once published, a paper becomes part of the wider scientific discussion that rigorously (sometimes brutally) determines which papers are reasonable and which are not. The initial peer review to get a paper published is little more than a sanity check to ensure that published papers pass a minimum quality bar. The primary benefit we get from peer review is that the papers which are published are usually somewhat higher-quality than the earlier drafts first sent to the publishers. That and outright crankery is usually weeded out, but sometimes still manages to make it through.

 

[Neuroglider]

But that's the beauty of GR. This recession IS a result of our galaxy receding from every other galaxy. Just like every other galaxy is receding from us.

Yeah, I "get" that. The whole balloon (or raisin-laden leavened dough) thing. So maybe the time vortex is just another analogy for the expansion. Except... I think I now appreciate the fact that while the "down" direction (Z-axis) of the vortex might escape our perception, the X-Y would still be non-uniform. The tidal-effect comment may have been what did it for me-- that was nagging at the back of my mind the whole time. I kept thinking that it seems possible for the singularity's effect to overwhelm the tidal effect. But I suppose it would still be fractionally detectable, eh? Kinda like blue shifting within a local cluster... WAIT! Whaaaat?!

Why do you think our minds are closed?

Oh, I dunno. Maybe it has something to do with two different responders assuming I was talking about collapse when I never used that word and described in detail a scenario quite different from collapse. Or the several folks who kept telling me that the red shift is uniform when it is clearly not; generally uniform, perhaps, but not absolutely.

The problem is that so many people THINK scientists minds are closed when it's usually the opposite. The only difference is that most scientists require that new things fit into the current laws of physics, as we have observe the universe to work that way. The average person doesn't think this way.

Yep, I'm fully onboard with the need to fit current laws. Because, you see, I am a scientist. Of a different breed-- one that doesn't know all those laws of physics to which I nevertheless agree that we must adhere. Trying to learn here, thank you.

 

[Neuroglider]

Huh? No. It's just that the initial peer review that papers go through to get published is the beginning of peer review, not the end. Once published, a paper becomes part of the wider scientific discussion that rigorously (sometimes brutally) determines which papers are reasonable and which are not.

Spoken like a PLoS afficionado. It's hard to believe there's not a PLoS Physics!

As a biologist, I am somewhat frustrated by the inability to provide independent confirmation of the data I review in a submitted manuscript. I always assumed that the peer-review process was more satisfying in math and theoretical physics. In biology, repeating the experiments of a submitted paper would be exorbitantly expensive and time-consuming. But I tend to think of math and physics as "A-ha!" fields, driven by Gedankenexperimenten, where all the author has to do is lead the reader down a one-way mental street. It would seem that theorems and proofs of this sort could be reviewed relatively quickly and thoroughly in the first go. In the example of the Kashlinsky papers, you said it was the statistics that was their undoing. How hard is it for a reviewer to check stats? OK, that is acknowledged to be a question born of ignorance; the stats in biology are pretty simple. Physics/cosmology stats must be quite the bear. You have my sympathies on that one.