New map of Universe may reconcile conflicting cosmological observations

Sep 11, 2013 by Lisa Zyga feature
This plot shows the confidence areas for the Hubble constant (h) and the matter density parameter (Ωm), obtained from the Planck experiment on the one hand (black contours), and from the Hubble diagram on the other hand (colored areas). The green area, obtained by interpreting the Hubble diagram using a very clumpy Swiss-cheese model, is clearly in better agreement with Planck than the blue area, obtained with the standard FL interpretation. Credit: Fleury, et al. ©2013 American Physical Society

(Phys.org) —In Jonathan Swift's 1726 book "Travels into Several Remote Nations of the World. In Four Parts," the miniature Lilliputians experience the world very differently from the giant Brobdingnagians.

Because they see the world on different scales, the two types of creatures use maps with different resolutions. Using this analogy, physicists from France have proposed that we need maps of the Universe with different resolutions depending on the resolution of our experiments. The physicists show that using an alternative "map" (or model) to interpret the Hubble diagram—which is based on high-resolution supernova observations—produces results that more closely match the results from low-resolution (CMB) observations than when using a traditional model.

The physicists, Pierre Fleury, Hélѐne Dupuy, and Jean-Philippe Uzan, at the Institut d'Astrophysique de Paris (CNRS) and the Institut de Physique Théorique (CEA), have published a paper on interpreting with different models in a recent issue of Physical Review Letters.

"Our work emphasizes the model-dependence of the interpretation of cosmological observations, by showing explicitly the impact of taking the small-scale inhomogeneity of our Universe into account," Fleury told Phys.org. "Thus, we may need to refine our standard in order to consistently interpret all the current high-accuracy observations together."

In their work, the scientists were confronting a problem from a recent analysis of the results from the Planck experiment. Two areas that the Planck experiment is investigating are the average density of matter in the Universe and the speed at which galaxies are receding due to the expansion of the Universe. These areas are measured by the parameter and the Hubble parameter, respectively. Knowing accurate values of these parameters will enable scientists to better understand the composition and fate of the Universe, among other things.

However, the problem is that the Hubble diagram and the CMB produce slightly different best fits for the values of the matter density parameter and Hubble parameter, and they cannot both be correct. Currently, both the supernova experiments used to construct the Hubble diagram and the CMB experiments are interpreted using the same "map" to describe the Universe, which is the Friedmann-Lemaître (FL) geometry. The FL geometry describes the Universe as homogeneous and isotropic, in strict accordance with the cosmological principle.

Fleury, Dupuy, and Uzan wondered if perhaps the FL geometry is too simple to accurately interpret the supernova observations. Noting that the supernova experiments involve light beams with a much smaller angular size than the light beams involved by the CMB experiments, the physicists investigated what would happen if they interpreted the supernova observations using a model that describes the Universe as clumpier.

So the physicists turned to a model proposed by Einstein and Straus in 1945 called the Swiss-cheese model. In this model, clumps of matter (that model galaxies, for example), each lying at the center of a spherical void, are embedded in an otherwise homogeneous FL spacetime.

Compared to a strictly homogeneous , the Swiss-cheese model is characterized by the size of the voids and the fraction of the remaining FL regions. The traditional FL geometry is the extreme instance of the Swiss-cheese model with no voids. On the other end of the spectrum is the case where matter is exclusively in the form of clumps inside voids.

Interpreting the supernova observations with a Swiss-cheese model gives different results because the of the distribution of matter causes gravitational lensing. Since the light traveling from the supernovae to Earth rarely cross clumps of matter, it essentially experiences an underdense universe; consequently, the light beams are defocused—the supernovae appears fainter, that is, farther—compared to the case in which light would travel through a strictly homogeneous universe.

The physicists' calculations revealed that, using a very clumpy Swiss-cheese model to interpret the Hubble diagram can shift the best fit values of the matter density parameter—but not the Hubble parameter—to be in much closer agreement with the values obtained from the CMB observations.

Why is there still disagreement on the Hubble parameter? The physicists explain that supernova observations alone cannot fully constrain the Hubble diagram, since other factors also play a role.

Alleviating the tension between the best fits for the Hubble parameter remains an open problem.

One speculative possibility is that our local environment is underdense compared to the rest of the Universe, and accounting for this underdensity could help explain the disagreement.

Overall, the idea of using scale-dependent models to interpret different observations could have far-reaching effects throughout the study of cosmology.

"Our analysis, though relying on a particular class of models, indicates that the FL geometry is probably too simplistic to describe the Universe for certain types of observations, given the accuracy reached today," the physicists wrote. "In the end, a single metric may not be sufficient to describe all the cosmological observations, just as Lilliputians and Brobdingnag's giants cannot use a map with the same resolution to travel. A better cosmological model probably requires an atlas of maps with various smoothing scales, determined by the observations at hand. Other observations, such as lensing, may help to characterize the distribution and the geometry of voids, in order to construct a better geometrical model. For the first time, the standard FL background geometry may be showing its limits to interpret the cosmological data with the accuracy they require."

In the future, the physicists plan to further investigate the possibility of a cosmological model that involves an atlas of maps.

"Our future plans in this area are twofold," Fleury said. "On the one hand, we try to construct models for the spacetime geometry of the Universe which would be more realistic than the simple Swiss-cheese model we started with. On the other hand, we are interested in using other types of , e.g., weak gravitational lensing, which would be able to distinguish between the standard model of cosmology and alternative ones."

Explore further: Hubble bubble may explain different measurements of expansion rate of the universe

More information: Pierre Fleury, et al. "Can All Cosmological Observations Be Accurately Interpreted with a Unique Geometry?" PRL 111, 091302 (2013). DOI: 10.1103/PhysRevLett.111.091302

Related Stories

Recommended for you

Timely arrival of Pharao space clock

29 minutes ago

ESA has welcomed the arrival of Pharao, an important part of ESA's atomic clock experiment that will be attached to the International Space Station in 2016.

First in-situ images of void collapse in explosives

Jul 25, 2014

While creating the first-ever images of explosives using an x-ray free electron laser in California, Los Alamos researchers and collaborators demonstrated a crucial diagnostic for studying how voids affect ...

User comments : 35

Adjust slider to filter visible comments by rank

Display comments: newest first

shavera
4.3 / 5 (16) Sep 11, 2013
can't wait for the armchair physicist nutters to come by and tell us why the real scientists are wrong. *grabs some popcorn*
axemaster
5 / 5 (12) Sep 11, 2013
I wouldn't bother with the popcorn, it really isn't that entertaining.
cantdrive85
1.2 / 5 (23) Sep 11, 2013
can't wait for the armchair physicist nutters to come by and tell us why the real scientists are wrong. *grabs some popcorn*

They do that just fine on their own.
Tektrix
3 / 5 (4) Sep 11, 2013
This seems a very sensible approach. Any data-set analysis requires a schema by which the data are interpreted. More degrees of freedom within the observations are afforded by more flexible schema, such as the one being described here.
HannesAlfven
1.2 / 5 (24) Sep 11, 2013
Re: "can't wait for the armchair physicist nutters to come by and tell us why the real scientists are wrong. *grabs some popcorn*"

It's arguably the price paid for introducing ideology into the notion of "thinking like a scientist", and weeding out the physics PhD students who stop to think about what it is they are memorizing. That ideology is now filled with all sorts of invisible and non-falsifiable entities, and so society has a more difficult choice to make than a PhD student or scientist. The PhD student is simply worried about surviving the program & the scientist is focused on specialty, whereas society is worried about its long-term investment and the meaning of the consensus which these programs generate.

If you see a lot of people coming at you with wacky ideas, it's probably worth asking what motivates them. It seems to me that it is the big questions in science which remain unanswered, and which our PhD programs appear to not be scrupulously hedging their bets on.
Q-Star
3.9 / 5 (18) Sep 11, 2013
It's arguably the price paid for introducing ideology into the notion of "thinking like a scientist", and weeding out the physics PhD students who stop to think about what it is they are memorizing.


So ya got weeded out because ya were to lazy to memorize the basics?

If you see a lot of people coming at you with wacky ideas, it's probably worth asking what motivates them.


Why ask them what motivates them? It's apparent, they didn't have what it takes to do science, and now they are angry and want to take out their feelings of rejection on those who were successful.

It seems to me that it is the big questions in science which remain unanswered, and which our PhD programs appear to not be scrupulously hedging their bets on.


Naaa, the big question is: Why do failed science students feel compelled with displaying the reasons they failed, to all the world.

It's your turn to post 8 or 10 pages of stuff ya collected from other people.
brt
3.4 / 5 (15) Sep 11, 2013
Re:Hannesalfven:

YEAH! all they have to do is memorize things. It's not like the things they memorize have some sort of function that must work on equations or anything like that. It's not like the stuff they memorize has to work on things in the real world 100% of the time.

It's hard as a graduate student, ya know? Always being taught the most recent trends in science...I wish we would just go more in depth on advanced topics and THEN use those principles to write our thesis on some trendy topic, thereby expressing our interest to professionally pursue a career in that field; but no. oh well.
HannesAlfven
1 / 5 (22) Sep 11, 2013
Re: "So ya got weeded out because ya were to lazy to memorize the basics?"

Well, that's rather simplistic and self-serving.

Re: "It's apparent, they didn't have what it takes to do science"

No, I think the point being made by Jeff Schmidt is that they had something(s) extra -- like an open mind to alternatives, the free will to follow lines of evidence & arguments which are not part of the program, and a desire to question that which they are being taught.

Re: "and now they are angry and want to take out their feelings of rejection on those who were successful."

But, all you've done here is redefined the meaning of the words "science" and "successful". This new version of science includes a very particular ideology, and this new version of "successful" is less about talent and more about preserving the status quo. The students who are chosen are (rather selfishly) chosen as those most likely to defend the existing theory -- at great cost to both students and society.
brt
3.5 / 5 (16) Sep 11, 2013


No, I think the point being made by Jeff Schmidt is that they had something(s) extra -- like an open mind to alternatives, the free will to follow lines of evidence & arguments which are not part of the program, and a desire to question that which they are being taught.

.


YEAH! then maybe they would create some sort of Modified Newtonian Gravity or some sort of Theory of Relativity or discover that the earth is round instead of flat, that the earth is not the center of the universe; but no...we will never discover any of that because ALL physicists are too narrow minded to formalize those ideas.

If only they would question the things they are taught and try to prove them wrong by doing some sort of well ordered procedure; lets call it an experiment. THEN we could really get some sort of evidence that we could fall back on every time some stupid crackpot called our ideas into question.

HannesAlfven
1 / 5 (20) Sep 11, 2013
Re: "It's not like the things they memorize have some sort of function that must work on equations or anything like that. It's not like the stuff they memorize has to work on things in the real world 100% of the time."

It's a reasonable response, unlike Q-Star's pretense to not understand, even after he's seen all of the highlights of Schmidt's analysis. I would only point out that critical thinking does not just happen by chance; you have to teach students to do it, and you have to create an atmosphere which is conducive to it, for it to happen.

I'm not going to pretend to know all of the answers here. But, what I would suggest is that people better start seriously talking about these things right now if there's going to be any chance that they will be resolved within our lifetimes. This is far too important to pretend that it's just not happening, and you don't have to believe anything about the EU in order to see the inherent contradictions within our physics PhD programs.
Q-Star
3.5 / 5 (11) Sep 11, 2013
Re: "So ya got weeded out because ya were to lazy to memorize the basics?"

"It's apparent, they didn't have what it takes to do science"

"and now they are angry and want to take out their feelings of rejection on those who were successful."

But, all you've done here is redefined the meaning of the words "science" and "successful". This new version of science includes a very particular ideology, and this new version of "successful" is less about talent and more about preserving the status quo. The students who are chosen are (rather selfishly) chosen as those most likely to defend the existing theory -- at great cost to both students and society.


So ya are one of the talented ones who got the boot. All the other people who could do the course work, displayed discipline, & loved their chosen career path, took the easy way out, boyo, ya sure do make so very much sense.

Ya failed, and bear a grudge, na, na, na, na, na. Davies is a moron, right?

brt
3.7 / 5 (12) Sep 11, 2013
It's a reasonable response, unlike Q-Star's pretense to not understand, even after he's seen all of the highlights of Schmidt's analysis. I would only point out that critical thinking does not just happen by chance; you have to teach students to do it, and you have to create an atmosphere which is conducive to it, for it to happen.

I'm not going to pretend to know all of the answers here. But, what I would suggest is that people better start seriously talking about these things right now if there's going to be any chance that they will be resolved within our lifetimes. This is far too important to pretend that it's just not happening, and you don't have to believe anything about the EU in order to see the inherent contradictions within our physics PhD programs.


Give 1 example. One example that has actually been reported or proven and is not simply your belief on what is happening; since belief without any evidence has no basis and could be accurately called bullshit.
HannesAlfven
1 / 5 (22) Sep 11, 2013
Re: "If only they would question the things they are taught and try to prove them wrong by doing some sort of well ordered procedure; lets call it an experiment."

Physics PhD's are trained to think as specialists because this is what will be needed when they work for an organization. But, keep in mind that specialization is not effective as a worldview in science. The problem of training students exclusively as specialists rather than as independent, competent systems thinkers is that they tend to simplify the world around them, in accordance with their limited training.

In this instance, you want us to believe that conventional science is better because the evidence is better; and yet, what you're leaving out is that you don't support allocating even 1% of the resources or people to the competing claims.

A systems thinker would not waste anybody's time with such suggestions.
HannesAlfven
1 / 5 (22) Sep 11, 2013
Re: "One example that has actually been reported or proven and is not simply your belief on what is happening"

We appear to have another physics student here who has never heard of Jeff Schmidt. Schmidt was a physics PhD and reporter for Physics Today for 19 years (one of their best). He wrote a scathing critique of the way in which the physics PhD program trains physicists. The American Institute of Physics fired him for the book, and he sued. After many hundreds of researchers (plus one Noam Chomsky) signed their names in his defense, a very large settlement was reached in his favor. It ended up being the physics discipline's largest freedom of expression case in its history, and yet, it's a story which is apparently NEVER told to physics grad students.

Trouble is, it's actually not the only important detail not told to physics grad students. There are in truth many, many more.

Why re-discover how the PhD program works? Why not just read Disciplined Minds?
Pressure2
1 / 5 (14) Sep 11, 2013
Quote from article: "Since the light traveling from the supernovae to Earth rarely cross clumps of matter, it essentially experiences an underdense universe; consequently, the light beams are defocused—the supernovae appears fainter, that is, farther—compared to the case in which light would travel through a strictly homogeneous universe."

An obvious answer they seem to overlook is that these supernovae may be further then the BB theory allows for.

brt
3.5 / 5 (15) Sep 11, 2013
Schmidt was a physics PhD and reporter for Physics Today for 19 years (one of their best). He wrote a scathing critique of the way in which the physics PhD program trains physicists. The American Institute of Physics fired him for the book, and he sued....It ended up being the physics discipline's largest freedom of expression case in its history...

It appears we have another crackpot who has no idea what they are talking about, selling a book.

I was not aware that there was 1 singular PhD program that all universities must teach. The American Institute of Physics is also not a global (or national) governing body of Physics. It is equivalent to National Geographic. This has no basis. Physicists who aren't specialists are called theoretical physicists -_-

All physics students (including graduate students) are given a wide ranging education that covers everything. They are given the OPTION of specializing their course of study if they want to. Nobody forces them to do it.
brt
3.7 / 5 (15) Sep 11, 2013
Re: "If only they would question the things they are taught and try to prove them wrong by doing some sort of well ordered procedure; lets call it an experiment."

Physics PhD's are trained to think as specialists because this is what will be needed when they work for an organization. But, keep in mind that specialization is not effective as a worldview in science. The problem of training students exclusively as specialists rather than as independent, competent systems thinkers is that they tend to simplify the world around them, in accordance with their limited training.

In this instance, you want us to believe that conventional science is better because the evidence is better; and yet, what you're leaving out is that you don't support allocating even 1% of the resources or people to the competing claims.

A systems thinker would not waste anybody's time with such suggestions.


how can I refute terminology that you pull straight out of your ass?
RealityCheck
1.6 / 5 (19) Sep 11, 2013
No, I think the point being made by Jeff Schmidt is that they had something(s) extra -- like an open mind to alternatives, the free will to follow lines of evidence & arguments which are not part of the program, and a desire to question that which they are being taught.
YEAH! then maybe they would create some sort of Modified Newtonian Gravity or some sort of Theory of Relativity...
If only they would question the things they are taught...
Hi brt. You can't have it both ways. Revolutions in science came from those NOT following orthodoxy. Supporting evidence and experimental confirmation come AFTER 'Big Ideas' questioning the training/orthodoxy. Courage and Originality, and preparedness to 'UNLEARN' rote-learning and to break training-to-orthodoxy in order to confront orthodoxy inconsistencies, is how great advances are made, and what distinguishes 'true greats' from 'trained hacks' in ANY field/profession. It takes all kinds for vibrancy of discourse/advance:)
indio007
1.2 / 5 (17) Sep 11, 2013
can't wait for the armchair physicist nutters to come by and tell us why the real scientists are wrong. *grabs some popcorn*


According to the article CMB and Hubble expansion data are at odds.

So which one of those 2 theories are put forth by "armchair physicist nutters" ?

I think both of them are nutters for using a theory put forth by Lemaitre.
A person that was a Jesuit priest and confessed to intentionally coming up with a theory that would conform to Aquinas "creation ex nihilo".
ralph638s
1 / 5 (4) Sep 11, 2013
I am wondering why nobody ever brings up Nottale's theory of Scale Relativity in these discussions. It seems more than appropriate. Is it because he's a real astrophysicist and so cannot be dismissed as simply another crackpot? Or are people just unaware of his work?

https://en.wikipe..._Nottale
Q-Star
3.8 / 5 (13) Sep 11, 2013
I am wondering why nobody ever brings up Nottale's theory of Scale Relativity in these discussions. It seems more than appropriate. Is it because he's a real astrophysicist and so cannot be dismissed as simply another crackpot?


Scale Relativity is seldom talked about anymore because it didn't pan out, I suppose it may be considered a "work in progress". It has many of the same problems that MOND has, in that it only works in very special cases that are cherry picked to apply it in. Meaning it lacks that most important attribute of being self-consistant. Nottale, while not quite a crackpot, is considered on the fringe of physics in so far as his Scale Relativity. It requires a mechanism for relativity to manifest differently in different locations & times in the universe. That's pretty much a non-starter in modern physics.
Q-Star
3.6 / 5 (14) Sep 11, 2013
Hi brt. You can't have it both ways. Revolutions in science came from those NOT following orthodoxy. Supporting evidence and experimental confirmation come AFTER 'Big Ideas' questioning the training/orthodoxy. Courage and Originality, and preparedness to 'UNLEARN' rote-learning and to break training-to-orthodoxy in order to confront orthodoxy inconsistencies, is how great advances are made, and what distinguishes 'true greats' from 'trained hacks' in ANY field/profession. It takes all kinds for vibrancy of discourse/advance:)


Well Reality man,,, how come ya never share any of your "true great" insights with us. Ya never discuss anything but deportment and demeanor. Now, don't get me wrong, ya give a fine speech sure, and gratuitous advice on how to talk to one another is very nice. But can we get a little science to go along with it? Ya should be miles ahead of the game, seeing as how so far ya don't seem to be burdened with all that baggage to UNLEARN.
Protoplasmix
2.3 / 5 (16) Sep 11, 2013
how can I refute terminology that you pull straight out of your ass?

roflmao

Pro'ly best not to feed 'em but I respect the effort. Far better to have educated people for neighbors than morons.

_____________________________
"But the power of instruction is seldom of much efficacy, except in those happy dispositions where it is almost superfluous" - Edward Gibbon
RealityCheck
1.2 / 5 (18) Sep 11, 2013
Hi Q-Star.
,,, how come ya never share any of your "true great" insights with us. Ya never discuss anything but deportment and demeanor. Now, don't get me wrong, ya give a fine speech sure, and gratuitous advice on how to talk to one another is very nice. But can we get a little science to go along with it? Ya should be miles ahead of the game, seeing as how so far ya don't seem to be burdened with all that baggage to UNLEARN.
Now come on, mate; you know that is not true. How many times in the past I have made incidental hints, assessments, comments re various partial scientific aspects/perspectives of mine/others when interested enough to post on the relevant news items comments/discussions?

I haven't published my complete ToE yet because I wanna publish it COMPLETE. I'm not driven by mercenary "Publish or Perish" imperative. Comprende?

If you resort to 'expedient misrepresentation' to mislead others like that, you will lose all credibility real fast. Do better Q-S. :)
Q-Star
3.4 / 5 (10) Sep 11, 2013
If you resort to 'expedient misrepresentation' to mislead others like that, you will lose all credibility real fast. Do better Q-S. :)


I'll try to do better. So maybe ya could point to one of your posts where ya talk about the nuts and bolts of science, instead of about the proper way to discuss science. To be sure a nuclear engineer such as yourself can find some scientifical thing to say?

Ya crow about "working on something" and past great accomplishments, but what do ya have for today? Besides lessons on the proper way to discuss science. (Ya don't even do that very well.)

Ya can have the last word and play pretend "the new Einstein" without me, ya seem to not be able to make this interesting. Pose on Reality man.
RealityCheck
1 / 5 (16) Sep 11, 2013
If you resort to 'expedient misrepresentation' to mislead others like that, you will lose all credibility real fast. Do better Q-S. :)
I'll try to do better. So maybe ya could point to one of your posts where ya talk about the nuts and bolts of science, instead of about the proper way to discuss science....

... play pretend "the new Einstein" without me, ya seem to not be able to make this interesting. Pose on Reality man.
You forget so quickly. Attention span and memory so short? I long ago mentioned I was withdrawing from extended internet exchanges on 'details' because my Complete ToE finishing/publishing is imminent and why risk being 'gazzumped' by some plagiarist and having to waste time and life energy/health fighting on that front when it's avoidable?

Stop your inane posing and mischaracterizations tactics, Q-S. Just go read the Einstein paragraph I posted (in "Quantum steps towards the Big Bang" thread) which should help in understanding Zephyr's work. :)
Urgelt
5 / 5 (10) Sep 11, 2013
Crackpots and scientists invariably approach 'critical thinking' differently.

Crackpots automatically reject evidence that does not conform to their opinion; they 'cherry pick' evidence that does conform to their opinion.

Scientists *try* to address all evidence available. This article describes an effort that would not be possible for crackpots, since the researchers aren't wedded to a particular hypothesis, they're just exploring how different models affect interpretation of evidence and in which direction Planck research seems to be constraining those models.

Uncertainty is - must be - tolerated by scientists. Crackpots have no need of uncertainty at all.

When a scientists argues for a particular hypothesis, he may become heated and emphatic... but he never relinquishes the possibility that he might be wrong.

Crackpots *begin* by relinquishing the possibility that they might be wrong. It's a whole different method of cognition, and not one that's healthy.
martin_ciupa
1 / 5 (10) Sep 12, 2013
I'd rather reinterpret that results presented by the physicists, that... their analysis, of recent Planck Satellite Cosmic Microwave Background (CMB) radiation though (relying on a particular class of models, indicates that the Friedmann-Lemaître (FL) geometry) is probably too convenient to describe the Universe for certain types of observations, given the accuracy reached today.

The authors write in the abstract of the paper... "Such an approach does not require us to invoke new physics nor to violate the Copernican principle.". However, it may be that we have to violate the principle, if the principle is an assumption that is not correct. E.g., the "Hubble Bubble" IS a violation of it, and we should work out what that really means and not produce fixes, like Ptolemaic cosmologists did with epicycles, when the Copernican vision was available to them. No assumption in Science is inviolable.

And... http://prl.aps.or.../e091302
brt
3.4 / 5 (10) Sep 12, 2013
Revolutions in science came from those NOT following orthodoxy. Supporting evidence and experimental confirmation come AFTER 'Big Ideas' questioning the training/orthodoxy. Courage and Originality, and preparedness to 'UNLEARN' ...


That's exactly the point I was making. I was being sarcastic. Armchair physicists (crackpots) are always making the claim that we NEVER challenge popular belief. Yet every famous physicist has become famous and changed our view of reality by challenging popular belief. What was the difference between Einstein and Michelson/Morley? Einstein's observations proved his ideas correct, so we stuck with them. Michelson/Morley's observations PROVED their ideas INcorrect, so we abandoned them. That's how science works...we validate things. It's not philosophy or religion. We don't ignore answers because we don't like what they say; if that were true then we would ignore dark matter & dark energy. Experiments ARE the challenge to orthodoxy.
Torbjorn_Larsson_OM
2.3 / 5 (3) Sep 12, 2013
It is no surprise that the astronomical observations, and supernova observations in particular, are changed when precision is increased. They are less well constrained and more imprecise.

And Planck has already done what is now done here. Gravitational changes on light from both dark matter and the baryonic acoustic oscillations have been included. (As mentioned, CMB does not need to account for all lumpiness.)

So to say that this is a refinement of the standard cosmology as such is a bit of an oversell. The basic model, if not the observations, lives in FL space.

The remaining discrepancy, in the Hubble function ("constant" in late times) itself, is however spread among CMB observations. So here something else is causing tension.
Torbjorn_Larsson_OM
3.7 / 5 (3) Sep 12, 2013
@martin_ciupa: There is no "Hubble Bubble" in these observations. Nor should we expect one.

The reason is that WMAP could exclude such a feature.

The current observational tension may have made a new gap for it to creep back. (But I doubt it, I suspect it is fringe suggestions that would fold under peer review. As the article says "speculative".) However, the entirety of its history means it isn't a) a robust feature, b) mainstream. (Both of which goes hand in hand, generally.)

Adding constraints is a good thing, it makes for better precision. (Though you want to keep things as simple as possible too.) It is multiplying parameters within the same precision that means the likelihood of the theory goes down (and its simplicity). E.g. epicycles adds parameters, multiverses does not.

Here constraints (parameters) were added for better precision, as would be expected.
brt
1 / 5 (3) Sep 12, 2013
Re: Torbjorn_Larsson_OM

It is no surprise that the astronomical observations, and supernova observations in particular, are changed when precision is increased. They are less well constrained and more imprecise.

And Planck has already done what is now done here. Gravitational changes on light from both dark matter and the baryonic acoustic oscillations have been included. (As mentioned, CMB does not need to account for all lumpiness.)

So to say that this is a refinement of the standard cosmology as such is a bit of an oversell. The basic model, if not the observations, lives in FL space.

The remaining discrepancy, in the Hubble function ("constant" in late times) itself, is however spread among CMB observations. So here something else is causing tension.
brt
3 / 5 (8) Sep 12, 2013
how can I refute terminology that you pull straight out of your ass?

roflmao

Pro'ly best not to feed 'em but I respect the effort. Far better to have educated people for neighbors than morons.

_____________________________
"But the power of instruction is seldom of much efficacy, except in those happy dispositions where it is almost superfluous" - Edward Gibbon


I imagine it's similar to working at a retirement home or in a mental hospital. Another analogy would be that it's like a CD skipping. Most of the time I'm just interested in how they'll respond to a certain type of comment. I wish I had their compulsive tunnel vision in my exercise routine.
A_Paradox
not rated yet Sep 14, 2013
As someone who looks between the knees of most giants rather than standing on their shoulders I have private speculations but only questions for the public place.
Q. 1/ If, as the article says, the Great Cheese has Swiss type holes with galaxies at their centres then presumably this is because gravity caused the ordinary matter and dark matter to concentrate together, and the process is still going on. Yes?
.. 1/a/ Does this mean that in the distant past the green and blue areas of the chart would have been closer together? [because gravitational in-falling had been happening for shorter time?]

Q. 2/ How does dark energy fit into this? If most of the 'mass' of the universe is constituted by dark energy, which presumably only exists at the speed of light, does that mean that the otherwise missing mass is pretty much homogenous throughout the universe?
Woutertje
not rated yet Sep 16, 2013
light/dark = finestructure

The arxiv link of there article is:
http://arxiv.org/abs/1304.7791