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P. Kroupa (U Bonn): 'Standard Model of Cosmology Falsified'

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Robert L. Oldershaw

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Apr 13, 2012, 2:06:16 AM4/13/12
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In Friday's batch of new preprints at arXiv.org is:

http://arxiv.org/abs/1204.2546

Title: "The dark matter crisis: falsification of the current standard
model of cosmology"

Author: Pavel Kroupa, Argelander Institute for Astronomy (U of Bonn)

Looks like a "must read" paper.

Do I detect some serious instability in the aged standard paradigm?

RLO
Discrete Scale Relativity
http://www3.amherst.edu/~rloldershaw
Discrete Fractal Cosmology

Phillip Helbig---undress to reply

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Apr 13, 2012, 3:46:28 AM4/13/12
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In article <mt2.0-12636...@hydra.herts.ac.uk>, "Robert L.
Oldershaw" <rlold...@amherst.edu> writes:

> In Friday's batch of new preprints at arXiv.org is:
>
> http://arxiv.org/abs/1204.2546
>
> Title: "The dark matter crisis: falsification of the current standard
> model of cosmology"
>
> Author: Pavel Kroupa, Argelander Institute for Astronomy (U of Bonn)
>
> Looks like a "must read" paper.

Do you know what it is about? It is about MOND. This is the idea,
which has been around for decades, that when observed motions don't
correspond to the observed matter distribution, then instead of dark
matter one modifies the law of gravity.

What does DSR say about the law of gravity? Does it predict MOND?

Since DSR predicts the dark matter, as you have said many times, then
this paper contradicts DSR.

> Do I detect some serious instability in the aged standard paradigm?

No. You detect a healthy debate. Also note that MOND has been around
longer than the current cosmological standard model.

[Mod. note: and, in its simplest form, is falsified by observation --mjh]

eric gisse

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Apr 13, 2012, 10:39:16 AM4/13/12
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"Robert L. Oldershaw" <rlold...@amherst.edu> wrote in news:mt2.0-
12636-13...@hydra.herts.ac.uk:

> In Friday's batch of new preprints at arXiv.org is:
>
> http://arxiv.org/abs/1204.2546
>
> Title: "The dark matter crisis: falsification of the current standard
> model of cosmology"
>
> Author: Pavel Kroupa, Argelander Institute for Astronomy (U of Bonn)
>
> Looks like a "must read" paper.
>
> Do I detect some serious instability in the aged standard paradigm?

Robert, you interpret any paper challenging the status quo as evidence of
a "serious instability". This is a familiar dance, as you have played it
out quite frequently.

While I am going to read the paper because it looks reasonably
interesting, I can say the following things straight off the bat:

1) Your numerology makes absolutely no predictions at these scales anyway
so injecting yourself into the debate is a very silly thing to do because
it just reminds everyone of the numerous holes present in your
numerology.

2) Dwarf galaxies and their various permutations have been an ongoing
challenge in cosmology both in terms of theoretically as well as
observationally because the damn things are just not that luminous.

3) MOND, a cited alternative to general relativity in this context, has
significantly better observational support than your numerology. Even
then, it has been repeatedly falsified.

I am curious though, when I have finished reading the paper will you be
able to say the same?

I'd hate to find out that you are (again) using sci.astro.research as
your personal blog where you take shots at stuff then slink off into the
ether...

Robert L. Oldershaw

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Apr 13, 2012, 10:41:24 AM4/13/12
to
On Apr 13, 3:46 am, Phillip Helbig---undress to reply
<hel...@astro.multiCLOTHESvax.de> wrote:
> In article <mt2.0-12636-1334297...@hydra.herts.ac.uk>, "Robert L.
>
> >http://arxiv.org/abs/1204.2546
> > Title: "The dark matter crisis: falsification of the current standard
> > model of cosmology"
> > Looks like a "must read" paper.
>
> Do you know what it is about?  It is about MOND.  This is the idea,
> which has been around for decades, that when observed motions don't
> correspond to the observed matter distribution, then instead of dark
> matter one modifies the law of gravity.
----------------------------------------------------------------------------

Yes, I am fully aware of what the paper is about.

It has two main points.

1. There are serious empirical shortcomings related to the SMoC that
should cause an open-minded scientists to question whether the
standard model of cosmology has major, but under-appreciated, flaws.
Possibly a radicaly different model is called for, and that will be
decided by the identification of the correct answer to the dark matter
enigma.

2. The second theme is possible replacement models, and Kroupa thinks
the MOND approach shows the most promise. Obviously, I would advocate
a very different candidate for the replacement paradigm, and DSR's
predictions about the resolution of the dark matter enigma are
available in print in may places.

I anticipate that microlensing efforts, which have recently started to
make some very surprising discoveries, will soon radically alter the
thinking on the dark matter problem.

When you add up the initial highly negative LHC results, the apparent
discovery of trillions of unbound planetary-mass nomads, and the
unorthodox properties of exoplanet systems, I think you have prima
facie evidence for major paradigm-change in the forseeable future.

But again, it is the solution of the dark matter enigma that holds the
key to the future of physics regarding our overarching paradigm for
how nature is organized and how its symmetry properties unify it.

RLO
http://www3.amherst.edu/~rloldershaw
Discrete Scale Relativity
Discrete Fractal Cosmology

Phillip Helbig---undress to reply

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Apr 14, 2012, 10:42:28 AM4/14/12
to
In article <mt2.0-14234...@hydra.herts.ac.uk>, "Robert L.
Oldershaw" <rlold...@amherst.edu> writes:

> 1. There are serious empirical shortcomings related to the SMoC that
> should cause an open-minded scientists to question whether the
> standard model of cosmology has major, but under-appreciated, flaws.
> Possibly a radicaly different model is called for, and that will be
> decided by the identification of the correct answer to the dark matter
> enigma.

OK.

> 2. The second theme is possible replacement models, and Kroupa thinks
> the MOND approach shows the most promise. Obviously, I would advocate
> a very different candidate for the replacement paradigm, and DSR's
> predictions about the resolution of the dark matter enigma are
> available in print in may places.

The current problems with the idea of dark matter in dwarf galaxies
doesn't depend on what the dark matter is, as long as it is cold. Thus,
DM from DSR is just as bad in this context as DM of a more standard
kind.

eric gisse

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Apr 15, 2012, 2:50:07 AM4/15/12
to
"Robert L. Oldershaw" <rlold...@amherst.edu> wrote in
news:mt2.0-14234...@hydra.herts.ac.uk:

> On Apr 13, 3:46 am, Phillip Helbig---undress to reply
> <hel...@astro.multiCLOTHESvax.de> wrote:
>> In article <mt2.0-12636-1334297...@hydra.herts.ac.uk>, "Robert L.
>>
>> >http://arxiv.org/abs/1204.2546
>> > Title: "The dark matter crisis: falsification of the current
>> > standard model of cosmology"
>> > Looks like a "must read" paper.
>>
>> Do you know what it is about?  It is about MOND.  This is the idea,
>> which has been around for decades, that when observed motions don't
>> correspond to the observed matter distribution, then instead of dark
>> matter one modifies the law of gravity.
> -----------------------------------------------------------------------
> -----
>
> Yes, I am fully aware of what the paper is about.
>
> It has two main points.
>
> 1. There are serious empirical shortcomings related to the SMoC that
> should cause an open-minded scientists to question whether the
> standard model of cosmology has major, but under-appreciated, flaws.
> Possibly a radicaly different model is called for, and that will be
> decided by the identification of the correct answer to the dark matter
> enigma.

So we should consider your numerology, which is observatioanlly falsified
at every turn?

Or consider MOND which as a substantial number of observational failings
that cannot be explained away even when you *DON'T* include the fact that
MOND doesn't match what the background radiation shows us?

The cosmological standard model's issues are quite well known despite
your usual level of conspiratorial siliness.

>
> 2. The second theme is possible replacement models, and Kroupa thinks
> the MOND approach shows the most promise. Obviously, I would advocate
> a very different candidate for the replacement paradigm, and DSR's
> predictions about the resolution of the dark matter enigma are
> available in print in may places.

Yes, they are availabine in print in many places!

For example, how you explain how the dark matter composition is defined
and how it is also x-ray luminious...interestingly enough both your
claims about x-ray luminosity and composition have been completely
falsified.

>
> I anticipate that microlensing efforts, which have recently started to
> make some very surprising discoveries, will soon radically alter the
> thinking on the dark matter problem.

Since none of the microlensing observations are consistent with your
numerology I personally find it odd that you keep mentioning them. The
previous 15 years of observations are entirely consistent with the MOA
group observations which in turn tell you that dark matter is NOT
comprised of anywhere-near-stellar mass ultracompacts.

>
> When you add up the initial highly negative LHC results, the apparent
> discovery of trillions of unbound planetary-mass nomads, and the
> unorthodox properties of exoplanet systems, I think you have prima
> facie evidence for major paradigm-change in the forseeable future.

The paradigm will change. Just not in your direction.

Robert L. Oldershaw

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Apr 15, 2012, 3:12:00 AM4/15/12
to
On Apr 14, 10:42 am, Phillip Helbig---undress to reply
<hel...@astro.multiCLOTHESvax.de> wrote:
> In article <mt2.0-14234-1334328...@hydra.herts.ac.uk>, "Robert L.
>
> The current problems with the idea of dark matter in dwarf galaxies
> doesn't depend on what the dark matter is, as long as it is cold.  Thus,
> DM from DSR is just as bad in this context as DM of a more standard
> kind.
----------------------------------------------------------------------------------

Two well-known problems with standard dark matter predictions
associated with the standard model of cosmology are as follows.

1. The SMoC DM model predicted a DM distribution that peaks at the
center of galaxies.

Empirical evidence has falsified this prediction and it is clear that
the DM distribution in "cored", i.e., there is a relatively low
density of DM at the center. The DM abundance seems to peak in the
outer parts of the galaxies.

2. The SMoC DM model predicted 1000s of something poorly defined
[i.e., adjustable] called "DM halos" associated with typical
galaxies. Typically they are interpreted as compact conglomerations
of primarily DM, with little LM.

This has also been empirically falsified since the number of small
satellite objects of galaxies [and GCs do not count in this context]
are definitely NOT in the 1000s but are found in much lower numbers
and may not even correspond to the poorly defined "DM halos" at all.

3. Since the primordial stellar-mass black holes model for the
galactic DM does not predict either of the above phenomena, it does
not run afoul of the empirical falsifications discussed above.

I would say that Discrete Scale Relativity's predictions regarding the
DM has more empirical support [albeit still tentative] than the SMoC's
predictions regarding the DM [no supporting evidence, not one "WIMP"
after 40 years of searching, and several falsifications].

Microlensing observations will definitively settle the matter at some
time in the future. Until that crucial evidence is in hand, it would
be prudent to keep an open mind regarding the very long-running enigma
of galactic DM. Such long-running problems, like the physical meaning
of the fine structure constant and the vacuum energy density crisis,
are long-running because existing assumptions are probably obscuring
the path to their resolutions.

RLO
Discrete Scale Relativity
Discrete Fractal Cosmology
http://www3.amherst.edu/~rloldershaw

Phillip Helbig---undress to reply

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Apr 15, 2012, 5:51:20 AM4/15/12
to
In article <mt2.0-12047...@hydra.herts.ac.uk>, "Robert L.
Oldershaw" <rlold...@amherst.edu> writes:

> >
> > The current problems with the idea of dark matter in dwarf galaxies
> > doesn't depend on what the dark matter is, as long as it is cold. Thus,
> > DM from DSR is just as bad in this context as DM of a more standard
> > kind.
> ----------------------------------------------------------------------------------
>
> Two well-known problems with standard dark matter predictions
> associated with the standard model of cosmology are as follows.
>
> 1. The SMoC DM model predicted a DM distribution that peaks at the
> center of galaxies.

Right.

> 2. The SMoC DM model predicted 1000s of something poorly defined
> [i.e., adjustable] called "DM halos" associated with typical
> galaxies. Typically they are interpreted as compact conglomerations
> of primarily DM, with little LM.

Right.

> 3. Since the primordial stellar-mass black holes model for the
> galactic DM does not predict either of the above phenomena, it does
> not run afoul of the empirical falsifications discussed above.

This is simply wrong. The things you mention above are generic
predictions from CDM, and stellar-mass black holes are CDM. Please
explain how stellar-mass BHs predict something different in this regard.

> I would say that Discrete Scale Relativity's predictions regarding the
> DM has more empirical support [albeit still tentative] than the SMoC's
> predictions regarding the DM [no supporting evidence, not one "WIMP"
> after 40 years of searching, and several falsifications].

Note that numerical simulations of structure formation just use generic
dark matter. There is no distinction between WIMPs, stellar-mass black
holes etc. The only reason many people mention WIMPs is because other
candidates have been ruled out for OTHER reasons.

> Microlensing observations will definitively settle the matter at some
> time in the future.

They already have, but not in favour of your ideas.

Jos Bergervoet

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Apr 15, 2012, 3:38:43 PM4/15/12
to
On Apr 15, 9:12 am, "Robert L. Oldershaw" <rlolders...@amherst.edu>
wrote:
...
> 3. Since the primordial stellar-mass black holes model for the
> galactic DM does not predict either of the above phenomena, it does
> not run afoul of the empirical falsifications discussed above.
>
> I would say that Discrete Scale Relativity's predictions regarding the
> DM has more empirical support [albeit still tentative] than the SMoC's
> predictions

What has discreteness of the scale to do with it? If
DM contains primordial black holes that are *not*
discrete, wouldn't that just as well serve your needs?

--
Jos

eric gisse

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Apr 16, 2012, 2:56:17 AM4/16/12
to
"Robert L. Oldershaw" <rlold...@amherst.edu> wrote in
news:mt2.0-12047...@hydra.herts.ac.uk:

> On Apr 14, 10:42 am, Phillip Helbig---undress to reply
> <hel...@astro.multiCLOTHESvax.de> wrote:
>> In article <mt2.0-14234-1334328...@hydra.herts.ac.uk>, "Robert L.
>>
>> The current problems with the idea of dark matter in dwarf galaxies
>> doesn't depend on what the dark matter is, as long as it is cold.
>>  Thus, DM from DSR is just as bad in this context as DM of a more
>> standard kind.
> -----------------------------------------------------------------------
> -----------
>
> Two well-known problems with standard dark matter predictions
> associated with the standard model of cosmology are as follows.
>
> 1. The SMoC DM model predicted a DM distribution that peaks at the
> center of galaxies.

Not really, as simulations don't have the resolution to make that kind of
claim. It is a simplifying assumption, nothing else.

>
> Empirical evidence has falsified this prediction

No, Robert, it has not. If you are going to make claims like this you
need to provide literature references.

The DM distribution in galactic centers is very hard to constrain. This
is empirical reality.

> and it is clear that
> the DM distribution in "cored", i.e., there is a relatively low
> density of DM at the center. The DM abundance seems to peak in the
> outer parts of the galaxies.
>
> 2. The SMoC DM model predicted 1000s of something poorly defined
> [i.e., adjustable] called "DM halos" associated with typical
> galaxies. Typically they are interpreted as compact conglomerations
> of primarily DM, with little LM.

Yeah it does sound bad when you write it an in ignorant and dismissive
manner..

What is predicted in reality is a reasonably large number of dwarf
galaxies, which was largely the central thesis of that paper you cited
earlier. Unfortunately the problem is twofold:

1) What is actually predicted?

Nobody really knows since, again, simulation resolution isn't there yet.
Plus even if it is you would then have to figure out whether what you
have is a falsifcation or a corner case.

Personally I think folks are reaching very hard when they complain about
how dark matter has been 'falsified' by halo contents not being exactly
as expected.

2) Observation is hard.

I already pointed out that it is hard to constrain the inner parts of a
galaxy's DM distribution. Further its' really hard to get an accurate
picture of how many dwarf galaxies there are even in the Milky Way
because they simply aren't that luminious.

>
> This has also been empirically falsified since the number of small
> satellite objects of galaxies [and GCs do not count in this context]
> are definitely NOT in the 1000s but are found in much lower numbers
> and may not even correspond to the poorly defined "DM halos" at all.

....and how fixed in stone is that 'thousands' number? Sounds like it was
pulled out of the air.

>
> 3. Since the primordial stellar-mass black holes model for the
> galactic DM does not predict either of the above phenomena, it does
> not run afoul of the empirical falsifications discussed above.

Huh?

First off, you have shown a great reluctance to do any legwork when it
comes to showing what your numerology predicts so any claims of "I don't
see it" don't really hold much muster.

Next, black holes are textbook dark matter. Low scattering cross section,
only gravitational interactions, and capable of being around for a very
long time. They were in fact the most likely dark matter candidate for a
very long time.

Unfortunately microlensing observations have conclusively falsified the
notion that dark matter is made of black holes outside of a very small
mass range that is also very far outside your numerology's predictions.
You do not seem concerned about this, but that's par for the course...

Finally, your willingness to make this statement indicates you don't
understand the subject as well as you believe. You should probably do
some light reading before making claims you can't back up.

>
> I would say that Discrete Scale Relativity's predictions regarding the
> DM has more empirical support [albeit still tentative] than the SMoC's
> predictions regarding the DM [no supporting evidence, not one "WIMP"
> after 40 years of searching, and several falsifications].

What empirical support? Your numerology has been falsified conclusively
at every turn.

Besides, nobody cares about your complaints about WIMPs. Nobody. Nary a
soul. Why? Let me be clear:

THE STANDARD MODEL OF COSMOLOGY DOES NOT DEPEND ON THE NATURE OF DARK
MATTER

Do you have any questions about that?

>
> Microlensing observations will definitively settle the matter at some
> time in the future.

True, if you were posting from ten years ago.

Fortunately for everyone else, we are not operating from a perspective
that is deliberately ignorant of observational evidence.

The microlensing surveys I have repeatedly, repeatedly, repeatedly given
to you (and am tired of referencing) have falsified your numerology.
OGLE, EROS, SuperMACHO, MOA group...they all rather clearly falsify your
claims.

Your numerology is wrong, by the standards set in your own paper back in
the late 80's.

> Until that crucial evidence is in hand,

What's your argument? That you have a severe case of the butterfingers?

The fact of the matter is that it does not matter what you think but
rather what the broader scientific community things. If you can't
convince anyone other than yourself, then you are going to be perpetually
upset.

> it would
> be prudent to keep an open mind regarding the very long-running enigma
> of galactic DM.

Does that include you considering the possibility that your numerology is
wrong? Or is being "open minded" one of those doors that only swings one
way for the person who uses the term?

>Such long-running problems, like the physical meaning
> of the fine structure constant and the vacuum energy density crisis,
> are long-running because existing assumptions are probably obscuring
> the path to their resolutions.

Maybe/maybe not.

However there is no value in clinging to theories that are definitely
falsified.

eric gisse

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Apr 16, 2012, 2:58:29 AM4/16/12
to
Phillip Helbig---undress to reply <hel...@astro.multiCLOTHESvax.de>
wrote in news:mt2.0-300-...@hydra.herts.ac.uk:

[...]

> Note that numerical simulations of structure formation just use
> generic dark matter. There is no distinction between WIMPs,
> stellar-mass black holes etc. The only reason many people mention
> WIMPs is because other candidates have been ruled out for OTHER
> reasons.

I'm holding out marginal hope for the sterile neutrino.

Every time a large volume of cosmological observations are brought
together (WMAP + BAO + SDSS, and such) enough degeneracies are eliminated
in regards to what is predicted with relativistic species at decoupling.
What is invariably found is four neutrino species. This is always a 1
sigma result that can be slapped down with better data should it be
wrong, but it perpetually amuses me to see it stick around.


>
>> Microlensing observations will definitively settle the matter at some
>> time in the future.
>
> They already have, but not in favour of your ideas.
>

This is what baffles me. I have given him reference after reference
regarding the microlensing observations and all he can come up with is
'questionable assumptions' even though his paper cites the exact same
references as the later papers for how lensing works...

I don't think I ever got a response at all to that above point :D

Phillip Helbig---undress to reply

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Apr 16, 2012, 4:44:00 PM4/16/12
to
In article <mt2.0-3652...@hydra.herts.ac.uk>, eric gisse
<jowr.pi...@gmail.com> writes:

> > 1. The SMoC DM model predicted a DM distribution that peaks at the
> > center of galaxies.
>
> Not really, as simulations don't have the resolution to make that kind of
> claim. It is a simplifying assumption, nothing else.

The last I heard (from Eva Grebel, at a popular talk she gave in
Frankfurt about a year ago) was that with higher-resolution simulations
the problem does NOT go away. It thus doesn't seem to be an artefact of
finite resolution.

> THE STANDARD MODEL OF COSMOLOGY DOES NOT DEPEND ON THE NATURE OF DARK
> MATTER

Right, as long as it is cold.

Phillip Helbig---undress to reply

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Apr 16, 2012, 4:54:46 PM4/16/12
to
In article <mt2.0-3652...@hydra.herts.ac.uk>, eric gisse
<jowr.pi...@gmail.com> writes:

> > Note that numerical simulations of structure formation just use
> > generic dark matter. There is no distinction between WIMPs,
> > stellar-mass black holes etc. The only reason many people mention
> > WIMPs is because other candidates have been ruled out for OTHER
> > reasons.
>
> I'm holding out marginal hope for the sterile neutrino.
>
> Every time a large volume of cosmological observations are brought
> together (WMAP + BAO + SDSS, and such) enough degeneracies are eliminated
> in regards to what is predicted with relativistic species at decoupling.
> What is invariably found is four neutrino species. This is always a 1
> sigma result that can be slapped down with better data should it be
> wrong, but it perpetually amuses me to see it stick around.

This seems to be a result which many groups have found independently,
though the error bars are still large.

Eric Flesch

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Apr 17, 2012, 5:57:44 AM4/17/12
to
On Mon, 16 Apr 12 20:54:46 GMT, Phillip Helbig wrote:
>eric gisse writes:
>> What is invariably found is four neutrino species. This is always a 1
>> sigma result that can be slapped down with better data should it be
>> wrong, but it perpetually amuses me to see it stick around.
>
>This seems to be a result which many groups have found independently,
>though the error bars are still large.

I have a dark secret: not only have I a science degree, but also a
<shudder> full anthropology degree. And do you know what they study
in anthropology? Well, among other things, people who are bound by
their culture. For example, a culture of setting error bars so large
as to accomodate whatever needs to be accomodated.

Have either of you gentlemen ever taken note of the historical adage
that "actual error is twice estimated error"? What, you doubt that?
Check any paper of 100 years ago and it will become abundantly clear.
You think you are better than they were? You are not. The rigor of
the scientific method of 1815-1915 is astonishing for anyone who
looks.

My point is, if you think that the investigator is totally separate
from the subject, you are profoundly mistaken. Double the error bars
to get the true errors, and remember that :

------------------------------------------------
(from http://www.sheldrake.org/Onlineexp/offline/constants/index.html)
"From around 1928 to 1945, the velocity of light appeared to be about
20 km/s lower than before and after this period. The 'best' values,
found by the leading investigators using a variety of techniques, were
in impressively close agreement with each other, and the available
data were combined and adjusted by Birge in 1941 and Dorsey in 1945.
In the late 1940s the speed of light went up again. ...

"How can the lower velocity from 1928 to 1945 be explained? If it was
simply a matter of experimental error, why did the results of
different investigators and different methods agree so well? And why
were the estimated errors so low?"
--------------------------------------------------

cheers, Eric

Phillip Helbig---undress to reply

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Apr 17, 2012, 6:29:28 AM4/17/12
to
In article <mt2.0-28102...@hydra.herts.ac.uk>, Eric Flesch
<er...@flesch.org> writes:

> >> What is invariably found is four neutrino species. This is always a 1
> >> sigma result that can be slapped down with better data should it be
> >> wrong, but it perpetually amuses me to see it stick around.
> >
> >This seems to be a result which many groups have found independently,
> >though the error bars are still large.

This conclusion was based on talks at the last Moriond cosmology
meeting, just a few weeks ago. These days, raw data are available and
different groups can and do analyze things independently...[continued
below]

> their culture. For example, a culture of setting error bars so large
> as to accomodate whatever needs to be accomodated. ^^^^^
>
> Have either of you gentlemen ever taken note of the historical adage
> that "actual error is twice estimated error"?

This would be setting the error bars to be too SMALL, whereas above you
talked about setting them too LARGE. From the tenor of your post,
though, it looks like you mean setting them to be too SMALL.

> What, you doubt that?
> Check any paper of 100 years ago and it will become abundantly clear.
> You think you are better than they were? You are not. The rigor of
> the scientific method of 1815-1915 is astonishing for anyone who
> looks.

[continued from above]...so while I don't doubt that there are examples
of the behaviour you cite, I see no evidence that it applies in THIS
case. (If you think it automatically applies, then it would apply no
matter what, even if people intentionally took action to counteract it,
which is absurd (the idea that it ALWAYS MUST apply).)

> My point is, if you think that the investigator is totally separate
> from the subject, you are profoundly mistaken. Double the error bars
> to get the true errors, and remember that :

Interestingly, one speaker at the Moriond conference noted that error
bars seem to be too LARGE in another case, namely the measurement of the
equation of state of "dark energy", with a normal cosmological constant
having w=-1. He noted that measurements were like 0.9ą0.5, 1.05ą0.6,
1.0ą0.3 etc. Of course, it is better to have too large an error bar
than too small an error bar. Also, one has to take into account how the
error bar is defined in each case, as there are various conventions in
use.

Homo Lykos

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Apr 18, 2012, 2:22:37 AM4/18/12
to
Am 16.04.2012 22:54, schrieb Phillip Helbig---undress to reply:

> This seems to be a result [4 neutini] which many groups have found independently,
> though the error bars are still large.

One (little) reason more to abandon LCDM.

Here a better and stronger new reason to abandon DM:

http://www.dgcs.unam.mx/boletin/bdboletin/2012_158.html
http://arxiv.org/abs/1105.1873.

And here the best reasons until now to abandon the Big Bang and DE:

www.wolff.ch/astro

[Mod. note: caveat emptor -- mjh]

Phillip Helbig---undress to reply

unread,
Apr 19, 2012, 3:21:36 AM4/19/12
to
In article <mt2.0-30682...@hydra.herts.ac.uk>, Homo Lykos
<ly...@bluewin.ch> writes:

> Am 16.04.2012 22:54, schrieb Phillip Helbig---undress to reply:
>
> > This seems to be a result [4 neutini] which many groups have found independently,
> > though the error bars are still large.
>
> One (little) reason more to abandon LCDM.

The number of "neutrinos" is essentially a free parameter. As long as
one has a good fit to all the data, and the number is not 100% to be
something else as a result of other tests, this has nothing to do with
the viability of LCDM.

Juergen Barsuhn

unread,
Apr 19, 2012, 3:23:09 AM4/19/12
to
Just now I found a contribution from the European Southern
Observatory (ESO) in my mailbox, that challenges the Dark
Matter hypothesis:
http://www.eso.org/public/news/eso1217/

The first lines of this report are:
The most accurate study so far of the motions of stars in
the Milky Way has found no evidence for dark matter in a
large volume around the Sun. According to widely accepted
theories, the solar neighbourhood was expected to be filled
with dark matter, a mysterious invisible substance that can
only be detected indirectly by the gravitational force it
exerts. But a new study by a team of astronomers in Chile
has found that these theories just do not fit the
observational facts. This may mean that attempts to directly
detect dark matter particles on Earth are unlikely to be
successful.

Regards Jurgen

eric gisse

unread,
Apr 19, 2012, 3:24:25 AM4/19/12
to
Homo Lykos <ly...@bluewin.ch> wrote in
news:mt2.0-30682...@hydra.herts.ac.uk:

> Am 16.04.2012 22:54, schrieb Phillip Helbig---undress to reply:
>
>> This seems to be a result [4 neutini] which many groups have found
>> independently, though the error bars are still large.
>
> One (little) reason more to abandon LCDM.
>
> Here a better and stronger new reason to abandon DM:
>
> http://www.dgcs.unam.mx/boletin/bdboletin/2012_158.html
> http://arxiv.org/abs/1105.1873.

"That is, under modified gravity theories, binary stars
with physical separations beyond around 7000 AU should
exhibit "flat rotation curves" and a "Tully-Fisher rela-
tion", as galactic systems in the same acceleration regime
do."

Binary stars...flat rotation curve...TULLY FISHER RELATION?

I saw no particular reason to keep reading once I read that. But I did so
anyway because I have nothing better to do today. I skimmed through the
paper and I am unclear how some SDSS and Hipparcos plots establish that
there is a "lower limit" to wide separation binary speed.

I don't even see a discussion of the respective limitations of hardware
and how the speeds were detected, as accelerations in the 10^-10m/s^2
regime don't really impart that much in terms of velocities...

>
> And here the best reasons until now to abandon the Big Bang and DE:
>
> www.wolff.ch/astro

http://translate.google.com/translate?hl=en&sl=auto&tl=en&u=http%3A%2F%
2Fwww.wolff.ch%2Fastro%2F

This is fun! You sure do select quality sources.

In regards to how the scientific community needs an english
publication...

"A publication in English, for example, astro-ph is mandatory.

If the vote really so, then this would mean that we have in this
regard already worse conditions than those prevailing in countries
occupied by Hitler. I'm active but with neither in nor Germano-
Anglo culture racist extermination campaigns."

I'm reasonably sure this isn't a mistranslation.

The rest proceeds roughly about as you'd expect from there...

>
> [Mod. note: caveat emptor -- mjh]
>

No kidding.

eric gisse

unread,
Apr 19, 2012, 3:25:00 AM4/19/12
to
Phillip Helbig---undress to reply <hel...@astro.multiCLOTHESvax.de>
wrote in news:mt2.0-19291...@hydra.herts.ac.uk:

> In article <mt2.0-3652...@hydra.herts.ac.uk>, eric gisse
> <jowr.pi...@gmail.com> writes:
>
>> > 1. The SMoC DM model predicted a DM distribution that peaks at the
>> > center of galaxies.
>>
>> Not really, as simulations don't have the resolution to make that
>> kind of claim. It is a simplifying assumption, nothing else.
>
> The last I heard (from Eva Grebel, at a popular talk she gave in
> Frankfurt about a year ago) was that with higher-resolution
> simulations the problem does NOT go away. It thus doesn't seem to be
> an artefact of finite resolution.

I didn't seriously expect otherwise given the dynamics involved.

My broader point is that, to my knowledge, there isn't enough
observational data to strongly constrain a galaxy's dark matter core
beyond the basic requirements of continuity.

Most of the "problems" that stem from this tend to be because the model
is overly simplistic, eg how the NFW model isn't exactly true. Folks seem
to have a hard time distinguishing the differences between a theory, and
models of the theory.

Jonathan Thornburg [remove -animal to reply]

unread,
Apr 19, 2012, 11:13:02 AM4/19/12
to
The technical paper is arXiv:1204.3924, and has been accepted for
publication in the Astrophysical Journal. The abstract is informative,
and the paper itself looks like a fascinating read:

arXiv:1204.3924
Authors: C. Moni Bidin, G. Carraro, R. A. Mendez, R. Smith
Title: Kinematical and chemical vertical structure of the Galactic
thick disk II. A lack of dark matter in the solar neighborhood

We estimated the dynamical surface mass density Sigma at the solar
position between Z=1.5 and 4 kpc from the Galactic plane, as inferred
from the kinematics of thick disk stars. The formulation is exact
within the limit of validity of a few basic assumptions. The resulting
trend of Sigma(Z) matches the expectations of visible mass alone,
and no dark component is required to account for the observations.
We extrapolate a dark matter (DM) density in the solar neighborhood
of 0+-1 mM_sun pc^-3, and all the current models of a spherical DM
halo are excluded at a confidence level higher than 4sigma. A
detailed analysis reveals that a small amount of DM is allowed in
the volume under study by the change of some input parameter or
hypothesis, but not enough to match the expectations of the models,
except under an exotic combination of non-standard assumptions.
Identical results are obtained when repeating the calculation with
kinematical measurements available in the literature. We demonstrate
that a DM halo would be detected by our method, and therefore the
results have no straightforward interpretation. Only the presence
of a highly prolate (flattening q>2) DM halo can be reconciled with
the observations, but this is highly unlikely in LambdaCDM models.
The results challenge the current understanding of the spatial
distribution and nature of the Galactic DM. In particular, our
results may indicate that any direct DM detection experiment is
doomed to fail, if the local density of the target particles is
negligible.

--
-- "Jonathan Thornburg [remove -animal to reply]" <jth...@astro.indiana-zebra.edu>
Dept of Astronomy & IUCSS, Indiana University, Bloomington, Indiana, USA
"Washing one's hands of the conflict between the powerful and the
powerless means to side with the powerful, not to be neutral."
-- quote by Freire / poster by Oxfam

Homo Lykos

unread,
Apr 19, 2012, 12:51:41 PM4/19/12
to
Until now the (weak) "prediction" of 3 Neutrini by BBN was seen as a
(little) success of LCDM. Under the same assumptions 4 neutrini speak


[Mod. note: non-ASCII characters removed. Please post in 7-bit ASCII.
In English, the plural of 'neutrino' is 'neutrinos' -- mjh]

Phillip Helbig---undress to reply

unread,
Apr 19, 2012, 4:34:46 PM4/19/12
to
In article <mt2.0-4335...@hydra.herts.ac.uk>, Juergen Barsuhn
<jw.ba...@t-online.de> writes:

> Just now I found a contribution from the European Southern
> Observatory (ESO) in my mailbox, that challenges the Dark
> Matter hypothesis:
> http://www.eso.org/public/news/eso1217/
>
> The first lines of this report are:
> The most accurate study so far of the motions of stars in
> the Milky Way has found no evidence for dark matter in a
> large volume around the Sun. According to widely accepted
> theories, the solar neighbourhood was expected to be filled
> with dark matter, a mysterious invisible substance that can
> only be detected indirectly by the gravitational force it
> exerts. But a new study by a team of astronomers in Chile
> has found that these theories just do not fit the
> observational facts. This may mean that attempts to directly
> detect dark matter particles on Earth are unlikely to be
> successful.

I've just read the press release and not the paper yet. However, any
sort of dynamical test cannot detect anything smooth on a scale larger
than that surveyed. Later on, it is mentioned that one possible
explanation (not as sensationalistic, of course) is that a different
distribution of dark matter could explain the negative results. In this
case, of course, assuming dark matter consists of particles, then this
does not lessen the probability of finding them directly in laboratory
experiments. Also, it is hard to see how it challenges the entire
dark-matter paradigm since it is precisely the same type of dynamical
studies (on the larger scale of entire galaxies) which led to the idea
of dark matter in the first place. These results still need to be
explained.

eric gisse

unread,
Apr 19, 2012, 4:39:38 PM4/19/12
to
"Jonathan Thornburg [remove -animal to reply]"
<jth...@astro.indiana-zebra.edu> wrote in
news:mt2.0-1332...@hydra.herts.ac.uk:

[...]

> The technical paper is arXiv:1204.3924, and has been accepted for
> publication in the Astrophysical Journal. The abstract is
> informative, and the paper itself looks like a fascinating read:

[...]

Personally I think it makes *perfect* sense that after me going on for a
few days about how the interior of a galaxy is not well constrained by
observational data, this pops out.

A reasonable chunk of the analysis didn't interest me as it is a
relatively straight forward abuse of the Poisson equation with the real
trick being the required observational astronomy to pull it off.

A few thoughts...

I'm a little fuzzy on the convention used, as far as mass goes. 1 m M_sun
= 10^-3 M_sun (ok) = 0.038 GeV (what?). Later usages of the units all
make sense physically (in terms of M_sun) so I'm now wondering what the
M_sun symbol really stands for or if I'm just tweaking over something
irrelevant.

All the discussion of whether the halo is prolate or oblate immediately
reminded me of this:

http://arxiv.org/abs/0908.3187

The takehome from that is that the Milky Way's DM halo was able to be
empirically determined to be rather solidly triaxial rather than
axisymmetric or even spherical like other models assume. This is very
important to this paper because of the (anti)symmetry and somesuch
assumptions explicitly detailed out on page 4 of the paper. The
triaxiality breaks all of that rather strongly, and later in this paper
it is discussed that highly non-spherical models could function fine with
the observations.

I raise my eyebrow a bit at assumption VI in regards to the test mass
distribution falling off exponentially. That doesn't sound right but
apparently it has some level of observational support?

My particular takehome from this is a final falsification of the notion
that the dark matter halo is spherical and that other distributions need
to be considered, such as the previously mentioned triaxiality.

Though I cannot wait for the proclaimations that 'dark matter has been
falsified'. One of which I've already seen...

Homo Lykos

unread,
Apr 19, 2012, 4:42:36 PM4/19/12
to
Am 19.04.2012 09:24, schrieb eric gisse:
> Homo Lykos<ly...@bluewin.ch> wrote in
>>
>> One (little) reason [4 neutrini] more to abandon LCDM.
>>
>> Here a better and stronger new reason to abandon DM:
>>
>> http://www.dgcs.unam.mx/boletin/bdboletin/2012_158.html
>> http://arxiv.org/abs/1105.1873.
>
> "That is, under modified gravity theories, binary stars
> with physical separations beyond around 7000 AU should
> exhibit "flat rotation curves" and a "Tully-Fisher rela-
> tion", as galactic systems in the same acceleration regime
> do."
>
> Binary stars...flat rotation curve...TULLY FISHER RELATION?

In the sense of „MOND-like“ theories or approaches the „Tully-Fisher
relation“ is based on orbits in the „MOND-regime“.

>>
>> And here the best reasons until now to abandon the Big Bang and DE:
>>
>> www.wolff.ch/astro
>
> In regards to how the scientific community needs an english
> publication...
>
> "A publication in English, for example, astro-ph is mandatory.
>
> If the vote really so, then this would mean that we have in this
> regard already worse conditions than those prevailing in countries
> occupied by Hitler. I'm active but with neither in nor Germano-
> Anglo culture racist extermination campaigns."
>
> I'm reasonably sure this isn't a mistranslation.

I don't know. Some parts of this translation I cannot understand.
In my poor English I would say:

*****
A publication in English (e.g. in astro-ph) is compelling.

If this should be really true, then this would mean that we have in this
context [publication of scientific texts] today already a worse state,
than it prevailed in occupied countries under Hitler. However, I don't
take part actively in cultural destruction campaigns, neither by
"german-racist" nor by "english-racist" motivated campaigns.
*****

[Mod. note: presumably prior to the 19th century, when the language of
scientific discourse was Latin, that was the result of a
'Roman-racist' motivated campaign? Don't answer that; this part of
this thread should stop here -- mjh]

Because this is off topic, at least partially, I give a direct link to
the actually newest version of an introduction to the World Potential
Theory (WPT), which denies the Big Bang, DE and DM:

www.wolff.ch/astro/q.pdf

eric gisse

unread,
Apr 20, 2012, 3:30:24 AM4/20/12
to
Homo Lykos <ly...@bluewin.ch> wrote in
news:mt2.0-12098...@hydra.herts.ac.uk:

> Am 19.04.2012 09:24, schrieb eric gisse:
>> Binary stars...flat rotation curve...TULLY FISHER RELATION?
>
> In the sense of 'MOND-like' theories or approaches the
> 'Tully-Fisher relation' is based on orbits in the
> 'MOND-regime'.

Given that the Tully-Fisher relation is an empirical observation about
the relationship betwee the mass and luminosity of a galaxy, I believe it
would be useful for you to do some light reading on the subject.

> Because this is off topic, at least partially, I give a direct link to
> the actually newest version of an introduction to the World Potential
> Theory (WPT), which denies the Big Bang, DE and DM:
>
> www.wolff.ch/astro/q.pdf
>

A few thoughts:

1) No English copy?
2) Not published in a peer reviwed journal?
3) Why should I take this seriously, re: confusion regarding Tully-Fisher
relation?

[Mod. note: quoted text trimmed -- mjh]

jacob navia

unread,
Apr 20, 2012, 3:31:26 AM4/20/12
to
Le 19/04/12 22:34, Phillip Helbig---undress to reply a écrit :
Also, it is hard to see how it challenges the entire
> dark-matter paradigm since it is precisely the same type of dynamical
> studies (on the larger scale of entire galaxies) which led to the idea
> of dark matter in the first place. These results still need to be
> explained.

The authors of that paper say:

<quote>
It is clear that the local surface density measured in our work,
extrapolated to the rest of the Galaxy, cannot retain the Sun in a
circular orbit at a speed of ~220 km s-1. A deep missing mass problem is
therefore evidenced by our observations. Indeed, we believe that our
results do not solve any problem, but pose important, new ones.
<end quote>

Eric Flesch

unread,
Apr 20, 2012, 3:34:37 AM4/20/12
to
On Thu, 19 Apr 12, eric gisse <jowr.pi...@gmail.com> wrote:
>The takehome from that is that the Milky Way's DM halo was able to be
>empirically determined to be rather solidly triaxial ...

"solidly triaxial"??? You do realize, I hope, that triaxiality is a
hypothesis only, comprised of either:

(1) three populations of single-axis orbits which have sad denouements
when encountering each other, or

(2) a single population of three-axis orbiters for which no stability
is modelable, so the galaxy implodes.

(3) triaxial dark matter halos, i.e., magic.

Amusing papers like arXiv:1008.2753 do real such calculations with
mournful outcomes.

Eric Flesch

eric gisse

unread,
Apr 20, 2012, 4:39:12 PM4/20/12
to
Eric Flesch <er...@flesch.org> wrote in news:mt2.0-1509-1334907277
@hydra.herts.ac.uk:

> On Thu, 19 Apr 12, eric gisse <jowr.pi...@gmail.com> wrote:
>>The takehome from that is that the Milky Way's DM halo was able to be
>>empirically determined to be rather solidly triaxial ...
>
> "solidly triaxial"??? You do realize, I hope, that triaxiality is a
> hypothesis only, comprised of either:

Yes, it is a hypothesis. Which was then tested, and the success of which
is written in a paper for you to ignore at your leisure.

>
> (1) three populations of single-axis orbits which have sad denouements
> when encountering each other, or
>
> (2) a single population of three-axis orbiters for which no stability
> is modelable, so the galaxy implodes.
>
> (3) triaxial dark matter halos, i.e., magic.

Yeah, magic is the way to go on this one.

If you read the paper I cited you might notice the triaxiality being a
predicted outcome of simulations. But magic works too.

>
> Amusing papers like arXiv:1008.2753 do real such calculations with
> mournful outcomes.

"It is widely accepted that since both elliptical galaxies and
dark matter halos form via hierarchical mergers, they should
be triaxial."

That was the very first sentence of the article.

>
> Eric Flesch

Homo Lykos

unread,
Apr 20, 2012, 4:39:43 PM4/20/12
to
Am 20.04.2012 09:30, schrieb eric gisse:
> Homo Lykos<ly...@bluewin.ch> wrote in
>>
>> In the sense of 'MOND-like' theories or approaches the
>> 'Tully-Fisher relation' is based on orbits in the
>> 'MOND-regime'.
>
> Given that the Tully-Fisher relation is an empirical observation about
> the relationship betwee the mass and luminosity of a galaxy, I believe it
> would be useful for you to do some light reading on the subject.

In 'MOND-like' theories or approaches v (speed) is proportional to
sqrt[4]{M} in the 'Mond-regime'; a MOND-regime exists not only in
galaxies (about the 'correct' use of words or names I discuss not in
English).

A light reading especially for you (section 2.1):

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

>> ... link to an introduction to the World Potential
>> Theory (WPT), which denies the Big Bang, DE and DM:
>>
>> www.wolff.ch/astro/q.pdf
>
> 1) No English copy?
> 2) Not published in a peer reviwed journal?

The answer one finds in:

www.wolff.ch/astro/AP_Briefwechsel.pdf
and in a very crude translation:
www.wolff.ch/astro/AP_Briefwechsel_en.pdf

eric gisse

unread,
Apr 21, 2012, 3:23:25 AM4/21/12
to
Homo Lykos <ly...@bluewin.ch> wrote in
news:mt2.0-8592...@hydra.herts.ac.uk:

> Am 20.04.2012 09:30, schrieb eric gisse:
>> Homo Lykos<ly...@bluewin.ch> wrote in
>>>
>>> In the sense of 'MOND-like' theories or approaches the
>>> 'Tully-Fisher relation' is based on orbits in the
>>> 'MOND-regime'.
>>
>> Given that the Tully-Fisher relation is an empirical observation
>> about the relationship betwee the mass and luminosity of a galaxy, I
>> believe it would be useful for you to do some light reading on the
>> subject.
>
> In 'MOND-like' theories or approaches v (speed) is proportional to
> sqrt[4]{M} in the 'Mond-regime'; a MOND-regime exists not only in
> galaxies (about the 'correct' use of words or names I discuss not in
> English).
>
> A light reading especially for you (section 2.1):
>
> http://en.wikipedia.org/wiki/Modified_Newtonian_Dynamics

Oh my.

"The proportion between the "flat" rotation velocity to the observed mass
derived here is matching the observed relation between "flat" velocity to
luminosity known as the Tully-Fisher relation."

Again, the Tully-Fisher relation is an empirical relation between the
luminosity of a galaxy (and only a galaxy) and its' mass. Which, just so
we are clear, has literally not a single thing to do with what you wrote.

[Mod. note: the T-F relation, observationally, is between luminosity
and *rotation velocity*, measured by the width of spectral lines. See
http://adsabs.harvard.edu/abs/1977A%26A....54..661T . In the standard
picture, of course, the correlation arises because of a common
correlation with mass -- mjh]

Please don't cite poor sources as an argument against what I'm saying.

Right now I'm wondering if the person who wrote the paper read the same
thing...

>
>>> ... link to an introduction to the World Potential
>>> Theory (WPT), which denies the Big Bang, DE and DM:
>>>
>>> www.wolff.ch/astro/q.pdf
>>
>> 1) No English copy?
>> 2) Not published in a peer reviwed journal?
>
> The answer one finds in:
>
> www.wolff.ch/astro/AP_Briefwechsel.pdf
> and in a very crude translation:
> www.wolff.ch/astro/AP_Briefwechsel_en.pdf
>

That's not a translation. Its' a one page article.

Besides, the big bang theory does predict the cosmic microwave background
along with its' substructure. Please don't make fundamental errors about
simple things like that.

jacob navia

unread,
Apr 22, 2012, 2:53:49 AM4/22/12
to
Le 19/04/12 22:39, eric gisse a écrit :
>
> All the discussion of whether the halo is prolate or oblate immediately
> reminded me of this:
>
> http://arxiv.org/abs/0908.3187
>
> The takehome from that is that the Milky Way's DM halo was able to be
> empirically determined to be rather solidly triaxial rather than
> axisymmetric or even spherical like other models assume. This is very
> important to this paper because of the (anti)symmetry and somesuch
> assumptions explicitly detailed out on page 4 of the paper. The
> triaxiality breaks all of that rather strongly, and later in this paper
> it is discussed that highly non-spherical models could function fine with
> the observations.
>

That paper is a very beautiful piece of science. They use the stream of
stars from a dwarf galaxy being destroyed by our galaxy to "see" the
gravitational field and they come with a conclusion of a deformed rugby
balloon of dark matter around the galaxy.

OK.

But that "balloon" includes of course the galaxy. How is it possible
then that the density of dark matter is so low?

I cite from the ESO press release:
<quote>
Theories predict that the average amount of dark matter in the Sun’s
part of the galaxy should be in the range 0.4-1.0 kilograms of dark
matter in a volume the size of the Earth. The new measurements find
0.00±0.07 kilograms of dark matter in a volume the size of the Earth.
<end quote>

The simulations that the authors of that paper conducted supposed the
very existence of dark matter. WITHIN THAT HYPOTHESIS they are correct,
but if that hypothesis is proved wrong the whole simulation has no sense.

We can for instance assume that black holes push matter in a 4th spatial
dimension unseen from us. Then, given the form of the distortion of the
sagittarius dwarf galaxy stream we could deduce the "form" of that 4th
dimensional matter. But our simulation even if they would explain the
observed facts would be tied to the original hypothesis of black holes
pushing matter in some unseen dimension.

If that hypothesis is falsified our whole simulation collapses.

In the same way, if the very existence of DM is falsified, any
simulations assuming its existence are falsified also.


> I raise my eyebrow a bit at assumption VI in regards to the test mass
> distribution falling off exponentially. That doesn't sound right but
> apparently it has some level of observational support?
>
> My particular takehome from this is a final falsification of the notion
> that the dark matter halo is spherical and that other distributions need
> to be considered, such as the previously mentioned triaxiality.
>
> Though I cannot wait for the proclaimations that 'dark matter has been
> falsified'. One of which I've already seen...

Yes, because the paper says:
<quote>
In conclusion, the observations point to a lack of Galactic DM at the
solar position, contrary to the expectations of all the current models
of Galactic mass distribution.
<end quote>

In a scientific paper you never say: "This theory is nuts. DM doesn't exist"

You say the same thing but with more restraint.

This paper is an atomic bomb at the heart of cosmology. We have lost 80%
of the mass of the Universe nothing less !

jacob

Phillip Helbig---undress to reply

unread,
Apr 22, 2012, 5:15:44 AM4/22/12
to
In article <mt2.0-18851...@hydra.herts.ac.uk>, jacob navia
<ja...@spamsink.net> writes:

> This paper is an atomic bomb at the heart of cosmology. We have lost 80%
> of the mass of the Universe nothing less !

No, it is not. There are many studies which indicate the existence of
dark matter. One study which indicates something different cannot
invalidate all of those other studies. Of course, something is wrong
somewhere---observations, theory, assumptions---but we don't know now
what, exactly. One has to weigh things up carefully, confirm the
results with other studies etc.

It seems that the main result is that the concentration of dark matter
is lower near the Sun than expected from some models. It is a big jump
from this conclusion to "dark matter does not exist". Even if this
result holds up and models which predict a higher concentration of dark
matter near the Sun are ruled out, that doesn't rule out dark matter
altogether.

In any case, any theory without dark matter will have to explain all the
observations which point to dark matter.

jacob navia

unread,
Apr 22, 2012, 8:26:40 AM4/22/12
to
Le 22/04/12 11:15, Phillip Helbig---undress to reply a écrit :
> In article<mt2.0-18851...@hydra.herts.ac.uk>, jacob navia
> <ja...@spamsink.net> writes:
>
>> This paper is an atomic bomb at the heart of cosmology. We have lost 80%
>> of the mass of the Universe nothing less !
>
> No, it is not. There are many studies which indicate the existence of
> dark matter. One study which indicates something different cannot
> invalidate all of those other studies. Of course, something is wrong
> somewhere---observations, theory, assumptions---but we don't know now
> what, exactly. One has to weigh things up carefully, confirm the
> results with other studies etc.
>

What about all that experiences that searched dark matter without EVER
finding anything?

After decades of searching we still have no idea what this "dark" matter
is or what it is made of. At some point somebody has to start crying:

"The emperor has no clothes"!

:-)


> It seems that the main result is that the concentration of dark matter
> is lower near the Sun than expected from some models.

In the paper they say "ALL models"

> It is a big jump
> from this conclusion to "dark matter does not exist". Even if this
> result holds up and models which predict a higher concentration of dark
> matter near the Sun are ruled out, that doesn't rule out dark matter
> altogether.
>

Well, nothing is ruled out completely. If you go to sci.astro there are
several people that propose an "aether" filling the whole space. But not
many people take that seriously any more. The same will happen with this
"dark" matter. Physics must rest on observable quantities, if not it is
not physics any more.

> In any case, any theory without dark matter will have to explain all the
> observations which point to dark matter.

Yes. In that you are right.

Phillip Helbig---undress to reply

unread,
Apr 22, 2012, 3:14:09 PM4/22/12
to
In article <mt2.0-30059...@hydra.herts.ac.uk>, jacob navia
<ja...@spamsink.net> writes:

> What about all that experiences that searched dark matter without EVER
> finding anything?

What do you mean by "find"? Do you mean "direct detection"? If so, you
have to have a detector. If one doesn't know what the dark matter is,
then one can't say in advance which detector can detect it.

> After decades of searching we still have no idea what this "dark" matter
> is or what it is made of. At some point somebody has to start crying:
>
> "The emperor has no clothes"!

If it is obvious that he has none. However, that's not the case here.

For decades neutrino masses were compatible with zero, now we know that
neutrinos have non-zero masses. Some things are difficult. It took
almost 100 years for the cosmological parameters to be determined
accurately and precisely. Should one have said in, say, 1970, that it
is hopeless to measure them, or that they don't even exist?

> Well, nothing is ruled out completely. If you go to sci.astro there are
> several people that propose an "aether" filling the whole space. But not
> many people take that seriously any more. The same will happen with this
> "dark" matter. Physics must rest on observable quantities, if not it is
> not physics any more.

The whole idea of dark matter is motivated by OBSERVATION. One still
has to explain these anomalous observations, with dark matter or with
something else.

Thomas Womack

unread,
Apr 22, 2012, 3:19:04 PM4/22/12
to
In article <mt2.0-30059...@hydra.herts.ac.uk>,
jacob navia <ja...@jspamsink.org> wrote:
>Le 22/04/12 11:15, Phillip Helbig---undress to reply a écrit :
>> In article<mt2.0-18851...@hydra.herts.ac.uk>, jacob navia
>> <ja...@spamsink.net> writes:
>>
>>> This paper is an atomic bomb at the heart of cosmology. We have lost 80%
>>> of the mass of the Universe nothing less !
>>
>> No, it is not. There are many studies which indicate the existence of
>> dark matter. One study which indicates something different cannot
>> invalidate all of those other studies. Of course, something is wrong
>> somewhere---observations, theory, assumptions---but we don't know now
>> what, exactly. One has to weigh things up carefully, confirm the
>> results with other studies etc.
>>
>
>What about all that experiences that searched dark matter without EVER
>finding anything?

Well, if the local kinetic modelling has shown that there isn't much
dark matter in a medium-sized sphere around the Sun, that's not a bad
explanation of why we don't see anything in our detectors on Earth.

Though the experiment is measuring instantaneous velocities, and you
need quite a lot of assumptions to map those velocities to
gravitational potential; more than you require to map shear
measurements of background galaxies to mass distribution in clusters.

I don't know whether Gaia astrometry (positions with a few
microarcseconds error) and VLT spectroscopy (velocities with a few
tens of centimetres per second error) would be enough to measure
acceleration directly as change in velocity over a reasonable period;
I think probably not, because the orbital velocities around the galaxy
are small and the orbital periods long.

Tom

Homo Lykos

unread,
Apr 23, 2012, 3:47:24 AM4/23/12
to
> Am 20.04.2012 09:30, schrieb eric gisse:
....
> Oh my.
>
> "The proportion between the "flat" rotation velocity to the observed mass
> derived here is matching the observed relation between "flat" velocity to
> luminosity known as the Tully-Fisher relation."
>
> Again, the Tully-Fisher relation is an empirical relation between the
> luminosity of a galaxy (and only a galaxy) and its' mass.

I repeat, that I don't discuss in English the more or less puristic use
of technical terms like the 'Tully-Fisher relation'.

> That's not a translation. Its' a one page article.

AP_Briefwechsel_en is a (very crude) translation of AP_Briefwechsel

> Besides, the big bang theory does predict the cosmic microwave background
> along with its' substructure.

Not without inflation and DM.

[Mod. note: quoted text trimmed. The language used in this newsgroup
is English; if you don't want to discuss these matters in English, you
will find yourself at a disadvantage -- mjh]

Homo Lykos

unread,
Apr 23, 2012, 10:34:23 AM4/23/12
to
Am 20.04.2012 09:30, schrieb eric gisse:
> "The proportion between the "flat" rotation velocity to the observed mass
> derived here is matching the observed relation between "flat" velocity to
> luminosity known as the Tully-Fisher relation."
>
> Again, the Tully-Fisher relation is an empirical relation between the
> luminosity of a galaxy (and only a galaxy) and its' mass.

I repeat, that I don't discuss in English the more or less puristic use
of technical terms like the 'Tully-Fisher relation'.

> That's not a translation. Its' a one page article.

AP_Briefwechsel_en is a (very crude) translation of AP_Briefwechsel
>
> Besides, the big bang theory does predict the cosmic microwave background
> along with its' substructure.

Not without inflation and DM.

[Mod. note: quoted text trimmed. The meta-discussion on the language
used should cease here; the language used in this newsgroup is
English, and participants who decline to use it will be at a
disadvantage -- mjh]

Martin Hardcastle

unread,
Apr 23, 2012, 12:26:40 PM4/23/12
to
In article <mt2.0-18080...@hydra.herts.ac.uk>,
Phillip Helbig---undress to reply <hel...@astro.multiCLOTHESvax.de> wrote:
>The whole idea of dark matter is motivated by OBSERVATION. One still
>has to explain these anomalous observations, with dark matter or with
>something else.

This seems like a good time to mention http://arxiv.org/abs/1204.4649
....

Martin
--
Martin Hardcastle
School of Physics, Astronomy and Mathematics, University of Hertfordshire, UK
Please replace the xxx.xxx.xxx in the header with herts.ac.uk to mail me

Nicolaas Vroom

unread,
Apr 24, 2012, 1:48:39 AM4/24/12
to
Op zondag 22 april 2012 11:15:44 UTC+2 wrote Phillip Helbig:
> In article <mt2.0-18851...@hydra.herts.ac.uk>, jacob navia
> <ja...@spamsink.net> writes:
>
> > This paper is an atomic bomb at the heart of cosmology. We have
> > lost 80% of the mass of the Universe nothing less !
>
> No, it is not. There are many studies which indicate the
> existence of dark matter.

That is correct.
There are many books/articles that describe the concept of darkmatter
within a spiral Galaxy. If that is what you mean.
The problem is they can all use the same argumentation.
Starting point is the galaxy rotation curve.
See for example: http://en.wikipedia.org/wiki/Galaxy_rotation_curve
In that document they distinquish between two:
1. One which is observed. This is curve B.
The shape in this case is called flat.
2. One which is predicted or calculated. This is curve A.
You can easily see that there is a problem because both curves do not match.
The whole issue is how is Curve A calculated.

When you study the curve A and B in detail you can see that the left part
describes the bulge and the right part the disc.
The left parts match, that means the problem is with the disc.
(This indicates there is no dark matter in bulge)
In order to calculate the right part you assume a certain mass
distribution in the disc based on visible observations.
This is all normal matter, the building blocks of the stars and planets.
There are two problems:
First of all there is a lot of normal matter which is invisible
because the temperature is too low to emit light.
In this category fall all the planet sized objects and smaller.
Secondly telescopes become better to observe star sized objects.
One result of the second is that the range of the galaxy rotation
curve increases and as such that Curve A becomes longer and flatter.

What my understanding of the above mentioned paper is that the
total number of stars in our region has increased.
This means that the mass of the disc increases, which again moves
curve A upward.
The whole issue finally boils down to: how much matter is required
to make curve A equal to curve B and what is the mass density.
If this mass density is small compared to the mass density of curve A
than the whole idea to explain that by imposing dark matter
is not necessary.

Nicolaas Vroom
http://users.pandora.be/nicvroom/

Phillip Helbig---undress to reply

unread,
Apr 24, 2012, 1:49:51 AM4/24/12
to
In article <mt2.0-23612...@hydra.herts.ac.uk>, Martin Hardcastle
<m.j.har...@xxx.xxx.xxx> writes:

> In article <mt2.0-18080...@hydra.herts.ac.uk>,
> Phillip Helbig---undress to reply <hel...@astro.multiCLOTHESvax.de> wrote:
> >The whole idea of dark matter is motivated by OBSERVATION. One still
> >has to explain these anomalous observations, with dark matter or with
> >something else.
>
> This seems like a good time to mention http://arxiv.org/abs/1204.4649

Indeed. The situation is much more complicated than "this new paper has
this result---which depends on a lot of assumptions---therefore dark
matter does not exist. Note that the arguments for dark matter on
galactic scales are different than those for dark matter on cosmological
scales. (There would be a conflict only if the former implied more dark
matter than the latter.)

A couple of balanced discussions from the blogosphere:

http://telescoper.wordpress.com/2012/04/22/on-the-dearth-of-dark-matter-in-the-solar-neighbourhood/

http://blogs.discovermagazine.com/cosmicvariance/2012/04/20/puzzles/

Phillip Helbig---undress to reply

unread,
Apr 24, 2012, 4:08:54 AM4/24/12
to
In article <mt2.0-31828...@hydra.herts.ac.uk>, Nicolaas Vroom
<nicolaa...@pandora.be> writes:

> Op zondag 22 april 2012 11:15:44 UTC+2 wrote Phillip Helbig:
> > In article <mt2.0-18851...@hydra.herts.ac.uk>, jacob navia
> > <ja...@spamsink.net> writes:
> >
> > > This paper is an atomic bomb at the heart of cosmology. We have
> > > lost 80% of the mass of the Universe nothing less !
> >
> > No, it is not. There are many studies which indicate the
> > existence of dark matter.
>
> That is correct.

[Good summary snipped.]

> The whole issue finally boils down to: how much matter is required
> to make curve A equal to curve B and what is the mass density.
> If this mass density is small compared to the mass density of curve A
> than the whole idea to explain that by imposing dark matter
> is not necessary.

Right. But for essentially all galaxies where the observations have
been done this discrepancy has been discovered, which is the motivation
for dark matter in the first place. Even if this new paper holds up and
there is less dark matter than expected near the Sun, all these other
observations have to be explained somehow.

Nicolaas Vroom

unread,
Apr 24, 2012, 2:11:23 PM4/24/12
to
Op dinsdag 24 april 2012 07:49:51 UTC+2 schreef Phillip Helbig het volgende:
> In article <mt2.0-23612...@hydra.herts.ac.uk>, Martin Hardcastle
> <m.j.har...@xxx.xxx.xxx> writes:
>
> > In article <mt2.0-18080...@hydra.herts.ac.uk>,
> > Phillip Helbig---undress to reply <hel...@astro.multiCLOTHESvax.de> wrote:
> > >The whole idea of dark matter is motivated by OBSERVATION. One still
> > >has to explain these anomalous observations, with dark matter or with
> > >something else.
> >
> > This seems like a good time to mention http://arxiv.org/abs/1204.4649
>

Correct.
The issue is not what is the calculated mass distribution of a galaxy
which galaxy rotation curve is flat
(IMO A large part of this document is about that subject)
The issue is partly: is there enough visible matter and planet sized
objects and gas clouds in our neighbourhood (At the distance R of the sun)
Enough meaning the same amount as the calculated mass at distance R.
Apparently in the past this answer was no.
I get the impression that the impression of this document it is a Yes.
However no clear information is shown about an historical evaluation.
Accordingly to this document the answer is Yes
at a distance of 13000 ly around the Sun
But no at a distance of 30000 ly from the Galactic Centre.
That means the curve A (predicted/calculated) in
http://en.wikipedia.org/wiki/Galaxy_rotation_curve
is wrong.
One important issue is the total (disc) size of our Galaxy.
I expect that this size is larger than the visible disc size.
I expect that this extra belt (Like the Kuiper belt in Our Solar
system) in the plane of our Galaxy is filled with large
planet sized invisible objects which should be taken into account
in order to calculate the A curve.
That means that the distance between the A and B curve (observation)
is even smaller.

Nicolaas Vroom
http://users.pandora.be/nicvroom/

Jonathan Thornburg [remove -animal to reply]

unread,
May 24, 2012, 3:00:00 PM5/24/12
to
In mid-april we discussed a recent paper

arXiv:1204.3924
Authors: C. Moni Bidin, G. Carraro, R. A. Mendez, R. Smith
Title: Kinematical and chemical vertical structure of the Galactic
thick disk II. A lack of dark matter in the solar neighborhood

which argued that the local dark matter density in the solar neighborhood
is very low.

Bovy and Tremaine have just released a rebuttal arguing that Moni Bidin
et al's analysis is mistaken, and estimating a substantial dark-matter
density:

arXiv:1205.4033
Authors: Jo Bovy, Scott Tremaine
Title: On the local dark matter density
Abstract:
An analysis of the kinematics of 412 stars at 1-4 kpc from the
Galactic mid-plane by Moni Bidin et al. (2012) has claimed to
derive a local density of dark matter that is an order of
magnitude below standard expectations. We show that this result
is incorrect and that it arises from the invalid assumption
that the mean azimuthal velocity of the stellar tracers is
independent of Galactocentric radius at all heights; the correct
assumption---that is, the one supported by data---is that the
circular speed is independent of radius in the mid-plane. We
demonstrate that the assumption of constant mean azimuthal
velocity is physically implausible by showing that it requires
the circular velocity to drop more steeply than allowed by any
plausible mass model, with or without dark matter, at large
heights above the mid-plane. Using the correct approximation
that the circular velocity curve is flat in the mid-plane, we
find that the data imply a local dark-matter density of 0.008
+/- 0.002 Msun/pc^3= 0.3 +/- 0.1 Gev/cm^3, fully consistent
with standard estimates of this quantity. This is the most
robust direct measurement of the local dark-matter density to
date.

There are brief synopses at (among many other places)
http://blogs.discovermagazine.com/cosmicvariance/2012/05/23/dark-matter-still-existing-one-in-a-continuing-series/
http://telescoper.wordpress.com/2012/05/23/dark-matter-dearth-evaded/

Bovy and Tremaine point out that ESA's GIAI mission (scheduled for
launch in summer 2013) should provide vastly-improved data on the
stellar position & velocity distribution in our galaxy, allowing
for much more accurate dark-matter estimates of this type.

jacob navia

unread,
Jun 24, 2012, 5:06:55 PM6/24/12
to
Le 24/05/12 21:00, Jonathan Thornburg [remove -animal to reply] a écrit :
> In mid-april we discussed a recent paper
>
> arXiv:1204.3924
> Authors: C. Moni Bidin, G. Carraro, R. A. Mendez, R. Smith
> Title: Kinematical and chemical vertical structure of the Galactic
> thick disk II. A lack of dark matter in the solar neighborhood
>
> which argued that the local dark matter density in the solar neighborhood
> is very low.
>
> Bovy and Tremaine have just released a rebuttal arguing that Moni Bidin
> et al's analysis is mistaken, and estimating a substantial dark-matter
> density:
>
> arXiv:1205.4033
> Authors: Jo Bovy, Scott Tremaine
> Title: On the local dark matter density
[Mod. note: snip -- mjh]

The astronomy magazine "Ciel et espace" (in French Sky and Space)
publishes a note today saying that the conclusion is not over. Yes,
apparently Moni-Bidin made an error in their calculations, but redoing
the calculations makes the case for Mond even stronger because Mond
arrives to explain the movement of the stars in the observed region
"better" than the dark matter theory.

'Le travail de Jo Bovy et de Scott Tremaine conforte l'hypothese de
la matiere noire, mais aussi celle de Mond', souligne Benoit Famaey
(observatoire de Strasbourg).

"The work of Jo Bovy and Scott Tremaine goes in the direction of
the dark matter hypothesis but also that of Mond, underscores
Benoit Famaey from Strasbourg Observatory." (my translation,
I hope it is faithful :-) )

Now, there is no paper associated with those declarations, it is
just another interpretation of the data worked by Bovy and Tremaine.

This is discussed in Ciel et Espace issue 506 page 13.

[Mod. note: non-ASCII characters replaced with their unaccented
equivalents; j'espere que les lecteurs francophones me pardonneront
-- mjh]

Eric Gisse

unread,
Jun 25, 2012, 3:10:10 AM6/25/12
to
On Jun 24, 4:06 pm, jacob navia <ja...@spamsink.net> wrote:

[...]

>
> "The work of Jo Bovy and Scott Tremaine goes in the direction of
> the dark matter hypothesis but also that of Mond, underscores
> Benoit Famaey from Strasbourg Observatory." (my translation,
> I hope it is faithful :-) )

Results that favor dark matter invariably favor MOND as well. It is an
annoying feature of the theory.

MOND already has its' falsifications in trying to model the CMBR so it
is somewhat difficult to take it seriously in 2012.

If folks want to dedicate time to explaining why it works in the
reigmes it does, that's great. I just have a hard time understanding
why it is taken seriously as a theory.

[...]
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