Gravitational Scalar & Redshift Distortion

On Thu, 20 Feb 14, Steve Willner wrote:
_Probably_ more significant, different
planets should give different values for "solar mass" (technically
the Gaussian gravitational constant) because larger orbits would
enclose more mass. Perhaps the OP or someone else could
calculate the magnitude of these effects...

Can't be much, because of the exquisite trajectory of Voyager 2 which
must have confirmed the true distance of the giant planets to a very
small delta.

Eric

Op zondag 16 februari 2014 08:58:26 UTC+1 schreef Phillip Helbig
In article , Nicolaas Vroom

writes:

IMO the evidence only comes from WMAP data ie CMB radiation.
When you study the literature for our "local" universe almost no one
discusses the issue of non baryonic matter.

Look up "baryon fraction in clusters". There is a regime between the
local environment (Local Group, say) and the observable universe. There
is evidence from galaxy clusters, for example, that there is
non-baryonic matter.

An interesting article to read is: http://arxiv.org/abs/1402.1764
"Cold dark matter heats up."
The sentence near the beginning reads:
"The remaining 95% consists of dark energy and dark matter (DM).
LambdaCDM is being challenged by its apparent inability to explain the
low density of DM measured at the centre of cosmological systems,
ranging from faint dwarf galaxies to massive clusters containing
tens of galaxies the size of the Milky Way."

However there exists also an article in nature. See:
http://www.nature.com/nature/journal...ture12953.html
The sentence near the beginning reads:
"In the LambdaCDM paradigm, the remaining 95 per cent consists of dark
energy Lambda and cold dark matter."
IMO meaning non-baryonic matter.

The problem with the article is that they often mention the words baryons
and dark matter, but almost never cold dark matter or non-baryonic matter.
(I wished they did not use the word dark matter at all but only
baryonic cold- or warm- and non-baryonic matter)

Roughly speaking the current assumption is that 20% of matter in the
universe is baryonic and 80% is non-baryonic.
The picture that emerges from this article is that in our local universe
(in the galaxies) this is more 80% baryonic and 20% non-baryonic
(but most probably this last number is much too high).
The reason is because in many cases IMO when they use the word dark matter they mean cold baryonic matter (gas)
Of course this raises serious issues.

Nicolaas Vroom

Op zondag 16 februari 2014 08:58:26 UTC+1 schreef Phillip Helbig
In article , Nicolaas Vroom

Look up "baryon fraction in clusters". There is a regime between the
local environment (Local Group, say) and the observable universe. There
is evidence from galaxy clusters, for example, that there is
non-baryonic matter.

I have performed a second literature study

1) http://news.brown.edu/pressreleases/2013/10/lux
First results from LUX dark matter detector
At the beginning of this document we read:
"Though dm has not yet been detected directly, scientists are fairly certain that it exists. Without its gravitational influence, galaxies and galaxy clusters would simply fly apart into the vastness of space."
This line of reasoning only shows that there is a missing matter problem.

2) http://mnrasl.oxfordjournals.org/con...09/1/L128.full
"Nearly 80 per cent of the mass density in the Universe cannot be
explained with ordinary baryonic matter and requires an additional non-
baryonic component aptly named dark matter to reconcile the inferred
mass budget The next best targets may be hiding among the recently
discovered population of ultrafaint dwarf galaxies around the Milky Way"

3a) http://arxiv.org/pdf/1402.2301v1.pdf
DETECTION OF AN UNIDENTIFIED EMISSION LINE IN THE STACKED X-RAY SPECTRUM
OF GALAXY CLUSTERS
At page 11 we read (slightly modified):
Mdm = Mtot - Mgas - Mstar
The article in table 4 only shows Mdm but not Mtot.
This article discusses galaxy clusters.

3b) http://arxiv.org/pdf/1402.4119v1.pdf
An unidentified line in X-ray spectra of the Andromeda galaxy
and Perseus galaxy cluster
Same subject as 3a

The problem with the articles is the total mass, the baryonic mass and the predicted nonbaryonic mass involved in the different galaxies (and clusters) discussed.
In order to calculate the projected dm masses the NFW profile is used.
IMO this assumes that the missing matter is in the halo. A different
scenario is to assume that the missing matter is in the disc
which could lead to much lower estimates.

The big question is that if baryonic matter is discovered for example
in the Milky Way this can be used (extrapolated) as a solution for
the missing matter problem in the universe at large.

Nicolaas Vroom.

[dark matter in solar system]

In article ,
Eric Flesch writes:
Can't be much, because of the exquisite trajectory of Voyager 2 which
must have confirmed the true distance of the giant planets to a very
small delta.

I agree the various spacecraft results will give the most sensitive
limits, but "much" has to be made quantitative and compared with
expected values to be of any use.

If I'm doing this right, the critical density is about 0.9E-29
g/cm^3. Inside a 1 AU sphere, that's about 1E11 g and inside
Jupiter's 5.2 AU orbit about 1.8E13 g or about 9E-21 solar masses.
(Feel free to check my work!) I think Gaussian gravitational
constants are known to 12 or so significant digits but not 20, so at
first glance it looks as though the upper limit is far from
significant. But I'd really like to see someone do the calculation
correctly.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

On Tue, 25 Feb 14, Steve Willner wrote:
[dark matter in solar system]
If I'm doing this right, the critical density is about 0.9E-29
g/cm^3. Inside a 1 AU sphere, that's about 1E11 g and inside
Jupiter's 5.2 AU orbit about 1.8E13 g or about 9E-21 solar masses.

Taking the term "dark matter" to mean the source of the extra gravity,
because we can't see it, the working assumption of your calculation is
that it is smeared out into a uniform distribution -- I think that's
the unspoken assumption behind most current work on dark matter. My
OP puts forth the alternative that its distribution is instead quite
structural, and includes spherical asymptotes to large matter
distributions. That's why I wouldn't pursue your calculation -- also
because Voyager 2's trajectory would have been exceedingly sensitive
to any variations from the inverse square rule.

Still wondering if the Galactic halo has a well-defined outer
perimeter. Imaging seems to show it, but my search for any literature
on that has turned up nothing.

In article ,
Eric Flesch writes:
... the alternative that [dark matter] distribution is instead quite
structural, and includes spherical asymptotes to large matter
distributions.

Any hypothesis needs a _quantitative_ test. At first glance, the
numbers suggest solar system tests won't be significant, Voyager or
no. (I'd actually expect Galileo and Cassini to give more
significant tests than Voyager.)

Still wondering if the Galactic halo has a well-defined outer
perimeter. Imaging seems to show it,

What observations are those? As a practical matter, signal to noise
limits the detectability of faint haloes.

I'd not expect a sharp boundary but something like an exponential
density dropoff, but I'm certainly no expert. The Milky Way has
high-velocity stars that will leave the Galaxy, so the intergalactic
stellar abundance cannot be identically zero. Whether to count those
stars as part of the halo can, of course, be debated.

--
Help keep our newsgroup healthy; please don't feed the trolls.
Steve Willner Phone 617-495-7123
Cambridge, MA 02138 USA

On Fri, 28 Feb 14, Steve Willner wrote:
Eric Flesch writes:
... the alternative that [dark matter] distribution is instead quite
Still wondering if the Galactic halo has a well-defined outer
perimeter. Imaging seems to show it,

What observations are those? As a practical matter, signal to noise
limits the detectability of faint haloes.

Oops, the imaging that I had in mind was of the bulge, not the halo.
So maybe I shouldn't have extended the topic to include the halo.
Sorry for the confusion.

Eric

In article , Nicolaas Vroom
writes:

Op zondag 16 februari 2014 08:58:26 UTC+1 schreef Phillip Helbig
In article , Nicolaas Vroom

Look up "baryon fraction in clusters". There is a regime between the
local environment (Local Group, say) and the observable universe. There
is evidence from galaxy clusters, for example, that there is
non-baryonic matter.

I have performed a second literature study

Right, but did you look up "baryon fraction in clusters"? This is the
main argument for a large fraction of dark matter or missing matter
being non-baryonic.

On 2/25/14, 12:56 AM, Steve Willner wrote:
[dark matter in solar system]

If I'm doing this right, the critical density is about 0.9E-29
g/cm^3. Inside a 1 AU sphere, that's about 1E11 g and inside
Jupiter's 5.2 AU orbit about 1.8E13 g or about 9E-21 solar masses.
(Feel free to check my work!) I think Gaussian gravitational
constants are known to 12 or so significant digits but not 20, so at
first glance it looks as though the upper limit is far from
significant. But I'd really like to see someone do the calculation
correctly.

Look at:
http://arxiv.org/abs/gr-qc/0103044
It should help.

RDS

On 3/12/14, 5:00 PM, Phillip Helbig---undress to reply wrote:
In article , Nicolaas Vroom
writes:

Op zondag 16 februari 2014 08:58:26 UTC+1 schreef Phillip Helbig
In article , Nicolaas Vroom

Look up "baryon fraction in clusters". There is a regime between the
local environment (Local Group, say) and the observable universe. There
is evidence from galaxy clusters, for example, that there is
non-baryonic matter.

I have performed a second literature study

Right, but did you look up "baryon fraction in clusters"? This is the
main argument for a large fraction of dark matter or missing matter
being non-baryonic.


It generally accepted that
there are many more baryons observed in clusters than allowed by
nucleosynthesis.

But nucleosynthesis calculations could be wrong.
All seems to be based on 1991 ref:
http://ned.ipac.caltech.edu/cgi-bin/...pJ...376...51W
that may require updating based on the National Ignition Facility
experimental data.

RDS