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Doppler Tests on Local Stars



 
 
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  #1  
Old March 1st 07, 05:28 PM posted to sci.astro.research
Oh No
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Posts: 433
Default Doppler Tests on Local Stars

Doppler Tests on Local Stars

Our knowledge of stellar kinematics and cosmology is almost entirely
dependent on red shift measurements. We assume that the Earthbound
Doppler laws apply but there has been no test of whether that same law
applies unmodified on astronomical scales. For some while I have been
saying that the teleconnection would require us to reinterpret almost
every astronomical measurement, giving an "Einstein preferred" closed
universe with no cosmological constant, but although I have shown that
it gives a good fit with data, up to now I have only had a marginally
better fit than standard, not a conclusive test which could clearly
falsify one model or the other.

An objection sometimes raised to the teleconnection is that it says that
light from distant astronomical objects cannot be treated as a classical
e.m. wave, and hence implies that Maxwell's equations do not hold in
empty space. Responding that Maxwell's equations apply to the
measurement of a test charge, and that by definition this means that
they apply when space is not empty seems to be unconvincing to many
physicists.

What should be much more convincing is to make a prediction of something
which is not known, and then to demonstrate the prediction from data. I
am going to describe a straightforward test which can be done using only
a spreadsheet and on-line databases. Here I am only going to give a
general description. If anyone wants to do these tests I will follow up
with details of the method and references to the databases.

A prediction of the teleconnection is that the reason for the flattening
of galaxy rotation curves is that radial velocity measured using Doppler
requires a correction due to cosmological expansion. If this is true
then the orbital velocity of the sun about the Milky Way is ~160km/s,
not ~220km/s as is usually stated (neither CDM nor modification to
Newtonian gravity is used). I have for some while been looking for a way
to test this, and finally came up with a simple statistical test on
local stars. For stars in perfect circular orbits, Doppler shifts,
together with the teleconnection correction, would cancel, but real
measured velocities show a wide random scatter. We can't measure the
true motion of any individual star without using Doppler, but if the
teleconnection is right then the radial component of velocity will be
overstated. I have been looking for a way to show that quoted radial
motions are systematically large compared to transverse ones. If the
earth is not at the centre of the universe, and systematic errors can be
minimised, this can potentially give a convincing demonstration that
radial velocities measured by standard Doppler are overstated.

With some help from Erik Anderson in specifying the test and finding
data, I took 12 axes in different directions from the Earth, and looked
at the component of velocity for each star along that axis. For each
axis I divided the population into four quadrants, those going in either
direction along the axis, those approaching and those receding. I then
plotted the component of velocity against the cosine of the angle of
approach/recession (using cosine does two things, a) it gives an even
distribution along the horizontal axis and b) it makes the
teleconnection prediction roughly linear). This produces a pretty wide
scatter, but if the teleconnection is correct there should be a
correlation of increasing velocity towards cos=+-1.

In two additional tests I used the direction of motion of the star as
the axis. This made 38 tests in all.

The scatter is large and correlation coefficients are very low. None of
the tests produces a statistically significant result on its own. But if
the standard model is correct and there is no systematic error in radial
velocity there should be a fifty-fifty split of slopes going with the
teleconnection prediction and those going against it.

Although the tests are not entirely independent one would expect that
accidental alignments leading to a slope on one axis should lead to the
opposite alignments on another, so the standard prediction should head
closer to the mean than a strict binomial distribution which I used in
the tests.

In order to give a valid test I screened populations for single star
systems (multiple systems give inflated values of radial velocity
compared to proper motion). To avoid a systematic understatement in
distance because parallax is an inverse law (with a corresponding
understatement of transverse velocity), I used, for the radial distance
in parsecs

Rpc = 1000/(1-(e_Plx/Plx)^2)

where Plx is the measured parallax and e_Plx is the stated error margin.

I checked my test harness by feeding in a population with random motions
(weighted toward disc motions). I ran this a few times and it always
gave close to the expected result of 19 successes out of 38. Erik and I
also checked the tests by building separate spreadsheets, and checking
that they produce identical results, and by checking calculated figures,
such as U,V and W velocities against published figures for those
velocities, and by comparing plots with published plots.

The Geneva-Copenhagen survey claims to provide a complete, magnitude-
limited, and kinematically unbiased sample of 16,682 nearby F and G
dwarf stars. A sample of 4,820 stars was taken by excluding binaries and
multiple star systems, and by restricting to stars with parallax errors
less than 10% and within 100pc of the Sun - Hipparcos parallaxes are
more accurate away from the equator. A cut at 100pc gives a uniform
space distribution. To avoid a systematic error by overstating parallax
distances For a good test it is desirable to start with as near as
possible to a homogeneous stellar distribution. The sample was further
restricted to 1955 mainly disc stars with conventional motions by
observing from the velocity plots in the U-V, U-W and V-W planes that
there is a greater density of stars within the velocity ellipsoid

(U+11)^2 + 1.6*(V+11)^2 + 7*(W+6.5)^2 40^2

(U is toward galactic centre, V in direction of rotation and W
perpendicular to galactic plane).

The result of this test was 26 successes for the teleconnection
prediction out of 38. This rejects the null hypothesis (i.e. the
standard model) with a confidence of 98%.

If the standard prediction were correct one would not expect the region
of UVW space to make much difference to the results of the tests. This
is not true for the teleconnection. While it is generally the case that
the teleconnection had more successes than failures in the trials, to
achieve the highest success rates the cut in UVW space must be made with
reasonable precision. The chosen region is not absolutely critical, but
too narrow a cut, into the densely populated region, will preferentially
remove too many stars with teleconnection enhanced velocities, whereas
too broad a cut will include too many outliers to the main distribution.
In either case a more random result is expected. Some allowance may be
made for the fact that, to a degree, the regions were chosen according
to the number of successes. This is inevitable because of the nature of
the test, and one should compensate by requiring a higher than usual
stated level of confidence in the results.

A problem with the sample of F and G stars is that they contain bulk
motions (e.g. the Ursa Major stream and the Hyades), and a high
proportion of fast stars with a very different distribution from smooth
background thin disc stars. Both these factors make the test less
reliable. I repeated it for type A and B dwarfs, and for A&B giants a
from the CRVAD database, using velocities when available from the more
accurate Pulkovo Compilation of Radial Velocities. Because star
formation in our neck of the woods is largely for smaller stars, these
contain fewer bulk motions a much more even random distribution, and
they are massive enough, and young enough, that there are fewer fast
moving stars. It was not required to impose a velocity ellipsoid, but I
made a cut at 3 standard deviations from the mean. As the populations
were rather small I allowed parallax errors up to 20% and distances to
200pc. This gave me 1676 A dwarves, 471 B dwarves and 210 A&B Giants,
for which I got results of 31, 26, and 32 successes out of 38,
respectively, rejecting the standard theory with confidence levels of
99.994%, 98%, and 99.999% respectively.

I applied the test to the Beers catalogue of metal-poor (i.e. very old)
stars. These are mainly halo or thick disc stars with much higher
velocities (the teleconnection is expected to have more impact). I only
used stars with quoted photometric distances, distance limited to 500pc
(parsecs). Beyond that point a uniform distribution of velocities cannot
be assumed, due to the depth of the disc. I applied a truncation of
velocities at 3 s.f of total velocity. That left 253 stars. The result
of the test was 29 successes in 38 trials, or 99.92% confidence

For the greatest validity, a homogeneous population is required. By
examining the velocity plots, the I split the distribution into halo
stars, with velocities

(U + 8)^2 + (V+18)^2 + 4(W+6)^2 120^2

and thick disk stars with velocities

(U + 8)^2 + (V+18)^2 + 4(W+6)^2 110^2

For 129 halo stars there were 31 successes in 36 valid trials, rejecting
the standard model with 99.9994% confidence, and for 116 stars in the
thick disc sample there were 28 successes in 38 trials, a rejection at
99.7% confidence.

I have now tested ten populations of stars for which one might expect a
reasonably homogeneous velocity distribution (the test does not
necessarily work for mixed distributions). The overall result of 376
trials has been 283 successes for the teleconnection prediction, a level
of confidence within 10^-23 of certainty.

There are a sufficient number of independent databases that I can
run single axis tests on all data bases. I had nine axes, XYZ are the
equatorial axes, UVW galactic, and ABC where A was vaguely in the
direction of the solar apex and B was in the galactic plane. For five
populations (GF dwarfs, AB background, KM Giants, error halo, thick
disk) I had total results

Axis success trials Confidence
U 26 40 96%
V 31 38 99.994%
W 37 40 99.999999%
X 31 40 99.97%
Y 31 40 99.97%
Z 27 38 99.31%
A 33 40 99.998%
B 31 40 99.68%
C 27 40 96%

Thus we can reasonably expect that the teleconnection prediction would
show up on an axis chosen in any direction in space.

Due to the simple nature of these tests, if one rejects the notion that
the sun occupies a preferred position in space, the only conclusions I
can see are that there is a systematic error in radial velocities, as
predicted by the teleconnection, or that there is a systematic error in
distances. I tried a systematic percentage increase in distances past
the point which I thought reasonable, and was still able to reject the
affine connection.



Regards

--
Charles Francis
moderator sci.physics.foundations.
substitute charles for NotI to email
  #2  
Old March 1st 07, 06:39 PM posted to sci.astro.research
Stupendous_Man
external usenet poster
 
Posts: 57
Default Doppler Tests on Local Stars

... I have for some while been looking for a way
to test this, and finally came up with a simple statistical test on
local stars. For stars in perfect circular orbits, Doppler shifts,
together with the teleconnection correction, would cancel, but real
measured velocities show a wide random scatter. We can't measure the
true motion of any individual star without using Doppler, but if the
teleconnection is right then the radial component of velocity will be
overstated. I have been looking for a way to show that quoted radial
motions are systematically large compared to transverse ones. I


Have you included the systematic deviations from random
velocities due to the differential rotation of stars in the disk
and their actual, non-circular motions?

Suppose stellar orbits are elliptical, not circular. Then stars
in our local neighborhood will be a mixture of populations,
which we can describe as a) stars with semi-major axes
smaller than the Sun's, which are currently at the apoapsis
of their orbits, b) stars with semi-major axes about the same
as the Sun's and c) stars with semi-major axes larger
than the Sun's, which are currently at the periapsis
of their orbits. The orbital velocities of these populations
will be different in systematic ways. The number of stars
from each population which we measure locally depends
on the overall radial gradient of stellar density in the
Milky Way, and on some geometry.

It is possible that the effect of these different
populations could mimic the effect you see.
  #3  
Old March 1st 07, 07:03 PM posted to sci.astro.research
Kent Paul Dolan
external usenet poster
 
Posts: 225
Default Doppler Tests on Local Stars

"Oh No" wrote:

An objection sometimes raised to the
teleconnection is that it says that light from
distant astronomical objects cannot be treated as
a classical e.m. wave, and hence implies that
Maxwell's equations do not hold in empty space.
Responding that Maxwell's equations apply to the
measurement of a test charge, and that by
definition this means that they apply when space
is not empty seems to be unconvincing to many
physicists.


Why is this subtext even meaningful?

No "vacuum" is never empty, it is seething with
short-lived charged particles, the so called "energy
of the vacuum", thus a light wave in space is never
"lonely", so it is never in some context where
Maxwell's equations fail to apply.

Did you mean something different than what you
wrote?

xanthian.



--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
  #4  
Old March 1st 07, 07:13 PM posted to sci.astro.research
Kent Paul Dolan
external usenet poster
 
Posts: 225
Default Doppler Tests on Local Stars

"Oh No" wrote

restricting to stars ... within 100pc of the Sun


By doing so you've selected this tiny ball of
stars (compared to the size of the galaxy) all in
essentially the same part of the galaxy, all going
essentially in the same direction around the center
of the galaxy.

It seems to me, then, that essentially _all_ you
are seeing is proper motion of those stars with
respect to the sun, and that you're not at all
looking at your subject matter, speeds of approach
or recession on opposite limbs of galaxies that
tell us how fast those galaxies are turning.

Have I missed something?

xanthian.


--
Posted via Mailgate.ORG Server - http://www.Mailgate.ORG
  #5  
Old March 1st 07, 07:45 PM posted to sci.astro.research
Oh No
external usenet poster
 
Posts: 433
Default Doppler Tests on Local Stars

Thus spake Kent Paul Dolan
"Oh No" wrote:

An objection sometimes raised to the
teleconnection is that it says that light from
distant astronomical objects cannot be treated as
a classical e.m. wave, and hence implies that
Maxwell's equations do not hold in empty space.
Responding that Maxwell's equations apply to the
measurement of a test charge, and that by
definition this means that they apply when space
is not empty seems to be unconvincing to many
physicists.


Why is this subtext even meaningful?

No "vacuum" is never empty, it is seething with
short-lived charged particles, the so called "energy
of the vacuum", thus a light wave in space is never
"lonely", so it is never in some context where
Maxwell's equations fail to apply.

Did you mean something different than what you
wrote?

No. Remember this is a prediction of a model in which the standard
mystique of the energy of the vacuum does not hold.

Regards

--
Charles Francis
moderator sci.physics.foundations.
substitute charles for NotI to email
  #6  
Old March 1st 07, 07:47 PM posted to sci.astro.research
Oh No
external usenet poster
 
Posts: 433
Default Doppler Tests on Local Stars

Thus spake Stupendous_Man
... I have for some while been looking for a way
to test this, and finally came up with a simple statistical test on
local stars. For stars in perfect circular orbits, Doppler shifts,
together with the teleconnection correction, would cancel, but real
measured velocities show a wide random scatter. We can't measure the
true motion of any individual star without using Doppler, but if the
teleconnection is right then the radial component of velocity will be
overstated. I have been looking for a way to show that quoted radial
motions are systematically large compared to transverse ones. I


Have you included the systematic deviations from random
velocities due to the differential rotation of stars in the disk
and their actual, non-circular motions?

Suppose stellar orbits are elliptical, not circular.


Indeed, they are. More so than I had naively imagined.

Then stars
in our local neighborhood will be a mixture of populations,
which we can describe as a) stars with semi-major axes
smaller than the Sun's, which are currently at the apoapsis
of their orbits, b) stars with semi-major axes about the same
as the Sun's and c) stars with semi-major axes larger
than the Sun's, which are currently at the periapsis
of their orbits. The orbital velocities of these populations
will be different in systematic ways. The number of stars
from each population which we measure locally depends
on the overall radial gradient of stellar density in the
Milky Way, and on some geometry.


It is extremely complicated. Its not actually possible to divide the
whole into discrete populations like this. Moreover not all stars have
the same eccentricity. Although older stars give a fairly random, and
not exactly ellipsoidal mix (nearer three quadrants in the U-V plane,
though more even in the U-W and V-W planes), young ones do not and
contribute bulk motions.

It is possible that the effect of these different
populations could mimic the effect you see.


Certainly not all the effects. Even if some of the effects could be
mimicked in the manner you suggest (and I don't think they can) your
argument does not apply to halo stars, which gave the strongest
correlation of any population, rejecting the standard prediction with
99.999% confidence. Nor does it apply to correlations on the W axis,
which gave the highest correlation of any axis, rejecting the standard
prediction with 99.999999% confidence.

The fact that these two tests gave such strong results is entirely in
accordance with the teleconnection prediction. It is expected that the
Doppler error is largest for faster moving stars, and it is expected
that the correlations should show up best when the distribution is more
uniform.


Regards

--
Charles Francis
moderator sci.physics.foundations.
substitute charles for NotI to email
  #7  
Old March 1st 07, 07:49 PM posted to sci.astro.research
Oh No
external usenet poster
 
Posts: 433
Default Doppler Tests on Local Stars

Thus spake Kent Paul Dolan
"Oh No" wrote

restricting to stars ... within 100pc of the Sun


By doing so you've selected this tiny ball of
stars (compared to the size of the galaxy) all in
essentially the same part of the galaxy, all going
essentially in the same direction around the center
of the galaxy.

It seems to me, then, that essentially _all_ you
are seeing is proper motion of those stars with
respect to the sun, and that you're not at all
looking at your subject matter, speeds of approach
or recession on opposite limbs of galaxies that
tell us how fast those galaxies are turning.

Have I missed something?


Yes. You have missed so much that I do not even know where to begin.


Regards

--
Charles Francis
moderator sci.physics.foundations.
substitute charles for NotI to email
  #8  
Old March 1st 07, 09:41 PM posted to sci.astro.research
Martin Hardcastle
external usenet poster
 
Posts: 63
Default Doppler Tests on Local Stars

In article ,
Oh No wrote:
A prediction of the teleconnection is that the reason for the flattening
of galaxy rotation curves is that radial velocity measured using Doppler
requires a correction due to cosmological expansion. If this is true
then the orbital velocity of the sun about the Milky Way is ~160km/s,
not ~220km/s as is usually stated


You need to worry about how these results are consistent with the
observed parallactic motion of the galactic centre -- see e.g. Reid &
Brunthaler 2004 ApJ 616 872.

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
  #9  
Old March 1st 07, 09:43 PM posted to sci.astro.research
Oh No
external usenet poster
 
Posts: 433
Default Doppler Tests on Local Stars

Thus spake Kent Paul Dolan
"Oh No" wrote

restricting to stars ... within 100pc of the Sun


By doing so you've selected this tiny ball of
stars (compared to the size of the galaxy) all in
essentially the same part of the galaxy, all going
essentially in the same direction around the center
of the galaxy.


I am looking at the essentially random differences in orbit, due largely
to differences in eccentricity and the alignments of the axes.

It seems to me, then, that essentially _all_ you
are seeing is proper motion of those stars with
respect to the sun,


I am not sure if you know what proper motion is. It is the visible
movement of a star over time, measured in milliarcsecs per year. I am
converting that, together with radial velocity measurements into
velocities in km/s relative to the Sun. Now there is no a priore reason
why, on any axis we look out into space, there should be a stronger
alignment of velocities along that axis than there is perpendicular to
it, both for stars approaching and for stars going away, but that is
what must be happening if the standard model is right.

and that you're not at all
looking at your subject matter, speeds of approach
or recession on opposite limbs of galaxies that
tell us how fast those galaxies are turning.


The MONDian rotation curve applies in the Milky Way, just as it applies
in distant galaxies.



Regards

--
Charles Francis
moderator sci.physics.foundations.
substitute charles for NotI to email
  #10  
Old March 1st 07, 09:49 PM posted to sci.astro.research
Oh No
external usenet poster
 
Posts: 433
Default Doppler Tests on Local Stars

Thus spake Kent Paul Dolan
"Oh No" wrote

restricting to stars ... within 100pc of the Sun


By doing so you've selected this tiny ball of
stars (compared to the size of the galaxy) all in
essentially the same part of the galaxy, all going
essentially in the same direction around the center
of the galaxy.


I am looking at the essentially random differences in orbit, due largely
to differences in eccentricity and the alignments of the axes.

It seems to me, then, that essentially _all_ you
are seeing is proper motion of those stars with
respect to the sun,


I am not sure if you know what proper motion is. It is the visible
movement of a star over time, measured in milliarcsecs per year. I am
converting that, together with radial velocity measurements into
velocities in km/s relative to the Sun. Now there is no a priore reason
why, on any axis we look out into space, there should be a stronger
alignment of velocities along that axis than there is perpendicular to
it, both for stars approaching and for stars going away, but that is
what must be happening if the standard model is right.

and that you're not at all
looking at your subject matter, speeds of approach
or recession on opposite limbs of galaxies that
tell us how fast those galaxies are turning.


The MONDian rotation curve applies in the Milky Way, just as it applies
in distant galaxies.



Regards

--
Charles Francis
moderator sci.physics.foundations.
substitute charles for NotI to email
 




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