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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 |
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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. |
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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 |
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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 |
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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 |
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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 |
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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 |
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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 |
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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
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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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