Hi to all and Nick,
Einstein always liked his students to question his theoretical claims (interpretation of facts, consistency, coherence, etc) and I'm sure Nick doesn't shy away from such questioning.
So with that in mind I want to address some astronomical questions that relates to the GC and GEN.
The following statements are cited in the wiki articles.http://en.wikipedia.org/wiki/Milky_Way#Sun.27s_location_and_neighborhoodThe Sun is currently 5–30 parsecs (16–98 ly) from the central plane of the Galactic disk.
Based on this wide range of measure isn't there a considerable percent error needed to be factored in when calculating the GEN?
I would think +/- 2 or 3 degrees from the 5 degree fiducial.The Sun's orbit around the Galaxy is expected to be roughly elliptical with the addition of perturbations due to the Galactic spiral arms and non-uniform mass distributions. In addition, the Sun oscillates up and down relative to the Galactic plane approximately 2.7 times per orbit.
With respect to the GC the Sun makes a complete orbit every 225 million years which on the scale of millions of years would change the position of the GC with respect to the Sidereal Zodiak. Based on our human time scale it can be observed and experienced as fixed but actually is not fixed.
I would think that the oscillation motion of the Sun above and below the Galactic Plane causes a nonfixed GEN over long time periods. It is also calculated that one complete oscillation takes approx 83 million years based on the 2.7 oscillations per orbit so the rate of GEN movement is considerable in astronomical terms.
Here's another cited statement:http://en.wikipedia.org/wiki/Solar_apexThe sun's motion in the Milky Way is more complex than a simple orbit, it also shifts ("bobs") up and down with respect to the galactic plane.
So, for all practical purposes and for short human time scales the GC and GEN is fixed. But the huge measurement range of error of the Sun's distance from the Galactic Plane is a concern and so the accuracy of the 5 degree fiducial may be in question.
I would think that the projection of the ecliptic is very sensitive to distance from the plane of the galaxy. Somewhat like sensitivity to initial conditions of a nonlinear function.
Also, a related question is why wouldn't the GEN fiducial be considered as the 0 degree Aries point of a reformatted and reconfigured Sidereal and astronomical constellation system? Why accept the present astronomical constellation system?
I understand it has historical precedence and probably based on the 'Biopsychic Field' notion proposed in Arguelles book Earth Ascending
but in terms of exoplanet models all galactic sun/solar systems should base their Sidereal Zodiak on their respective GEN fiducial. (GEN as primary and local star neighborhood as secondary)
Sorry to be such a stickler but these are probably the kind of questions that would be asked in a classroom setting by a bunch of Astronomy Grads who want to understand Astrology (aka Metaphysical Astronomy).
Look forward to your feedback.
March 10 Update
The wiki article stating 5 - 30 parsecs for Sun distance to Galactic Planes needs some more corroboration.
Here's a few recent studies using various techniques to determine distance of Sun to GP. The various distances are in bold green.
1. the wiki citation of 5-30 pchttp://adsabs.harvard.edu/abs/2009MNRAS.398..263MThe distance of the Sun from the Galactic plane inferred from classical Cepheid variables is Z solar = 26 +/- 3pc, a result dependent on the sample's distance and direction because of the complicating effects of Gould's Belt and warping in the Galactic disc.
2. Displacement of the Sun from the Galactic planehttp://adsabs.harvard.edu/abs/2007MNRAS.378..768JAbstract
We have carried out a comparative statistical study for the displacement of the Sun from the Galactic plane (z solar) following three different methods. The study has been carried out using a sample of 537 young open clusters (YOCs) with log(Age) < 8.5, lying within a heliocentric distance of 4 kpc, and 2030 OB stars observed up to a distance of 1200 pc, all of which have distance information. We statistically separated the members of the Gould Belt before investigating the variation in the z solar estimation with different upper cut-off limits in the heliocentric distance and distance perpendicular to the Galactic plane. We have found that z solar varies in the range ~13-20 pc from the analysis of YOCs and in the range ~6-28 pc from the analysis of OB stars. A significant scatter in zs olar, because of different cut-off values, is noticed for the OB stars, although no such deviation is seen for the YOCs.
3. The Sun's Displacement from the Galactic Plane from Spectroscopic Parallaxes of 2500 OB Starshttp://adsabs.harvard.edu/abs/2006JRASC.100..146RAbstract
The Sun's vertical displacement from the galactic plane, Z_sun, is determined model-independently from 3526 spectroscopic parallax distance estimates for 2488 OB stars within 1200 pc of the Sun. The result, 19.6+/-2.1 pc, agrees well with various other recent determinations. The distribution of stellar z-values as a function of galactic longitude shows a very scattered sinusoidal dependence with an amplitude of about 27 pc.
4. The Sun's Distance from the Galactic Planehttp://link.springer.com/article/10.1023%2FB%3AASTR.0000005097.18183.64?LI=trueAstrophysics and Space Science
12-2003, Volume 288, Issue 4, pp 313-325
R.L. Branham Jr.
Use is made of 93,106 parallaxes from the Hipparcos catalog, with a mixture of spectrum-luminosity classes, to derive the position of the Galactic plane. The reduction technique, mixed total least squares-least squares, takes into account the errors in the parallaxes, and the condition that the direction cosines of the Galactic pole have unit Euclidean norm is rigorously enforced. To obtain an acceptable solution it is necessary to eliminate the stars of classes O and B that belong to the Gould belt. The Sun is found to lie 34.56±0.56 pc above the plane.
5. The Sun's Distance Above the Galactic Planehttp://adsabs.harvard.edu/abs/1995AJ....110.2183H Humphreys, Roberta M.; Larsen, Jeffrey A.
Astronomical Journal v.110, p.2183
We have determined the Sun's distance (Zsun) from the galactic plane using optical star counts in 12 Palomar Sky Survey fields, six each at the North and South galactic poles. The star counts were made in t6 square degree regions at the center of each field in the O (blue) magnitude range 15-18. All stars with O - E color greater than 1.8 mag (B - V- 1.1 mag) were selected to isolate a sample of disk population stars in this magnitude range. The total counts show significantly more stars in the six fields at the SGP indicating that the Sun is above the galactic plane as defined by neutral hydrogen. The observed ratio of N(SGP)/N(NGP) is 1.11±0.O2 leading to Z sun=20.5±3.5 pc above the galactic midplane.