Quoting: Azeratel Axo
I have recently taken an interest in ancient Egyptians.
in my recent astrophysical research wanderings (trying to slueth out what the deal is with the precesion of the equinoxes) i have realized that it is very dificult to measure our (the solar system's) position and velocity within the greater (local) galactic context, beacuse, well, everything is moving...
it turns out that where we are is relative to where everything else is and our position and velocity depends on what we choose as referance points. Seeing this truth, i asked myself: how do we measure the length of our year (wanting to start small, u know?
and goddammit if even *that* is on shaky ground. I mean, think about it: how do we know we've gone one full rotation around Sol? It seems simple and obvious, but it is far from. I mean it's easy to know aproximatly from the seasons and the position of the sun in the sky, but to know *exactly*? not so much.
We used to think of the stars as fixed and used them as a measure, but what with the realazation that the large majority of the sky presseses, spins 'backwards' with respect to our yearly roation, it becomes a bit problematic.
look into "sidereal time" to get a feel for it.
current science measures our earth year using very distant quazars, cuz they *seem* to be the most 'stable' referance and we believe that pression (the great year = roughly 25,000 years) is caused by a gyroscopic 'wobble' in the earth's rotation and this works kinda if you think about it a while.
but there's a problem: first, this hypothosis, assumes that the earth is a solitary system (which we - meaning us here on this thread- know is not correct) and this pression and woble depends only on earth based dynamics. There are some incredibly complex math that 'almost' predicts the rate of pression, but here again is a problem, cuz this rate changes and current theroy cannot predict this changing rate, so every few years or so they (the mathematicians) tweak their equations to account for measured data.
it's all quite mind bending when you take the time to really look into the subject...
back to the egyptians : they had a very unique (to us calendar) and it was based on Sirius, the dog star. It was delightfully simple: 12 30 day months followed by 5 (and once every 4 years 6) holy days, or days out of time. and unlike any other calendar, the months stayed true year after year within sidereal time!
so what is so interesting about the dogstar (the brightest star in the sky, comprised of two stars actually: a binary system)?
1: if we choose sirius as our stellar referance (sirius is only 7 light years away, btw) then our earth year is *exactly* 365 and 1/4 days long, as apoosed to a few minutes shorter or longer, measured using the distant quasars or earth, respectively.
2: sirius is the *only* star that does not precess along with all the rest of the zodiac. that is to say that while Ares has been replaced by Pisces at the spring spring eqinox, sirius resolutly remains still in the sky.
3: if we consider the precession as a consequence of the solar system's rotation about a near stellar mass, then not only does the dogstar become the perfect canidate for that mass, but the change in rate of the pression of the eqinoxes becomes easily explainable in terms of keplarian eliptical orbital dynamics and the observed change in rate becomes predictable.
[link to en.wikipedia.org
[link to www.viewzone.com
[link to www.binaryresearchinstitute.org
be prepared to have your mind bent