"Henri Wilson" HW@.. wrote in message
...

| I don't think we can judge the whole universe by our local knowledge
of it. For
| instance even an SRian wouldn't use the sun as a model for one of
their
| imaginary cepheids?

Blackwell Synergy: Monthly Notices RAS, Vol 0, Issue 0: Sun's ...
"The Sun wobbles about the Solar system barycentre with the distance
varying up to two times its radius." - (RAS - Royal Astronomical
Society)

The sun is an irregular cepheid with a period of 4330 days when seen
from M31.

FYI, H, this is well thought-out applet.
http://www.astro.wisc.edu/~dolan/con...rsa_Major.html


http://www.astro.uiuc.edu/~kaler/sow/mizar.html
"MIZAR (Zeta Ursae Majoris). One of the most famed stars of the sky,
second magnitude (2.27) Mizar, 78 light years away, is the Zeta star of
Ursa Major, the Greater Bear, the second star in from the end of the
handle of the Big Dipper, and the Dipper's fourth brightest star. In
large part its fame comes from the coupling of the star with a nearby
visual companion, fourth magnitude Alcor, only 12 minutes of arc (a
fifth of a degree) to the northeast. The two, Mizar and Alcor, termed
the "horse and rider" by the Arabians, are a good test of minimal
vision. The star's Arabic name derives from a word meaning "the groin"
of the celestial Bear that plods silently around the north celestial
pole (the name mistakenly drawn from Merak, in the Dipper's bowl).
However even without Alcor, Mizar takes its place in the celestial hall
of fame as the first known "double star," one that consists of a pair of
stars that orbit each other. Found to be double in 1650, Mizar is a
prime target for someone with a new telescope, as the components are an
easy 14 seconds of arc apart (at least 500 astronomical units), the two
taking at least 5000 years to make their orbit about each other. More
remarkably, each of these two components is AGAIN double. The brighter
of the two contains a very close pair a mere 7 or 8 thousandths of a
second of arc apart (an angle made by a penny at a distance of 300
miles) that has an orbital period of 20.5 days; the fainter of them
contains a pair with a period of about half a year. Mizar is thus
actually a quartet of stars, a double-double. It is moving through space
together with its more-distant companion, Alcor. Mizar and Alcor
together therefore probably make a quintuple star, Alcor taking at least
750,000 years to make a single round trip around its quadruple
companion. All of the stars are similar, all "main sequence"
hydrogen-fusing stars like the Sun, but of white class A (the brighter
both A2, the fainter probably both A5 or A7) with temperatures ranging
between around 7500 and 9000 degrees Kelvin and luminosities from 10 to
30 times solar. The orbit of the brighter double that makes Mizar has
been observed with a sophisticated "interferometer" that makes use of
the interfering properties of light. Analysis shows the component stars
to have masses 2.5 times that of the Sun; the masses of the fainter pair
are estimated at around 1.6 solar. The stars have odd chemical
abundances as a result of slow rotation, which allows for quiet
atmospheres and chemical separation. The brighter of the pair seen
through the telescope is rich in silicon and strontium, whereas the
fainter is a "metallic line star" that is deficient in aluminum and
calcium but high in silicon and in rare earths like cerium and samarium.
"




http://www.uwgb.edu/dutchs/planets/resonanc.htm

Chaos does not mean: Events are not governed by laws of nature.
Chaos does mean: Events are governed by the laws of nature but their
behavior is too complex for simple description.

Chaos does not mean: Events are random or unpredictable.
Chaos does mean: Events may be predictable in the short term
but not over arbitrarily long times. Small errors at the start of a
prediction compound later on into great differences.

Chaos does not mean: Chaotic systems are unstable and will
eventually fall apart (the Jurassic Park Fallacy)

Chaos does mean: Chaotic systems may remain within fixed bounds
but their behavior within those bounds may be hard to predict.

Wilson half spirals (WHS) are chaotic.
Wilson program-writing rating: One Brewery.
Androcles.