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Date: 29 Aug 2007 04:54:28
From: oriel36
Subject: Dynamicists and astronomy
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There are many who wish to remain stuck with the late 17thg century
terrestrial ballistics agenda applied to planetary motion which Newton
attempted to explain orbital geometries and that is fine.There
is,however,a 21st century way to revisit Keplerian orbital geometries
in such a way that it should provide a lively discussion .
There is every reason to believe that the Earth's orbital geometry is
conditioned by compound orbital motions insofar as combining planetary
heliocentric orbital motion with the fact that the Earth spends
months travelling in the direction of the Sun in one direction around
the galactic axis and months travelling in the opposite direction,the
results would produce a geometry that is not circular.
The basis for assuming compound motions in creating planetary orbital
geometries with variations in orbital speed is derived from taking an
even wider perspective.The structure of galaxies may be a product of
external rotations acting on the vast stellar island just as the
external rotation of the Earth supplies the characteristic spiral arms
of hurricanes -
http://www.badastronomy.com/pix/bablog/2005/katrina_galaxy.jpg
The linkage between ever greater rotations and smaller ones is far
more productive than the local ballistic solutions provided by Isaac
on the basis of an isolated solar system.
Different era with modern imaging and it is about time dynamicists
worked for a change instead of relying on the old cobblers of Newton
and the exotic 20th century stuff.
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Date: 02 Sep 2007 22:19:09
From: Quadibloc
Subject: Re: Dynamicists and astronomy
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oriel36 wrote:
> "That the fixed stars being at rest, the periodic times of the five
> primary planets, and (whether of the sun about the earth, or) of the
> earth about the sun, are in the sesquiplicate proportion of their mean
> distances from the sun." Newton
>
> As none of you are astronomers,I would not expect you to be shocked at
> that junk statement nor even attempt to understand the original
> statement of Kepler based on orbital comparisons between planets -
>
> The proportion existing between the periodic times of any two planets
> is exactly the sesquiplicate proportion of the mean distances of the
> orbits, or as generally given,the squares of the periodic times are
> proportional to the cubes of the mean distances." Kepler
I can see that Kepler, unlike Newton, didn't drag the "fixed stars"
into it, and from your other posts I presume that is what you object
to.
You can certainly *derive* an inertial reference frame from the
motions of the planets about the Sun and Kepler's law without having
to look at the stars. If you accept that it would be absurd for the
Earth and Sun to stand still while Venus and Mars moved according to
their synodic periods - and the outer planets moved around the Sun in
*always* a retrogade direction according to their synodic periods -
but instead all the planets should move in the same direction, by a
uniform law -
then you get Kepler's law _and_ an inertial reference frame.
Which happens to coincide (over limited periods of time, because our
Sun's motion among the stars is very slow compared to the distances
between the stars) with the frame of the stars - which helped make
this law of Kepler easier to notice in the first place.
Newton mentioned the fixed stars because they are an easy way to
understand which things are rotating and which way. Otherwise, Mercury
could be standing still, with the Earth orbiting the Sun in around 120
days or so, as far as we knew.
John Savard
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Date: 29 Aug 2007 12:10:54
From: oriel36
Subject: Re: Dynamicists and astronomy
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On Aug 29, 6:19 pm, AustinMN <tacooper...@hotmail.com > wrote:
> On Aug 29, 6:54 am, oriel36 <geraldkelle...@yahoo.com> wrote:
>
> > The structure of galaxies may be a product of
> > external rotations acting on the vast stellar island just as the
> > external rotation of the Earth supplies the characteristic spiral arms
> > of hurricanes -
>
> Classic. Trying to use something that is driven by terrestrial
> ballistics to prove terrestrial ballistics don't work.
>
> What an idiot.
>
> Austin
The framework Newton used to promote his terrestrial ballistics
agenda is based on Flamsteed's astrological Ra/Dec system,,he
isolated the solar system within the astrological framework with not
the slightest chance of escaping it -
"That the fixed stars being at rest, the periodic times of the five
primary planets, and (whether of the sun about the earth, or) of the
earth about the sun, are in the sesquiplicate proportion of their mean
distances from the sun." Newton
As none of you are astronomers,I would not expect you to be shocked at
that junk statement nor even attempt to understand the original
statement of Kepler based on orbital comparisons between planets -
The proportion existing between the periodic times of any two planets
is exactly the sesquiplicate proportion of the mean distances of the
orbits, or as generally given,the squares of the periodic times are
proportional to the cubes of the mean distances." Kepler
Using terrestrial ballistics as an example is fine for this is what I
have done in showing generalised principles which link hurricane
with galactic structure ,what is not correct is using a framework that
is astrological to achieve the objective and that is where Newton
jumps the tracks.He assumed that a hypothetical observer on the Sun
was equivalent to watching retrogrades from Earth hence -
"...(whether of the sun about the earth, or) of the earth about the
sun, are in the sesquiplicate proportion.." Newton
So,being from the 21st century and recognising the solar system's
galactic orbital motion along with the oft remarked resemblance
between hurricane and galactic structure,it is easy enough to work
with compountd motions.You are stuck in a late 17th century celestial
sphere and if you can stomached being trapped in soimebody else's
imagination (Flamsteed's astrological reasoning in this case) then
good for you.
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Date: 29 Aug 2007 10:19:19
From: AustinMN
Subject: Re: Dynamicists and astronomy
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On Aug 29, 6:54 am, oriel36 <geraldkelle...@yahoo.com > wrote:
> The structure of galaxies may be a product of
> external rotations acting on the vast stellar island just as the
> external rotation of the Earth supplies the characteristic spiral arms
> of hurricanes -
Classic. Trying to use something that is driven by terrestrial
ballistics to prove terrestrial ballistics don't work.
What an idiot.
Austin
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