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Old November 17th 17, 07:33 AM posted to sci.astro.amateur
Quadibloc
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Default Focus on RA/Dec modeling concluded

On Wednesday, November 15, 2017 at 12:08:47 AM UTC-7, Gerald Kelleher wrote:

You are welcome to your idea that rotation around Polaris has a greater
relevance than rotation to our central star


Greater relevance in what sense?

When I get up in the morning, when I eat my meals, that's guided by rotation to
the central star; so are the clock cycles of other living things. That's a lot
of relevance, while the apparent rotation of the stars around the planets only
affects things like pointing a telescope.

But the Earth's orbit around the Sun is an ellipse, not a circle. The Equation
of Time is the result of the 24-hour daily cycle of sunlight deriving from a
compound motion - the Earth's own rotation as a physical object, and the *non-
uniform* change in the direction from the Earth to the Sun over the course of a
year.

If the Earth's rotation were to be properly defined in relation to the Sun, then
why does it speed up and slow down in concert with its orbit around the Sun so
as to make stellar circumpolar motion, as opposed to the Sun's apparent motion,
regular like clockwork?

Retrogrades show that the apparent motion of planets around the Earth is a
compound motion, while their motion around the Sun is a simple motion.

The Equation of Time shows that the motion of the Earth gauged against the fixed
stars is a simple motion, while the apparent motion of the Sun in our skies is a
compound motion.

John Savard