On Thursday, February 27, 2014 at 9:22:16 PM UTC-7, palsing wrote:
>
> So now you are claiming to be smarter than Galileo, but you are simply wrong.
> There is only one definition of the word retrograde, and it does not differentiate
> between inner or outer planets. There are not separate causes, but there are
> different perspectives. What do you know about perspectives, anyhow?

It is true that "retrograde" means only one thing: moving backwards.

And the cause of apparent retrograde motion, whether of an inner or outer
planet, is the orbital motion of the Earth, so there is only one cause.

But that doesn't mean there is no difference between the sequence of causes
that leads to the apparent motion of the other planets in our sky between inner
and outer planets.

The apparent paths of planets around the Earth are circular in shape, but with
multiple loops along the way. In the case of an outer planet, the overall circle
corresponds to the planet's real motion, and the loops correspond to the change
made by the Earth's motion.

In the case of an inner planet, the overall circle corresponds to the Sun's apparent
motion around the Earth - the effect of the Earth's motion, and the loops correspond
to the planet's real motion.

That's definitely a difference of some sort.

John Savard

This thread was revisited in order to demonstrate that a lot of supplementary information has made the insight more enjoyable for observers.

https://www.youtube.com/watch?v=f7kL-kf2uZg

The new demonstration alone that the Earth orbits the centre of the solar system where our parent star exists and made possible by a tracking satellite and the annual change in position of the stars parallel to the orbital plane takes the most prominent position while the planets change position to the Sun and to a moving Earth in different ways with different luminosities and different rates.

Now that these celebrities have partitioned direct/retrograde motions, even with proper attribution and the difference in frameworks needed to complete a single narrative of a central Sun orchestrating the motions of the planets within the solar system structure, the nuisances in this newsgroup can cease their interruptions as they act like unruly kids in a restaurant while people are acting with discipline and integrity.

* "Now that these celebrities have partitioned direct/retrograde motions, even without proper attribution"

The original astronomers did not partition direct/retrogrades by virtue they were chained to observations made through the Ptolemaic framework so had to propose a moving Earth and other planets in a Sun-centred system as a hypothesis in the same manner as the geocentric astronomers-

"In the Ptolemaic hypotheses, there are the diseases, and the Copernican their cure. . . . With Ptolemy, it is necessary to assign to the celestial bodies contrary movements, and make everything move from east to west and at the same time from west to east, whereas with Copernicus all celestial revolutions are in one direction, from west to east. And what are we to say of the apparent movement of a planet, so uneven that it not only goes fast at one time and slow at another but sometimes stops entirely and even goes backwards a long way after doing so? To save these appearances, Ptolemy introduces vast epicycles, adapting them one by one to each planet, with certain rules about incongruous motions -- all of which can be done away with by one very simple motion of the Earth." Galileo

With 21st-century satellite imaging, no hypothesis is needed as direct/retrogrades of the inner planets are represented by their back-and-forth looping motions while the Earth's motion is largely accounted for by the new framework ( actually the oldest via heliacal rising dawn observations) -

https://www.youtube.com/watch?v=w2uCtot1aDg

Clearly, this topic now will find a home elsewhere even though I previously asked for cooperation in getting the two different resolutions for direct/retrograde motions out into the education system. Must be strange for contributors to this forum to see a celebrity explain what they refused to acknowledge all those years ago but then again, such people may be soo mind-numbingly dull to notice.

On Thursday, May 11, 2023 at 2:42:17 AM UTC-6, Quadibloc wrote:
> On Thursday, February 27, 2014 at 9:22:16 PM UTC-7, palsing wrote:
> >
> > So now you are claiming to be smarter than Galileo, but you are simply wrong.
> > There is only one definition of the word retrograde, and it does not differentiate
> > between inner or outer planets. There are not separate causes, but there are
> > different perspectives. What do you know about perspectives, anyhow?
> It is true that "retrograde" means only one thing: moving backwards.
>
> And the cause of apparent retrograde motion, whether of an inner or outer
> planet, is the orbital motion of the Earth, so there is only one cause.
>
> But that doesn't mean there is no difference between the sequence of causes
> that leads to the apparent motion of the other planets in our sky between inner
> and outer planets.
>
> The apparent paths of planets around the Earth are circular in shape, but with
> multiple loops along the way. In the case of an outer planet, the overall circle
> corresponds to the planet's real motion, and the loops correspond to the change
> made by the Earth's motion.
>
> In the case of an inner planet, the overall circle corresponds to the Sun's apparent
> motion around the Earth - the effect of the Earth's motion, and the loops correspond
> to the planet's real motion.
>
> That's definitely a difference of some sort.

In fact, it could indeed be considered that retrogrades of the inner planets have
a different "cause".

Outer planets have an apparent orbital period of direct motion which has the length
of their actual orbital period around the Sun, and apparent retrogrades caused by
the Earth's orbital motion.

Inner planets have an apparent orbital period of direct motion which has the length
of *the Earth's year*, caused by the Earth's orbital motion, and apparent retrogrades
caused by their own real orbital motion around the Sun!

Where the original poster is wrong, of course, is to think that something so
thumpingly obvious was never noticed by Copernicus and Kepler - never mind
Galileo, who discovered the moons of Jupiter - even if they thought it far too
obvious to write down an explicit explanation of it. Or at least one that he
noticed and recognized.

John Savard