A Space & astronomy forum. SpaceBanter.com

Go Back   Home » SpaceBanter.com forum » Astronomy and Astrophysics » Amateur Astronomy
Site Map Home Authors List Search Today's Posts Mark Forums Read Web Partners

A better view of direct/retrogrades for Mercury/Venus



 
 
Thread Tools Display Modes
  #11  
Old November 13th 18, 11:52 PM posted to sci.astro.amateur
palsing[_2_]
external usenet poster
 
Posts: 3,068
Default A better view of direct/retrogrades for Mercury/Venus

On Tuesday, November 13, 2018 at 3:03:13 AM UTC-8, Quadibloc wrote:
On Monday, October 22, 2018 at 10:34:19 PM UTC-6, palsing wrote:

Explain this...


http://www.nakedeyeplanets.com/mercu...b-may-2012.png


It is true that the aparent motion of Mercury resembles the apparent motion of
Mars; there is an overall motion through the Zodiac, and there are retrogade
loops.


Which is the only point I was trying to make. The 'reality' of Mercury's motion is way beyond Gerald's capacity to learn, which is essentially non-existent. He still denies that the inferior planets perform apparent retrograde loops, despite overwhelming evidence otherwise.

\Paul A
  #12  
Old November 14th 18, 06:43 AM posted to sci.astro.amateur
Quadibloc
external usenet poster
 
Posts: 7,018
Default A better view of direct/retrogrades for Mercury/Venus

On Tuesday, November 13, 2018 at 4:52:55 PM UTC-7, palsing wrote:
He still denies that the inferior planets perform apparent retrograde loops,
despite overwhelming evidence otherwise.


You are right that the apparent path of an interior planet also includes
retrogade loops, just like the apparent path of a superior planet.

I don't argue with that, and your image certainly proves that.

Where my dispute is that from the way I understand what he is saying, he isn't
denying that loops are a feature of the apparent path of an inferior planet as
seen in the sky.

It is true that he is not applying the term "apparent" to the loops, he is
calling them "real". But conventionally, when the apparent path of a superior
planet is described, it is often the retrogade loops specifically that are
called "apparent", not the planet's overall progress through the Zodiac.

If you go back to Ptolemy, the distinction that I think is being made becomes
explicit.

In the case of Jupiter, the _cycle_ has a period of about 12 years, while the
_epicycle_ has a period of 365 1/4 days.

In the case of the inferior planet Mercury, though, the _cycle_ has a period of
365 1/4 days, and the _epicycle_ has a period of 88 days.

That's what I mean when I say the "overall orbit" of an inferior planet is the
illusion - like the retrogade loops in the apparent path of a superior planet -
while the "retrogade loops" in the apparent path of an inferior planet are *not*
an illusion caused by the Earth's motion around the Sun, they reflect the
planet's real motion arount the Sun.

This is what he is trying to say. And since he isn't right that often, I think
giving him credit when he does get something right for once is important.

John Savard
  #13  
Old November 14th 18, 07:23 AM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default A better view of direct/retrogrades for Mercury/Venus

All this is predictable and normally the lot of innovative astronomy, even in an era where all things are affirmed by time lapse and other observations but despite the lack of kindness, it all eventually makes it into circulation.

"How many men attacked my Letters on Sunspots, and under
what disguises! The material contained therein ought to have
opened to the minds eye much room for admirable speculation;
instead it met with scorn and derision. Many people disbelieved
it or failed to appreciate it. Others, not wanting to
agree with my ideas, advanced ridiculous and impossible opinions
against me; and some, overwhelmed and convinced by
my arguments, attempted to rob me of that glory which was
mine, pretending not to have seen my writings and trying to
represent themselves as the original discoverers of these impressive
marvels" Galileo

My contribution is done on this matter so the images of the exoplanet as it passes behind the Sun will in future be complimented by a planetary transit as it completes its loop of its parent star much like Venus and Mercury are seen to do. The only additional difference is the special case where the Earth's motions are inclusive of the faster moving planets whereby the background stars transition from left to right of the Sun in order to set the Sun up as a stationary and central reference.

  #14  
Old November 14th 18, 10:25 AM posted to sci.astro.amateur
Gerald Kelleher
external usenet poster
 
Posts: 1,551
Default A better view of direct/retrogrades for Mercury/Venus

It is perhaps best to get these objections over with in this thread.

http://web.stanford.edu/~jsabol/cert...eo-Assayer.pdf

There is a pattern when something new and innovative appears ranging from silence to noise but this is common among those who operate with icons and celebrity.

I can understand the irritation of Galileo in an era where academic politics and social politics were more or less the same so the jockeying to protect redundant concepts or to exploit new observations often swamp the individual presenting observations for scrutiny. The Pope in the era of Galileo initially seemed open to striking a balance between old and new but ultimately opted for old familiar ways that destroyed Christian involvement in astronomy up to this day.

There is so much celebrity and icons around these days that it is quite a wonderful experience to be left alone and develop insights that I enjoy on my walks and in quieter moments. It would be these people that would find resonance with the astronomical interpretations as a satisfying experience so although the same set of characters exist as in the time Galileo wrote that letter, the outcome will be the same as productive views make it into circulation.

Nobody can accomplish insightful work if they propose themselves before what they are promoting as ideas. All people can do is share in the enjoyment where pieces of a puzzle fit together.

 




Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
What the direct/retrograde motion of Venus looks like Gerald Kelleher Amateur Astronomy 22 January 15th 18 07:33 PM
Retrogrades oriel36[_2_] Amateur Astronomy 0 September 17th 13 01:06 PM
Mercury & Venus Daniele Gasparri Amateur Astronomy 7 June 29th 05 03:39 PM
Venus and Mercury Bill-in-Forres UK Astronomy 0 June 27th 05 10:57 PM
Mercury & Venus 25-03-04 Pete Lawrence UK Astronomy 1 March 26th 04 04:22 PM


All times are GMT +1. The time now is 08:55 AM.


Powered by vBulletin® Version 3.6.4
Copyright ©2000 - 2024, Jelsoft Enterprises Ltd.
Copyright 2004-2024 SpaceBanter.com.
The comments are property of their posters.