![]() | This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
Please note. In Auguest 2009, this article was moved from Retrograde and direct motion. All of its talk, history and log pages went with it because it was decided that virtually all the article itself was about Apparent Retrograde Motion. Retrograde and direct motion now directs to Retrograde motion, not here. The first 15 sections below were created before the renaming took place and may discuss topics that are no longer present. -- RoyGoldsmith ( talk) 01:22, 19 August 2009 (UTC)
Im looking for an authoritative source that uses the term retrogradation. If there isn't such a source, I still like the idea of the word as it is defined here, but I'd like to know if this word is actually used atm. Lir 15:09 Nov 4, 2002 (UTC)
I removed:
In Religion
what is interesting here is to know that the religion of muslims (islam) talked about this motion through the Prophet Muhammed9(SAW), by saying that sun someday will rise from west after three days of not rising and this will be a sign of groups of group of signs before the day of judgment.
Since this is way OT, having nothing to do with retrograde orbit (since this would have to affect rotation not orbit), and since prophecy doesn't lend itself to verification. Dominick 12:06, 30 Jun 2004 (UTC)
"Muslims knew about this thousands of years ago. To read more go to http://www.shiaconnect.com/forum/showthread.php?t=223 (iam not advertising)."
I have removed it on the grounds that the tone is distinctly un-wikipedia-ish, and also, as a forum, the content may be volatile. A link along the same lines but to a proper website, not a forum, can certainly be added if someone can find it. 128.232.250.254 23:34, 23 May 2006 (UTC)
--- True enough that Muslim texts do mention the Sun rising from the West. However, muslim texts also allude to the sun moving in it's own exclusive orbit. Is it farfetched to ponder the possibility of the Orbit of our solar system meshing our coming near to the orbit of another solar system? Would it not create the same effect of our sun or a sun rising from the west?
Dr. Maurice Bucaille in his brief yet informative booklet entitled "The Bible, the Qur’an and Science" edited by Dr. A. A. B. Philips writes:
..."Orbits
Today, the laws governing the celestial systems are well known. Galaxies are balanced by the position of stars and planets in well-defined orbits, as well as the interplay of gravitational forces produced by their masses and the speed of their movements. But is this not what the Qur’an describes in terms which have only become comprehensible in modern times. In chapter al-Ambiyaa we find:
“(God is) the one who created the night, the day, the sun and the moon. Each one is traveling in an orbit with its own motion.” Qur’an,21:33
The Arabic word which expresses this movement is the verb yasbahoon which implies the idea of motion produced by a moving body, whether it is the movement of one’s legs running on the ground, or the action of swimming in water. In the case of a celestial body, one is forced to translate it, according to its original meaning, as ‘to travel with its own motion.’
In my book, The Bible, The Qur'an and Science, I have given the precise scientific data corresponding to the motion of celestial bodies. They are well known for the moon, but less widely known for the sun."... - Dr. Maurice Bucaille
- Abu Raihanah Chris Medlock
---
--- —Preceding unsigned comment added by 66.53.214.137 ( talk) 05:05, 26 January 2009 (UTC)
This article suggests looking at Retrograde for the musical term, but that now redirects to this article. What's up? Confusing Manifestation 16:51, 30 January 2006 (UTC)
In the 2nd image ("Like that") with a retrograde motion, either the symbols A2 and A4 are swapped (if you start from left A1), or there are 2x A1 !
Well, I cannot edit swg graphics... Would you correct it?
The article says that planets beyond the Earth's orbit appear to switch direction. I think it's true to say that the planets inside the Earth's orbit would also exhibit this behaviour as they periodically overtake the Earth, but it is not seen because it always occurs during the day time.
Retrograde motion and venus. Remarkable. —Preceding unsigned comment added by Merwin21 ( talk • contribs) 01:42, 22 November 2007 (UTC)
Have edited article to describe Pluto as a planetoid, not a planet as was implied by the original text. —Preceding unsigned comment added by 198.54.202.94 ( talk) 23:54, 24 July 2008 (UTC)
See the sentence "The north orbital pole ... is defined to be south."
The same sentence in the "Orbital Pole" article is "The north orbital pole ... is defined to be north."
I'll leave it to an expert to decide which is right.
216.22.31.10 ( talk) 17:21, 15 October 2008 (UTC)
I've just edited this bit to make it clear that the explanation given is not accepted by all astrologers. I've credited it to "a contributor" because I can't make out from the history who put it in. If whoever it is wants to sign it they're welcome. Wombat140 ( talk) 21:02, 11 March 2009 (UTC)
Weatherlawyer ( talk) 19:50, 23 January 2016 (UTC)
The text has 2009-2010, but the picture of Mars has 2003. —Preceding unsigned comment added by 92.11.229.26 ( talk) 14:57, 22 May 2009 (UTC)
Section Retrograde motion in astrology contains some very low-quality logic:
The "since" subclause is false. All motions are relative, involving Earth's motion and the planet's motion, and no planet travels retrogradely as seen from a fixed point far above the north pole of sun. Hence the entire clause is false. ... said:
Rursus (
bork²)
15:39, 25 June 2009 (UTC)
And the source provided claims nothing of that kind. ... said:
Rursus (
bork²)
15:41, 25 June 2009 (UTC)
Can we get some figures or animation involving the process of retrograde involving an inferior planet? As the article says, "Mercury in retrograde" is a very common astrological phrase, but there is not enough description differentiating how the retrograde motion would appear or its frequency. MMetro ( talk) 09:36, 11 August 2009 (UTC)
Now I get it ;). 92.229.60.199 ( talk) 10:43, 11 August 2009 (UTC)
WASP-17b is the first planet (really exoplanet) discovered that exhibits true retrograde motion, like Triton. The article about Retrograde and direct motion talks mainly (or exclusively, I'm not sure) about apparent retrograde motion. Now that a retrograde planet has been observed, this should be made clear, possibly with links to Triton and WASP-17b. I'd do it myself but I'm not an astronomer. -- RoyGoldsmith ( talk) 12:47, 14 August 2009 (UTC)
The astrology section is nothing more than some evidence-free claims made up out of whole cloth. If you check the citations, they say things like "When a person is born with Mercury Retrograde, it indicates that in past lives there was a discrepancy between the words the native was speaking, and what they truly thought on their own." [1] Why does this information deserve to be in an encyclopedia? Gary ( talk) 17:33, 15 August 2009 (UTC)
The discussion links at the tops of the articles Apparent retrograde and direct motion and Retrograde and direct motion both direct a user to the same talk page. This is confusing. Both articles should have their own talk pages, because not everything on the talk page is applicable to both articles. For example, when I questioned the need for an astrology section, I based that question according to Apparent retrograde and direct motion, which has an astrology section, not on Retrograde and direct motion, which lacks an astrology section (as it should). Gary ( talk) 18:32, 16 August 2009 (UTC)
This is a decent article, but I feel like there needs to be a section covering the effect this had on astronomers such as Aristotle, Eudoxus, etc. This apparent retrograde motion is what caused ancient astronomers to begin using concepts such as equants, eccentrics, and epicycles. It also led to Eudoxus' nested sphere model of planetary motion. These subjects are extremely important when looking at the history of science and since they were completely caused by apparent retrograde motion, there should be a section discussing these effects. Nro87 ( talk) 20:01, 24 May 2013 (UTC)
This article is about Apparent retrograde motion. We don't mention fringe beliefs in mainstream articles without good reason, otherwise that would give them undue weight ( WP:ONEWAY). Issues with Astrology should not be discussed in this article on Apparent retrograde motion since there are no independent reliable sources which "connect the topics in a serious and prominent way". IRWolfie- ( talk) 23:45, 28 June 2013 (UTC)
One thing that puzzled me - and which the article doesn't seem to currently cover - is exactly when the direction reversal happens. In terms of Earth and Mars, I guess it's basically when the direction of the Earth is directly at Mars, i.e. the tangent line of the Earth's orbit at Earth's location passes through Mars. And the regular motion resumes when the tangent line again crosses through Mars on the other side. Maybe worth mentioning? Wknight94 talk 14:54, 4 March 2015 (UTC)
In the section "Apparent Motion" -> "From Earth," we read:
This is followed by a reference to "Carrol, Bradley and Ostlie, Dale, An Introduction to Modern Astrophysics, Second Edition, Addison-Wesley, San Francisco, 2007. pp. 4." While the deferents and epicycles as a possible explanation to retrograde motion are indeed discussed in the passage quoted, An Introduction to Modern Astrophysics makes no mention to Apollonius at that page, or even in that chapter at all.
IMHO, this reference should be changed, or the sentence modified to remove mention of Apollonius (a solution which I deem wrong, though, because it's Apollonius who demonstrated that planets can have a retrograde motion in this model).
Opinions?
CielProfond ( talk) 22:17, 16 April 2023 (UTC)
I removed the three tables giving the dates each planet began and ended retrogradation. They were for the years 2018, 2019, and 2020. Totally in the past and giving information that can be easily found by a google search. I suggest that these tables not be replaced here, because they are not being updated in a timely manner. Rather a sentence giving the name of a source for this information, with a link to it, be placed here instead. Nick Beeson ( talk) 22:08, 30 October 2023 (UTC)
![]() | This article is rated C-class on Wikipedia's
content assessment scale. It is of interest to the following WikiProjects: | ||||||||||
|
Please note. In Auguest 2009, this article was moved from Retrograde and direct motion. All of its talk, history and log pages went with it because it was decided that virtually all the article itself was about Apparent Retrograde Motion. Retrograde and direct motion now directs to Retrograde motion, not here. The first 15 sections below were created before the renaming took place and may discuss topics that are no longer present. -- RoyGoldsmith ( talk) 01:22, 19 August 2009 (UTC)
Im looking for an authoritative source that uses the term retrogradation. If there isn't such a source, I still like the idea of the word as it is defined here, but I'd like to know if this word is actually used atm. Lir 15:09 Nov 4, 2002 (UTC)
I removed:
In Religion
what is interesting here is to know that the religion of muslims (islam) talked about this motion through the Prophet Muhammed9(SAW), by saying that sun someday will rise from west after three days of not rising and this will be a sign of groups of group of signs before the day of judgment.
Since this is way OT, having nothing to do with retrograde orbit (since this would have to affect rotation not orbit), and since prophecy doesn't lend itself to verification. Dominick 12:06, 30 Jun 2004 (UTC)
"Muslims knew about this thousands of years ago. To read more go to http://www.shiaconnect.com/forum/showthread.php?t=223 (iam not advertising)."
I have removed it on the grounds that the tone is distinctly un-wikipedia-ish, and also, as a forum, the content may be volatile. A link along the same lines but to a proper website, not a forum, can certainly be added if someone can find it. 128.232.250.254 23:34, 23 May 2006 (UTC)
--- True enough that Muslim texts do mention the Sun rising from the West. However, muslim texts also allude to the sun moving in it's own exclusive orbit. Is it farfetched to ponder the possibility of the Orbit of our solar system meshing our coming near to the orbit of another solar system? Would it not create the same effect of our sun or a sun rising from the west?
Dr. Maurice Bucaille in his brief yet informative booklet entitled "The Bible, the Qur’an and Science" edited by Dr. A. A. B. Philips writes:
..."Orbits
Today, the laws governing the celestial systems are well known. Galaxies are balanced by the position of stars and planets in well-defined orbits, as well as the interplay of gravitational forces produced by their masses and the speed of their movements. But is this not what the Qur’an describes in terms which have only become comprehensible in modern times. In chapter al-Ambiyaa we find:
“(God is) the one who created the night, the day, the sun and the moon. Each one is traveling in an orbit with its own motion.” Qur’an,21:33
The Arabic word which expresses this movement is the verb yasbahoon which implies the idea of motion produced by a moving body, whether it is the movement of one’s legs running on the ground, or the action of swimming in water. In the case of a celestial body, one is forced to translate it, according to its original meaning, as ‘to travel with its own motion.’
In my book, The Bible, The Qur'an and Science, I have given the precise scientific data corresponding to the motion of celestial bodies. They are well known for the moon, but less widely known for the sun."... - Dr. Maurice Bucaille
- Abu Raihanah Chris Medlock
---
--- —Preceding unsigned comment added by 66.53.214.137 ( talk) 05:05, 26 January 2009 (UTC)
This article suggests looking at Retrograde for the musical term, but that now redirects to this article. What's up? Confusing Manifestation 16:51, 30 January 2006 (UTC)
In the 2nd image ("Like that") with a retrograde motion, either the symbols A2 and A4 are swapped (if you start from left A1), or there are 2x A1 !
Well, I cannot edit swg graphics... Would you correct it?
The article says that planets beyond the Earth's orbit appear to switch direction. I think it's true to say that the planets inside the Earth's orbit would also exhibit this behaviour as they periodically overtake the Earth, but it is not seen because it always occurs during the day time.
Retrograde motion and venus. Remarkable. —Preceding unsigned comment added by Merwin21 ( talk • contribs) 01:42, 22 November 2007 (UTC)
Have edited article to describe Pluto as a planetoid, not a planet as was implied by the original text. —Preceding unsigned comment added by 198.54.202.94 ( talk) 23:54, 24 July 2008 (UTC)
See the sentence "The north orbital pole ... is defined to be south."
The same sentence in the "Orbital Pole" article is "The north orbital pole ... is defined to be north."
I'll leave it to an expert to decide which is right.
216.22.31.10 ( talk) 17:21, 15 October 2008 (UTC)
I've just edited this bit to make it clear that the explanation given is not accepted by all astrologers. I've credited it to "a contributor" because I can't make out from the history who put it in. If whoever it is wants to sign it they're welcome. Wombat140 ( talk) 21:02, 11 March 2009 (UTC)
Weatherlawyer ( talk) 19:50, 23 January 2016 (UTC)
The text has 2009-2010, but the picture of Mars has 2003. —Preceding unsigned comment added by 92.11.229.26 ( talk) 14:57, 22 May 2009 (UTC)
Section Retrograde motion in astrology contains some very low-quality logic:
The "since" subclause is false. All motions are relative, involving Earth's motion and the planet's motion, and no planet travels retrogradely as seen from a fixed point far above the north pole of sun. Hence the entire clause is false. ... said:
Rursus (
bork²)
15:39, 25 June 2009 (UTC)
And the source provided claims nothing of that kind. ... said:
Rursus (
bork²)
15:41, 25 June 2009 (UTC)
Can we get some figures or animation involving the process of retrograde involving an inferior planet? As the article says, "Mercury in retrograde" is a very common astrological phrase, but there is not enough description differentiating how the retrograde motion would appear or its frequency. MMetro ( talk) 09:36, 11 August 2009 (UTC)
Now I get it ;). 92.229.60.199 ( talk) 10:43, 11 August 2009 (UTC)
WASP-17b is the first planet (really exoplanet) discovered that exhibits true retrograde motion, like Triton. The article about Retrograde and direct motion talks mainly (or exclusively, I'm not sure) about apparent retrograde motion. Now that a retrograde planet has been observed, this should be made clear, possibly with links to Triton and WASP-17b. I'd do it myself but I'm not an astronomer. -- RoyGoldsmith ( talk) 12:47, 14 August 2009 (UTC)
The astrology section is nothing more than some evidence-free claims made up out of whole cloth. If you check the citations, they say things like "When a person is born with Mercury Retrograde, it indicates that in past lives there was a discrepancy between the words the native was speaking, and what they truly thought on their own." [1] Why does this information deserve to be in an encyclopedia? Gary ( talk) 17:33, 15 August 2009 (UTC)
The discussion links at the tops of the articles Apparent retrograde and direct motion and Retrograde and direct motion both direct a user to the same talk page. This is confusing. Both articles should have their own talk pages, because not everything on the talk page is applicable to both articles. For example, when I questioned the need for an astrology section, I based that question according to Apparent retrograde and direct motion, which has an astrology section, not on Retrograde and direct motion, which lacks an astrology section (as it should). Gary ( talk) 18:32, 16 August 2009 (UTC)
This is a decent article, but I feel like there needs to be a section covering the effect this had on astronomers such as Aristotle, Eudoxus, etc. This apparent retrograde motion is what caused ancient astronomers to begin using concepts such as equants, eccentrics, and epicycles. It also led to Eudoxus' nested sphere model of planetary motion. These subjects are extremely important when looking at the history of science and since they were completely caused by apparent retrograde motion, there should be a section discussing these effects. Nro87 ( talk) 20:01, 24 May 2013 (UTC)
This article is about Apparent retrograde motion. We don't mention fringe beliefs in mainstream articles without good reason, otherwise that would give them undue weight ( WP:ONEWAY). Issues with Astrology should not be discussed in this article on Apparent retrograde motion since there are no independent reliable sources which "connect the topics in a serious and prominent way". IRWolfie- ( talk) 23:45, 28 June 2013 (UTC)
One thing that puzzled me - and which the article doesn't seem to currently cover - is exactly when the direction reversal happens. In terms of Earth and Mars, I guess it's basically when the direction of the Earth is directly at Mars, i.e. the tangent line of the Earth's orbit at Earth's location passes through Mars. And the regular motion resumes when the tangent line again crosses through Mars on the other side. Maybe worth mentioning? Wknight94 talk 14:54, 4 March 2015 (UTC)
In the section "Apparent Motion" -> "From Earth," we read:
This is followed by a reference to "Carrol, Bradley and Ostlie, Dale, An Introduction to Modern Astrophysics, Second Edition, Addison-Wesley, San Francisco, 2007. pp. 4." While the deferents and epicycles as a possible explanation to retrograde motion are indeed discussed in the passage quoted, An Introduction to Modern Astrophysics makes no mention to Apollonius at that page, or even in that chapter at all.
IMHO, this reference should be changed, or the sentence modified to remove mention of Apollonius (a solution which I deem wrong, though, because it's Apollonius who demonstrated that planets can have a retrograde motion in this model).
Opinions?
CielProfond ( talk) 22:17, 16 April 2023 (UTC)
I removed the three tables giving the dates each planet began and ended retrogradation. They were for the years 2018, 2019, and 2020. Totally in the past and giving information that can be easily found by a google search. I suggest that these tables not be replaced here, because they are not being updated in a timely manner. Rather a sentence giving the name of a source for this information, with a link to it, be placed here instead. Nick Beeson ( talk) 22:08, 30 October 2023 (UTC)