Talk:Moon/Archive 14

Archive 10

←

Archive 12

Archive 13

Archive 14

Archive 15

Archive 16

Seasons

   I found

Although the Moon's minute axial tilt (1.54 degrees) means that seasonal variation is minimal, it is just enough to create a 3-degree variation in the Sun's elevation at the poles, resulting in a very slight "summer" and "winter".

but the cited ref at 'Coldest place' found on the Moon doesn't support "just enough" (except combining the imprecise sense of "just" with the trivial fact that 2×1.54≈3).
   Discussion of this requires dealing with distinction between its tilt relative to its orbit around the earth (6.68 degrees) and its tilt relative to the earth/moon system's orbit around the sun; i am not yet confident that subtracting the 5.14 degree tilt between the two orbits (to get 1.54) is valid, even in light of the tidal lock, rather than one of the numbers being some WP editor's defective original research, so i'm deferring writing all that is probably called for about angles. I think whoever wrote the caption blew it, and the 3-degree variation applies at lunar noon at all latitudes. In any case, the real story is not seasons but the near immunity of some near-polar points to summer increases.
--Jerzy•t 09:57, 24 August 2010 (UTC)

"The Moon's axial tilt of 1.54 degrees produces much less seasonal variation of illumination than the Earth's 23.44 degree tilt" How much lunar seasonal variation does Earth's 23.44 degree tilt cause? Seems to me it's essentially zero. If that's not what was meant by that statement, I suggest the statement needs to be clarified. Victor Engel (talk) 20:15, 24 August 2010 (UTC)

It seems clear to me. The Moon's axial tilt affects the Moon, the Earth's axial tilt affects the Earth, and that's what it's comparing: the lunar seasonal variation, if any, with that of the Earth which is significant (at least here in England). I don't see any problems with the angle. Orbit of the moon goes into more detail on the reasons why it has that value and gives a more precise value of 1.543° and a ref. I'm sure this will be covered in a more accessible form, such as a good general reference on the solar system or Moon. here's another source that mentions it for example. Looking at it as a whole I can't see major problems with that section.--JohnBlackburne^words_deeds 21:45, 24 August 2010 (UTC)

Thanks. I modified the sentence so that it's clear the Earth's tilt refers to Earth's seasons, not Moon's seasons as was implied by the previous wording. It's a bit clumsy as is. If someone think of a way to say the same thing less clumsily, please do. Victor Engel (talk) 21:55, 24 August 2010 (UTC)

   Thank you, Victor, for fixing that ambiguity, which escaped my notice. (But I urge you against the slangy misuse, on WP, of imply where there is merely insinuation or (as here) wording that creates the occasion for someone to invalidly infer something.)
--Jerzy•t 09:18, 25 August 2010 (UTC)

The word "imply" is not slang. It was a word carefully chosen to describe the essence of the problem with the sentence. That word is both accurate and efficient. Besides, this is a talk page. Victor Engel (talk) 14:01, 29 August 2010 (UTC)

Quasi-moons

   I removed:

There are several known near-Earth asteroids that have unusual Earth-associated horseshoe orbits: 3753 Cruithne, 54509 YORP, (85770) 1998 UP1 and 2002 AA29. They are co-orbital with the Earth, so that their orbits bring them close to Earth for periods of time but then alter in the long term, and they are not natural satellites of Earth.<ref>Connors, Martin (September 2002). "Earth coorbital asteroid 2002 AA29". Retrieved 16 April 2010. {{cite web}}: Unknown parameter |coauthors= ignored (|author= suggested) (help)</ref>

This is relevant to Other moons of Earth, and presumably covered there. It is a non-sequitur where i found it (Moon#Orbit and relationship to Earth, which i moved to Moon#Orbit, and does not deserve more than footnote mention (which already occurs at "nb4", a footnote to the lead sent).
--Jerzy•t 10:11, 24 August 2010 (UTC)

I have rescued the deleted ref to a peer-reviewed article and added it to the lead footnote. That text was in the article before the lead footnote was added. Iridia (talk) 02:10, 25 August 2010 (UTC)

Moon Image

I modified the description of the image on the moon page. It's not, in fact, a full moon image as was previously indicated. You can tell by looking that it's not a full moon. Additionally, the date/time of the image is the evening following the date of actual full moon that month. I suggest another full moon image be used if one is available. If not, I may contact some photographer friends to possibly upload another one. Victor Engel (talk) 15:53, 26 August 2010 (UTC)

There are a few on commons like File:FullMoon.jpg, File:Full moon.png, all from the category commons:Category:Full moon. But I don't have a problem with the current image: it's not so far off a full moon that anything is obscured, and the slight angle between the sun and the viewer adds shadows to the right side which usefully highlights craters. There is also an article full moon for those readers more interested in that particular phase of the moon.--JohnBlackburne^words_deeds 16:15, 26 August 2010 (UTC)

Thanks. I agree, the image is fine for the article, as long as it's not identified as a full moon. Just noticed the same image is used in the full moon article you cited, so I removed it from that article. Victor Engel (talk) 16:59, 26 August 2010 (UTC)

Both sides of the moon get EXACTLY the same amount of sunlight?

Both sides of the moon get exactly the same amount of sunlight? Can someone please either explain how that is possible, or find a reference that is accurate? As far as I knew, though the amount of sunlight is similar, it isn't exactly the same (or even nearly exactly the same). Something to do with the Earth being in the way when the near side of the moon is on the night side of the Earth, reducing the amount of light hitting it (what we know as phases).

Meanwhile, when the far side of the moon, when it is turning towards the sun, is not being blocked by the Earth (to nearly as large of an extent).

Perhaps I am misremembering my astronomy class. Hence my two part question above.

Thanks, RobertMfromLI | User Talk 03:38, 29 August 2010 (UTC)

Yes, "exactly" is too strong. The near side is sometimes shaded by the Earth (during a lunar eclipse), but the far side never is. The near side does benefit from sunlight reflected from the Earth, if you count that, while the far side does not. And the division into "far side" and "near side" is not a true dichotomy, due to libration, which makes the situation even more complex. Still, the purpose of the sentence you've queried is to debunk the idea that there is a "dark side of the moon", and with that in mind, I think "exactly" is a reasonable simplification. (Perhaps "essentially" would be better.) We should at least add a caveat in a footnote, though. --Avenue (talk) 09:11, 29 August 2010 (UTC)

   That response helps a great deal

Crescent or not crescent?

Hello. The lunar phase during the last quarter of the synodical cycle is called "waning crescent" in this article, and in some other pages, too. I didn't like this phrase so I have looked it up in my dictionary, and I found "decrescent" there. The "waning" and the "crescent" (increasing, greatening, waxing) are definitely contradictive words, the opposite direction of a "crescent" motion is "decrescent". So, I made a new (and proper) illustration about the phases, and I really would like to use the most and only correct phrases on that. I ask the native English speakers this question: which version is the correct, the official, the commonly used? Or if "decrescent" is as good as "waning crescent", am I allowed to change that in the text? - Orion 8 (talk) 21:12, 29 August 2010 (UTC)

In my opinion, waning crescent is better than decrescent. My firefox dictionary doesn't even recognize decrescent as a word. It's counterpart should be increscent, not crescent. Etymologically, increase and decrease both have the same root as crescent does, so I really don't see the problem with the word. First crescent is extremely important in certain cultures because it determines the calendar. So the first crescent is more significant than the last crescent (last crescent is the last visible sliver before new moon, not the phase just before first quarter or even just before full, which would be the alternatives if they must be increasing). Victor Engel (talk) 02:01, 30 August 2010 (UTC)

P.S. Increscent and decrescent are adjectives. Crescent is a noun. This is going to sound really redundant, but the first crescent is an increscent crescent. The last crescent is a decrescent crescent. Victor Engel (talk) 02:06, 30 August 2010 (UTC)

I'm a native (British) English speaker, and 'waxing crescent' (or 'crescent waxing') and 'waning crescent' sound natural to me. I'd never heard of the word 'decrescent', though on looking it up in the OED I find that it's the antonym of increscent. The OED also gives two separate meanings for 'crescent' - one specific to the waxing moon, and one for either waxing or waning. My experience is that the latter is the more commonly used, so 'waning crescent' is no contradiction.

Also, crescent is both a noun and an adjective (as in 'crescent moon'); the OED states that the same is true of 'increscent' and 'decrescent'. Olaf Davis (talk) 11:34, 31 August 2010 (UTC)

The following contrib has had its formatting corrected (indenting it below the deepest-indented contrib that it responds to), lest it appear that the first contributor to a discussion possesses the prerogative of responding at the left margin to close it.

Thank you for your answers. All right, I receive the judgement. Although I found 'decrescent' more consequent and rational, the evolution of a language is not rational, and I will follow the language. The modified image, with 'waxing crescent' and 'waning crescent', will be uploaded soon. Üdv! - Orion 8 (talk) 00:29, 3 September 2010 (UTC)

   A spell-checker rejection is a ridiculously bad criterion for foregoing a word: i've seen the Firefox one reject a word bcz (IRCC, but if i'm mistaken it was an analogous situation) bcz (presumably) someone decided there was no need to ever use its plural form, as i chose to.
   And checking the OED is a nuclear fly-swatter -- my 1st try, the 8th Collegiate, sufficed.
   But both adjectives are preciously obscure, in contrast to the very ordinary noun "crescent" (and its equally ordinary attributive use in "crescent moon"): the adjectives have been overtaken and largely displaced by the noun derived from one of their common root (Latin crescere, to grow), and are effectively archaic terms; they are in dictionaries not to encourage their use but mainly to permit those who would not use them to understand archaic works -- and modern ones by those who imitate archaic ones.
--Jerzy•t 20:25, 5 September 2010 (UTC)

Increscent and descrescent are nouns in heraldry: crescents with their horns to dexter or sinister, respectively, rather than to chief. HTH. —Tamfang (talk) 01:39, 18 October 2010 (UTC)

List of man made objects on the moon surface

Is there an article with all the artifacts on the moon surface ? Even the smallest objects like the golf balls (?), the NASA pin and the family photo in the zip bag, it would be interesting to have one. --79.168.10.241 (talk) 07:03, 17 September 2010 (UTC)

There's List of man-made objects on the Moon, but it doesn't list the smaller objects. Still pretty interesting, in case you haven't already seen it. --Bongwarrior (talk) 07:12, 17 September 2010 (UTC)

Thanks. --79.168.10.241 (talk) 17:46, 19 September 2010 (UTC)

Confirmed verification

J8079s deleted this sourced info,[1] claiming "failed verificaiton". Yet I have verified that this info is sourced properly and the source in question does indeed say that. (In restoring I have reworded the info, though the oriignal quote exists in the source).Bless sins (talk) 23:28, 1 October 2010 (UTC)

or not

The source here is a book review your edit is an improvement but your source is not reliable. al-Haytham's theory is that the moon is self-luminous with light borrowed from the sun,see Badeau, John Stothoff; Hayes, John Richard (1983-06-15). The Genius of Arab civilization: source of Renaissance. MIT Press. p. 166. ISBN 9780262580632. Retrieved 2 October 2010. and Tassoul, Jean Louis; Tassoul, Monique (2004). A concise history of solar and stellar physics. Princeton University Press. p. 21. ISBN 9780691117119. Retrieved 2 October 2010. if you read German then you could go to the source Schramm, Matthias (1963). Ibn al-Hayt̲h̲ams Weg zur Physik. Steiner Franz Verlag. Retrieved 2 October 2010.

To summarize; The claims of the book review cannot be verified. Although al-Haythams theories were wrong about the moon and other planets his demonstrations led to some insights about his theories of light and color. His theory needs to be accurately portrayed if its going to be here at all. Thank you for your help. J8079s (talk) 05:30, 2 October 2010 (UTC)

Please see;

• WP:Requests for comment/Jagged 85 April 2010
• WT:Requests for comment/Jagged 85 discussions and cleanup plans
• WP:Requests for comment/Jagged 85/Evidence
• WP:Requests for comment/Jagged 85/Recent evidence
• User:Spacepotato/Examples of original research in Wikipedia
• User:Spacepotato/Misuse of sources
• WP:Sockpuppet investigations/Jagged 85/Archive also edited as contributions and contributions

This edit Islamic astronomer and physicist, Alhazen (965–1039), found that sunlight was not reflected from the Moon like a mirror, as had been previously thought, but that light is emitted from every part of the Moon's illuminated surface.Toomer, G. J. (December 1964). "Review: Ibn al-Haythams Weg zur Physik by Matthias Schramm". Isis. 55 (4): 463–465. doi:10.1086/349914. although improved by Bless sins (talk is typical of the problem with the edits of jagged 85. It is misleading at best.J8079s (talk) 23:41, 3 October 2010 (UTC)

Perhaps because of my lack of expertise, I have a hard time understanding your arguments. Are you saying that a book review in Isis, an academic journal published by the University of Chicago Press is an unreliable source? A book review would be considered tertiary source under WP:PSTS. If there are contesting claims, though at this point I don't see any, then, per WP:DUE, we should present all of them, giving due wieght to each.

Both policies support inclusion of the passage in question, though its wording is certainly up in the air.Bless sins (talk) 19:47, 5 October 2010 (UTC)

I prefer the second wording, a direct quotation in English from an apparently German review of an Arab scholar was really pushing it. Bless Sins, if you are saying that you personally have viewed the source and are able to read the language and verify the source supports the revised wording, that's really good enough since we all work on trust. J8079s, if you too have read the source, can you outline your specific objection to the new wording? And either or anyone, I can't get at the source text - if you can send it to me, most appreciated. Franamax (talk) 21:19, 5 October 2010 (UTC)

And more, J8079s you say above that "al-Haytham's theory is that the moon is self-luminous with light borrowed from the sun" - but that is exactly correct! A photon emitted from the Sun interacts with surface matter on the Moon, it is absorbed then re-emitted, possibly at a different frequency but often with the same, i.e. reflection. The modern concept is albedo. So did al-Haytham have an explanation for the dark (low-albedo) bits demonstrably receiving sunlight? Franamax (talk) 21:36, 5 October 2010 (UTC)

Issues

1. Interpretation - when a source talks about "the quiddity" of light it is, it seems to me, easy to interpret that in so many ways that would destroy its value. Quiddity means quiddity, nature, type, essence, kind. It does not mean "frequency" "healing power" or even "colour" or "brightness" unless the source makes it explicitly clear.
2. Source. There is confusion over (and maybe in) the guidelines about primary/secondary/tertiary sources. Remote sourcing is not encouraged to promote "academic Chinese whispers", but to provide balanced insight. Thus the technically best source for what Al-Hytham said is the original Arabic, but since very few en: readers will understand that, a professional translation scores better. Having said that Al-Hytham in Arabic book form is likely to be secondary in the sense that there are, presumably, a number of manuscript versions which will have different readings internally and between manuscripts, and be in both the language, idioms and script of the time, and may have been damaged, redacted, changed, copied, improved etc.. Even so traps for the unwary WP editors exist in that the purposes of the translator may not be the same as ours of the instant . Hence to understand what Al-Hytham meant we are better turning to scholarly works of interpretation - secondary sources. And here the rub is that these may well be biased, or said to be biased. If there is sufficient tertiary source material that can help us remain NPOV. "The majority of modern scholars, according to Gnasher, interpret "quiddity" to refer to the warmth of the light, whereas those that follow Dennis, notably Minx and Plug.... "

For those that wish to follow up, and have access to suitable library facilities, here is a ref for a translation in English of Al-Hytham's work.

• Sabra, AI (1989). The optics of Ibn al-Haytham: Books I-III : on direct vision. Studies of the Warburg Institute. Warburg Institute, University of London. {{cite book}}: Unknown parameter |vol= ignored (|volume= suggested) (help)

Rich Farmbrough, 11:34, 11 October 2010 (UTC).

As far as I can see, the removed material was substantially correct. The primary source for the claim is ibn Al-Haytham's The Light of the Moon (Maqāla fī ḍawʾ al-qamar), not his Book of Optics. This work has been summarized as follows:

Ibn al-Haytham showed here that if the moon behaved like a mirror, the light it receives from the sun would be reflected to a given point on the earth from a smaller part of its surface than is actually observed. He accordingly argued that the moon sends out its borrowed light in the same manner as a self-luminous source, that is, from every point on its surface in all directions. This is confirmed through the use of an astronomical diopter having a slit of variable length through which various parts of the moon could be viewed from an opposite hole in a screen parallel to the slit. The treatise is a beautiful combination of mathematical deduction and experimental technique. The experiments do not, however, lead to the discovery of a new property, but only serve to prove that the mode of emission from the moon is of the same kind as the already known mode of emission from self-luminous objects.... (p. 195, "Ibn Al-Haytham", A. I. Sabra, article in the Dictionary of Scientific Biography, vol. 6, pp. 189–210.)

Also, Matthias Schramm discusses this work of al-Haytham in his book Ibn Al-Haythams Weg zur Physik (Wiesbaden: Franz Steiner Verlag, 1963.) Schramm paraphrases the final passage of the work, in which al-Haytham summarizes his results, as follows (p. 83):

Abschließend stellt Ibn al-Haytham die Forderungen zusammen, zu denen seine Untersuchungen zwingen: das Licht des Mondes darf nicht als von einer spiegelnden Fläche reflektiertes Licht der Sonne aufgefaßt werden. Der Mond verhält sich vielmehr in seiner Ausstrahlung wie ein selbstleuchtender Körper: von jedem seiner Oberflächenpunkte geht, im Gegensatz zu einer spiegelnden Fläche, Licht zu jedem außerhalb liegenden Punkt aus. Dennoch kann die Ausstrahlung nur in Abhängigkeit vom Sonnenlicht erfolgen. Durch Einwirkung der Sonne auf seine Substanz wird seine Farbe leuchtend.

This is consistent with the Sabra summary—the Moon does not reflect as a mirror, but, under the influence of the Sun, radiates light from every point of its surface in all directions.

The question was also raised of ibn Al-Haytham's view of the light emitted from the other planets and the fixed stars. This seems not directly relevant to this article, but ibn Al-Haytham discussed it in The Light of the Stars (Maqāla fī aḍwāʾ al-kawākib.) Sabra summarizes this work by saying that it "argues that all stars and planets, with the sole exception of the moon, are self-luminous." (also from p. 195, "Ibn Al-Haytham", Dictionary of Scientific Biography.) For a translation of the work, with some commentary, see Brit. J. Hist. Sci. 5, #3 (June 1971), pp. 282-288, JSTOR 4025317.

The sources quoted above don't seem to contradict any of this (although I was not able to read the complete passage from the Badeau et al. book.) Unless there are further objections, I will restore the factoid. Spacepotato (talk) 01:25, 16 October 2010 (UTC)

Daylight section?

I was just doing some day dreaming, trying to imagine what a 'day' on the moon would be like, quickly realizing the importance of position on the surface. 'Daily' (every 24 hours) sunrises and sunsets would be highly unlikely, I thought, and off in search I went. Wouldn't here be a good place to have a chart for various strategic positions on the surface of the moon and how much sunlight they get? I'm gonna keep looking to see if it's been done anywhere else? I wanna a job on the moon. 74.124.87.189 (talk) 19:32, 13 November 2010 (UTC)

Day and night on the Moon are just like on Earth but thirty times slower, and with no twilight; and the axial tilt is less than 2°, so the annual variation is tiny. —Tamfang (talk) 00:59, 14 November 2010 (UTC)

Movie of the moon

This movie of the Moon at National Oceanic and Atmospheric Administration site, was removed from the article earlier this year, under the edit summary "External links: tidying up" and marked minor. I think it should be readded to the article. 2.97.19.174 (talk) 21:25, 26 November 2010 (UTC)

Second moon

On QI, it was stated that there was a secondary natural satellite of Earth that orbited every hundred or so years and there is no reference of it here. I forgot it's name but was wondering if someone who did know it could add such corrections. 220.244.162.100 (talk) 00:07, 4 December 2010 (UTC)

See Other moons of Earth. —Tamfang (talk) 00:50, 4 December 2010 (UTC)

Hill sphere

We currently say this:

This tidal drag will continue until the spin of the Earth has slowed to match the orbital period of the Moon; however, long before this could happen, the Sun will have become a red giant, engulfing the Earth.

I think this is not quite true: if the Sun were to remain as it is, the moon would eventually leave the Earth's Hill sphere before it tidally locked the Earth. --Doradus (talk) 21:16, 22 December 2010 (UTC)

Would it? Unfortunately the relevant articles don't give either the period or the distance to which the process converges. :( —Tamfang (talk) 21:55, 22 December 2010 (UTC)

Temperatures on the moon

The article does not mention the temperatures on the "lit side of the moon" during sun exposure and during darkness. What are the lowest temperatures when there is no sunlight, and what are the temperatures when there is sunlight? Same for the "dark side of the moon" (not dark at all during sun eclipses), what are the temperatures over there? Currently, the article mentions only the freezing temperatures in the south pole craters. John Hyams (talk) 21:20, 31 December 2010 (UTC)

By "lit side" and "dark side" do you mean near side and far side, or what? —Tamfang (talk) 04:17, 1 January 2011 (UTC)

Yes, the side facing Earth and the side not facing Earth. In short, what is the temperature on the moon when lit by the sun and when not lit by the sun? John Hyams (talk) 14:03, 1 January 2011 (UTC)

Fractions and Public Outreach

It is of the utmost importance that Wikipedia be understandable to all who read it. It is unfortunate and still entirely true that a very large portion of people (especially in the US) who are not fully able to comprehend fractions and mental math procedures. In the case of comparing the size of the the Moon to Earth and the size of Charon to Pluto, it may be fully visible to you that 1/9 is a larger fraction than 1/81, but many others may not be able to comprehend that. Others may understand that 1/9 is larger than 1/81 but it then makes it difficult to understand how much larger it is relatively. It is for this reason, that I feel that stating, 'slightly more than 9/81' is vastly more informative to a wider audience than '1/9' is. I have left the original provided percentage in for those who wish for more accuracy and feel that 1/9 just isn't suitably informative. --Xession (talk) 09:35, 8 January 2011 (UTC)

I think you're repeating a myth. But we could sidestep this battle of the unsupported assertions and replace both fractions with something else. For example, "Earth has 81 times the Moon's mass, but Pluto has only 9 times Charon's"; or (ugh) "1.2% ... 11.6%".

How much bigger is unimportant. —Tamfang (talk) 19:35, 8 January 2011 (UTC)

It most certainly is not a myth that American education is behind that of other countries (Link). However, it would seem acceptable to replace it with "Earth has 81 times the Moon's mass, but Pluto has only 9 times Charon's". I find it very important to be able to compare the two planetary bodies if the sentence is intended to stay. Otherwise, many people will not be able to compare them without a picture reference. The sentence can be taken out altogether to simplify matters as well, but I was simply attempting to collaborate with the editor who felt importance in the addition of that information. --Xession (talk) 20:02, 8 January 2011 (UTC)

The first sentence of that article is: "American students even in low-performing states like Alabama do better on math and science tests than students in most foreign countries, including Italy and Norway, according to a new study released yesterday." —Tamfang (talk) 21:24, 8 January 2011 (UTC)