Talk:Solstice

From Wikipedia, the free encyclopedia

	Portal This article is within the scope of WikiProject Astronomy, which collaborates on articles related to astronomy, and WikiProject Physics, which collaborates on articles related to physics.
B	This article has been rated as B-Class on the assessment scale.
Help with this template Comments: edit – history – watch – refresh Everybody why don't you put definitions in laymans terms? maybe make it simpler? if you make it simpler more people recieve help and that's the point right to help people? Please take this into consideration Thank You Godbruther 02:57, 11 May 2007 (UTC)

	Time Portal This article is within the scope of WikiProject Time, an attempt to build a comprehensive and detailed guide to Time on Wikipedia. If you would like to participate, please join the project.
B	This article has been rated as B-Class on the quality scale.
High	This article has been rated as High-importance on the Project's importance scale.

Contents 1 WikiProject Time assessment rating comment 2 Discussion 3 Please correct misconceptions 4 Altitude 5 capitalization of directions 6 solstice definition 7 Video Game Disambig 8 Illumination of the Earth Images 9 Animated pictures 10 Pedant alert 11 Tipping vs change of orientation 12 needs complete rewrite 13 Defining moments 14 Table of Solstices 15 preferred terms 16 switched images 17 Current Event 18 Confusing paragraph 19 Time Between Solstices 20 Seemingly a nice article but no references 21 Solstice a worldwide phenomenon 22 Constellations irrelevant 23 Midsummer 24 Northern-Centric terms 25 Image:Earth-lighting-winter-solstice EN.png 26 Some sections of this article must be placed in an external article

[edit] WikiProject Time assessment rating comment

Want to help write or improve articles about Time? Join WikiProject Time or visit the Time Portal for a list of articles that need improving.
—Yamara ✉ 09:16, 12 February 2008 (UTC)

[edit] Discussion

I don't believe solstice (or summer solstice or winter solstice) should be capitalized—it's not capitalized in Britannica or Merriam-Webster)—and so I am lowercasing it in this article. — Knowledge Seeker দ 02:56, 14 Jun 2005 (UTC)

I believe that they would be lower case when used as scientific terms but if they were being used as the direct titles for religious holy-days they should be capitalized. Such editors' conventions have not yet caught up with the times: "The solstice in June is when I join the other Druids at Stonehenge for our Summer Solstice observance." Rejecting that as "wrong" simply perpetuates the prevailing religious chauvanism that leaves us with sentences like "Jesus turned His face to the setting sun while behind Him the moon was already above the earth's eastern horizon." User: Earrach, (Ordained Druid Priest)

Proper nouns should be capitalized, and common nouns (such as "solstice") should not. Unfree (talk) 18:47, 22 December 2007 (UTC)

Looks like the angles are messed up in the tropics: should be 23 not 26, and 46 not 43?

Yes, you are correct in believing the correct angles for the tropics of capricorn is 23 and 46. --Wired2Narnia

No, there's only one angle: that between the plane of the ecliptic and that of the equator. Unfree (talk) 18:47, 22 December 2007 (UTC)

[edit] Please correct misconceptions

The orbital diagram is beautiful, but misleading. It suggests that the earth's axis points in a different direction at different seasons of the year. It does not. The earth's axis should be tipped in the same direction for both the summer and winter solstice illustrations. You should then change the direction from which the sunshine comes from -- from the right in one, and from the left in the other -- just as it actually does when the earth shifts position by 180 degrees in its orbit. I'd omit the illustration for the equinoxes entirely. Anything you would draw would suggest that the earth's axis is oriented straight up and down, which is of course not correct. In reality, the sunlight would be streaming perpendicular to the page, which is not possible to draw in a two-dimensional illustration. User:BartBenjamin

It would also probably be better to use the terms "December Solstice" and "June Solstice" instead of "winter" and "summer." That way, it is correct for all hemispheres. That is how the International Planetarium Society solves this dilemma for its members located in both hemispheres. User:BartBenjamin

Adding December and June would be OK, but the traditional names are summer and winter. The illustrations fail to show what the labels are pointing at. They should be more schematic. PatShannon

in the Southern hemisphere the winter solstice falls in June while the summer solstice falls in December. As the solstices are important religous holidays in many Pagan traditions and the way in which they are celebrated depends on wether they mark the longest day or the longest night the important distinction is not which month they are in, but rather which season in the location in which they are celebrated. Babylon Horuv 23:27, 22 October 2006 (UTC) Babylon Horuv

[edit] Altitude

The term "altitude" is used a lot to describe the angle of the sun. It's obvious what it means, but can "altitude" strictly be used to describe an angle rather than a distance? Should we instead refer to inclination above the horizon? TerraGreen 00:14, 7 January 2006 (UTC)

Altitude is routinely used to express the angle above the horizon. See for example the much cited US navy site. However the more formal astronomical term is elevation. Inclination is not normally used for positions but for planes (e.g. between equator and ecliptic). The full apparent location of a heavenly body is given by the combination azimuth and elevation. Although not scientific evidence, a quick search on Google reveals:

• azimuth elevation: 1.27M hits
• azimuth altitude: 1.57M hits

−Woodstone 14:21, 7 January 2006 (UTC)

Altitude and azimuth go together in astronomy. In surveying, what astronomers call altitude is called elevation. (Both altitude and elevation can be used to refer to a height, in linear measure, above sea level or the surrounding ground level, but that's a different issue; here, we're referring to angular measures.) One can measure the elevation (not altitude) of one thing above another using a sextant, but altitude always refers to an object's elevation above the horizon. Using a theodolite, surveyors determine what they call elevations, but I don't know what they call the difference between two elevations. Since "solstice" is not of much use in surveying, it's the astronomical altitude that we mean here. It's measured perpendicularly to the observer's horizon (considered perpendicular to the direction of the earth's center, regardless of the surrounding landscape), and azimuth is measured along the horizon, from due north, so the celestial north pole has an azimuth of zero, and an altitude equal to the observer's latitude. Unfree (talk) 20:36, 22 December 2007 (UTC)

[edit] capitalization of directions

Directions such as south and north are capitalized in this article. According to the Manual of style , they shouldn't.

[edit] solstice definition

I changed the definition from "the moment the Sun reaches its furthest angular distance to the equator" to "the moment Earth tilts at its greatest distance towards or away from the Sun" because the former conveyed that the sun moves as opposed to Earth's rotational axis tilting. I'm sorry if I this change is incorrect. If I am wrong, please tell me why. Jecowa 07:01, 21 April 2006 (UTC)

"To tilt at" means to attack with a lance. An angular distance is an angle. Earth's greatest distance from the sun is its aphelion, and Sun's apogee. This is whimsy; don't take it seriously -- unless I'm your elder. ;-) Unfree (talk) 21:24, 22 December 2007 (UTC)

Thank you, thank you. IMHO, geocentric coordinate systems have no place in explanations of the "why" of solstices and equinoxes yet they do seem to comprise 98% of the text in the leading paragraphs of dictionary, encyclopaedia and textbook definitions. Your choice of words actually explains what the event is / is caused by. Spherical Astronomy terms simply list the aparrent positions and motions seen from the ground: telling us only about certain effects rather than the "cause". Defining the summer solstice as "the moment when the sun has reached its highest declination above the celestial equator" - "explains" virtually nothing. I would though change your phrasing slightly, hopefully to make it even a little more clear: "Solstices: the moments on opposite sides of our annual orbital path where the Earth's constant 23 degree axial tilt comes directly in line with the Sun." 6_21_06 earrach

Speaking from a complete dummy's perspective, I found your definition (directly above, in your quotes), Earrach the most helpful in getting this concept through my overly thick skull, while sounding at least professional/astronomical (for my own mind, the words I would use, although they are trippy and untechnical are "the moment in the annual orbital path of the Earth when the sun gets the most light "spread across" the Earth). I am going to try to transpose the definition you offered here into the article. Matthew 04:00, 17 February 2007 (UTC)

I'm not sure if "directly in line with the Sun" fully describes the process of the Solstice. Combining the two may help to further add to this defenition. Maybe it should read, "Solstices: the moments on opposite sides of our annual orbital path where the Earth's constant 23 degree axial tilt allows the earth to come in line with the Sun at its furthest declination above or below the celestial equator." —Preceding unsigned comment added by Nthnbtlv4u (talk • contribs) on 6 September 2006

At the time of writing this, the definition (i.e., the first couple sentences) is horribly confusing and generally terrible.Matthew 11:37, 3 June 2007 (UTC)

One would think there would be a standard astronomical definition. Trying to write one ourselves verges on WP:OR, but I might point out the solstices are the moments when the axis of the earth's rotation actually intersects its axis of revolution around the sun. If nothing else, that would be pretty easy to illustrate in a diagram. Glycerinester 09:40, 21 June 2007 (UTC)

[edit] Video Game Disambig

There is also a video game called Solstice. I was looking for info on it, but got this instead. I decided to add a disambig link to the top of the page. What do you think? GLmathgrant 13:45, 12 May 2006 (UTC)

Good job, GLmathgrant. Jecowa 08:50, 20 June 2006 (UTC)

[edit] Illumination of the Earth Images

In the images shown for the summer and winter solstices the orientation of the Earth's pole shifts from left to right while in actuality the direction of the pole is fixed in at a point near the North Star. Here is an image showing correct views of the Earth at the Jun and Dec solstices but which unfortunately lack some of the astronomical definitions contained in the images shown.

[edit] Animated pictures

The recently added animated pictures are a bit confusing. The Sun appears to rotate around the Earth. There seems to be a static cloud cover rotating around Earth as well. Animation is nice, but Earth should rotate, the Sun should be still and there should be no falsely repeatedly moving wheather pattern. −Woodstone 20:29, 20 June 2006 (UTC)

Okay, those are both goods ideas. If Earth rotates, then the phase could remain constant which would allow the diagram information to be included as well. Thanks, Jecowa 20:50, 20 June 2006 (UTC)

[edit] Pedant alert

Capitalization of "North/South Pole" is inconsistent in this article. Moreover, 'pole' is here in lowercase, while the North Pole and South Pole articles have it the other way around. It's rarely seen written in lowercase anywhere else, but I'm wary of changing it: Britannica has it capitalised, the OED doesn't. Any suggestions? The article should at least be consistent.

I'm sorry for any inconsistency I've caused. I capitalized North Pole because that's the way it was done in the North Pole article. Jecowa 03:22, 23 June 2006 (UTC)

[edit] Tipping vs change of orientation

The current version of the article states that an Earth's hemisphere tips towards the Sun. That evokes an image of the Earth nodding (in a yearly cycle) towards and away from the Sun. Clearly in a section discussing the Outside View, this is incorrect. The Earth's axis is fixed in space and does not tip. Only its orientation relative to the Sun changes. That was the basis of my preceding edits that were reverted (unjustly).

Secondly "inclination" perhaps even more an official name than obliquity for the angle between two great circles.

−Woodstone 17:26, 21 July 2006 (UTC)

It seems to me to be a struggle between two groups of people. Those who understand how it works, and are frustrated if non technical terms are used, because they may not convey the exact meaning. And those who do not know yet know how it works, and get confused by the technical terms, looking for simpler words. I think the explanations should cater for the latter, but the definitions for the former.

Also a lot on confusion seems to come from the question whether the rotation axis keeps its orientation in space or not. I would think the article together with the first two pictures is very clear about that. Or is it? --Tauʻolunga 20:47, 21 July 2006 (UTC)

[edit] needs complete rewrite

Personally I think "outside view" and "inside view" is a bad way to go about it. Firstly, this should be adapted for all change. The axis won't always be tilted at 23.44 degrees and the solstice won't always be on a specific Gregorian calendar month. Secondly, the eccentricity on the earth does have an impact on the Earth's climate, this is probably one of the main reasons for more extreme climate in the south, but it won't always be so due to precession of the equinoxes. The mechanics should be explained better as such. John Riemann Soong 01:58, 25 July 2006 (UTC)

won't always be tilted at 23.44 degrees you have already mentioned by currently makes of about 23.44° (called the "obliquity of the ecliptic") which last link gives full additional information.

solstice won't always be on a specific Gregorian calendar month is (indirectly) mentioned with Refer to the equinox article for some remarks, (and they will remain to happen in June and December for many 1000 years to come).

eccentricity on the earth does have an impact on the Earth's climate, this is probably ^{[citation needed]} one of the main reasons for more extreme climate in the south you have already mentioned by adding Due to Milankovitch cycles, what more is needed?

"outside view" and "inside view" is a bad way, no, they give two different viewpoints of the same phenomenon. Only perhaps some better titles can be found.

Briefly, you have already addressed most problems yourself; a complete rewrite seems to me somewhat excessively. --Tauʻolunga 09:11, 25 July 2006 (UTC)

A complete rewrite is completely uncalled for. Minor corrections only. Hmoul 21:43, 29 November 2006 (UTC)

[edit] Defining moments

202.20.5.206 added "fact" to "defining moments". I'm not sure what statement he wants a citation for. The Explanatory Supplement to the Astronomical Almanac defines the solstices as the two points on the ecliptic where the ecliptic longitude of the Sun is either 90° or 270° (which is not mentioned in the article). It does not mention the start of the astronomical seasons. — Joe Kress 06:03, 1 September 2006 (UTC)

[edit] Table of Solstices

The table of solstice dates and times appears without any attribution as to its source or, alternatively, an explanation of how it might have been computed. Is tehre a risk that this may have been swiped froma copyright source?

87.112.73.171 14:21, 10 October 2006 (UTC)

For your reassurance, the table comes from the named reference Earth's Seasons Equinoxes, Solstices, Perihelion, and Aphelion 1992-2020. As a public site by the U.S.A. government, this is free of copyright. And this information was present in the talk page of template:solstice-equinox from the very beginning. −Woodstone 20:22, 10 October 2006 (UTC)

That's gone now, but this exists: Earth's seasons. Unfree (talk) 18:55, 22 December 2007 (UTC)

[edit] preferred terms

I switched the terms from winter/summer and June/December to northern/southern, for reasons that other contributors had already explained in the entry. -gmail "ww0308", not yet a registered wp user, 15 December 2006

[edit] switched images

Also, it appears that someone swapped the images for the heliocentric and geocentric sections! I went ahead and switched them back. -gmail "ww0308", not yet a registered wp user, 15 December 2006

[edit] Current Event

If we are filing this as a current event at the appropriate times, shouldn't we also be noting articles such as "December", "Monday", "day", and "night" as current events? Current event kind of implies that it is something which is expected to happen only once (not true here - this is a cyclical event), and that people, or a limited group of people, will be able to influence in some manner (not true with today's technology). I'm removing the tags. Rhialto 04:18, 21 December 2006 (UTC) ETA: someone beat me to it.

[edit] Confusing paragraph

"The northern solstice is in June on Earth, when the sun is directly over the Tropic of Cancer in the Northern Hemisphere, and the southern solstice is in December,"

I think this should be "The northern summer solstice is in June on Earth, when the sun is directly over the Tropic of Cancer in the Northern Hemisphere, and the southern summer solstice is in December". Agree? —The preceding unsigned comment was added by Craigfis (talk • contribs) 23:11, 21 December 2006 (UTC).

Negative. I feel northern and southern distinctly identify the two and the term summer is ambiguous as already stated in the article.

[edit] Time Between Solstices

According to the data the time span between solstices is as follows:

 - 2002-03: 365d 5h 44m
 - 2003-04: 365d 5h 49m
 - 2004-05: 365d 5h 44m
 - 2005-06: 365d 5h 53m
 - 2006-07: 365d 5h 41m
 - 2007-08: 365d 5h 41m
 - 2008-09: 365d 5h 56m

Is this correct? Shouldn't the time from solstice to solstice be the same each year? If not, can somebody explain why in the article.

There are a variety of reasons why the dates of the solstices may change from year to year. It may have something to do with the calender not being exact with regard to astronomical phenomena. For instance, every four years we "correct" this inaccuracy by adding one day to the end of February. There is additional inaccuracy that is corrected over longer periods of time. See Leap year for an explanation. Also, the length of a year increases by a small amount each year. However, this amount is probably too small to be noticable from one year to the next, so I bet it doesn't explain the differences you noted, above. SharkD (talk) 04:30, 13 February 2008 (UTC)

Update: it is also due (in part) to the gravitational attraction of the moon. See here. SharkD (talk) 23:58, 15 February 2008 (UTC)

The table I posted is spans of time NOT dates. The question is not about dates! Leap years have nothing to do with it. If it has to so with the moon's gravity then that info should appear in the article. LogicalOctopus (talk) 23:03, 5 March 2008 (UTC)

[edit] Seemingly a nice article but no references

This looks like a nice, informative article. Unfortunately, there are no external references given so it is not easy for a reader to verify anything here. Articles should comply with WP:V and WP:RS. I am tagging the article as being completely unreferenced as of this summer solstice. There are also some weasel terms such as "Some consider these terms to be the most neutral and unambiguous." Who is "some"? Statements like this need to be attributed to a particular person or group so that the reader can better evaluate who makes such a claim. I hope that someone knowledgeable about the topic will be able to readily improve upon these areas. Johntex\^talk 19:48, 21 June 2007 (UTC)

[edit] Solstice a worldwide phenomenon

"Solstice" refers to a strictly earthly phenomenon, since it refers to the passage of the earth through a point in its orbit, or the point in time at which the passage occurs, which is defined by the extension of the earth's equator into space.

Consider two planes, that of the earth's orbit (the "ecliptic"), and that of the equator (the projection of which onto the celestial sphere is called the "celestial equator"). The passages of Earth through the points in its orbit which coincide with the ecliptic are called equinoxes, and its passages through the points farthest from the ecliptic are called solstices.

It's one thing for most of Earth's population, who live in the northern hemisphere, to call one solstice the "winter" solstice and the other the "summer" one in common parlance, but that's dreadfully provincial. Only "northern" and "southern" make sense worldwide, and this is the World-Wide Web, isn't it? So let's not insult everybody south of the equator by calling the solstice which marks the beginning of summer the "winter" solstice! Unfree (talk) 18:41, 22 December 2007 (UTC)

[edit] Constellations irrelevant

"First point of Cancer and first point of Capricorn. One disadvantage of these names is that, due to the precession of the equinoxes, the astrological signs where these solstices are located no longer correspond with the actual constellations."

This reflects the misconception that "Cancer" and "Capricorn" refer to constellations. Actually, they refer to signs of the zodiac, which is of little use in astronomy. But even today, one point in Earth's orbit is called the first point of Aries, referring not to the constellation Aries, but to the first of twelve equal sectors (the "signs") of the zodiac, which is defined by the coincidence of the ecliptic with the equator, and moves in accord with Earth's slowly meandering axis. Unfree (talk) 19:17, 22 December 2007 (UTC)

Actually, the zodiac and the tropical lines are related in exactly this way. They used to point at constellations, hence why these positions are named after constellations. SharkD (talk) 04:12, 13 February 2008 (UTC)

[edit] Midsummer

"The term solstice can also be used in a wider sense, as the date (day) that such a passage happens. The solstices, together with the equinoxes, are connected with the seasons. In some languages they are considered to start or separate the seasons; in others they are considered to be centre points (in English, in the Northern hemisphere, for example, the period around the June solstice is known as midsummer, and Midsummer's Day is 24 June, about three days after the solstice itself)."

I suspect that this peculiarity, that "Midsummer's Day" and "midsummer" refer to the solstice, doesn't reflect general differences among languages, but merely an anomaly in one meaning of one word in one language, and that the idea of seasons beginning at solstices and equinoxes is easily understood and expressible among all languages. The idea of "summer" refers to the warmest quarter of the year in either hemisphere, and its beginning is defined by convention to coincide with a solstice. Regardless of the word "midsummer," this understanding of what "summer" means is as true in England as elsewhere, isn't it? Unfree (talk) 20:04, 22 December 2007 (UTC)

In all East Asian languages (Chinese, Korean, Japanese) the solstices and equinoxes mark the middle of the seasons. In Chinese, of the 24 solar terms, those which describe the beginning of the seasons are lichun, literally meaning begin spring, which occurs when the Sun reaches a celestial longitude of 315° (45° before the northern vernal equinox at 0°); lixia (begin summer) is 45° (45° before 90°); liqiu (begin autumn) is 135° (45° before 180°); and lidong (begin winter) is 225° (45° before 270°). In Korean the corresponding terms are ipchun, ipha, ipchu, and ipdong, whereas in Japanese they are risshun, rikka, risshu, and ritto. — Joe Kress (talk) 23:34, 22 December 2007 (UTC)

[edit] Northern-Centric terms

Can someone actually go through the article and remove the Northern Hemisphere bias from the article? It's currently stating Christmas happens on the winter solstice, which is incorrect for half the world. I have changed the cultural piece to reflect a December and a June solstice because that is more descriptive and accurate. —Preceding unsigned comment added by 60.240.63.102 (talk) 05:27, 23 December 2007 (UTC)

[edit] Image:Earth-lighting-winter-solstice EN.png

First of all I'd like to say that this image is really great! It would be nice, however, to have the images used to map the surface of the Earth correspond to the date (winter solstice) depicted in the diagram. I checked the links to the images used. The "Earth's City Lights" image [1] appears to have been taken on 2000-10-23. The "The Blue Marble: Land Surface, Ocean Color and Sea Ice" image [2] corresponds to 2002-02-08. Having images for the correct date allows one to show how ice and snow patterns are affected by the amount of sunlight reaching the Earth's surface. One could create a matching image for the summer solstice showing growth of the ice packs in Antarctic regions. This would allow the diagram to be reused in other articles that deal more specifically with seasonal changes in climate. Unfortunately, I don't think images for each day of the year exist, and I suppose October and February are pretty close. SharkD (talk) 04:12, 13 February 2008 (UTC)

[edit] Some sections of this article must be placed in an external article

"Heliocentric view of the seasons" and "Geocentric view of the seasons" must be placed in an external article. The reason is both sections are in Solstice and Equinox articles, and corrections in one are not synchronized with the other. —Preceding unsigned comment added by Cablop (talk • contribs) 14:09, 16 February 2008 (UTC)