Talk:Equinox

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[edit] Discussion

Which of the following is a better sentence?

  "A zebra is a zoological term for when an animal has a long neck."

  "In zoology, a zebra is an animal with a long neck."

The former sentence is how this article and the ones on vernal equinox and autumnal equinox were written.

Improving an article is good, but there is no need for unfriendly remarks. Patrick 21:48 Nov 2, 2002 (UTC)

lol Lir 00:06 Nov 3, 2002 (UTC)

[edit] mathematical calculation

"The time at which the sun passes through each equinox point can be calculated precisely—so the equinox is actually a particular moment, rather than a whole day."

I was wondering, how accurate the equinox can be found out. Certainly the mathematically exact moment can not be calculated. The sea quake in the Indian ocean 2004 tilted earths axis by several centimeters so with enough wobbling or vibrations there might even be multiple spring/autumn equinoxes per year. So, is the calculated precision of equinoxes a matter of seconds, ms, us, ns?

There is a difference between the "rotation axis" of the earth and the geographical location where this axis intersects the surface. Because of conservation of angular momentum, the rotation axis cannot be changed by events on earth and so the celestial equator is fixed in space and equinoxes can be determined very accurately (sorry to admit I do not know the current margins). The wobbling mentioned is the movement of the earth's crust relative to the rotation axis and has no bearing on the time of equinox. −Woodstone 12:04, 2005 Mar 28 (UTC)

You are correct that the rotation axis itself cannot be changed by events on earth. However, the 2004 Indian Ocean earthquake article also mentions that "theoretical models suggest the earthquake shortened the length of a day by 2.68 microseconds", which throws off most time calculations by nearly 1 millisecond/year.

It would be nice if this article mentioned the actual formula for calculating the equinox. (If it's too ugly and scary-looking, maybe add a link to some other web page with the actual formula). Alas, my quick Google turns up many pages that mention the book "Astronomical Algorithms" by Jean Meeus, but don't give the actual formula.

[edit] Factual accuracy questions

This article makes two claims which contradict others on the 'pedia. I am uncertain of exactly which is right/wrong, but I suspect this one is:

Article claims that at equinoxes day/night are equal. Vernal equinox article says that is not true, and that day/night equal day occurs a few days before or after equinox.
Article claims that at poles sun passes from six month day to six month night & vice versa. Other articles (Midnight sun, Polar night) imply the period at the poles is not quite six months day/six months night, but slightly less.

Also, article should explain what a sidereal equinox is, and how it differs from a normal one. --137.111.7.212 10:27, 9 September 2005 (UTC)

It is not a question of right or wrong. It depends on the definition of day versus night.

Simple definition:
- day is the period that the true position of the middle of the sun is above the horizon
- the day and night are equal at the equinox
- polar night and day are half a year each
More common definition:
- day is the period that some direct light of the sun reaches the ground in absense of local obstacles
- this definition makes the day longer by some 7 minutes or more (width of solar disk plus atmospheric refration)
- equal day and night occurs a few days before the vernal equinox and a few days after the autumnal equinox
- polar day is much longer than polar night (and very long twilight)

I will add a short explanation in the text and remove the banner.−Woodstone 20:31:58, 2005-09-09 (UTC)

Also, the picture in the introduction is kind of flat, anyone have a real satalite photo they'd like to share?--Hello'from^'SPACE 23:48, 14 November 2005 (UTC)

[edit] Merge

In response to the suggestion that the entry for 'Equinox' be merged with the entry for 'Equinoctial Point', I favour the retention of the term 'Equinox'. The purpose of an encyclopaedia is to provide access to information to people who may know little about a topic. Otherwise why are they looking it up? Equinox is a term more likely to be used in such cases. The term 'Equinoctial point' can be covered within that entry and in its own entry if more detail is required. P J Lock 130.220.79.98 00:17, 28 September 2005 (UTC).

I have merged Equinoctial Point into this article, as per listing in Category:Articles to be merged. Brisvegas 03:10, 10 October 2005 (UTC)

Perhaps as a result of merging, the article does not sufficiently describe Vernal and Autumnal. It discusses them; but: when does Vernal equinox occur? When does Autumnal? This information is not disclosed in the article. Gekritzl 00:49, 6 April 2007 (UTC)

As a result of the merging, someone searching for vernal point, perhaps going from celestial coordinates pages, lands on this page and, IMHO, has a hard time finding the connection. I added in the Names section explicit reference to vernal point. Rlupsa 16:37, 2 October 2007 (UTC)

fixed--Hello'from^'SPACE^{^{00:27, 15 November 2005 (UTC)}}

[edit] Help with confusion

I am confused when reading this article because it says on the equinox, day and night are of equal length, 12 hrs each. But from the Sunrise and Sunset times given in my World Almanac, it seems this occurs a few days before the equinox. I was hoping for some kind of simple explanation for why this is so. Thanks ፈቃደ (ውይይት) 22:52, 28 December 2005 (UTC)

Never mind, I see now that the article does give it, I just wasn't reading carefully enough... ፈቃደ (ውይይት) 22:54, 28 December 2005 (UTC)

You can find slightly more information in the article day. −Woodstone 22:57, 28 December 2005 (UTC)

Thanks, I added to that article the Damascus Document's definition of when the Sabbath begins: "No one is to do any work on Friday from the moment that the sun's disk stands distant from the horizon by the length of its own diameter... What I am wondering now is, if one were to define "night" as beginning at that time, and "day" as beginning when the sun was a corresponding distance from sunrise, it would make the day a bit shorter than the night, instead of longer, right? So by that definition, would there be an equinox, and would it occur a few days after the accepted equinox instead of before, and how could it be calculated? ፈቃደ (ውይይት) 23:42, 28 December 2005 (UTC)

Interesting observation. If the sun's disk stands its own diameter from the horizon, that would make the center 16'+32'=48' above the horizon. Subtracting the atmospheric lift of 34', the true position of the sun would be 14'. So indeed the day by this definition would be shorter than the night. The effect is opposite and about 1/3 of the size compared to the modern definition.

Your edit in the article is incorrect. Equinox is defined by the astronomical position of the sun, not the daylight observed. The deviation in time because of the elliptic orbit of the Earth is only about +/- 15 minutes.

−Woodstone 10:44, 29 December 2005 (UTC)

The elliptic orbit seems to mean the Earth is getting more sunlight on one hemisphere for six months even though it's passing farther away, simply because it's tilted toward the Sun during that time, so just facing the Sun does more to affect the seasons than actual distance from it. ፈቃደ (ውይይት) 13:41, 29 December 2005 (UTC)

[edit] Lead section

The lead section does not summarize the entire process of an equinox. There is no mention of what dates the equinoxes occur, and it does not explain how long the daytime and nighttime last. (Twelve hours would be a fair hypothesis, but when you look into it, a true equinox divides approximately eleven hours and fifty-some minutes between both the day and night.) The graph does not properly display equinoxes and should be replaced; perchance I will create one myself. Any suggestions concerning my comments? Eternal Equinox 19:44, 28 January 2006 (UTC)

I am going to copy-edit the article since some of my edits were reverted. –Eternal Equinox 21:03, 31 January 2006 (UTC)

The last few edits have created quite a lot of redundancy in the article. The ecliptic/equator and length of day/night issues are both explained three times. Major clean up will be needed. −Woodstone 09:35, 1 February 2006 (UTC)

Agreed, I'll get around to doing that whenever I have the time. Could one please explain this edit? The way I look at it is that once we reach the year 2050, there will be fifty years placed in the article. Is this really necessary? —Eternal Equinox | talk 23:17, 1 February 2006 (UTC)

There was still a lot of reduncancy after the recent clean up. I have now moved the full discussion of "equal night" into the lead section. The more detailed astronomical description and equinoctial point is drawn together with (almost?) complete elimination of redundancies.

I see no harm in having a table with precise date and time for e few years back and quite some years ahead as long as it does not pass beyond the regular text of the article. −Woodstone 14:35, 4 February 2006 (UTC)

IMHO, the following far-better explains what an equinox is :

"Every year, around March 20th (occasionally the 21st) and then six months later around September 23rd (occasionally the 22nd), our planet reaches a position relative to the Sun wherein, if it had no atmosphere and was perfectly spherical, its north and south poles would be simultaneously poised on the plane of the Earth's terminator (the globe's boundary line between night and day). These two moments on our calendar are referred-to as equinoxes." (added to the main article 8/31/06 by earrach)

Of course, considering those IF's, I suppose we wouldn't be having this conversation, eh? Regardless, I think the above idealized definition is a highly instructive "seed-point" for the discussion and would suggest you consider trying it on your students. Please, ANYTHING other than that utterly despicable "...when the sun crosses the celestial equator." -line used virtually everywhere else. Ugh, ugh, ugh. It "explains" n o t h i n g. earrach

The standard explanation is used because it is indeed used everywhere else. The fundamental and most easily understood definition of an equinox is already in the opening paragraph, that days and nights are equal. That can easily be the opening definition. Your proposed paragraph does not follow Wikipedia style which requires that the title of the article to be the subject of the first sentence, that is, that the title of the article be defined before any explanations are given. I do not regard the positions of the north and south poles relative to the terminator as being particulary instructive for the equinox. It does not belong at the head of the article. — Joe Kress 07:48, 1 September 2006 (UTC)

I am considering your other points but your statement about the day and night being equal as the fundamental descriptor, although being the derivation of the word "equinox" -is- technically inaccurate and has in point already caused quite a lot of discussion here and I fear will continually keep this article's content in dispute without my help. Due to our atmosphere, the globe as a whole always has more day than night because the lit "half" of the globe is always more than half: the sunset and sunrise both "over-wrap" the ideal terminator due to refraction - - a fact that I have embedded in my suggested revision for a "standard" definition. This pushes the local "equal-night" dates off, subjectively/calendrically, relative to the official date which is determined from when the Earth, due to its orbit and tilt, reaches orientation implied in my preferred definition. Unfortunately for purposes of clarity, the only way of being both accurate and concise regarding the "equal-nights" would be to be intentionally fuzzy: "The days around the equinoxes have approximately equal days and nights." - and we know how wikipedians deal with fuzzyness. 9/6/06 earrach

[edit] Spring/Autumn ?

The March equinox is only in the Spring in the Northern Hemisphere. Down in the South, it's in the middle of the Autumn. Furthermore, Spring doesn't start on the equinox - it starts halfway between the solstice and the equinox. The equinox would be mid-spring or mid-autumn. 2006-03-02 16:42:17 Vhata

Where exactly in this article do you see the North-centricity? I cannot find it. I see it explaining both ways. Whether spring starts at the equinox or halfway from the solstice is a matter of local culture. Again, where precisely in this article is it biased? For a more extensive comparison, see season. −Woodstone 19:33, 2 March 2006 (UTC)

I was going to make the same remark as the original poster here. There does seem a bit of 'North-centricity' in the table with dates & times at the beginning of the article. By stating 'March (spring starts)' or 'September (Autumn starts)' or however it's exactly put up (don't have firefox at work, can't open tabs!), it's showing a northern-hemisphere bias. It seems like these references connecting specific equinoxes with seasons should either be removed, or prefaced with 'in the northern/southern hemisphere...' 140.142.226.76 19:37, 7 March 2006 (UTC)

You were both right, I overlooked the table. It has been corrected now. −Woodstone 20:21, 7 March 2006 (UTC)

There is also the point that only the temperate climates (between polar circles and tropics) have 4 seasons. In the tropics there are only 2, wet and dryShniken 04:21, 15 March 2007 (UTC)

The term "season" used without qualifiers in a calendrical discussion will always cause dispute and confusion. This is why it may be best to defer to the terms "seasonal quarters" or simply "quarters" (of Earth's orbit / the year...) rather than to whip-up the old annual weather patterns vs astronomical quarters debates. Sept 11th2007 earrach

[edit] Image

The image that shows the rays of the sun hitting the earth is perhaps a bit inaccurate. The north pole of the earth should probably be tilted 23.5 degrees toward or away from the viewer (ie, we should be able to see either the north or south pole), since most people will assume that the image is perpendicular to the earth's orbit. 68.6.85.167 01:11, 5 May 2006 (UTC)

The image they've used is actually correct but virtually useless due to the orientation of the view. The image I have always used (see my original rendering below) sidesteps this problem and IMHO, illustrates the -reason- for the equinox pictorially like no other diagram does...

...I thought I was the only one who ever thought to "look-down" on the whole pattern for clarification it but did find find one a bit similar but not really the same up in the corner of a page in Guy Ottwell's good old "Astronomical Companion". Now THERE is a great illustrator of astronomical ideas!

Earrach 22:46, 21 June 2006 (UTC)

Your image cannot be used on Wikipedia because it is copyrighted. — Joe Kress 00:47, 2 October 2007 (UTC)

You should be clear that this is from a NORTHERN hemispheric perspective. Arthurian Legend 04:35, 21 March 2007 (UTC)

Eric's image is much better than the ones on the Wikipedia page. A famous study of how people understand (or misunderstand) the solar system, including interviews with random students at Harvard, and other research shows that the "perspective view" of the solar system that shows the orbit as an ellipse is one of the main causes of confusion. Most folks see this and interpret it as the earth is at times closer to the sun, and thus this is summer (they just don't get that when the N hemisphere has summer, the S hemisphere has winter). While I think Eric's image may need improvement (I think it's still a little unclear what's going on in it), I believe it is important to move away from images that show elliptical orbits.

For a bit of my own background and why I might know this, I have taught high school science (mostly physical) for fifteen years, and spent one year writing curriculum for a program at Lawrence Hall of Science where we spent much time reviewing research into scientific misunderstandings. Lee 18:09, 24 June 2007 (UTC)

I agree that this image is much better than any currently in the article. I do have one suggestion: Turn the season names around so that they are read in the correct order (counterclockwise). --Lasunncty 03:44, 25 June 2007 (UTC)

[edit] Aurora Borealis

What are the effects the Equinox has on the Aurora Borealis? 71.112.224.112

- Aurora Borealis is caused when fast charged particles of the solar wind hit the outer atmosphere of Earth. As such, the relative position of Earth and Sun to one another (on the date of Equinox or anytime else) should have no effect on Aurora Borealis - these are two independent phenomena. --Hyugens 10:41, 5 October 2007 (UTC)

[edit] Equilux

Statment moved from article:

Although the word "equinox" implies equal length of day and night, as is noted elsewhere, this simply isn't true. But for most locations on earth, there are two distinct identifiable days a year where the length of day and night are the closest to being equal. Those days are commonly referred to as the "equiluxes" to distinguish them from the equinox. The equinox is a point in time, but the equiluxes are days. By convention, the equiluxes are the days where sunrise and sunset are closest to being exactly 12 hours apart. This way, you can refer to a single date as being the equilux, when, in reality, it spans sunset on one day to sunset the next, or sunrise on one to sunrise the next. As an example, for a city 45 degrees N and 123 degrees W (Portland, OR), the 2006 autumnal equilux is on Sept 25 when sunrise is at 7:01 am and sunset is at 7:02 pm. The 2006 autumnal equinox is on Sept 22 at 9:03 pm. Note that for the Northern Hemisphere, the autumnal equilux lags behind the equinox, and the reverse is true in the spring. As you might suspect, the whole situation is also reversed for the Southern Hemisphere.

I cannot find any substantial support for the name "equilux" on Google. Please provide a good citation for its "common" use and for its "conventional" meaning. If not, then reword without "equilux". — Joe Kress 07:01, 24 August 2006 (UTC)

From google:

http://groups.google.com/group/sci.astro/browse_frm/thread/95431b5b56640874/d6ae5b193523fbfa?lnk=st&q=equilux&rnum=3&hl=en#d6ae5b193523fbfa

The term equilux is discussed and used by both professional and amateur astronomers from organizations as diverse as the Lick Observatory and Swedish Amateur Astonomer Federation (SAAF) going back at least 12 years. OK to move statement back?

Wiredknight 22:32, 24 August 2006 (UTC)

Maybe equilux its own article? (with a link from equinox) --Tauʻolunga 23:33, 24 August 2006 (UTC)

Thanks for the citation. If the paragraph is moved back, the ref must be included. I do remember a rather detailed discussion in another article on a related subject that mentioned the semi-diameter and refraction of the Sun. I'm not sure whether it discussed earliest sunset/latest sunrise (near winter solstice) or something akin to 'equilux'. So it is discussed elsewhere on Wikipedia in some form, which may or may not be more appropriate. — Joe Kress 04:37, 26 August 2006 (UTC)

It's described in for example in the wiki article day. −Woodstone 12:33, 26 August 2006 (UTC)

The article I was thinking of was equation of time, which was actually discussing something related but different, the shift of sunrise/sunset times caused by tilt and eccentricity. However, this shift does not change the relative amount of daylight and nighttime. — Joe Kress 05:03, 27 August 2006 (UTC)

[edit] When are the days equal?

The sentence "The real equality of day and night happens a few days towards the winter side of each equinox." appears to be incorrect because as written the winter side is dependent on which hemisphere you are in. Readers in different hemispheres would assume opposite meanings. Personally I do not know the correct solution, but I would like to read what it is. --Roger Bays 05:11, 19 March 2007 (UTC)

Well, the correct solution is, "In the Northern Hemisphere, the real equality happens before the March equinox and after the September one. In the Southern Hemisphere, after the March one and before the September one." So the sentence is not uncorrect, but probably a bit ambiguious. I agree that readers may be confused. Rija 14:40, 19 March 2007 (UTC)

Indeed it seems that the formulation in the article is a bit sloppy in suggesting that the day and night can be equally long at the equator. On the equator precisely, looking at only the true position of the Sun (midpoint, no atmospheric lifting) the time between successive passings of the horizon is always 12 hours. So still at a position on the equator, but now taking into account the diameter of the apparent Sun's disk and the atmospheric lifting, the day is always longer than the night. Only at positions far enough from the equator to eliminate these effects by a shortening day (and equal lengthening of the night), the day can be equally long as the night. These positions are always located in a well defined hemisphere, so the concept of winter is well defined. −Woodstone 19:34, 19 March 2007 (UTC)

[edit] Not to be offensive

but this is English Wikipedia and the equinoctes (equinoxes) aren't known by their Chinese names at all, so i'm going to delete that. there is already a separate section on the equinox in East Asia therefore it is redundant to state that information twice

[edit] What does this have to do with the actual Equinox?

Okay seriously... Solar terms in East Asia

Main articles: Chunfen and Qiufen

The traditional East Asian calendars divide a year into 24 solar terms (節氣). Chūnfēn (pīnyīn) or Shunbun (rōmaji) (Chinese and Japanese: 春分; Korean: 춘분; Vietnamese: Xuân phân; literally: "vernal equinox") is the 4th solar term. It begins when the Sun reaches the celestial longitude of 0° and ends when it reaches the longitude of 15°. It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 0°. In the Gregorian calendar, it usually begins around March 20 and ends around April 4 (April 5 East Asia time). Qiūfēn (pīnyīn) or Shūbun (rōmaji) (Chinese and Japanese: 秋分; Korean: 추분; Vietnamese: Thu phân; literally: "autumnal equinox") is the 16th solar term. It begins when the Sun reaches the celestial longitude of 180° and ends when it reaches the longitude of 195°. It more often refers in particular to the day when the Sun is exactly at the celestial longitude of 180°. In the Gregorian calendar, it usually begins around September 23 and ends around October 8. The Chinese character 分 means division, so the vernal equinox and the autumnal equinox signify the middle of spring and autumn, respectively, unlike in Western cultures.

This should be in the SEE ALSO section and its own article or in an later paragraph, not the initial paragraph about its name in English. Did the words Chungen and Qiufen have any influence on the word aequus nox? No? Then it doens't belong in this section. IT DEFINITELY does not belong in the beginning of this article as it doesn't explain what an equinox is and it is not relevant to the definition or the important of equinoxes in the English speaking/Western world. —The preceding unsigned comment was added by Arthurian Legend (talk • contribs) 04:42, 21 March 2007 (UTC).

That section was moved from near the end of the article to its present position near its beginning (with some modification) by Yao Ziyuan on 25 November 2006. Obviously, he didn't want it near the end of the article. However, I agree that in this English version it doesn't belong near the beginning because interrupts the explanation via an excursion. — Joe Kress 20:42, 21 March 2007 (UTC)

[edit] Terminology: Coordinate System vs Reference Frame

minor nit

I suggest distinguishing between Coordinate System and Reference Frame. The former is a description of the quantities used to describe a reference frame e.g. the Cartesian Coordinate System, the Spherical Coordinate System. Reference Frame refers to Coordinate Systems in practice, or an Instance of a Coordinate System if you will, though a single Reference Frame may of course be described using more than one Coordinate System. bcarcich@astro.cornell.edu 24.59.125.201 19:12, 9 April 2007 (UTC)

[edit] Formal Defintion of Equinox Times

The US Naval Observatory and Her Majesty's Nautical Almanac Office both use a very precise definition of the equinox (and solstice) times. It is the time at which the apparent ecliptic longitude of the Sun is 0° or 180° (90 or 270 for the solstices). See http://asa.usno.navy.mil/SecM/Glossary.html This definition has no direct link to the seasons, but nevertheless it the one used by the USNO and HMNAO to calculate the equinox times. As authorities on the matters astronomical, their values are the ones published in newspapers around the world, and mentioned on TV.

ExtonGuy 03:10, 4 September 2007 (UTC) ExtonGuy

As the ecliptic longitude is defined in relation with the vernal point and the vernal point is one of the intersection points of the ecliptic and the celestial equator, the above is equivalent to the definition in the article. However, it would be worth noting it in the article. -Rlupsa 07:03, 26 October 2007 (UTC)

There's a nice table of equinoctes in the article, complete with time. However, which time zone is shown? UTC? EDT?--Pgranzeau (talk) 16:20, 18 March 2008 (UTC)

As the first word in the top line says: it's UTC, the only fitting choice for a document with international readership. −Woodstone (talk) 20:58, 18 March 2008 (UTC)

[edit] Amount of Discussion/Focus on Equal Day/Night

For a particular latitude (not the equator), an equal day and night can occur at no more than one spot at that latitude on the Earth’s surface per equinox. This would be true even if the Earth's orbit was circular, the Sun was a point light source, and there was no refraction of light. The tilt and orbit of the Earth are all that is required to insure the above result.

Given that an equal day and night is rare, I wonder if the amounts of discussion/focus on the phenomena which affect the equality of day and night are needed. Possibly, these phenomena could be grouped together in a section with the discussion of “equiluxes”. There are several comments which imply that widespread equality of day and night can be achieved on the day of the equinox if these phenomena are ignored. I do not believe this to be the case. Irrespective its Latin roots, the connection of equinox with more than an approximate equality of day and night appears to be problematic.

An instructive connection can be made between equinox and orbital elements and geometry. By considering the Sun to be in an apparent tilted orbit around the Earth (with the equatorial plane as the reference), the ascending node of the Sun’s “orbit” can be seen to correspond to the northern vernal equinox and assigned a longitude (along the reference plane) of zero. The descending node of the Sun’s “orbit”, which is in line with the ascending node (two planes intersect in a line), corresponds to the northern autumnal equinox and has a longitude of 180 degrees, etc. Like northward and southward equinoxes, ascending and descending (nodes) equinoxes are not dependent on one’s hemisphere. A benefit of discussing orbital elements and geometry is that a strong relationship between the equinoxes and the solstices can be developed.

AikBkj 06:31, 23 September 2007 (UTC)

I disagree. The title of this article is equinox, hence its most important characteristic, equality of day and night, should be prominently discussed, regardless of its rarity. Orbital characteristics are already discussed in the article. You can improve that discussion. — Joe Kress 19:38, 25 September 2007 (UTC)

The fact that the name implies equality of day and night is my major concern. This implication is incorrect in that an equinox is a moment in time and not an extended period of time. Additionally, this popular notion does not match the actual technical meaning of equinox. Equinox is a misnomer (A misnomer is a term which suggests an interpretation known not to be true, also, ...a difference between popular and technical meanings of a term.). So, should the article bow to and help to propagate the popular misinterpretation and misunderstanding of equinox or should it try to clarify the more accurate meaning of equinox? I think that a large amount of discussion and focus on the phenomena which affect the equality of day and night does the former. AikBkj 02:41, 26 September 2007 (UTC)

We should recognise that there are several meanings: the precise astronomical instant and the date on which by "some" definition day and night are close to equal. Explanation of the difference merits attention. −Woodstone 10:01, 26 September 2007 (UTC)

Agreed, I can see your points, a triumph of practicality over technicality. But in another couple hundred years when the technical definition has become the most popular usage, ... AikBkj 15:43, 26 September 2007 (UTC)

[edit] Tides

Why was there no mention of the flood tides caused by the equinoxes?

I took a quick look at the wikis on Tide and Flood. I was not able to find any connections between them and equinoxes. The phrase "spring tide" is commonly used, but, "spring" used in that case was not a reference to the season. AikBkj 18:25, 11 October 2007 (UTC)

There is very much a connection between the tides and the equinoxes. The British Marine Life Study Society states that "the highest spring tides of the year occur after the equinoxes in March and September, and these tides are often the best time to visit the shore."

When I lived in Washington (state), I knew that the best time to visit the beach was during the equinox, because the pull on the tides is much greater; during one equinox the tide is much higher than normal (this is most likely the "flood tide" mentioned above), and during the other it is extremely low, and you can walk hundreds of feet out on ground that is normally underwater, and find all kinds of little critters that you don't see closer to the shore, like chitons. My mom and I visited the beach every year at that time. I am surprised that Wikipedia doesn't mention this fact. 75.208.228.90 (talk) 15:51, 15 April 2008 (UTC)

[edit] Re Trivia, Facts and Fables

I'm a new user (W7632416, Brian, San Diego).

I have taken the new-user tutorial. I do not recall seeing a detailed policy concerning trivia, but I see that trivia sections are discouraged. (I happen to agree.)

I think I see how editing works in general and how this discussion page is the vehicle. So let me try my hand at this.

How do we feel about the appropriateness of the first entry under "Trivia, Facts and Fables" section?<br />

"Ancient people with astronomical knowledge knew that the Vernal Equinox shifts into the next Zodiac sign (constellation) every 2150 years, and the passing of every age was celebrated. it is said that the birth of Moses is the biblical translation for the end of the age of the worship of Taurus the bull (false idols) into Aries, and the birth of Jesus is the translation of the shift from Aries to Pisces-the fish. Researchers state that the three kings and the star above Jesus's birthplace were the Three Kings Stars from Orion's belt that align with the star Sirius when the december 25 Equinox shifts into Pisces. Thus Jesus represents the sun, and his most important dates are the Christmas equinox and the Easter equinox. Some people even say that Jesus was created as a earthly person when the holy Roman Bible was written in 300AD in their translation of the Astrological Scriptures."

I recognize the content as part of the documentary film Zeitgeist II, but that's not the point. I think the paragraph should be removed for being unverifiable. Or out of place, or something. My Wiki experience level is too low for me to simply delete the passage even though I think a consensus to do so will occur (arise?).

I hope it's appropriate to invite comments about this, my first attempt at initiating an edit, to my user page, I think it's called. (Talk page?) Thanks for bearing with me.
--W7632416 03:00, 26 October 2007 (UTC)

Paragraph removed. Btw, this is not your user page, which would be User:W7632416. This page is the article's discussion page, and you used it appropriately. And welcome ;) --Gulliveig 03:16, 26 October 2007 (UTC)

[edit] Atmospheric Effect

The 100 arcminutes of extra daylight makes the day about 7 minutes longer than 12 hours. Similarly, the night is about 7 minutes shorter than 12 hours. So, (12 hours + 7 minutes) - (12 hours - 7 minutes) gives a difference between day and night of about 14 minutes as the article stated. AikBkj (talk) 17:19, 8 January 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) 14:12, 16 February 2008 (UTC)

[edit] Cultural Aspects

The section has a part beginning : "The Christian churches calculate Easter as the first Sunday after the first full moon on or after the March equinox.". That is not so.

The Easter dates given by the British Calendar Act are based on March 21st; the Equinox is I think not mentioned. The date of the true Equinox depends on one's longitude. The moon used is not the actual one, but a defined approximation. Since the Catholic rule gives the same Easter dates, it must correspond.

Perhaps : "The Christian churches calculate Easter as the first Sunday after the first nominal full moon on or after March 21st.".

In this part of the article, one must discriminate carefully between the instant of the true astronomical equinox and the calendar date chosen to represent it.

82.163.24.100 (talk) 12:05, 7 June 2008 (UTC)

You ignored the next sentence: "The official definition for the equinox is on 21 March." Although the date of the astronomical equinox does depend on your time zone and hence your longitude, this addendum fixes it on 21 March. Although you are correct that the British Calendar Act of 1750 does not mention the equinox, the original 1582 Catholic papal bull Inter gravissimas does explicitly mention both the equinox and 21 March: "the vernal equinox, which was fixed by the fathers of the [first] Nicene Council at XII calends April [March 21]" (English translation). You are also correct regarding the "full moon", so "Paschal" should be prefixed to it. Hence some slight rewording is warranted. As a sidebar, both the Protestant portions of the Holy Roman Empire as well as Denmark, Norway, and Sweden used both the astronomical full moon and the astronomical equinox at Uraniborg via Kepler's Rudolphine Tables to calculate Easter from 1700 until either 1775 or 1844, depending on the country. — Joe Kress (talk) 19:54, 7 June 2008 (UTC)