Talk:December solstice

Requested move

 * The following discussion is an archived discussion of the proposal. Please do not modify it. Subsequent comments should be made in a new section on the talk page. No further edits should be made to this section. 

This move discussion was suppose to have been closed on December 2012, as it was merged with Talk:June solstice, but apparently this was not properly done so.] Feel free to restart a new requested move discussion, as page moves from "December" and "June" back to "Southern" and "Northern" solstice, respectively, will now be viewed as controversial (likewise with proposals to move the current March equinox and September equinox article titles to "northward" and "southward"). Thanks. Zzyzx11 (talk) 04:07, 31 July 2013 (UTC)

Southern solstice → December solstice – The solstice occurs in the Northern Hemisphere and Southern Hemisphere, and the references say "December solstice" 70.24.250.110 (talk) 00:44, 3 December 2012 (UTC)

Survey

 * Feel free to state your position on the renaming proposal by beginning a new line in this section with  or  , then sign your comment with  . Since polling is not a substitute for discussion, please explain your reasons, taking into account Wikipedia's policy on article titles.


 * Disagree - "Northern solstice" and "Southern solstice" are preferable as being the more culturally neutral terms, and based on the natural order rather than human cultural constructs. While the labels "North" and "South" are of human origin, the division of the earth into a northern and southern hemisphere is based on nature (the equator is not an arbitrary line of human invention, unlike the prime meridian which divides the east and west hemispheres). By contrast, "December" and "June" are essentially arbitrary divisions of time in the Gregorian or Julian calendars, and are products of particular human cultures rather than having an close connection with nature (the calendar months were originally inspired by the motion of the moon, but have become quite divorced from them in the Western tradition.) SJK (talk) 10:08, 4 January 2013 (UTC)
 * Disagree (and agreeing with SJK), especially since for the Julian calendar the Southern Solstice can occur outside December. TeraCard (talk) 03:46, 31 July 2013 (UTC)

Discussion

 * Any additional comments:


 * See Talk:Northern solstice Apteva (talk) 05:10, 3 December 2012 (UTC)
 * The above discussion is preserved as an archive of the proposal. Please do not modify it. Subsequent comments should be made in a new section on this talk page. No further edits should be made to this section.

Move discussion in progress
There is a move discussion in progress on Talk:Northern solstice which affects this page. Please participate on that page and not in this talk page section. Thank you. —RMCD bot 05:14, 3 December 2012 (UTC)
 * This article is a barely literate mess. It should be merged somehow with something better written. Huw Powell (talk) 03:45, 22 December 2013 (UTC)

2015 dec Solstice: 2015-Dec-22 04:47:57.771
It is very difficult to find the exact times of solstices and equinoxes, to better than a minute of resolution -- and therefore hard to resolve discrepancies in various sources. On the day of 2015 December Solstice, common media sources are stating 22dec15 at either 4:48 or 4:49 UTC/GMT. Which is more accurate?


 * stellafane.org/misc/equinox.html
 * This source has a handy any-year calculator that gives
 * Local = Mon Dec 21 2015 23:47:53 GMT-0500 (Eastern Standard Time)
 * UTC = Tue, 22 Dec 2015 04:47:53 GMT
 * TDT = Tue, 22 Dec 2015 04:49:20 GMT
 * but the footnotes explain that these times are only approximate, to about a minute of accuracy (and the following shows the UTC to be about 5 seconds off).


 * www.neoprogrammics.com/sun/Solstices_and_Equinoxes_1600_to_2400.php
 * This source computes

NORTHERN Year  Date  DoW    Time TDB  SOUTHERN    Delta T Est Winter   2015 Dec 22 Tue at 04:49:04  Summer      +01m 09s
 * which yields 4:47:55 UTC


 * www.survival.org.au/solstice2013.php
 * This is the best discussion of how hard it is to obtain exact times, and how to get them from an online NASA calculator:


 * ssd.jpl.nasa.gov/horizons.cgi

Using that engine yields: Ephemeris Type [change] : 	OBSERVER Target Body [change] : 	Sun [Sol] [10] Observer Location [change] : 	Geocentric [500] Time Span [change] : 	Start=2015-12-22 4:47:55, Stop=2015-12-22 4:48:05, Intervals=20 Table Settings [change] : 	QUANTITIES=1,9,20,23,24,30,31 Display/Output [change] : 	default (formatted HTML) 2015-Dec-22 04:47:57.000    68.183653 269.9999909  -0.0001291 2015-Dec-22 04:47:57.500    68.183653 269.9999968  -0.0001291 2015-Dec-22 04:47:58.000    68.183653 270.0000027  -0.0001291 2015-Dec-22 04:47:58.500    68.183653 270.0000086  -0.0001291 Date__(UT)__HR:MN:SC.fff         CT-UT          ObsEcLon              ObsEcLat

Which leads to: 2015-Dec-22 04:47:57.271      68.183653 269.9999941  -0.0001291 2015-Dec-22 04:47:57.771      68.183653 270.0000000  -0.0001291 2015-Dec-22 04:47:58.271      68.183653 270.0000059  -0.0001291 Times are UTC (not UT1). The dynamical Coordinate Time scale is used internally. It is equivalent to the current IAU definition of "TDB".

Giving a final result of:
 * 2015-Dec-22 04:47:57.771 UTC (+68.183653 = CT/TDB)

In conclusion, 4:47:58 and 4:48 UTC is the proper rounded time; 4:49 seems somewhat wrong, for any general usage.-71.174.188.32 (talk) 17:38, 21 December 2015 (UTC)

more precise Solstice and Equinox times
The English speaking world seems to be limited to approximate Solstice and Equinox times, to about the nearest minute. The French offer a more precise, to the second, master table:

2013 	20 	11:01:55 	21 	05:03:57 	22 	20:44:08 	21 	17:11:00 2014 	20 	16:57:05 	21 	10:51:14 	23 	02:29:05 	21 	23:03:01 2015 	20 	22:45:09 	21 	16:37:55 	23 	08:20:33 	22 	04:47:57 2016 	20 	04:30:11 	20 	22:34:11 	22 	14:21:07 	21 	10:44:10 2017 	20 	10:28:38 	21 	04:24:09 	22 	20:01:48 	21 	16:27:57 2018 	20 	16:15:27 	21 	10:07:18 	23 	01:54:05 	21 	22:22:44 Références :  mars • juin • sept. • déc. Institut de mécanique céleste et de calcul des éphémérides
 * fr.wikipedia.org/wiki/Mod%C3%A8le:Solstice-%C3%A9quinoxe

Most WP readers do not care about this -- but some might like access to the more accurate times. How can we provide such access in a good way? Would we ever want to replace our template master table with a more-precise master table of times? -71.174.188.32 (talk) 19:17, 22 December 2015 (UTC)

Confusing
The diagrams https://upload.wikimedia.org/wikipedia/commons/thumb/e/ee/Gregoriancalendarleap_solstice.svg/190px-Gregoriancalendarleap_solstice.svg.png are for the June Solstice. Similar diagrams for the December Solstice would be interesting, and relevant. 173.174.85.204 (talk) 16:17, 21 December 2016 (UTC)Eric