From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Ulrich Mueller Newsgroups: gmane.emacs.bugs Subject: bug#61460: 30.0.50; Calendar shows eclipse for quarter moon Date: Tue, 14 Feb 2023 08:59:29 +0100 Message-ID: References: <87sffab61y.fsf@web.de> <87cz6eb10y.fsf@web.de> <87r0uu9e5v.fsf@web.de> <87mt5i9cba.fsf@web.de> <875yc4q0ee.fsf@web.de> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="27331"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/28.2 (gnu/linux) Cc: 61460@debbugs.gnu.org, Nicholas Strauss To: Michael Heerdegen Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Tue Feb 14 09:00:24 2023 Return-path: Envelope-to: geb-bug-gnu-emacs@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1pRqEi-0006wt-1H for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 14 Feb 2023 09:00:24 +0100 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1pRqER-0007Jq-37; Tue, 14 Feb 2023 03:00:07 -0500 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1pRqEN-0007J2-G1 for bug-gnu-emacs@gnu.org; Tue, 14 Feb 2023 03:00:03 -0500 Original-Received: from debbugs.gnu.org ([209.51.188.43]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1pRqEM-0004EX-Qx for bug-gnu-emacs@gnu.org; Tue, 14 Feb 2023 03:00:02 -0500 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1pRqEM-0005ol-NF for bug-gnu-emacs@gnu.org; Tue, 14 Feb 2023 03:00:02 -0500 X-Loop: help-debbugs@gnu.org Resent-From: Ulrich Mueller Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 14 Feb 2023 08:00:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 61460 X-GNU-PR-Package: emacs Original-Received: via spool by 61460-submit@debbugs.gnu.org id=B61460.167636158322293 (code B ref 61460); Tue, 14 Feb 2023 08:00:02 +0000 Original-Received: (at 61460) by debbugs.gnu.org; 14 Feb 2023 07:59:43 +0000 Original-Received: from localhost ([127.0.0.1]:52417 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pRqE2-0005nV-Pk for submit@debbugs.gnu.org; Tue, 14 Feb 2023 02:59:43 -0500 Original-Received: from woodpecker.gentoo.org ([140.211.166.183]:52938 helo=smtp.gentoo.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1pRqE1-0005nG-0o for 61460@debbugs.gnu.org; Tue, 14 Feb 2023 02:59:41 -0500 In-Reply-To: <875yc4q0ee.fsf@web.de> (Michael Heerdegen's message of "Tue, 14 Feb 2023 06:30:33 +0100") X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.bugs:255552 Archived-At: >>>>> On Tue, 14 Feb 2023, Michael Heerdegen wrote: > I did not find good discussions of the eclipse limits in the English > Wikipedia version; I found good explanations in German however: > https://de.wikipedia.org/wiki/Finsternis-Limit#Finsternis-Limite_bei_So= nnenfinsternissen Thanks. I followed the legend of the diagram and was pointed to the following page, which contains a more comprehensive explanation: https://www.swetzel.ch/astronomie/finster/finster.html#3 > The limits for an eclipse to happen are not really constant, but taking > this into account is probably out of scope of the currently available > code in lunar.el. I wonder why the angles in above explanation are completely different from the ones given in eclipse-check: ((< moon-lat 2.42600766e-1) (concat "** " phase-name " Eclipse **")) ((< moon-lat 0.37) (concat "** " phase-name " Eclipse possible **")) These are in radians. The first angle is 13.9=C2=B0 (exactly) and the second one is 21.2=C2=B0. They are in argument of latitude, while (IIUC) the angles in "Finsternis-Limit" are given in ecliptic longitude. Still, with the moon's orbital inclination being only 5=C2=B0, one wouldn't expect much of a difference there. Or am I missing something? I've also found the book mentioned in lunar.el: https://books.google.de/books?id=3DvVBPtkABpUoC&lpg=3DPA186&vq=3Declipse&hl= =3Dde&pg=3DPA177#v=3Donepage&q&f=3Dfalse CCing Nicholas Strauss (who had originally submitted the code in bug #20414).