Why does the of Easter change every year?

[admin]

Easter can fall on any Sunday between March 22 and April 25. The took millennia to standardize for surprisingly complex reasons.

Why does the of Easter change every year? : Read more

 

[Daniel Rey M.]

Missing in that roundabout explanation is the basic and very simple reply (see MAN MAKES HIMSELF, V. Gordon Childe, ch. VI, "ad fin."): because there is no number of lunar months (lunations) that is exactly equal to one solar year. (All calendars are inescapably lunisolar, but some stress the solar aspects, others the lunar aspects.)

NOTE: You can trust me in matters astronomical without having to go ask the Astronomer Royal. I'm 71 yrs. old and have been an amateur astronomer ever since 1985, when Halley's Comet returned and disappointed everyone. Already 38 yrs. have gone by, so we must wait only an additional 38 to see how it will behave next time.

 

[Daniel Rey M.]

Missing in that roundabout explanation is the basic and very simple reply (see MAN MAKES HIMSELF, V. Gordon Childe, ch. VI, "ad fin."): because there is no number of lunar months (lunations) that is exactly equal to one solar year. (All calendars are inescapably lunisolar, but some stress the solar aspects, others the lunar aspects.)

NOTE: You can trust me in matters astronomical without having to go ask the Astronomer Royal. I'm 71 yrs. old and have been an amateur astronomer ever since 1985, when Halley's Comet returned and disappointed everyone. Already 38 yrs. have gone by, so we must wait only an additional 38 to see how it will behave next time.

... and even if there were such a number of lunations, leap years would ruin the coincidence because ever since that innovation introduced by the Julian Calendar in the 1st Century B.C. our solar years are not all of the same length. The additional day (Feb. 29) inserted every fourth year would be the fly in the ointment.

If calendar messiness disturbs a pondering devotee then maybe the following fantastic coincidence might help regain the faith: that the Moon happens to be about 400 times smaller than the Sun but also precisely that many times nearer than the Sun, which is why we can enjoy perfect total and annular solar eclipses (the latter when the Moon is slightly closer to us), since the coincidence makes the apparent diameter of the Sun identical to the apparent diameter of the Moon (½° of arc). Those amazingly neat happenings would be seen nowhere else in the Solar System.

(The aforementioned calendars that stress the solar features are therefore called "solar", and the others are called "lunar", which is misleading for beginners.)

 

[Daniel Rey M.]

Correction: not "slightly closer to us" but the opposite, slightly farther, closer to the Sun, so that it shrinks and will not be big enough to entirely cover the Sun as in a total eclipse. Surely such an obvious mistake would have been noticed quickly if anyone had read the comment. "Errare humanum est."