? I don’t want to belabor what might have been just a joke, but these aren’t actually analogous, right? There isn’t any physical reason that the moon’s size and distance from the earth had to work out the way they did, so that the disk of the moon is just about the same angular size as that of the sun. That really does count as a gen-u-wine coincidence (although not a perfect one, as the apparent size of the moon’s disk fluctuates somewhat).
Well, if that doesn’t bring back memories! I think this topic was the subject of my very first post here on the SDMB, many years ago. Fortunately, since it comes up quite a bit in my line of work, I kept the file and still have it. Lemme go dig:
IIRC, the 24-hour day division was first used by the Egyptians, possibly influenced by the Babylonian 12-beru day division.
It was a joke with a purpose, although on rereading I realise it wasn’t entirely appropriate…the moon is the correct size sometimes. Sometimes it’s larger than the sun, sometimes it’s smaller. One produces the same total eclipse, the other an annular eclipse.
Thanks for the additional comments on the 24/360 issue, Kimstu. It squares with what I’ve read from various sources. I was expecting a new wrinkle on the “24” issue, as opposed to just doubling “12” which I realize was the choice for having more divisors (2, 3, 4, 6) than 10 (2 and 5) for developing fractions that made common sense.
On a tangential issue, have you consider how Roman Numerals are partial to 1, 5, and 10 and multiples thereof. In fact, is there any basic Roman Numeral that isn’t a 1, 5 or 10? Examples: 10, 50, 100; 100, 500, 1000. They were pretty tied to fingers and toes, I guess.
The people of Ulm might disagree. When Napoleon laid seige to the city the people of Ulm expected the Russians to arrive in short order at a date that the Austrians and Russians had previously agreed upon. Oops, the Russians were on the Julian calendar and were two weeks behind the Austrians and therefore didn’t arrive in time for the battle.
Isn’t that enough of a reason? I was just thinking in terms of circles and divisions, and that the cycle of the day is divided into 24 because it fits into 360, and can also be further broken down into convenient parts that also fit the 360 degree pattern.
Re to the pope hiring astronomers: Popes prior to Gregory XIII had the problem investigated. Paul III, a few popes befory Gregory XIII, for instance. In 1563, the Council of Trent had approved a calendar reform to restore the equinox to the dates recorded in 325. This was a few years before Gregory XIII’s papacy. It’s got Gregory’s name on it because a proposal was finally implemented during his tenure. In fact, Roger Bacon, who lived about 3 centuries earlier, had sought to get the calendar reformed. People probably began noticing the slippage of the equinox long before then - by Bacon’s time the 325 AD observations would have been off by about 7 days.
Not necessarily all that spooky, since there are planets where the rates do coincide nicely. Mercury’s rotation, for instance, is exactly 2/3 as long as its year. And the Moon rotates once in exactly the same time it takes to orbit the Earth. It would be a bit surprising if a planet as far away from its star as the Earth showed such a pattern, and it would also be a bit surprising to see such a pattern with a ratio as high as hundreds to one. But even there, I think that it falls rather short of “spooky”. Spooky I would reserve for things like constants of cosmological significance being 10[sup]120[/sup] times smaller than expected, but still not quite zero. And yes, we are indeed spending a lot of effort trying to figure out that one.
Lemme go dig: