January 2, 2009 1:33 am at 1:33 am #1237634squeakParticipant
Rather than clog up the already stuffed riddle thread with non-riddles, I thought it would be nice to have a thread for non-riddle questions.
The one Joseph asked is a good one to start with – he asked:
Is it true that there is a leap year (Feb. 29) every 4 years (in the secular calendar)?
The answer is no. The secular (Gregorian) calendar follows the sun and uses a 365 day year. Unfortunately, nature is not so into round numbers. The true amount of time that it takes the Earth to go around the sun is approximately 365 and 1/4 days. Therefore, at the end of every 365 day year we are actually around 6 hours further behind in our orbital position compared to last year on the same day. At the end of 4 years, we are a full day behind so we have a leap day to catch up.
Unfortunately again, nature abhorrs a round number. 1/4 is not exactly 1/4 but closer to .24. So having a leap year EVERY 4 years overcompensates. As scientific ability to measure this kind of thing improved, they decided to make adjustments to the calendar structure to account for this. At one point, they decided that every 100 years they would skip a leap day. This way, there would be only 24 leap days per century instead of 25, which better corresponds to the .24 extra day.
Well, as time went on we found out that .24 is not exactly .24 (actually, they already knew that but hadn’t done anything about it) but something slightly more (I think close to .2425). So they had again overcompensated (though it is unlikely that the error would have ever be noticed – they were off by 1/4 of a day every 100 years so the seasons wouldn’t even be off by one week for 2800 years!!!!).
The final result is that now we have added back a leap day every 400 years. So in the year 2000 we had one, in the years 2100, 2200, and 2300 we will not, but we will again in the year 2400 – mark my words, and get back to me :). But as we know, things can always change and who knows if some yekkishe scientist will be disturbed by the current inaccuracy and make a new change to the leap year rules.
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