Re: Truly Offensive Bad Astronomy

In sci.astro.amateur message <1189136833.757291.162540@xxxxxxxxxxxxxxxxx
groups.com>, Thu, 6 Sep 2007 20:47:13, Quadibloc <jsavard@xxxxxxxxx>
posted:
oriel36 wrote:

I have oriel36 killfiled, and recommend the practice.

And his web site was very accurately informed about those leap seconds
that are in actual current use. Leaping back and forth every year to
stay with the sundial is not worth the bother, but avoiding a long-
term cumulative error because our second is the wrong size is needed.

It has recently occurred to me that, as well as the Leap Year (which is
really just a container for a Leap Day) and the Leap Second, another
form of Leap will in principle be needed in the distant future.

Choose any long-range algorithm for the Date of Gregorian Easter Sunday
as Day-Of-March. Inspection will show, and test will confirm, that the
dates repeat with a period of 5,700,000 years (EW is/was wrong). It's
clear that consecutive Easters separated by less than a year are 12
lunations apart, and those separated by more than a year are 13
lunations apart. So, by counting, one can get the number of lunations
in the repeat (it's prime), and hence the exact length of the Gregorian
Lunar Month.

Compare that with the current Real Lunar Month; the agreement is very
good but not perfect; I find a discrepancy of about 0.1s, which amounts
to a whole day in umpteen years, by which time a Lunar Leap Day
(positive? negative?) will be needed.

Of course, the Easter Rules should be changed correspondingly when the
secular calendar is altered to deal with the errors of 4/100/400-year
rules; and that would be a good time to include any Lunar adjustment.

Also, the Lunar Month Length is drifting, like the day length; someone
must know the rate.

IMHO, an Astronomer Papal (by analogy with the Astronomer Royal),
preferably with initials GC, should be appointed to make recommendations
on the matter - after all, having Easter at New Moon would be a definite
infelicity.

The Hebrews must need an Astronomer Rabbinic, on analogous grounds.

--
(c) John Stockton, Surrey, UK. ?@merlyn.demon.co.uk Turnpike v6.05 IE 6.
Web <URL:http://www.merlyn.demon.co.uk/> - w. FAQish topics, links, acronyms
PAS EXE etc : <URL:http://www.merlyn.demon.co.uk/programs/> - see 00index.htm
Dates - miscdate.htm moredate.htm js-dates.htm pas-time.htm critdate.htm etc.
.

Relevant Pages

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