[Avodah] The Molad of Tamuz

[Micha Berger]

On Mon, Jul 02, 2018 at 09:40:28AM +0300, Simon Montagu via Avodah wrote:
: But here again there is a sub-mahloket on the calculation of the hours and
: halakim: according to the Rosh and the second opinion in the Tashbetz we
: use the same sha`ot zemaniot that we use for all other halachic times: 12
: equal hours from sunset to sunrise, and 12 differently equal hours from
: sunrise to sunset. According to the first opinion in the Tashbetz we use 24
: equal hours, starting from sunset, and this is followed by the Mahatzit
: Hashekela and the Eliyahu Zuta.

Also, days. From the winter solstice to the summer one (+/- a bit for
the analemma, the variation of noon due to the tilt in the earth's
access) days are increasing. Sunset is a little later than yesterday.
The 29 days of the molad would be longer than 29 x 24 hours by the
amount sheqi'ah got later.


On Tue, Jul 03, 2018 at 06:09:10PM +0300, David Cohen via Avodah wrote:
: Given that the molad doesn't correspond to any actual event, it seems
: unlikely that the point is to be able to look at one's watch and say
: "now."  The fixed-interval molad was only "invented" for the purpose of the
: calendar and only "exists" at all in that context, where a translation to
: local clock time is irrelevant.

Good point! We could continue applying the calendar algorithm without
knowing anything about what the words we're saying mean -- other than the
day.

Which would give impetus to positions that say we're using the solar
sunset, rather than 6pm or 6 standard hours after chatzos. Because that
would preserve the day the month starts on even when the molad is around
that time of day.

But what would motivate sharing that information just when it would be
in mind the moment of qiddush hachodesh? Between the baqashah and the
actual qiddush, no less? The point appears to be knowing or announcing
the current month's molad, not future dates', something integral to the
qiddush being done.


On Tue, Jul 03, 2018 at 05:36:30PM +0300, Richard Fiedler via Avodah wrote:
: Micha Berger and Dr. Irv Bromberg of University of Toronto are very
: concerned about the accuracy of the Moladot. They presume that Chazal
: created the Molad to supplant simple actual witnesses to improve the
: accuracy of determining the new month but that time has made it out
: of wack. This is because the length of the interval between successive
: moladot is 532 ms longer than the astronomically determined value. Which
: means 3 1/2 hours error since the time of Rabban Gamliel.

The molad was used, around 1500 years ago, to give us the algorithm for
computing the calendar. The fact that there is now a 3-1/2 hour error
or so since the Sanhedrin established the calendar doesn't change that
such is our calendar. The replacement of eidim happened back then,
so what we have is what we have -- months declared, if implicitly, by
Sanhedrin.

R' Gamliel has nothing to do with anything I said, since his Sanhedrin
was centuries earlier and was not meqadeish future chadashim by canonizing
a calendar.

What the 3-1/2 hour error does highlight is the need to reinstate the
Sanhedrin and replace the current calendar.

: I created a spreadsheet from the time of creation of all of the moladot
: and discovered that occasionally the Old Moon could indeed be seen on the
: morning of the day before the Molad of Tishrei. Such was the case for the
: Molad of Tishrei 120 CE a time consistent with the life of Rabban Gamliel.

I don't know how knowing an average time in the 5th century could tell you
when the moon could be seen even in the 5th century. The time between
lunations is chaotic.

Unless you know the actual time of the previous molad for real, not
based on adding averages, you don't know how the interval the eidim were
claiming the moon appeared in since the previous month. You cannot
recreate Rabban Gamliel's situation to know whether it was possible
or not.

Tir'u baTov!
-Micha

-- 
Micha Berger                 Life is complex.
micha at aishdas.org                Decisions are complex.
http://www.aishdas.org               The Torah is complex.
Fax: (270) 514-1507                                - R' Binyamin Hecht