[Avodah] Molad Alert: Friday night

[Zev Sero]

On 9/03/2011 3:57 PM, Micha Berger wrote:
> Nisht azoi pashut. As I wrote last Fri
> <http://www.aishdas.org/avodah/vol28/v28n033.shtml#08>:
>  In the mid-4th century, the currently announced molad would have
>  been accurate for mid-way between the Nile and the Euphrates....
>  But the tides are still there and the month is still getting shorter
>  ...
>  At this point, the molad is something like 108 chalaqim
>  off. Alternatively, we could keep the molad correct and say the
>  "timezone" is sliding east. Not sure why we would want to, but enough
>  web sites and books do this excercise. So, we could say that we now
>  compute the molad accurately for Kandahar, Afghanistan.

I don't understand the basis for this.  What has the precession of the
equinoxes got to do with the molad, which only concerns the Sun-Earth-
Moon system?

> But as far as I can tell, it was never actually for Y-m. It was for the
> center of the Jewish world in the final days of the Sanhedrin.

The Rambam says it's for Yerushalayim and the areas within six or seven
days' travel around it, from where eidim might come. (Presumably a rider
on a fast horse can travel in one day what will take a person on foot
6-7 days, and so arrive in Y'm before the BD closes at noon.)  He further
defines the area for which his calculations are made as three degrees
longitude and latitude around Y'm, whose coordinates he gives as roughly
32 N and 24 W (from the prime meridian of his day).

> The Shaar haKollel's (and my father's or early-grade rebbe's) explanation
> implies that the qehillah should know what the time of the molad means
> in terms they think in.

I don't see how it implies that at all.  According to this explanation
the announcement that the molad is imminent (or has already occurred)
takes the place of the eidim's announcement that they'd seen the moon.
What has the exact time of the molad, or the scale in which it's
expressed, got to do with that?  It's not as if the eidim actually
announced the time of the molad.  All they announced was that the newly
born moon was visible the previous evening (on the western horizon just
after sunset, which is the only time and place a new moon can be seen),
at such a location, and with such a north/south declination.  How much
earlier than that was the molad?  How should they know?

[Email #2. -micha]

By the way, since we're on the subject, the Shaar Hakollel was the LR's
great-great-grandfather, not his father-in-law.  That was the previous LR.

-- 
Zev Sero                      The trouble with socialism is that you
zev at sero.name                 eventually run out of other people’s money
                                                      - Margaret Thatcher