[Avodah] Torah Geography & Dream Brachos

[Zev Sero]

Gilad Field wrote:

> 1) The Gemara, in Bava Basra 25b (it is also in the first perek of
> Gittin), wants to prove that Bavel is north of EY by quoting a Pasuk
> in Yermiyahu.  Why should we need a pasuk to teach us geography? This
> seems a bit strange to me.  Anyone have any thoughts on that?

The Amoraim's knowledge of geography was minimal.  In fact Bavel *isn't*
north of EY, and R Chanina's advice to R Ashi was wrong.  Bavel is pretty
much due east of EY.  The pasuk doesn't say anything about where Bavel is,
all it says is that the the Bavli invasion would come from the north.
The road from Bavel to EY goes north, turns west through Syria, and comes
down into EY from the north.  Also, if the pasuk refers to Yerushalayim
then *any* pre-modern invasion had to come from the north, because that
is the only side on which Y'm is vulnerable.  Nachal Kidron and Gei Ben-
Hinom protect it on the other three sides.  AFAIK WW1 was the first time
Y'm was taken from any other direction.

As for the direction of prayer from Bavel, there are two methods of
determining this, and either way R Chanina was wrong.  If it's determined
by drawing lines on a globe, then the proper direction from Bavel is due
west; if it's the road one would take to EY then in Bavel that is *north*.
There is no sense in which EY is south of Bavel, even though there is a
sense in which Bavel is north of EY.

PS: Another thing which may have confused R Chanina is that the Euphrates
is the *north-eastern* border of EY.  And as everyone knows, Bavel is on
the Euphrates.  Therefore it stands to reason that Bavel must be north of
EY.  The fallacy here is that the Euphrates is a long river, and it flows
south-west, not south.  The point at which it is one of the borders of EY
is in its far upper reaches, near Aleppo.

-- 
Zev Sero                    A mathemetician is a device for turning coffee
zev at sero.name               into theorems.                   - Paul Erdos