[Avodah] Rakia, Maaseh Bereishis, Halachah

[Micha Berger]

Rishonim disagree about what is the raqia' and the mayim asher mei'al
laraqia'.

Most of us know the opinion that it's a surface at the edge of the
universe, and the water above it some kind of supernal mayim. (Perhaps
"ein mayim ela Torah".) And the opinion that identifies it with the
spheres. Either of the Babylonian astronomy -- a dome that the sun goes
behind at night. Or of Greek astronomy (eg Rashi Ramban) that the stars
are embedded within and revolves around the earth. (Interestingly
the Rambam associates these with the sephiros, but the raqia' is
something else, leshitaso.)

Bereishis Rabba 4:2 speak of the raqia' congealing from a drop of
water. Based on this, the Rambam (Moreh 2:30) and Ralbag say that
raqia' is the atmosphere. Ibn Ezra reaches the same masqanah, but
via a different route. Mayim asher mei'al laraqia comes in cumulus,
stratus, nimbus, and so on.

Learning Eruvin, the thought hit me that this may have a nafqa minah
lehalakhah.

Numerous sattelites are in geostationary orbit; meaning, they orbit
the earth such that they are always over the same point. What if a
given sattelite is always over my home?

Reshus hayachid olah ad laraqia (Shabbos 52b, Eiruvin 7a).

So, whether or not that sattelite is on my reshus would depend on whether
ad laraqia is the top of the clouds, or ad infinitum. (Unless the universe
is finite, in which case...)

Tir'u baTov!
-Micha

-- 
Micha Berger             The Maharal of Prague created a golem, and
micha at aishdas.org        this was a great wonder. But it is much more
http://www.aishdas.org   wonderful to transform a corporeal person into a
Fax: (270) 514-1507      "mensch"!     -Rav Yisrael Salanter