[Avodah] Just How hot is Yad Soledes Bo anyway?

[Micha Berger]

On Wed, Dec 09, 2009 at 11:06:19AM -0000, Chana Luntz wrote:
: What I was trying to say was that I would have thought *any* type of burn
: should fall within the gemora test (ie even the most limited kind that could
: be classified as a burn).  The test in the gemora (well the Bavli anyway
: Shabbas 40b) is kol shecreiso shel tinok nichveis"....

Which is an odd test, since I'd be much less likely to actually try that
on a baby or toddler than to actually see if an adult's hand would recoil.
So, an adult has a reflex at the same temperature that a baby's skin
would actually cook.
Even with Rashi's explanation of added precision, since it's assur to
burn someone, but it is mutar to make your own hand recoil, how could
that more accurate measurement ever be obtained? You would end up using
an approximation of the better measure (eg by using a fetal pig's skin?),
and thus losing the precision anyway.

: I also wrote:
: > > The one in common use is to point out that the knife used for shchita
: > > is deemed cold (ie does not need to be treated as though it was cooked
: > > by the blood of the animal it schechted), even though it is in contact with
: > >the body temperature of an animal (43 degrees or so, although others have
: 
: And RMB replied:
: > But for how long? Does the actually knife heat up? (I would think that
: > if it does, pressure and friction might have more to do with it.)
: 
: The key thing is that you need to look at the gemora in Chullin 8b. The
: discussion there is regarding the knife of an akum and whether if such a
: knife was used for shchita what remedies you need to take in order to use at
: least the majority of the meat (just wash it or remove a layer of the meat).
: And the gemora there initially postulates that the machlokus between Rav and
: Raba bar bar Chana is that one holds "beis haschita tzonen" and the other
: holds "beis haschita roseach" - ie that the place at which the slaughter is
: done on the animal is considered halachically "cold" or "boiling"...

Thanks, but given that it isn't actually tzonein or rotzeiach, can we
use the chalos sheim to determine the physical temp implied? I supposed
so, since that's what is done. But that's the very point I found
surprising.

...
: What is not discussed is a time factor.  My knowledge of shchita is
: extremely rudimentary, but I believe that it is possible to perform a kosher
: shchita which involves moving the knife back and forth a number of times, ie
: that the time period can be extended and still result in a kosher shchita.

As long as it's continuous, shechitah can take arbitrarily long.
Shehiyah is only is the chalaf (or should I say saqin when writing
someone who became Sepharadiah?) loses contact before the simanim are /
siman is cut through.

Of course, I forgot 8b, so who knows how well I retained hilkhos
shechitah?

Tir'u baTov!
-Micha

-- 
Micha Berger             Man is a drop of intellect drowning in a sea
micha at aishdas.org        of instincts.
http://www.aishdas.org                         - Rav Yisrael Salanter
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