[Avodah] our understanding(s) of fire......change in halacha??

[Micha Berger]

On 09/15/2011 06:04 PM, Harvey Benton wrote:
: our understanding of fire (and its' associated electricity cousin) in
: the minds of the poskim, are not the
: same as they were at the turn of the century when they decided that 
: electricity was assur on shabbas...

The question is how much the halakhah is dependent on science. Often
halakhah depends on how we naturally see the world rather than how the
world is. A subcategory of this is that sometimes we define things based
on function rather than ontology.

It could be that the change in science is irrelevent. If we had any
consistent understanding of what the original pesaqim were based on, I
might be able to be less vague.

On Thu, Sep 15, 2011 at 07:57:49PM -0400, Joel C. Salomon wrote:
: Consider:  A flame, a glowing coal, and red-hot metal are all considered
: "fire".[1] ...

The red-hot metal may well be bishul.

The question could be how we understand the machloqes about gacheles
shel mateches. PERHAPS the Raavad won't call it havarah (labeling
it bishul or makeh bepatish instead) because he holds that it's not
burning unless something is being consumed. Maybe he holds that "aish"
is incandescence that consumes something. Or maybe not -- that would
contradict "haseneh bo'eir ba'eish, vehaseneh eineni ukal". It wouldn't be
"eish", technically, would it?

:             Is there anything in the way of equating this with
: "incandescence"?  Is there anything else halachikly defined as "aish"
: that does not fit this, aside from the Chazon Ish's view that all
: (most?) electric current qualifies?

AFAIK, the CI invokes boneh, not havarah.

And in any case, this doesn't revolve around whether electricity is eish,
but whether a filament that glows because of elevericity is.

We happen to have a great essay on the subject by RMJBroyde and RHJachter
at <http://www.aishdas.org/articles/rmjb_electricity1.pdf>

Tir'u baTov!
-Micha

-- 
Micha Berger             We are what we repeatedly do.
micha at aishdas.org        Thus excellence is not an event,
http://www.aishdas.org   but a habit.
Fax: (270) 514-1507                   - Aristotle