[Avodah] electricity on Shabbat

[Micha Berger]

On Thu, Jan 07, 2010 at 06:10:36AM -0500, david guttmann wrote:
: The issur is Lo Teva'aru Esh, there are therefore two components Biur and
: Esh. Making fire alone is not an issur, it is fire that has Bi'ur, some kind
: of longer term result (similar to veshilach et Be'iro Ubi'er besadeh acher).
: See Rambam Hilchot Shabbat 12:1 the issur is only if one makes fire on
: something - hamadlik et haner o et ha'etzim.... 

So the question is that the "fire" doesn't last long enough to consume
any metal?

In any case, that was a hypothetical I raised because someone wrote that a
spark of "just air" wouldn't be fire. The sparks actually contain metal;
it's a standard gacheles shel mateches issue, although very small. To
quote wikipedia" "a tiny bit of metal is heated to incandescence, melted,
and thrown off. On opening, a bluish arc may occur with a detectable
"electrical" (ozone) smell; afterwards the contacts may be seen to be
darkened and pitted." Pretty similar to a filament, no? There is even
the evidence of bishul ("darkented") and the missing metal that was
in the spark ("pitted"). If you ever had the misfortune to see sparks
sputtering out of a socket, you'll notice they fall in trajectories.

This hypothetical would only be an issue for a Jacob's Ladder (that spark
that leaps up wires in Mad Scientists' laboratory) or after rubbing your
feet on the carpet a long time in just the right humidity so that the
static itself is visible. In those cases, there would be no measurable
damage to the metal (or skin).

Tir'u baTov!
-Micha

-- 
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