Volume 33 Number 37
Produced: Thu Aug 31 21:17:21 US/Eastern 2000
Subjects Discussed In This Issue:
Electric Lights on Yom Tov
[Mike Gerver]
Electricity (3)
[Rick Turkel, Avi Feldblum, Dovid Oratz]
Psak based on flawed technical info
[Chaim Mateh]
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From: Mike Gerver <Mike.Gerver@...>
Date: Tue, 29 Aug 2000 09:08:37 +0200
Subject: Electric Lights on Yom Tov
The various postings on this topic in v33n28 seem to be generating more
heat than light. I just wanted to try to clarify a few things.
1) The question arose, in the postings of Eitan Fiorino and Berl
Nabutovsky, whether the halachic definition of "eish" (fire) has to
involve chemical reactions, i.e. the oxidation of fuel, as opposed to
using electric current passing through a resistance, or for that matter
mechanical friction, to generate the heat. This came up a few years ago
in the discussion of using fluorescent lights for havdalah. I think the
conclusion at that time was that the only halachic requirement for
"eish" is that something becomes hot enough to glow as a result of its
temperature. Thus, the filament in an incandescent light bulb would be
considered "eish" (I think even according to Torah law, if I am
remembering the discussion correctly) because it is white hot, and it
doesn't matter what mechanism was used to make it white hot, and it
doesn't matter that it is a solid (tungsten) rather than a gas (like an
ordinary flame). Come to think of it, the standard method of starting a
fire at the time of Matan Torah, using a flint to generate sparks to
ignite tinder, involved heating a solid (bits of metal or flint) to
incandescence by means of mechanical friction. Would using a flint to
generate sparks (without letting them fall on tinder) be considered
lighting a fire according to Torah law? If so, then I would think that
turning on an incandescent electric light bulb would be also.
2) I was recently working on modeling fluorescent light bulbs, so I'm up
on how they work. The gas in them does get substantially hotter than
room temperature, but not hot enough to glow. The glow comes about
because the atoms in the gas are excited by electrons, which are
accelerated by the voltage to a high enough energy to excite the
atoms. So it would seem that the glow in a fluorescent bulb is not
"eish" according to Torah law. But it's not so clear. The electrons in
a fluorescent bulb (as opposed to the atoms of the gas) are very hot,
even hotter than the filament in an incandescent bulb. True, the
electrons are not in thermal equilibrium with the gas, or even with each
other, but the mechanism by which light is emitted does have something
in common with the mechanism in an incandescent light. In both cases,
electrons in atoms are being jostled by other electrons (free electrons
in a fluorescent bulb, electrons attached to neighboring atoms in an
incandescent bulb), and are being raised to higher energy levels, from
which they then fall back to a lower level and emit a photon. It's not
obvious to me whether the differences in the two cases (thermal
equilibrium between electrons and atoms in an incandescent bulb, as well
as much more closely spaced electron energy levels, practically a
continuum) are enough to disqualify the fluorescent light from being
"eish."
3) The heat dissipated in the wires bringing electric power to a light
bulb does not seem relevant to the argument in the Aruch Hashulchan. In
normal circumstances (as opposed to faulty wiring or an overloaded
circuit) the rise in temperature is not enough to feel. And this heat
is not being used to power the light bulb. On the contrary, any heat
dissipated in the wires is taking away electric power that could
otherwise be used to power the light bulb.
4) Several people jumped on Dovid Oratz for saying, in v33n19, that a
spark is used to "ignite" the gas in a fluorescent light, since a
fluorescent light does not work by burning the gas inside it. I was
thinking of jumping on him too, when I first read his posting, but
thought better of it. I'm sure he knows that fluorescent lights do not
work by burning the gas inside them. Perhaps "ignite" was a poor choice
of words, but no doubt what he meant is that a spark is used to
initially ionize some of the gas, so that a current can start
flowing. "Break down" would have been a better choice of words than
"ignite."
5) Lawrence Kaplan mentions Shlomo Sternberg's responsum (to a question
posed by the Harvard adminstration) on the use of magnetic cards to open
doors on Shabbat and Yom Tov, and his conclusion that they are
permitted. In spite of this, the practice among Orthodox students at
Harvard is not to use them. When my daughter first registered for
Harvard, she had to return a special form, that was sent to all incoming
freshman, requesting a non-electronic lock for religious reasons.
Mike Gerver
Raanana, Israel
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From: Rick Turkel <rturkel@...>
Date: Tue, 29 Aug 2000 15:23:30 -0400 (EDT)
Subject: Electricity
Several posters over the past few weeks have discussed various
aspects of electricity as regards turning it on or off on shabbat or yom
tov, but one important issue has been ignored except in passing - the
actual closing of an electrical circuit. That would appear to be an
instance of "makeh bepatish" ("the final hammer blow"), one of the 39
avot melakha of mishnah shabbat. Regardless of the specific nature of
an electrical light or other appliance, no current flows to it unless
the switch in the circuit is closed (i.e., turned on). That, rather
than any question of heat or light generation, seems to me to be the
insurmountable obstacle to turning on (or off) anything electrical on
shabbat or yom tov (except for preset timers or gerama switches). A
household electrical circuit is not microscopic (except for those in
computer chips, which might be another interesting topic for discussion,
especially as it relates to computerized telephone systems), so it can't
simply be ignored in dealing with such issues. Does anyone know if any
posqim have dealt with this aspect of the electricity question?
Rick Turkel (___ _____ _ _ _ _ __ _ ___ _ _ _ ___
<rturkel@...> ) | | \ ) |/ \ ein |navi| be|iro\__) |
<rturkel@...> / | _| __)/ | ___) | ___|_ | _( \ |
Rich or poor, it's good to have money. Ko rano | rani, u jamu pada.
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From: Avi Feldblum <mljewish@...>
Date: Wed, 30 Aug 2000 05:37:22 -0400 (EDT)
Subject: Re: Electricity
On Tue, 29 Aug 2000 <rturkel@...> wrote:
> Several posters over the past few weeks have discussed various
> aspects of electricity as regards turning it on or off on shabbat or yom
> tov, but one important issue has been ignored except in passing - the
> actual closing of an electrical circuit. That would appear to be an
> instance of "makeh bepatish" ("the final hammer blow"), one of the 39
> avot melakha of mishnah shabbat. Regardless of the specific nature of
> an electrical light or other appliance, no current flows to it unless
> the switch in the circuit is closed (i.e., turned on). That, rather
> than any question of heat or light generation, seems to me to be the
> insurmountable obstacle to turning on (or off) anything electrical on
> shabbat or yom tov (except for preset timers or gerama switches). A
I see very little fundimental difference between electron flow in a
conductive path and fluid flow in a system of pipes. The electrons do
not flow until I flip the switch on way, stop when I flip it the other
way and restart when I flip it back to on. The water in my plumbing
system does not flow till I turn the fluid switch (water faucet) on,
flows till I turn it off, and then will flow again when I turn it back
on. Both states (on and off) are stable states of the system. I find the
arguement of Mache b'patish very weak.
Avi Feldblum
mail-jewish Moderator
<mljewish@...>
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From: Dovid Oratz <dovid@...>
Date: Tue, 29 Aug 2000 13:00:49 +0200
Subject: Re: Electricity
I must admit that I expected a bit more of a "fire" storm in response to
what I wrote about electricity on Yomtov; all in all it was not bad!
A few comments on some of the replies:
> Another point - the gas in a fluorescent bulb is not ignited - rather
> the molecules are excited by the passage of current through the gas and,
> based on particular chemical properties of the gas, fluoresce - a
> process that is distinctly not eish.
True, I never said it was; but I did mention the ignition of sparks for
the purpose of "turning on " the light which is desired (as opposed to
the sparks when a circuit is opened (or is it closed?) which is
unintended and destructive in nature). That could very well be
considered production of eish. [The Talmudic principle "Nitzotzot ein
bahem mamash" is irrelevant here.]
Another comment:
> I'm over 30 years away from engineering school but there is heat
> involved, not fire or flame, per se, but heat of mechanical friction in
> the hydroelectric generation process, and heat of electrical
> transmission -- on a much smaller scale, consider that an extension cord
> can overheat and has v'halilah cause a fire if amount of current flowing
> through it is greater than it's capacity.
Sure, but my major point is that the slight heat involved is certainly
not in the category of eish.
Another comment:
> Granted, some p'sak halacha re: electricity (and other "technical"
> topics) were based on limited or potentially inaccurate understanding of
> the physics or the phenomena involved.
> But I find it disturbing that this argument is
> typically used to justify ignoring only a flawed lenient psak, but not a
> flawed strict psak.
>
> I can think of several examples of the latter, but one good one is Rav
> Moshe's psak prohibiting the use of toothpaste on Shabbat on the grounds
> that the state of the toothpaste changes from a solid to a liquid while
> the teeth are being brushed. In the same psak, Rav Moshe allowed
> brushing with tooth powder, so he obviously saw no problems with
> brushing teeth on Shabbat other than the change of state in the
> toothpaste (e.g., one might have thought that s"xita could be a
> potential issue). The problem is that Rav Moshe's psak is based on
> incorrect physics, i.e., the toothpaste is still a solid even after it
> has been used. I wonder whether Dovid and others on this list would be
> as quick to dismiss Rav Moshe's psak and brush their teeth using
> toothpaste on Shabbat as they would be to dismiss Rav Epstein's psak and
> refuse to turn on their lights on Yom Tov.
Some other poster mentioned how important it is to be certain that the
we not base conclusions on scientific theories that can change with the
times. Even more important is to be certain that we understand what the
Gedolim actually said before we decide that they did not understand the
facts.
I just reviewed Rav Moshe's Tshuvah on toothpaste and found nothing
about the toothpaste changing from solid to liquid. What I did find in
his very short tshuvah was that the use of toothpaste is prohibited
because of the melachah Memachek. Memachek has a toladah "memareach"
which R' Moshe understood as prohibiting smearing of ointments or
pastes, regardless of whether they change to liquid or are just smoothed
down.
If a psak lechumrah were found to be based on faulty information, I
might not have much difficulty in not following it -- if I were certain
that:
a) I in fact understood the psak and its basis and
b) it is in fact based on erroneous information.
Finally, one poster spoke about gentle education being the method of
choice in changing faulty minhagim. That is exactly what I hope that I
am doing by writing here!
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From: Chaim Mateh <chaimm@...>
Date: Wed, 30 Aug 2000 20:26:17 +0300
Subject: Psak based on flawed technical info
The only tshuva of Rav Moshe that I found about toothpaste (Orech Chaim
1:112) makes no mention of solid-to-liquid and no mention of powdered
toothpaste. He clearly says that it's prohibited because of memachek
(smoothing out the toothpaste). Rav Moshe goes on to say that without
toothpaste, it's OK, but it's better not to wet the toothbrush so as not
come to schita (squeezing out liquid).
Perhaps you were referring to the latter comment of Rav Moshe, i.e., not
to wetten the brush so as not to come to squeeze. Perhaps Rav Moshe was
referring to brushes made of hair for which there would be schita. And
in fact, in the tshuva he refers to "schita basei-ar (squeezing of the
hair)". Today's toothbrushes have nylon bristles, which may not absorb
the water so that there wouldn't be schita. If my memory serves me well
(Dovid Oratz may remember better than me), Rav Tuvia Goldstein Shlita
ruled that nylon toothbrushes indeed do not have schita.
<<I wonder whether Dovid and others on this list would be as quick to
dismiss Rav Moshe's psak and brush their teeth using toothpaste on
Shabbat as they would be to dismiss Rav Epstein's psak and refuse to
turn on their lights on Yom Tov.>>
The reason for no tootpaste has nothing to do with solid-to-liquid.
Therefore this is _not_ an example of a flawed psak based on flawed
technical information. However, your question remains valid. I
personally would not dismiss _any_ psak by my own understanding, but
rather consult and refer to Rabbinic responsa and advice to determine
whether the psak was indeed flawed, be it a lenient or stringent psak.
Kol Tuv,
Chaim
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End of Volume 33 Issue 37
