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Path: utzoo!utcsrgv!dave
From: dave@utcsrgv.UUCP (Dave Sherman)
Newsgroups: net.religion.jewish
Subject: Re: Re: Shabbat electricity (what is work?)
Message-ID: <127@utcsrgv.UUCP>
Date: Sun, 21-Oct-84 03:09:25 EDT
Article-I.D.: utcsrgv.127
Posted: Sun Oct 21 03:09:25 1984
Date-Received: Sun, 21-Oct-84 03:43:52 EDT
References:  <348@wxlvax.UUCP> <2257@rochester.UUCP>
Organization: The Law Society of Upper Canada, Toronto
Lines: 43

In article <2257@rochester.UUCP> sher@rochester.UUCP (David Sher) writes:
~| If I attached a timer to the sensor so that 30 seconds after I enter
~| the room a light turns on, is this forbidden?
~| If I attached a probabilistic timer so that the sensor waited a
~| length of time which corresponded to an element of a exponential
~| distribution with a mean of 30 seconds, is this still forbidden?
~| If I attached a probabilistic device to the sensor so that 95% of the
~| time that I entered the room the light went on, is this forbidden?

Although I haven't consulted a Rav on this, I think I can shed
some light. The action is forbidden if there is *either*
(a) a direct, immediate electrical result (e.g., fridge light
	goes on), or
(b) an intention to cause the result, followed by the result (thus,
	fridge compressor turning on is OK, since you're opening the
	fridge to get food, not to cause it to go on).

A practical application of (b) occurs on Yomtov in the use of the
oven. Our practice is to turn up the oven only if the light is on
to indicate that the oven element is already on, and to turn it down
only if the light is off, indicating that the element is already off.
If we need to open the oven to put food in or take it out, we do so
regardless of the state of the light; but we will *not* open the oven
in order that the light may go on so that we can then turn the element
up to a high setting.

It would follow that, to answer David Sher's question, no "probabilistic"
device would be allowed if the purpose of using it was to have it go on
(e.g., by repeatedly walking into the room until you succeeded in getting
the light turned on). Similarly, the delay of 30 seconds is irrelevant.
I believe it is key to the fridge and furnace examples that the action
of opening the fridge or the house door is not done with the intent
of causing the compressor or furnace fan to go on.

Incidentally, we have friends who do not open their fridge
on Shabbos until they hear it's running. (We've sat waiting for the
next course in lunch more than once due to this.) They do, however,
open their front door in winter.

Dave Sherman
Toronto
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