Volume 32 Number 10
                 Produced: Mon Apr 17 22:36:20 US/Eastern 2000

Subjects Discussed In This Issue: 

Grama-operated electric wheelchair
         [David and Tamar Hojda]
Motion Detectors on Shabbos (6)
         [Carl Singer, A.J.Gilboa, David I. Cohen, David Charlap, Robert
Schoenfeld, Eli Turkel]
Shabbat and satellites
         [Carl Singer]


From: David and Tamar Hojda <hojda@...>
Date: Sun, 9 Apr 2000 01:23:08 +0300
Subject: Grama-operated electric wheelchair

A recent issue of the Israeli edition of the English language Yated
carried an extraordinarily nasty article entitled, " 'Indirect' Chilul
Shabbos", which essentailly ridiculed the "weak heter" used by Machon
Tzomet to produce a specially-designed electric wheelchair for use by
certain individuals on Shabbat. This heter is based on the concept of
grama combined with the special needs of maintaining the independance
and "Kavod HaBrios" of the target population for which this device is

The article quotes various Poskim as having stated that an electrical
device that is specifically designed to bypass Shabbos restrictions
through use of a grama switch is no better than any other electrical
device in regards to its permissibility for use on Shabbos. Therefore,
these devices offer absolutely no benefit and are more problematic than
the non-grama ones, as they lead to greater Chilul SHabbos by giving a
false sense that they involve no violations of Shabbos.

It is my understanding that these inventions were designed with the
approval and support of Rav Shlomo Zalman Auerbach.

The article is based on a recent sefer, SHevus Yitzchok, which claims
that Rav Elyashuv and Rav Shlomo Zalman both disapproved of these
devices. I have looked at this sefer and am told that its author may not
be a reliable source of information.

The issue that interests me is not how various members of this list
would vote as to the halachic propriety of these devices, but rather
what they would know as to the real position of various gedolei

The electric wheelchair that is now marketed for use on Shabbos, which
is somewhat similar to a golf cart, is what interests me most, as its
use is not tied to a heter of pikuach nefesh, but rather of kavod

A) What proof do we have that Rav SHelomo Zalman supported the use of
the grama-switch appliances and what do we know as to the limitations he
would have put on who would be eligible to use them and under what
conditions, specifically regarding the electric wheelchair?

B) I understand that both the Machon Tzomet and the Machon L'Technologia
V'Halacha rely on this concept. What practical differences exist between
the way each of these two institutes apply this heter?

Kol Tuv,
David Hojda


From: Carl Singer <CARLSINGER@...>
Date: Thu, 6 Apr 2000 12:46:26 EDT
Subject: Re: Motion Detectors on Shabbos

I, too, use the X10 based system -- most recently with a PC-based
product (IBM Home Director) --- I can't answer re: motion detectors from
an halachic basis, but as a work around in our previous home that had
them, we put a post-it (r) note over the detectors for Shabbos & Yom

Also, if you're using the dusk / dawn features, look under statistics
tab to set frequency (times per year) that dusk / dawn are recalculated
for your location.

Carl Singer

From: A.J.Gilboa <bfgilboa@...>
Date: Mon, 10 Apr 2000 16:45:03 -0700
Subject: Re: Motion Detectors on Shabbos

The specific questions you ask are intriguing and complex. I am certain
that these and similar situations have been addressed by contemporary
posqim although there may not be a consensus yet.

In principle, as I understand it, there are two issues that must be
considered from the purely halachic perspective:

1. An activity that is permitted on Shabbat but inevitably results in a
forbidden activity. This is called "psiq resheh (v'lo yamut?)", which
literally means "Can you cut off its head (and expect it to live?)",
i.e., the consequence is clearly unavoidable. In such cases, the next
question is - is the forbidden consequence desirable or undesirable to
the one who performs the original permitted activity? ("niha leh" or "la
niha leh"). If the forbidden consequence is desirable (niha leh), the
first activity is also forbidden; if the consequence is clearly
undesirable, however, the first activity is permitted. (There still
remains the gray area where the resulting consequence is neither clearly
desirable nor undesirable.)  A classic example of such a situation is
the opening of a refrigerator on Shabbat. "Psiq resheh" that this will
admit warm air to the refrigerator which will inevitably increase the
operation of the compressor. Is this result desirable or undesirable?
According to many posqim, one may open the door of the refrigerator
because it is clearly undesirable to use up electricity by forcing the
compressor to work longer.

2. The question of "grama", i.e., causation. How immediate is the
resulting forbidden action? If the result is something inevitable but
that will only happen later on, this may be a contributing factor to
permitting the original action.  The case of the refrigerator is
relevant to this issue as well. The compressor does not go on just as
soon as one opens the door but only after enough time has elapsed for
the thermostat to pick up the increase in temperature, etc. (Compare
this to opening the door of the refrigerator that mechanically operates
a switch to turn on a light in the refrigerator. Even if we could
somehow make a convincing argument that having the light go on is not
desirable, we have the immediacy issue - the light goes on as an
immediate consequence of opening the door - that makes it forbidden to
open the door unless the light has been dismantled before Shabbat.)

If I am not mistaken, these will be the halachic issues to be faced in
the hitech situations that you mention. Other issues, such as public
policy and hashqafa, will also play an important role in a "real life"
halachic decision.

Yosef Gilboa

From: David I. Cohen <BDCOHEN613@...>
Date: Fri, 7 Apr 2000 13:52:36 EDT
Subject: Motion Detectors on Shabbos

    Although this is a question best left to your LOR, and I am
certainly no scholar, it would seem to me that the inadvertent tripping
of a motion detector would be OK as a "davar shayno mitkaven" (an act
whose consequences are unintended), and even if you would say that it is
a "pesik raysha" (an inevitable consequence of the act though
unintended) which is forbidden, I would argue that it is "d'lo necha
lay" (unintended inevitable results that one would prfer did not occur)
and would therefore not be a problem.
    Just some thoughts before Shabbat. Any comment?
    David I. Cohen

From: David Charlap <shamino@...>
Date: Sun, 09 Apr 2000 16:17:03 +0000
Subject: Re: Motion Detectors on Shabbos

Danny Geretz wrote:
> Alan Strauss wrote:
>> So my question is, if a person's movement causes the motion detector
>> to send a signal to a controller and the controller then executes a
>> few lines of a program, is that a problem on Shabbos?
> What about high-resolution photographs taken from aircraft or
> sattelites? I'm not familiar with the resolution of these images, but
> I understand that the technology is constantly improving.  Should I
> time my Shabbat walks to and from shul so that I'm only outside when
> no sattelites or aircraft are overhead?
> Another scenario: What if I live in a building with video monitoring
> of the front door/halls/etc.? Or I walk by a 7-11 or a bank or a gas
> station with video monitoring (either to tape or to a monitor) of the
> property?
> We live in an increasingly technological world. What are the basic
> issues involved in each of these scenarios?

I'm no rabbi, so don't act on what I write without first presenting it
to your rabbi....

In response to Alan's question, I don't think executing code in the
computer is a problem.  With surveilance systems, the program is loaded
and running already.  Your walking in front of a sensor may cause the
program to execute a different subroutine, but that hardly seems like
any kind of "work".  This is especially true when you note that the
computer is not stopping and starting - some software (whether its
operating system, or something else) in that computer is running all the
time, whether or not the sensor is activated.

I think the real issue here is whether real work (like unlocking and
opening doors) is done in response to the computer's command, given
because you triggered the sensor.

If this is true (again, CYLOR), then we can divide the situations into
five categories:

1: Where no new work is done.  For instance, walking in front of a
   camera that's continuously recording and doing nothing else.
   Whatever work that is being done is done whether or not you walk in
   front of the sensor (or camera lens.)  I wouldn't expect a
   prohibitiion against this.

2: Where work is done, but you don't know about it.  For instance,
   walking outside while a satelite is gathering data on your locale.
   Again, I wouldn't expect a prohibition here.  The Torah doesn't
   expect us to change our lives over what we can't see.  (This is
   why we're not concerned with eating the millions of insects that
   can only be seen with a microscope.)

3: Where work is done, you know it, but you don't derive any benefit.
   For instance, walking in front of a sensor that unlocks a door that
   you have no intention of opening.  I don't know what a rabbi would
   say about this.

4: Where work is done, you know about it, and derive benefit, but you
   did not intend for the work to be done.  For instance, walking in
   front of a sensor that unlocks the door when you were ready, willing
   and able to use your key.  I suspect that rabbis would object to
   this, because it could easily be confused with situation 5:

5: Where work is done, you know about it, derive benefit, and you
   intended for the work to be done.  For instance, walking in front of
   a sensor that unlocks the door, and you were relying on the sensor
   to do its job for you (maybe you didn't bring your key.)  I think
   most rabbis say that this is not permitted.


From: Robert Schoenfeld <roberts@...>
Date: Sun, 9 Apr 2000 12:46:00 -0400 (EDT)
Subject: Motion Detectors on Shabbos

Motion detectors are a type of Gramma switch whereby the current is
switched indirectly and so are not muksa on shabbos The sane type of
control is used in the special shabbos phon efor doctors use made in
Eretz and also in controls used in electric wheelchair on shabbos

				73 de Bob
+            e-mail:<roberts@...>                   _____              +
+            HomePage:http://www.liii.com/~roberts     \   /              +

From: Eli Turkel <turkel@...>
Date: Sun, 9 Apr 2000 15:49:14 +0200 (IST)
Subject: Motion Detectors on Shabbos

There is a teshuva from Rav Wosner of Bnai Brak that says it is no
problem if ones movements causes a video camera to record the motion.

Eli Turkel


From: Carl Singer <CARLSINGER@...>
Date: Sun, 9 Apr 2000 12:15:25 EDT
Subject: Re: Shabbat and satellites

<< What about high-resolution photographs taken from aircraft or
sattelites? (sic) I'm not familiar with the resolution of these images,
but I understand that the technology is constantly improving.  Should I
time my Shabbat walks to and from shul so that I'm only outside when no
sattelites or aircraft are overhead?>>

I believe this is an absurd response (no offense.)  You might also
consider only going to shule on cloudy days (but then again, certain
imaging may be able to see through the clouds.)  Do you own or control
any satellites?

There are things that you can control and things that you can't.
Additionally, there are halachic issues of intention and of knowledge.
For example:

When you walk through a room, your body temperature impacts that of the
room and therefore as a result the air conditioner may turn on.

When you walk to shule on a snow day, the word "S'TAC WAP" may be
impressed into the snow as a result of your steps.  (That's "Cat's Paw",
a manufacturer of shoe heels."  Would you suggest walking on your hands.

But, again, there are things that you can, indeed, control.  I have a
neighbor who is renting and he had his landlord remove the light sensor
near his door, so that he could enter / exit his home on Shabbos without
turning the lights on.  Clearly as a home owner you have choices to make
and actions that you can take as a result.  The choice / configuration
of a security system is just one of those choices.

Carl Singer


End of Volume 32 Issue 10