[Avodah] kesiva and tzovea

[Chana Luntz]

R' Eli Turkel asked:

> Next Question:
> Kesiva requires 2 letters near each other.
> If one writes (on paper/parchment) only one letter why is one then not 
> chayav for tzovea anyway?

I am no dye expert, but I wouldn't have thought that the amount of colouring
involved in writing one letter would require the necessary shiur for
colouring - namely that it colours a thread of four tefachim in length- or
something from which it is possible to spin a thread of four tefachim
(Rambam, Hilchos Shabbas perek 9 halacha 13).

Then R' Micha Berger asked:

>A question I've been wondering about since the start of this thread....

>Ink can crack or peel off parchment. It more rests above the skin than
penetrate within it. Would medium be considered tzoveia in any case?

Well if you consider that not to be permanent, then you don't have the
melacha of kesiva either.  The Rambam in the continuation of the above
halacha on tzovea, notes that one is only chayav if the dying is permanent,
but if it is not permanent, then one is patur (of course, aval assur). The
two examples he gives of non permanence is painting one's face, and painting
on to iron or copper.  But the fact that non permanence is considered patur,
not chayav, is learnt out from kesiva, as the Magid Mishna there notes.  And
if you do consider it permanent, then it would seem yes, you do have the din
of tzovea - given the examples of painting on iron or copper, which is only
not chayav because it is not permanent.

Earlier RAM wrote:

 ...
: > Has anyone suggested tzove'a (coloring) as a basis to forbid these
: > devices?

I replied:

: Well tzovea always comes to mind if we are anywhere near ksiva (and
: kesiva vis a vis texting and computer use would seem to be a real
: question) - but, is the production of light photons really tzovea -
: much bigger step, it seems to me, that makeh b'patish, or LEDs being
: light and hence ma'avir.

And R' Micha Berger further replied:

>Plasma panels suffer from the same issues as fluorescent bulbs.

>More common is an LCD display backlit by CCFL (cold cathode fluoresent
lamps). The cathode is way hotter than yad soledes, but not hot enought to
glow. >I mentioned this and the problems defining it as aish or as
definitively saying it's not. Sometimes the backlighting is LED.

>But the tzovei'ah itself is the LCD, the phtons are being produced by
something else and passed through something whose colors you're changing.
>You're effectively coloring a window.

>Also, if things are judged by effect, does any of the above matter? It
still has the effect of giving a surface colors that it didn't have at the
start >of Shabbos.

>E-Ink is a bigger problem, as the text and drawings will persist on their
own. Most LCD systems require refreshing the picture, so that the original
>drawing is not "shel qayama". With e-Ink, though, the LCD will retain the
picture it was given for months or years unless someone sets a new image.
>I don't think a regular LCD would pose a deOraisa issue. I know kesivah
with disappearing ink is derabannan. What about tzoveia? 

As mentioned, the Rambam says explicitly that if it is not permanent, it is
not forbidden d'orisa.

One interesting data point is ROY's teshuva in Yechave Daat Chelek 2 siman
47 where he was asked about those glasses which turn into sunglasses in the
sun (ie change colour) and then go back to clear once in the house, and
whether there is an issur of wearing them (and in particular taking them in
and out, causing them to change colour) on Shabbas.

He answers permitting their use, and begins by quoting the Rambam I refer to
above, clarifying that the changing of colour of the glass must at most be a
d'rabbanan, since the colour is not permanent.  

But ROY then goes on to say that there is no issur at all, because all the
melachos that are forbidden on shabbas we learn from the melachos of the
mishkan  (Shabbat 47b) and all that the Rabbis instituted kein d'orisa
tikun, with the intention to forbid even a thing that is not permanent as a
gezera because of a thing that is permanent, and as the colouring that was
in the mishkan was by way of by putting one item (ie dye) onto another item,
like strings of wool (or, according to the Yerushalmi, skins) which then
became the colour of techelet or argaman.

ROY also brings one fascinating analogy to our original discussion - as a
possible support for this position - namely the Urim v'Tumim. Because
according to the Midrash Shmuel and the Yalkut Shimoni on Shmuel- when Dovid
HaMelech came to ask of the Urim V'Tumim, it was Shabbas.  And according to
the discussion in Yoma 73b, to get an answer from the Urim v'Tumim, the
letters either protruded or possibly lit up in their place - and yet asking
the Urim v'Tumim on Shabbas would seem to be mutar.  On the other hand, ROY
says it does not provide such good support for his case, because the person
asking does not do any action at all, he is just a cause, and it is only if
the kohen is fitting does a message come (in contrast to these sunglasses,
where to achieve the colouring he goes out into the sunlight, which is an
actual ma'aseh).  

But getting back to our discussion, it would seem that the Urim v'Tumim
would suggest that voice recognition software, at least, leading to words
appearing on a screen, would not be considered assur.  Unless you say that
the kohen being or not being fitting is a sufficient other cause to make a
significant differentiation.

Another fascinating case ROY brings is that discussed in Shut Nishal Dovid
and also in the Pri Megadim, regarding whether there is an issur of ksiva if
you had a piece of paper on which something was written in invisible ink,
and in order to read it, you put it close to a heat source, thereby
revealing the letters.  The Pri Megadim thinks there is an issur d'rabanan,
but it sounds like the Nishal Dovid doesn't think there is any issur at all,
even though here there clearly is a ma'aseh.  Now I am not sure whether in
the case of invisible ink, once you bring it close to a heat source, the
writing remains permanently there, or if, once you remove it from a heat
source, it goes back to the way it was - but whichever it is would seem to
impact on RMB's question about e-ink versus regular LCD.

Note that ROY quotes Rav Moshe as also having permitted colour changing
sunglasses - but he cites the relevant teshuva as being in Iggeros Moshe,
Orech Chaim chelek 5 siman 45, and my version of chelek 5 seems to only go
up to siman 43 (and so does the one on Hebrew Books) so I don't know where
this teshuva is.  If there is any reasoning in that teshuva (and not just a
psak) it could also shed some interesting light on our topic.

Regards

Chana