yes we talk like this

[cellio]

At the Giant Eagle pharmacy:

Me: Here's a prescription, and a gift card from Big Pharma that will pay for three months' worth. If I mail-order it I can get three months' worth at once; can you do that for me?

Her: I don't know; I'm just the front-desk flunky. Do you want to leave it and we'll give you as much as we're allowed to?

Me: Sure.

After I did my grocery shopping I returned.

Her: Sorry, we're only allowed to do one fill-up at a time.

Me: I understand. Have we completed this transaction, then?

Her: Um, yes?

Me: Will you take as given that I walked out through that exit and then came back in, or do I need to actually do it?

Her: Nice try, but you have to wait a month.

Oh well. I have until the end of the year to use the gift card.

---

Dani: So you can read on Shabbat; can you use a Kindle?

Me: No, because you have to manipulate the controls. It's like changing the channels on TV; technically you can watch it if it's on but you can't change the channel or volume. (Pause.) I suppose if, before Shabbat, you set in motion a smooth scroll at a readable pace, that would be like programming the lights. But it seems unworkable.

Dani: What about software that tracks your eye movements and turns the page at the right time?

Me: Seems like manipulation to me. Next you'll be bringing up sentient lightbulbs again.

Dani: How good does the programming have to be before your software qualifies as a servant?

I have no answer to that. Halacha geeks?

Comments

[dsrtao]

It all depends on how many layers of fences you want to build.

The mitzvah is to not work.

The 39 categories of melacha are all "creative activities that exercise control over one's environment".

But all of them except kindling and extinguishing are things that we now consider as work-of-livelihood. You allow automatic thermostats to continue to keep houses warm or cool, but to observe Shabbat, you don't change the setpoints.

So a mechanism which continually does something, should neither be started nor stopped. If there was a light dimmer rigged to a light sensor, such that it tried to always keep the brightness in an area constant, that should be permissible.

Now, a non-sentient device that responded to your natural actions without being asked -- that would be interesting. (A sentient device would be a servant or a friend; that would also be interesting, but already covered.) So a book which when you picked it up turned itself on, and when you had read the page, flipped itself without being signaled or asked... there's room for debate there. I think.

[dvarin.livejournal.com]

If you know ahead of time that it will turn itself on when you pick it up, doesn't picking it up itself constitute a signal?

I mean, otherwise I'm going to make a similarly-formed argument about light switches--the light isn't turned on by your flipping the switch, it's only responding to noticing you've flipped it by turning itself on.

[dsrtao]

Sorry -- I mispoke. Such a book would not turn itself on when it is picked up, because it was not off before.

Part of the problem with light switches is that the old ones might emit a spark when you flipped it, making it more like you were kindling a fire.

[dvarin.livejournal.com]

Sorry, I keep forgetting this is more complex than "Electricity is a subtype of fire."

[sanpaku.livejournal.com]

I'm reading a book about traffic and it mentioned that in parts of LA, pedestrian-detecting traffic signals were removed in favor of automatic ones after consulting with the orthodox rabbis. Once people figured out that their mere presence tripped the sensor, they avoided it. So presumably the act of picking up the book starts a process, and that has to be avoided.

[cellio]

I should have thought of this earlier: motion-sensor lights. My understanding is that halacha is opposed; the practice I've observed is that if you know they're there you avoid them but if you accidentally trigger one you didn't know about you just move on. (Certainly installing one at your house, assuming you planned to walk through that space on Shabbat, would be problematic.)