13
votes
2answers
293 views

Overhead projector on Shabbos?

A discussion came up with some guests over shabbos. One asked if one could use an overhead projector on Shabbos if it was turned on from before, i.e. could one put a new plastic sheet on it or not? In ...
6
votes
1answer
105 views

Is it permitted to use a thermochromic cup on Shabbos?

A novelty cup, see for example here, appears black when cold. When hot liquid is poured into it, the black changes to white and the previously concealed writing (underneath, so to speak) becomes ...
1
vote
1answer
85 views

Typing on Shabbos

If one would type on a computer on Shabbos would he be ovar an issur d'oraisa in regards to the malacha of writing? (The other malachos involved aside for a moment.) Is there any room to say this ...
11
votes
2answers
162 views

Gap zip up sweatshirt Kesivah on Shabbos?

Does zippering up a sweatshirt like this one, which when zippering causes the letter A to become a letter create a problem of Kesivah on Shabbos? Is an Old Navy sweatshirt where the word Old is on one ...
3
votes
1answer
182 views

Is drawing a line with a crayon forbidden on Shabbat?

There are board games that involve using a crayon to draw lines (not letters or figures) on a board (e.g. EuroRails). Are these activities problematic on Shabbat? There are two aspects: the drawing ...
7
votes
2answers
143 views

Games (on Shabas) that involve writing: whose writing?

I don't have good sources handy, but apparently some forbid the Shabas playing of games in which one usually writes, even if playing without writing: Scrabble, in which one writes scores, is sometimes ...
11
votes
2answers
358 views

Why does writing on Shabbos need two letters?

In order to transgress "writing" (כותב) on Shabbos, (m'd'oraysah) one must write two letters. (See for example here.) Why is this so? Shouldn't writing anything still be considered writing? For ...