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 ...
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 ...
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 ...
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 ...
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 ...
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 ...
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 ...