hello,
Did you see Rav Padwa’s ??????
http://www.theyeshivaworld.com/article.php?p=63097
He makes the same ????? that we’re “arguing” about. His ????? is like mine, but he somehow is assuming that most of the worm’s growth is in the ?? ????. I suppose that this is consistent with his rejection of ???? ???????.
Back to ???? ??????. If you look carefully at R’ Feivel’s letter, he is not talking about the size of the filter, but the ????? of ???? ??????. I quote again – “which will pick up anything 30 microns or bigger”. The size of the filter is only relevant regarding its ability to pick up anything which is a problem – something which is 30 microns or larger, and therefore ???? ??????. Although this should be sufficient evidence of his opinion, I knew this before finding this parsha sheet, having heard his opinion from his talmidim at the time the NYC bugs-in-water “crises” erupted.
As far as the length is concerned, of course you are correct that if an object can be so thin as to be sub-visible at any length. It should also be obvious, though, that that size would be somewhat smaller than the size given for sub-visible in three dimensions. I don’t know the precise number, but I think even the thinnest human hair is visible, as well as a fine (or even superfine) merino wool fiber.
http://en.wikipedia.org/wiki/Merino
My summer schedule and location is different than during the year; I don’t know for how much longer I can keep this up. I might still have some time (and web access) to respond, But in case not, I now will now wish everyone in the coffee room a happy and healthy summer, and ask anyone who I may have offended ?????.