In the solid state, LiCp adopts a polymeric multidecker structure where Li atoms are sandwiched between two Cp rings (shown in this diagram from Organometallics 1997, 16 (17), 3855–3858):
If we consider the η5-binding mode of the Cp rings, then it seems that the number of electrons around Li is more than eight. However, Li can't extend its octet. How can the structure and bonding be explained?
The Mishna at the end of the 14th perek of יבמות gives a few examples where יבום is required and חליצה cannot be done. For example, if there are two brothers, one a חירש (deaf-mute) and one a פיקח (not a חירש) and the פיקח dies, then the חירש must perform יבום and cannot perform חליצה.
Nowadays, however, we (Ashkenazim, at least) normally always do חליצה and never יבום. So what would we do now if this case or another such case were to arise? In particular, I am interested in what would happen if the brother the חירש were married considering the modern obligation (on Ashkenazim, at least) to remain monogamous? חליצה seems to be out of the question. So does he do יבום? A חירש is unable to divorce his יבמה after the fact, so does he have to divorce his wife and then do יבום? Perhaps the יבמה simply remains unmarried for the rest of her life like an aguna (this is what I suspect is the case). If that is the case, is there room to allow יבום either in the case where the brother is married or unmarried in order to prevent that situation?
Answer
In 1724, Rabbi Yaakov Reischer was approached by a woman named Chavah in this predicament: her deceased husband's only remaining brother Yissachar had a deformity on his foot which prevented Chalitza being done. He ruled that Yibbum must be performed, and that R Gershon's prohibition on polygamy does not apply where it would leave one party unable to ever remarry[1]. He elaborates on the text of the blessings involved, the Ketuba he used, etc. in his Shevut Yaakov 3:134-137.
This ruling is cited approvingly in Pitchei Teshuva EH 165:3. Such levirate marriages have since been prescribed by R Chaim Ozer Grodzinski (Achiezer 3:20) and R Joseph B. Soloveitchik (Nefesh HaRav, p. 265).
[1]In general it is a Machloket Rishonim if Rabbenu Gershon ever prohibited polygamy in the case of Yibbum. R Yosef Karo rules that there is no prohibition, while R Moshe Isserlis rules that there still is a prohibition and Chalitza would be necessary (ShA EH 1:10). In our case where Chalitza is impossible, the claim is even R Isserlis would agree that it is permitted.
Why in the past 150+ years did ashkenazim stop reciting the majority of selichot at shacharit, mussaf, and mincha of yom hakkipurim and only start selichot from the psukim before the chatanu or shma koleinu?
Answer
The Arukh haShulchan (OC 620:1) writes:
ומה שתמיהני: דהנה הרא"ש שלהי יומא, והטור בסימן זה הביאו בשם הגאונים לומר בשחרית חמש פעמים "ויעבור". ויש אומרים שלוש עשרה פעמים כנגד שלוש עשרה מדות. ויש אומרים שבע פעמים, ובמוסף שבע פעמים, וכן במנחה, עיין שם. ואנחנו אין מזכירין אפילו פעם אחת. ויש מנהגים שאין להם עיקר — ונזהרים בהם, וזה שהוא מהגאונים ובהזכרת שלוש עשרה מידות — ואין נזהרים בזה.
וזה נצמח הכל מאריכת הניגונים, עד שלא נשאר זמן לומר סליחות. ואמירת שלוש עשרה מדות – אי אפשר בלא אמירת סליחות. וכבר צווחו גאוני עולם על החזנים, אך אין כח בידינו למחות, וד' יכפר.
That which I wondered: the Rosh [] and the Tur here bring in the name of the Geonim to say [the 13 Attributes of Mercy] at Shacharit 5 times; and some say 13 times...; and some say 7 times, and 7 times at Musaf and also at Mincha... and we don't even say it one time. There are customs which have no basis which people are careful about, and this which is form the Geonim to recite the 13 Attributes of Mercy they are not careful about.
And this all derived from the lengthy tunes which don't leave time to say Selichot, and the saying of the 13 Attributes of Mercy is impossible without Selichot. And the great rabbis already yelled at the Chazzanim, but we don't have the strength to protest, and God should atone.
Recall the Arukh haShulchan is well known for being willing to go out on a limb in defending the customs of his community.
In recent years there has been a resurgence in some communities of reciting Selichot with the 13 Attributes of Mercy at all prayers. R. Joseph Soloveitchik for instance, and some communities that follow his rulings, insisted on adding in Selichot to all the prayers of the day.
What is the source or reason that a l'chaim is often said over a drink of alcohol instead of any other beverage, or over other foods, or even over no food at all?
Answer
A primary source would be the מדרש תנחומה in פרשת פקודי at סימן ב
העת שחוקרין העדים על העבירה שאדם עושה, יוצאין הסנהדרין וכל ישראל עמם לרחוב העיר, ומוציאין לשם לאיש שהוא מחוייב סקילה או אחד מארבע מיתות בית דין, ויוצאין שנים מהם או שלשה הגדולים מהם ודורשין לעדים. וכששבין מלחקור, אומר להם, סברי מרנן. והם אומרים, אם לחיים לחיים, ואם למיתה למיתה. אם הוא מחויב סקילה, מביאין לו יין טוב וחזק ומשקין אותו, כדי שלא יצטער מן הסקילה. ובאין העדים ועוקדין לו ידיו ורגליו ושמין אותו בבית הסקילה, ולוקחין העדים אבן אחת גדולה שימות בה ושמין אותה על לבו. כיצד שמין אותה על לבו. שמין אותה בעליה אחת, כדי שלא ישים האחד חלקו קודם חברו, אלא שישימו אותה ביחד על לבו, כדי לקיים מה שכתוב, יד העדים תהיה בו בראשונה (שם יז ז). ומאותה שעה ואילך, כל ישראל פטורין לרגום אותם באבנים. וכן עושים לכל מיתה ומיתה שהוא חייב למות מיתת בית דין. וכן שליח צבור כשיש בידו כוס של קדוש או של הבדלה [והוא ירא מסם המות שלא יהיה בכוס], והוא אומר סברי מרנן, ואומר הקהל לחיים, כלומר כי לחיים יהא הכוס.
In summary:
After the witnesses were cross-examined, the judges would return and would be asked "סברי מרנן" - "what do you think, Sirs?"
If he was innocent they would answer לחיים...
Which is why the Shliach Tzibbur says on the cup of Kiddush or Havdala [if he is worried about the poison in his cup] סברי מרנן and the congregation answers לחיים.
Is there any resource for looking at examples of the old forms of safrut from before the Second World War? I have seen un-sourced photos of strikingly different variations within the Ashkenazi and Chassidic ktavim and R' Melech Michaels once told me that there was actually a concerted effort to unify the method of writing for Beit Yosef and Ari after the war and the foundation of Israel.
there is a principle in halacha regarding doubts that if something is separated from a kavua (fixed place) it is treated as 50/50% chance even if the permitted is the majority.
but if it is found in the shuk then it goes by the majority.
so for example, if one finds a piece of meat outside and most stores are kosher then the meat is considered kosher.
but if one takes it from a store and it is unknown which store then it is 50/50 doubt even if the majority is kosher.
does anyone know whether there is a rational argument for this or is it just straight halacha without logic?
The Halacha is that we cover the Challa / Cake while we make Kiddush in order not to embarass it (Talmud Yerushalmi as quoted by the Tur, Orach Chaim 271) as we are not making Hamotzi / Mezonos first. Is a clear covering adequate (plastic / cellophane) or does it have to be non see through?
Answer
I remember at an "in Shabbos" at Yeshivah Gedolah Ateres Mordechai in Detroit there being Hallah on the tables Friday night in just their see-through bags. Some boys took napkins and started covering them. Rav Leib Bakst ZT"L, the Rosh HaYeshivah, did not say anything until they reached his table. When they reached his table he said "What?! You're worried about "embarrasing" the Challos?! Don't worry! They are not embarrased in plastic bags!"
He held that even lechatehilah they are good enough.
(I muttered to the guys who were covering them "They can't be 'embarrased' anymore because they suffocated in those plastic bags!)
