hashkafah philosophy - What were Alter Halpern's main issues with Marcus Jastrow's Dictionary?

I have heard that Alter Halpern, a Rabbi in England, published an article or kuntres presenting issues with Marcus Jastrow's Dictionary (for the Talmud, midrash, targum), i.e Sefer HaMilim.

What were his specific issues, and does he go so far as to assur it?

I know that Rav Yaacov Kaminetsky said that it was okay to learn from it.

Answer

A contribution to an answer - This article on Reb Alter z”l has the following paragraph:

Another of his original projects was the publication of a pamphlet which demonstrated some of the glaring mistakes in understanding gemoras made by Dr. Marcus Jastrow, author of the then widely used Talmudic dictionary. The booklet's entries were arranged in exactly the same format as the dictionary. In one of London's shops for sifrei kodesh, it was sold together with the dictionary.

So his issues seem to have been with errors in understanding gemoras. The article does not specify which gemoras.

From the facts that the booklet was arranged in the same format as the dictionary and it was sold together with it in one bookshop, we might deduce that he did not forbid the use of the dictionary.

grammar - Is it true that all verbs have a corresponding noun form?

Is it true that all verbs have a corresponding noun form (which is formed by making the -masu form and removing the -masu)?

Like 遊び and 遊びます 飲み and 飲みます 生き and 生きます 死に and 死にます

Answer

For the most part, yes. There are a few outliers that don't though. Most 尊敬語 and 謙譲語 verbs don't form nouns with their 連用形. And some 連用形, such as 「なり」, are specialized almost to the point of uselessness.

units - How will the periodic table change due to redefinition of the kilogram (May 2019)?

The definition of a kilogram has recently been changed. What effect, if any, will this change have on data on the periodic table?

Answer

Molar masses

The molar mass of the carbon-12 isotope used to be 12 g/mol exactly (by definition). Now, it is experimentally determined, with the current value $\pu{11.9999999958(36) g mol-1}$ (CODATA 2018). So the molar mass of carbon-12 changed. The standard atomic weights (relative atomic masses) shown in the periodic table are not affected by this. However, atomic weights (dimension one) are no longer exactly equal to molar mass divided by 1 g/mol. Instead, they differ by a tiny bit (you would need 9 or 10 significant digits to see the difference).

No visible changes

Here is an animated gif of a portion of the periodic table at ptable.com over the past four years (Jan 23rd 2016, Jan 10th 2017,Jan 6th 2018, May 2nd 2019). Nothing much has changed near carbon:

The standard atomic weights change a bit each year, as better estimates of the isotope compositions of elements with multiple stable isotopes are made. Also, the publishers of this specific periodic table decided to truncate atomic weights to 5 significant figures in 2018. The biggest change occurred when elements in period 7 were discovered and named.

The last image is from May 2nd 2019, before the change of the kilogram (and mole) definition. On May 29th 2019, the data shown at ptable.com is identical.

expressions - Definition and use of やれやれだ

Can anyone explain the expression やれやれだ/やれやれだぜ ? I saw it in a written journal entry to mean "Thank heavens!", and on further investigation have seen it translated as "Good god!" as well as "Sigh." It's probably an outdated expression, but could someone tell me if it's still used and why it means what it means?

shabbat - What is the hallachic definition of randomness?

A new Shabbat-friendly technology, KosherSwitch, uses randomly timed light pulses to create various safeks, so that flipping the switch does not hallachically count as switching the light on, even in terms of gerama. The process is explained on their website.

Different people mean different things when they say "random numbers" in mathematics and in the sciences. Asking a person to choose a random number, for example, will give rise to a distribution of numbers with certain definite biases- for instance, humans are more likely to repeat numbers. A short analysis of random number generation appears here: http://en.wikipedia.org/wiki/Random_number_generation

My question is whether anyone has written a definition of what the word "random" means in a hallachic context. I assume that a hallachic standard of randomness would be more lax than a standard of randomness in crytography, but I'm not sure just how lax. In particular, if somebody could write a computer programme to guess the pulse times with 99% accuracy, would that render KosherSwitch's patent non-Shabbat-safe?

Answer

I'd say if an average human, using an average human brain and eye, can't figure out the pattern, that's good enough.

Rabbi Asher Weiss discusses the criteria of "does an unaided human notice it?" with regards to triggering some change deep instead some semiconductor someplace that I'd never notice. He points out that I may not drag a heavy bench on shabbos that I know will dig a groove in the earth, but I am allowed to drag a lighter bench if there's reasonable doubt whether it will dig a groove. Wait!, asks Rabbi Weiss. What do you mean, reasonable doubt?! (The mass of this bench is far beyond the quantum threshold.) If you were an expert physicist and knew the exact mass, the coefficient of friction, the Young's modulus of the soil, and could calculate mgcos(θ) in your head, there would be no doubt!

The answer seems to be that we work with the average, unaided, human intellect and senses.

inorganic chemistry - Why are the densities of europium and ytterbium anomalously low?

Why do europium and ytterbium have lower densities than expected in comparison to other lanthanides? I know it has something to do with the fact that they have half-full and full 4f subshells in the +2 oxidation state, but how exactly does it relate to density? And how does it affect the melting point?

Answer

Expanding upon @Ivan's comment: Eu and Yb can access the +2 oxidation state instead of +3, due to the +2 ions having a relatively stable half-filled or filled f subshell.

That includes the embedded ions in the structure of the metal. Eu and Yb have $\ce{M^2+}$ instead of $\ce{M^3+}$ ions in the metal. The extra electron and reduced effective nuclear charge on the outer subshells make those $\ce{M^2+}$ ions larger, therefore these metals have lower densities than the surrounding lanthanides. The lower ion charge also means fewer electrons binding the ions together, making Eu and Yb easier to melt.

The difference in ion charge can also show up in other ways. Eu and Yb, for instance, resemble heavy alkaline earth metals more than other lanthanides by dissolving in liquid ammonia.

inorganic chemistry - How can I relate the reactivity series to electronegativity and ionization energy?

I am trying to figure out how the reactivity series comes about. My understanding is that elements with a higher electronegativity will be more reactive than elements with a lower electronegativity, and that elements with a low ionization energy will be more reactive than elements with a high ionization energy.

Here is a chart of electronegativity (from Wikipedia):

This shows electronegativity decreasing (as reactivity increases) down Group 1 and it also decreasing (as reactivity decreases) down Group 7.

Here is a chart of ionization energy:

This shows ionization energy decreasing (as reactivity increases) down Group 1 and it also decreasing (as reactivity decreases) down Group 7.

Neither electronegativity nor ionization energy can predict both reactivity trends, so what is going on?

kiddush hachodesh - What is the source for Hillel’s having included an expiration date in the calendar?

It’s often said that when Hillel instituted the current calendar, he set an “expiration date” of 6000 AM; at that point the calendar would be invalid. Since Mashiach presumably will come by then (as per Sanhedrin 97a et. al.) the calendar doesn’t need to run farther than that.

As often as I’ve heard this repeated, I’ve yet to find a concrete source for it. @Shalom asks a question here regarding the calendar post-6000, and @DanielBilar asks here whether the existence of a month hangs on its sanctification and thus if we even can have a calendar post-6000, barring Mashiach’s imminent arrival. In discussing this point with others in the comments to the latter question, we arrived at the Rambam, Hilchos Kiddush HaChodesh 5:2ff who says nothing about sanctification, merely that we can use a calendar if there’s no Sanhedrin around to sanctify the month, and a reference to the Netziv and other poskim, but it doesn’t have any sources.

Does anyone know where I can find someone who says this explicitly, that the calendar’s existence hangs on the fact that Hillel and his Beis Din sanctified the calendar for the following 1600 years, only up to the year 6000 in anticipation of Mashiach’s arrival?

Answer

You write that:

It’s often said that when Hillel instituted the current calendar, he set an “expiration date” of 6000 AM; at that point the calendar would be invalid. Since Mashiach presumably will come by then (as per Sanhedrin 97a et. al.) the calendar doesn’t need to run farther than that.

I think that this is a misunderstanding. What is actually said (as we shall see) is that Hillel sanctified all of the months until Mashiach's arrival, without specifying when that would be.

When this is coupled with the assumption that Mashiach will come by the year 6000, people may say that Hillel fixed the calendar until that time, but by no means is he said to have explicitly given an expiration date.

The earliest source I find for the assertion that Hillel pre-sanctified the months is Ramban in his glosses to Sefer HaMitzvot, Aseh 153:

רבי הלל הנשיא בנו של רבי יהודה הנשיא תקן חשבון העבור הוא קדוש חדשים ועיבור שנים הראויים להתעבר לפי מנינו עד שיבוא אליהו ז"ל ונחזור על פי הראיה בב"ד הגדול והקדוש אמן במהרה בימינו יהיה

R. Hillel the Prince, son of R. Yehudah the Prince, fixed the calculation of the ibbur, that is the sanctification of the months and the intercalation of the years which ought to be intercalated according to his count, until Eliyahu comes and we return to [the system] of observation in front of the great and holy court. Amen, may it be speedily in our days!

So, if for whatever reason, Mashiach has not arrived by the end of the sixth millenium, Hillel's pre-sanctification of each and every month will just keep going for as long as necessary.

(Of course, there may be other reasons why a reform of the calendar may be needed in the event of Mashiach's late arrival, not least the issues with the slowly shifting date of Pesach with respect to the solar calendar, but there would seem to be no need for a renewed sanctification of the months after the year 6000, even if one accepts Ramban's position over that of Rambam.)

Reading secular books on shabbat?

Which prominent halakhic authorities permit (or forbid) the reading of secular books, magazines, and newspapers from Friday evening until Saturday nightfall? Why? Is it uvda dechol? What if it is an oneg for me to read something that is not inherently Jewish?

(I am not asking for psak, I am just interested in learning all of the opinions on the matter.)

grammar dikduk - What does the /shin/ marker (like Petucha/Setuma) at the end of Torah books mean?

I've been reading about details of Torah sofrut, and after learning about the paragraph markers peh / פ (petucha) and samekh / ס (setuma), I noticed some similarly placed shin markers (mostly at the end of a sefer), but cannot find an answer in Google searches. What does it stand for? (Example: parsha VaYechi). I'm using an electronic version from Mechon Mamre similar to Keter Yerushalayim / Aleppo Codex.

Answer

The following information is recorded on the Mechon Mamre website:

בתנ"כים שלנו יש גם סימני הפרשייות {פ} {ס} {ר} {ש} שהם מסמנים פרשה פתוחה, פרשה סתומה, סוף שורה בשירות מסויימות, ושורה ריקה (או שורות ריקות בסוף ספר).‏

My translation:

In our Tanakhs there are also [the following] disjunctive symbols: פ,‎ ס,‎ ר,‎ ש, which stand for "open break" (פרשה פתוחה), "closed break" (פרשה סתומה), the "end of each line in determined poems" (סוף שורה בשירות מסויימות - eg: Exodus 15:1-19) and a "blank line" (or "blank lines at the end of a book" - שורות ריקות בסוף ספר).

That should answer your question, although I don't know where that tradition stems from. Obviously it's not the Aleppo Codex, since the Aleppo Codex is lacking most of the Torah (and I don't think these details were recorded prior to their being destroyed). I checked Rabbi Prof. Mordechai Breuer's Tanakh and I also checked the BHS, and neither of them recorded this. I have fascimiles of the Aleppo Codex and the Leningrad Codex, and neither record these symbols between other books in Tanakh (nor does the latter record it between Genesis and Exodus).

Finally, I looked at Yeivin's Tiberian Masorah and Tov's Textual Criticism of the Hebrew Bible, and they don't appear to mention it either. Regrettably, Mechon Mamre does not declare exactly which mss they are employing, save to note that they are close to the Aleppo Codex.

meaning - 「○○は草」とはどういう意味でしょうか？

Abemaの麻雀チャンネルを見ていたら、人のコメントの一部または全部をコピーして、最後に「は草」を付けて送信する人がいました。

例えば、コメント欄がとても盛り上がっていた時に「コメント読みてえのに多すぎて読めねえんだよ だから各自で控えろ」というコメントがありました。

これに対して

コメントを控えろは草

と送ってきました。

このようなことをいろんなコメントでずっと繰り返していました。これはただの荒らしかもしれないけど、何か意味があるなら知りたいです。

Answer

草 is Internet slang that means "laugh", "laughable", and 「笑える」,「うける」,「面白い」 in Japanese.

"w" is Internet slang that means "laugh", "laughable". People use it like "wwwwwwww" when they want to emphasize "w", and "wwwwwwww" looks like grass growing. So 草 came to mean "laugh", "laughable" as Internet slang.

Source:https://kw-note.com/internet-slang/kusa/

halacha theory - Mitzvot distribution by categories

This site gives a nice basic infographic on the distribution of the 613 Mitzvot by 4 categories: positive/negative, where, who, penalty. (I would love to have it in verbal tabular form though).

I'm looking for more [sites with] statistics on Mitzvos distribution by more categories, like:

1. 
   

   בין אדם למקום / לחבירו

   
   


2. 
   

   תמידיות / זמניות / שהזמן גרמן

   
   


3. 
   

   profession dependent/independent (king, Kohen Gadol etc)

   
   


4. 
   
   

   by performance type: thoughts, speech, actions, money etc.

   
   


5. 
   

   by body parts (like Sefer Haredim)

   
   


6. 
   

   unanimously accepted / debatable between Poskim (Rambam, Sma"g, Ramban etc)

   
   


7. 
   

   and more.

   
   
   

NB: Please don't argue about the legitimacy of the categories. I'm free to accept any additional division.

colloquial language - What is the よっか in はじめよっか?

I'm still playing Game Boy Wars Advance 2, and I keep running into colloquial forms I'm unfamiliar with. Here's one I haven't been able to look up:

じゃ、さっそく、はじめよっか。

My guess is that はじめよっか is a colloquial form of はじめようか. Is that right? If so, can I generalize and say okka is a colloquial form of ooka?

Image for context:

Answer

Nice guess :) As noted in the comments, はじめよっか is basically a shortened version of はじめようか.

Also, more than generalizing about that type of phrasing... I'd almost want to say it's more of just a way to make a phrase sound more "clipped" (e.g. something of a glottal stop, or possibly, a contraction...) or maybe even just an alternative way to put an accent or stress on a part of a phrase... as opposed to something grammatically formal or defined.

For example, the phrase "getting good" in English is sometimes phrased as "gettin' good" (in this case, read as "get-tin' good".) The syllable count is the same for each phrase... but the latter phrase can potentially sound more clipped (see glottal stops) though this example is not necessarily an exact match to the ようか / よっか change.

Usage note: you may want to be careful with using that style of speech unless you are older than the person with whom you are speaking. (Or if you are somehow related... or are really familiar with the person.)

halacha - Should one drink from the leader's cup after kiddush?

Inspired by the upcoming holiday of Pesach, where many minhagim seem to have each person drink from his own cup, I was wondering about the custom of drinking wine from the cup upon which kiddush is made on Shabbos (often not directly from the cup, but the same wine that has already been "blessed"). Is there any real reason to do this? We are blessing Hashem, not the wine, correct? (edit: is there possibly a problem vis-a-vis A"Z in treating the wine as blessed?) Why not have individual cups of wine pre-poured at every place, and the leader be motzei everyone? And if so, can the same go for challah?

pronouns - use of 〜ちゃん as a generic term

In a Shimajiro educational book I saw a line similar to this:

___ちゃんが知ってる乗り物は何ですか？

(the actual one had less Kanji but you get the point)

The question is why was ちゃん used here as a generic term. I thought ちゃん was used more for girls and くん for boys, and since I think the audience for Shimajiro might be more boys, why didn't they choose くん here? Or is ちゃん actually a more neutral term?

Answer

It's common to use ちゃん regardless of their sex when they're are very small... roughly under 6 years old or so.

http://oshiete.goo.ne.jp/qa/983087.html

平均的なところでは，
○未就学児は男女問わず「ちゃん」
○小学生～高校生は男子が「君」，女子が「さん」
○大学生以上の学生，社会人（18歳未満でも）は「さん」
○ただし政治面など硬めのニュースでは男女問わず「氏」

time - Was man created before or after the animals?

According to Genesis chapter 1, it seems that the animals were created first. According to Genesis chapter 2, it seems that man was created first.

What are the different understandings that have been put forth to this question?

In Genesis chapter 1 we see:

Genesis 1:25:

כה וַיַּעַשׂ אֱלֹהִים אֶת-חַיַּת הָאָרֶץ לְמִינָהּ, וְאֶת-הַבְּהֵמָה לְמִינָהּ, וְאֵת כָּל-רֶמֶשׂ הָאֲדָמָה, לְמִינֵהוּ; וַיַּרְא אֱלֹהִים, כִּי-טוֹב. 25 And God made the beast of the earth after its kind, and the cattle after their kind, and every thing that creepeth upon the ground after its kind; and God saw that it was good.

Genesis 1:27:

כז וַיִּבְרָא אֱלֹהִים אֶת-הָאָדָם בְּצַלְמוֹ, בְּצֶלֶם אֱלֹהִים בָּרָא אֹתוֹ: זָכָר וּנְקֵבָה, בָּרָא אֹתָם. 27 And God created man in His own image, in the image of God created He him; male and female created He them.

In Genesis chapter 2 we see:

Genesis 2:7:

ז וַיִּיצֶר יְהוָה אֱלֹהִים אֶת-הָאָדָם, עָפָר מִן-הָאֲדָמָה, וַיִּפַּח בְּאַפָּיו, נִשְׁמַת חַיִּים; וַיְהִי הָאָדָם, לְנֶפֶשׁ חַיָּה. 7 Then the LORD God formed man of the dust of the ground, and breathed into his nostrils the breath of life; and man became a living soul.

Genesis 2:18-19:

יח וַיֹּאמֶר יְהוָה אֱלֹהִים, לֹא-טוֹב הֱיוֹת הָאָדָם לְבַדּוֹ; אֶעֱשֶׂה-לּוֹ עֵזֶר, כְּנֶגְדּוֹ. 18 And the LORD God said: 'It is not good that the man should be alone; I will make him a help meet for him.' יט וַיִּצֶר יְהוָה אֱלֹהִים מִן-הָאֲדָמָה, כָּל-חַיַּת הַשָּׂדֶה וְאֵת כָּל-עוֹף הַשָּׁמַיִם, וַיָּבֵא אֶל-הָאָדָם, לִרְאוֹת מַה-יִּקְרָא-לוֹ; וְכֹל אֲשֶׁר יִקְרָא-לוֹ הָאָדָם נֶפֶשׁ חַיָּה, הוּא שְׁמוֹ. 19 And out of the ground the LORD God formed every beast of the field, and every fowl of the air; and brought them unto the man to see what he would call them; and whatsoever the man would call every living creature, that was to be the name thereof.

So according to Genesis chapter 1, animal is created before man, whereas according to Genesis chapter 2, man is created before the animals. Which is it?

One approach is to say that Chapters 1 and 2 are talking about the same events, but chapter 2 goes into more detail (as Rashi does). But if this is the case, there shouldn't be any contradictions between the order of events in each chapter.

beis hamikdash - Why Temples' dimensions were different from the Mishkan?

After asking "why-did-the-mizbeach-grow-40-times", I realized (thanks JoelK) that both measurements were dictated by G-d (it's unclear to whom: Moses, David or other prophets). See also Yalkut Shimoni 1081 (thanks Meir).

Both the Mishkan and the Temple served the same purpose, but the Temples' dimensions were significantly bigger on practically everything. As the population varied greatly I assume that populational fluctuations can't count for those differences, already given by G-d.

What is the reason those two holy dwellings were so different in dimensions? Do the variations hint on changes in G-d's manifestations, or some spiritual representations?

electrons - Please explain the shapes of the orbitals

For a lot of years, I had been believing that sphere was the most stable 3-dimensional shape. But after coming across the p,d and f-orbitals, I am unable to comprehend the fact that these orbitals have such crude shapes. Can we prove that these shapes(dumb bell and crossed dumb bell) are the regions in which the electrons would be most stable (No wave functions please. I am only in high school)?

P.S.: An intuitive answer would be much appreciated than a mathematical one.

P.S.S: This is not a duplicate question. I don't want to know how the shapes are like that. I know it is due to the probability functions, I want to know if it is just the rule of nature, or can we show it is because of stability.

Answer

I'm guess that you have read about orbital shapes in the wikipedia article, or done a google search on the term.

In general, such "orbitals" shown are typically calculated for a lone electron, not any "real" multi-electron configuration.

Think of an orbital like a single loop of cotton fiber wound into a cotton ball. The planetary model of the electron-nucleus pair indicates that the electron is a solid ball following the fiber. The quantum model of the electron-nucleus pair indicates that the electron has no fixed position, but that it is essentially at all places on the loop at the same time.

So how big is the cotton ball in diameter? It has no limiting diameter, it depends on how hard you squeeze! So if I catch a Hydrogen atom with my magic tweezers, there is a finite probability according to the Schrödinger wave equation that its electron can be in orbit even further away than the dwarf planet Pluto, or inside the nucleus! So we we talk of an the "size" of an ion it is somewhat of an artificial abstraction, and the Schrödinger wave equation can't be "the gospel truth." (I don't mean to badly disparage the Schrödinger wave equation for it is very useful.)

Not to leaving you totally confused, the size of an ions does have some real physical significance. For instance consider table salt, $\ce{NaCl}$. This is really $\ce{NaCl}$. Using x-ray diffraction we can measure how close the $\ce{NaCl}$ are, so we know their "size."

Starting with the Aufbau principle for the atoms, chemists can predict the electron structure of an atom, say carbon. Given the structure of bonds in the atoms, say carbon and hydrogen, then chemists can predict how carbon and hydrogen will bond to form molecules. The fact that chemists can make predictions about molecular structure is the "proof" that the models work.

Howver weird things do have with real electron orbitals. For instance if there was a single "normal electron configuration" for chromium, then there would only be one chromium chloride. However chemists have synthesized three.

• Chromium(II) chloride, also known as chromous chloride.



• Chromium(III) chloride, also known as chromic chloride or chromium trichloride


• Chromium(IV) chloride

So there must be weird configurations that are stabilized by some sort of "hybridization." As another example all the C-H bonds in methane, $\ce{CH4}$, are the same because the four carbon orbitals (one 2s, and three 2p) orbitals of the carbon atom hybridize into four $sp^3$ orbitals that are equivalent.

---

To put such orbital shapes into perspective, a chemist thinks a unicorn is simply a hybrid of a horse and a rhinoceros. So a model helps making predictions, but you can't have a fixated belief that the model is the whole truth.

---

Another example would be showing you a picture of a blueberry pie. Would just such a picture "explain" a blueberry pie? In order for the picture to have meaning you must have some underlying knowledge.

• You know in general what a pie is.



• You have know that pies contain fruit pieces, so this kind is made from blueberries.


• You know that pies are sweet.

theology - אלקים בגימטריא הטבע and not טבע?

There's a oft quoted saying that "אלקים בגימטריא הטבע." Why is it הטבע and not טבע? Isn't it "cheating" to add the extra "ה"?

inorganic chemistry - What is the definition of organic compounds?

According to the definition of organic compounds on Wikipedia:

An organic compound is any member of a large class of gaseous, liquid, or solid chemical compounds whose molecules contain carbon.

Carbonates, simple oxides of carbon, and cyanide molecules do have carbon, but they are not regarded as organic. The same Wikipedia article on organic compounds reads:

The modern meaning of "organic compound" is any one of them that contains a significant amount of carbon.

The current main definition for organic compounds doesn't fit for carbonates, simple oxides of carbon, steel, etc. So, what should be the redefined definition for organic compounds?

Answer

So, what should be the redefined definition for organic compounds?

We should not define organic compounds. As F'x pointed out in the comments, the distinction between organic and inorganic is largely arbitrary and mostly based on a distortion of historical precedent.

Rather, we should classify compounds by the type(s) of bonding interaction present in the substance. By this criterion, we have several classes of compounds:

1. Molecular (or covalent) compounds - the particles that make up these compounds are molecules held together by covalent bonds. This class of compound includes traditionally inorganic $\ce{CO2}$ and organic $\ce{CH4}$ carbon compounds. Covalent compounds also the majority of organometallic compounds, so we do not need a separate category for these. Other traditionally "inorganic" compounds, like glass, also belong in this category.


2. Ionic compounds - the particles that make up these compounds are largely ions held together by Coulombic forces. For the sake of simplicity most people would include in this class of compounds those ionic compounds where one or both ions is a small molecular ion held together by covalent bonds $($e.g. the $\ce{NH4^+}$ ion in $\ce{NH4Cl}$ or the $\ce{CO3^{2-}}$ ion in $\ce{Na2CO3})$.


3. Mixed covalent/ionic compounds - those in which there are some ionic functional groups, but mostly covalent bonds, like methyl orange. Many folks might list these substances in Category 1. This category would include most coordination compounds including such things as metal-organic frameworks and probably many composite and/or ceramic materials.


4. Metallic compounds - those substances with extremely delocalized bonding, typical of metals. Alloys, including steel, belong in this category.

Under this system, what we traditionally study as organic chemistry becomes redefined as the study of the structure, properties, and reactions of covalent compounds (Classes 1 and 3), especially the nature of the covalent bond and how it can be formed and broken selectively. What you might learn about the structure, properties, and reactions of organic compounds can easily be extended to the structure, properties, and reactions of molecular inorganic compounds. For example, we do not need two different branches of chemistry to study benzene and borazine.

marriage - What's the leading medical explanation for the "woman whose husbands keep dying" ("katlanit") phenomenon?

The Gemara says that if a woman gets married, then her husband dies; then marries another guy and is widowed from him; then once more; we then assume something about her is causing her husbands to die (three makes a pattern). The woman is considered a קטלנית, katlanit ("killer woman"), and should not marry again.

The Gemara then has two possible explanations to what's going on here:

• Whatever is going on with this woman is metaphysical ("karma", "mazal", whatever), in which case this halacha would apply even if the first husband died of lightning strike, the second of shark attack, and the third of ... well, pick your favorite absurdity.


• There's something medical/biochemical that this woman causes in her husbands. If so, the halacha would only apply if all three died of natural causes.

My understanding is the Gemara is saying "don't try to over-diagnose; even if you don't understand the mechanism, if it's consistently dangerous, stay away!"

Nonetheless, out of curiosity, are there any known medical conditions that could explain the phenomenon?

organic chemistry - Why is adenine aromatic?

I don't think it follows the $4n + 2$ rule. The double bonds give 8 π electrons. Then the lone pairs on the $\ce{NH}$ and $\ce{NH2}$ groups are delocalized (are they?) so they must contribute 4 π electrons. Thus in total there are 12 π electrons, which doesn't follow Hückel's rule. So, why is it aromatic?

minhag - Which Knot to Use on Tefillin Shel Rosh

When I was a child, I saw that all people had the same knot on their Tefillin Shel Rosh - a Double Daled (Ashkenazi community).

Recently I saw a comment that even those who grew up with a Double Daled, and even if their Father's minhag was a Double Daled, that they should all switch to a Single Daled.

My questions are:

1. What are the sources for this, if any?


2. Why is the Single Daled supposed to be "better"? Is this only for Kabbalistic reasons, or is there a real Halachic reason for this?


3. Are these poskim who require this change in minhag correct to do so?


4. Are there any Ashkenazi Poskim and/or Groups today that specifically say that a Double Daled is preferable?

Answer

As @NoachmiFrankfurt mentioned above, and suggested I convert into an answer:

Here's a partial answer: The MMA madrich gives requires a double-dalet knot http://www.moreshesashkenaz.org/en/guide.

Furthermore, there are Sephardim, such as the London community, who also maintain this practice: https://sites.google.com/site/londonsephardiminhag/tephillin

私はあおい車はすきだ (は as contrast particle) vs 私はあおい車がすきだ

I am learning about は particle that is used as contrast particle. suppose I want to express "I like blue car but I don't like any other colors". can I say it this way 私はあおい車はすきだ ? and what's the difference with 私はあおい車がすきだ ?

Answer

Yes, exactly. Both sentences are perfectly grammatical, but 私は青【あお】い車は好【す】きだ implies you don't like cars which aren't blue, because the contrast particle は is used at the place where が is normally used. 私は青い車が好きだ simply means "I like blue cars."

word choice - What is the difference between お手洗い and トイレ

Is one more polite than the other? Is there some situations where you'd use one or the other? Would different people prefer one?

Answer

In my generation, トイレ is definitely the most common word refers to that facility, over any native word. お手洗い is also usually heard, but whoever says お手洗い in daily conversations would be judged being overly polite or really well-born. Nonetheless, we hear お手洗い more often than not because it's very popular in salesperson-ese, thus you're quite likely to run into such a situation:

Customer: すいません。トイレはどこですか？

Waiter: お手洗いはあちらになります。

---

As other people already said, there are two more names of toilet room you may encounter in Japan today, but both aren't really spoken language.

• 
  

  便所: This word makes me feel either outdated or vulgar if spoken. Maybe because a typical 便所 I see is shabby, hoary, undermaintenanced equipments like the most of 公衆便所 standing outdoors.

  
  



• 
  

  化粧室: Most graceful word that only seen on signboards. Literally meaning "powder room", it might be a bit funny if you look at apparent characters 男性化粧室, but not many people seem to care about it.

  
  

sp2 hybridization Group V elements

I'm confused about $\mathrm{sp^2}$ hybridization in the formation of $\ce{NO3-}$ ion. Valence electrons of N are $\mathrm{(2s)^2}$ and $\mathrm{(2p)^3}$.

Is one of $\mathrm{2s}$ electrons kicked up to one of the $\mathrm{2p}$ orbitals, and then the remaining $\mathrm{2s}$ electron hybridized with the two remaining $\mathrm{2p}$ orbitals which have unpaired electrons? If so, that gives $\mathrm{sp^2}$ orbitals to bond with $\mathrm{p}$ orbitals of the oxygen atoms. However, there is now that remaining unhybridized $\mathrm{p}$ orbital of nitrogen, which has 2 electrons, so how can it be involved in $\pi$ bonding?

I would appreciate someone explaining this. I'm sure I'm missing something simple, but my book doesn't have an explanation of $\mathrm{sp^2}$ hybridization for Group V elements.

frequency - Understanding the $mathcal Z$-transform

I was studying $\mathcal Z$-transforms and found pretty good material on the topic, though I feel I do not have a proper understanding of the concept. Could someone help me clarify this?

I know that we apply $\mathcal Z$-transforms to sequences and convert them to the $z$ domain and find the values of $z$ for which we get zeros and poles and also find the region of convergence. What I didn't get is:

1. Why are we multiplying some $z$ values to the given sequence and finding for what values of $z$ the result gets pretty huge or dampens out?


2. What does poles and zeros have to do with the given sequence? It's not like we are applying the transform to a system and finding the system's response, it's just a sequence.


3. And they also say that its a frequency domain transformation. How do we realise frequency here?

Answer

Consider a liner discrete-time system. Assume we can define it in terms of an input-output relation as follows (you can assume a more general model but it is enough for our purpose):

$$a_0y[n]+a_{1}y[n-1]+\cdots+a_{N}y[n-N]=b_0x[n]+b_{1}x[n-1]+\cdots+b_{M}x[n-M]\tag{1}$$

When the coefficients $\{a_i\}$ and $\{b_i\}$ are constant, we call it a finite-order constant-coefficient ordinary difference equation. It explains the current output $y[n]$ in terms of a weighted sum of the current and past inputs and the past outputs:

$$y[n]=\frac{-a_{1}y[n-1]-\cdots-a_{N}y[n-N]+b_0x[n]+b_{1}x[n-1]+\cdots+b_{M}x[n-M]}{a_0}$$

It is very similar to a differential equation in continuous time.

Dealing with such equation to find the output of the system can become complicated. It is a recurrence relation. It defines the values recursively and for arbitrary inputs it is not straightforward to express the output in a closed-form representation.

How to deal with it in an easier way?

Consider the following transform (assume the sum exists): $$\mathcal{Z}(x[n])=\sum_{n=-\infty}^{+\infty}x[n]z^{-n}$$ You are right, it is just a transform that accept $x[n]$ and gives you $X(z)$. But it has a useful property. Lets calculate the $z$-transform of $x[n-\alpha]$: $$\begin{align}\mathcal{Z}(x[n-\alpha])&=\sum_{n=-\infty}^{+\infty}x[n-\alpha]z^{-n}\\[10pt] &=\sum_{n'=-\infty}^{+\infty}x[n']z^{-(n'+\alpha)}\tag{2}\\[10pt] &=\left(\sum_{n'=-\infty}^{+\infty}x[n']z^{-n'}\right)z^{-\alpha}\\ &=\left(\mathcal{Z}(x[n])\right)z^{-\alpha} \end{align}$$ where in $(2)$ I changed the variable $n'=n-\alpha \Rightarrow n=n'+\alpha$. Assume $\mathcal{Z}(x[n])=X(z)$. We have seen that a property of $z$-transform is: $$\boxed{\mathcal{Z}(x[n-\alpha])=z^{-\alpha}X(z)}$$

Applying this to the difference equation $(1)$ makes it (note that it is a liner transform and can be applied term by term):

$$a_0Y(z)+a_1z^{-1}Y(z)+\cdots+a_Nz^{-N}Y(z)=b_0X(z)+b_1z^{-1}X(z)+\cdots+b_Mz^{-M}X(z)$$

Note that all terms are expressed in terms of $Y(z)$ and $X(z)$. So we can say that

$z$-transform reduces usually difficult-to-handle recurrence relations to much easier to manipulate algebraic relations.

With an algebraic relation, we can factor the terms:

$$Y(z)\left(a_0+a_1z^{-1}+\cdots+a_Nz^{-N}\right)=X(z)\left(b_0+b_1z^{-1}+\cdots+b_Mz^{-M}\right)$$ and consequently,

$$Y(z)=X(z)\frac{b_0+b_1z^{-1}+\cdots+b_Mz^{-M}}{a_0+a_1z^{-1}+\cdots+a_Nz^{-N}}$$

where $$H(z)\triangleq\frac{b_0+b_1z^{-1}+\cdots+b_Mz^{-M}}{a_0+a_1z^{-1}+\cdots+a_Nz^{-N}}$$ is called the system function. So we distilled all the system into an algebraic expression as $H(z)$. Hence, the zeros and poles of $H(z)$ have a direct impact on the output.

---

There are also other reasons that make $z$-transform and $H(z)$ important, and we would prefer working with the $z$-domain rather than time-domain.

Assume the input to the system is $x[n]=z_{k}^n$, where $z_k$ is just a complex number (don't mix it with the $z$ variable in the $z$-transform at this moment! Also there are some restrictions on $z_k$ as we will see next). The output of the LTI system can be calculated by convolution of the input and the impulse response $h[n]$:

$$\begin{align} y[n]&=h[n]*x[n]\\ &=\sum_{m=-\infty}^{+\infty} h[m] x[n-m]\\ &=\sum_{m=-\infty}^{+\infty} h[m] z_k^{n-m}\\ &=z_k^n \sum_{m=-\infty}^{+\infty} h[m] z_k^{-m}\\ &=z_k^n H(z_k) \end{align}$$

What does it really mean?

The output of the system is an scaled version of the input. So the signal $z_k^n$ passes through the system and the only impact on it is a scaling. Note that the scaling factor is the system function when evaluated at $z_k$. Why is it important?

If we could decompose an arbitrary signal (not of the form $z_k^n$) into several components of the form $z_k^{n}$, then we can easily calculate the output of the system to each of the components, and then add them together to find the overall output (benefiting from the superposition property of LTI systems).

How can we decompose the signal $x[n]$ into components of the form $z_k^n$? It is easy as the following (assume the sum exists for now)

$$\left(\sum_{n=-\infty}^{+\infty}x[n]z_k^{-n}\right)z_k^n$$

Let's refer to this component as $X(z_k)z_k^n$. So the output to this component is $y_k[n]=H(z_k)X(z_k)z_k^n$. We can have as many components as possible. Potentially, we have thousands of $z_k$. So we refer to all of them by a variable $z$ and the component-wise output becomes $H(z)X(z)z^n$. The overall output $y[n]$ is in form of an integral (since we need to add them up). It can be shown that $y[n]$ is given by the following contour integral:

$$y[n]=\frac{1}{2\pi j}\oint_C\frac{H(z)X(z)z^n}{z}dz$$

where $C$ is a counterclockwise path inside the ROC (where $X(z)$ and $H(z)$ exist) that encircles the origin, which is the same as the inverse $z$-transform of $X(z)H(z)=Y(z)$.

---

Regarding your second question, in the definition of $z$-transform (when it exists on the complex unit circle) if you choose $z=e^{j\omega}$ it becomes the definition of the Discrete-Time Fourier transform Hence is the frequency-domain interpretation.

rabbis - Talmid Chacham today

The term talmid chacham is used commonly in our tradition to describe a Jew with a certain high level of knowledge, understanding, closeness to Gd, etc. Can the halachic label "talmid chacham" be used appropriately in our times?

halacha - Do the actions of animals have moral value?

I vaguely remember reading in the Torah some laws regarding the proper restitution when one person's livestock injures or kills someone else's livestock, but as far as I can recall, it was more related to what we might call property damage, as opposed to the animal having done something morally wrong.

Does Jewish law and/or scripture suggest that the actions of animals have moral significance? Can animals be evil/sinful or good/righteous?

Answer

There are inferences in scripture that can be interpreted that actions of animals have moral value. And even when scripture speaks of their actions not having moral value, it puts them on the same level as humans who don't have moral value.

Genesis 6 11 And the earth was corrupt before God, and the earth was filled with violence. יב וַיַּרְא אֱלֹהִים אֶת-הָאָרֶץ, וְהִנֵּה נִשְׁחָתָה: כִּי-הִשְׁחִית כָּל-בָּשָׂר אֶת-דַּרְכּוֹ, עַל-הָאָרֶץ. {ס} 12 And God saw the earth, and, behold, it was corrupt; for all flesh had corrupted their way upon the earth. {S} יג וַיֹּאמֶר אֱלֹהִים לְנֹחַ, קֵץ כָּל-בָּשָׂר בָּא לְפָנַי--כִּי-מָלְאָה הָאָרֶץ חָמָס, מִפְּנֵיהֶם; וְהִנְנִי מַשְׁחִיתָם, אֶת-הָאָרֶץ. 13 And God said unto Noah: 'The end of all flesh is come before Me; for the earth is filled with violence through them; and, behold, I will destroy them with the earth.

"All flesh had become corrupted." Since Hashem had already a few verses earlier talked about the evils of mankind, Rashi says that the rest that are included with "all flesh" must be the animal kingdom.

for all flesh had corrupted: Even cattle, beasts, and fowl would mate with those who were not of their own species. — [from Tan. Noach 12] כי השחית כל בשר: אפילו בהמה חיה ועוף נזקקין לשאינן מינן:

For those that would say that this means that animals became corrupted without doing evil, we need to define what evil is, or more clearly, what sinning is. According to Hovoth Halevavoth (as well as others) one that understands cannot sin, nor can they perform a miswah

Hovoth haLevavoth Part 2

A person who has lost his understanding, loses all the excellencies of a human being and is exempt from the mitzvot (precepts), and reward and punishment.

If you tell me that regardless of this, Rashi doesn't hold this opinion, and that what Rashi is saying is that the animals became corrupt without knowing what they were doing, i tell you that indeed Rashi is claiming that it was because of this morally wrong behavior they were punished, just as the fruit trees were

Genesis 1:11 with Rashi

11And God said, "Let the earth sprout vegetation, seed yielding herbs and fruit trees producing fruit according to its kind in which its seed is found, on the earth," and it was so.

fruit trees: That the taste of the tree should be like the taste of the fruit. It [the earth] did not do so, however, but“the earth gave forth, etc., trees producing fruit,” but the trees themselves were not fruit. Therefore, when man was cursed because of his iniquity, it [the earth] too was punished for its iniquity (and was cursed-not in all editions). - [from Gen. Rabbah 5:9] עץ פרי: שיהא טעם העץ כטעם הפרי, והיא לא עשתה כן, אלא (פסוק יב) ותוצא הארץ עץ עושה פרי, ולא העץ פרי, לפיכך כשנתקלל אדם על עונו נפקדה גם היא על עונה ונתקללה:

If a tree can have iniquity, as a man can have iniquity, then even the moreso an animal! This explains why God felt justified in killing the animals in the flood as well, otherwise you have a God that punishes the innocent of the world. We always say that Noah was saved because he was the most righteous man, i think it's also fair to say that the animals were the saved were also the most righteous of their generation.

Numbers 22: כח וַיִּפְתַּח יְהוָה, אֶת-פִּי הָאָתוֹן; וַתֹּאמֶר לְבִלְעָם, מֶה-עָשִׂיתִי לְךָ, כִּי הִכִּיתַנִי, זֶה שָׁלֹשׁ רְגָלִים. 28 And the LORD opened the mouth of the ass, and she said unto Balaam: 'What have I done unto thee, that thou hast smitten me these three times?' כט וַיֹּאמֶר בִּלְעָם לָאָתוֹן, כִּי הִתְעַלַּלְתְּ בִּי; לוּ יֶשׁ-חֶרֶב בְּיָדִי, כִּי עַתָּה הֲרַגְתִּיךְ. 29 And Balaam said unto the ass: 'Because thou hast mocked me; I would there were a sword in my hand, for now I had killed thee.' ל וַתֹּאמֶר הָאָתוֹן אֶל-בִּלְעָם, הֲלוֹא אָנֹכִי אֲתֹנְךָ אֲשֶׁר-רָכַבְתָּ עָלַי מֵעוֹדְךָ עַד-הַיּוֹם הַזֶּה--הַהַסְכֵּן הִסְכַּנְתִּי, לַעֲשׂוֹת לְךָ כֹּה; וַיֹּאמֶר, לֹא. 30 And the ass said unto Balaam: 'Am not I thine ass, upon which thou hast ridden all thy life long unto this day? was I ever wont to do so unto thee?' And he said: 'Nay.' לא וַיְגַל יְהוָה, אֶת-עֵינֵי בִלְעָם, וַיַּרְא אֶת-מַלְאַךְ יְהוָה נִצָּב בַּדֶּרֶךְ, וְחַרְבּוֹ שְׁלֻפָה בְּיָדוֹ; וַיִּקֹּד וַיִּשְׁתַּחוּ, לְאַפָּיו. 31 Then the LORD opened the eyes of Balaam, and he saw the angel of the LORD standing in the way, with his sword drawn in his hand; and he bowed his head, and fell on his face. לב וַיֹּאמֶר אֵלָיו, מַלְאַךְ יְהוָה, עַל-מָה הִכִּיתָ אֶת-אֲתֹנְךָ, זֶה שָׁלוֹשׁ רְגָלִים; הִנֵּה אָנֹכִי יָצָאתִי לְשָׂטָן, כִּי-יָרַט הַדֶּרֶךְ לְנֶגְדִּי. 32 And the angel of the LORD said unto him: 'Wherefore hast thou smitten thine ass these three times? behold, I am come forth for an adversary, because thy way is contrary unto me;

Bilam is on his way to curse the children of Israel. It says that God opened up the mouth of the donkey, not that God blessed it with divine intelligence, it implies that God simply allowed the donkey to speak its own thoughts. We can argue all day if this is metaphorical or not. But either way, when the Angel finally reveals itself, its first priority is to bring up how the donkey was abused, rather than to talk to Bilaam about the whole cursing Israel thing.

For those who ask how is this moral? The donkey sees the angel while his master does not, and the donkey knows that if he approaches the angel his master would die, but if he goes against his masters wishes the master will beat him. But the donkey struggled with what he should do, and decided to heed the angel of God, rather than his master. He did the moral thing, which is why he is innocent of his masters beating, and also why the angel takes up his cause, for the donkey made the correct moral judgment.

Yonah Chapter 4 י וַיֹּאמֶר יְהוָה--אַתָּה חַסְתָּ עַל-הַקִּיקָיוֹן, אֲשֶׁר לֹא-עָמַלְתָּ בּוֹ וְלֹא גִדַּלְתּוֹ: שֶׁבִּן-לַיְלָה הָיָה, וּבִן-לַיְלָה אָבָד. 10 And the LORD said: 'Thou hast had pity on the gourd, for which thou hast not laboured, neither madest it grow, which came up in a night, and perished in a night; יא וַאֲנִי לֹא אָחוּס, עַל-נִינְוֵה הָעִיר הַגְּדוֹלָה--אֲשֶׁר יֶשׁ-בָּהּ הַרְבֵּה מִשְׁתֵּים-עֶשְׂרֵה רִבּוֹ אָדָם, אֲשֶׁר לֹא-יָדַע בֵּין-יְמִינוֹ לִשְׂמֹאלוֹ, וּבְהֵמָה, רַבָּה. {ש} 11 and should not I have pity on Nineveh, that great city, wherein are more than sixscore thousand persons that cannot discern between their right hand and their left hand, and the many animals as well?'

What is interesting about God's hesitancy about destroying Ninweh is that he compares the animals to the humans on the same level. And he also does this earlier, in terms of repenting.

Jonah Chapter 3

ז וַיַּזְעֵק, וַיֹּאמֶר בְּנִינְוֵה, מִטַּעַם הַמֶּלֶךְ וּגְדֹלָיו, לֵאמֹר: הָאָדָם וְהַבְּהֵמָה הַבָּקָר וְהַצֹּאן, אַל-יִטְעֲמוּ מְאוּמָה--אַל-יִרְעוּ, וּמַיִם אַל-יִשְׁתּוּ. 7 And he caused it to be proclaimed and published through Nineveh by the decree of the king and his nobles, saying: 'Let neither man nor beast, herd nor flock, taste any thing; let them not feed, nor drink water; ח וְיִתְכַּסּוּ שַׂקִּים, הָאָדָם וְהַבְּהֵמָה, וְיִקְרְאוּ אֶל-אֱלֹהִים, בְּחָזְקָה; וְיָשֻׁבוּ, אִישׁ מִדַּרְכּוֹ הָרָעָה, וּמִן-הֶחָמָס, אֲשֶׁר בְּכַפֵּיהֶם. 8 but let them be covered with sackcloth, both man and beast, and let them cry mightily unto God; yea, let them turn every one from his evil way, and from the violence that is in their hands. ט מִי-יוֹדֵעַ יָשׁוּב, וְנִחַם הָאֱלֹהִים; וְשָׁב מֵחֲרוֹן אַפּוֹ, וְלֹא נֹאבֵד. 9 Who knoweth whether God will not turn and repent, and turn away from His fierce anger, that we perish not?' י וַיַּרְא הָאֱלֹהִים אֶת-מַעֲשֵׂיהֶם, כִּי-שָׁבוּ מִדַּרְכָּם הָרָעָה; וַיִּנָּחֶם הָאֱלֹהִים, עַל-הָרָעָה אֲשֶׁר-דִּבֶּר לַעֲשׂוֹת-לָהֶם--וְלֹא עָשָׂה. 10 And God saw their works, that they turned from their evil way; and God repented of the evil, which He said He would do unto them; and He did it not.

According to the grammar of these verses, both man and beast wear sack cloth, all cry out onto God, all repent from their evil ways, and therefore all are given forgiveness from the punishment God was planning on bringing upon them.

For those who would say that it was only the people who repented because verse 8 says וְיָשֻׁבוּ אִישׁ מִדַּרְכּוֹ הָרָעָה i say that these are the words of the king of Ninweh! "by the decree of the king and his nobles, saying..." (Verse 7) God does not make a distinction between man and beast, for verse 10 says י וַיַּרְא הָאֱלֹהִים אֶת-מַעֲשֵׂיהֶם, כִּי-שָׁבוּ מִדַּרְכָּם הָרָעָה; And God saw their works, that they turned from their evil way...

So yes, if you want to believe in the words of the king of Ninweh, the animals did not repent of their evil ways, but do not mix his words with being the words of God.

grammar - Is 「でいい」 the same as 「でもいい」?

For example in the sentence: 書くだけでいいですか.

computational chemistry - How to construct a QST2 input file for Gaussian16 for multiple reactants and products?

I am attempting to determine the transition state structure for the following reaction using the QST2 method on Gaussian 16:

$$\ce{CH3 + N -> HCN + H2 }$$

However, I am struggling to put together my input file. How do I format my z-matrices for multiple reactants and products? Here is what I have so far (though it is not running successfully):

%chk=sample2.chk
%mem=1500MB

#T UB3LYP/6-31G** opt=(qst2, redundant)

CH3 + N -> HCN + H2 reactants

0 3
C

X 1 1.0
H 1 r 2 90.0
H 1 r 2 90.0 3 120.0
H 1 r 2 90.0 3 -120.0

r 1.0828

CH3 + N -> HCN + H2 reactants

0 3

N

CH3 + N -> HCN + H2  products

0 1
C
X 1 1.0
H 1 rh 2 90.0
N 1 rn 2 90.0 3 180.0


rh 1.0587
rn 1.1326

0 1
H
H 1 r

r 0.741

I'm pretty new to this type of calculation on Gaussian so any help would be much appreciated!

organic chemistry - RO (alkoxide) as a leaving group

Why is RO (alkoxide) a better leaving group than OH, despite RO being more unstable due to the electron donating effect of the alkyl group on RO?

I read that the suitability of leaving groups is dependent also on their nucleophilicity, as good nucleophiles will tend to re-attack the molecule it left from. To what extent is this true?

kanji - How to read 二、三日

If you have the two separate words, it's 二日{ふつか} and 三日{みっか}. But how are they read together? ふた、みっか, に、さんにち, some combination thereof or something else entirely?

Source sentence for the curious:

アキちゃんは広いお屋敷で二、三日ゆったり過ごしてくればいいのよ。

Answer

It is read 「にさんにち」.

Colloquially, people say 「にさんち」 as well.

fft - Taking audio frequency and picking out peaks (Peak Detection)

So I have a unique challenge. I want to take an audio file, and pick out the peaks in the samples and plot that onto a graph. Each point based on the amplitude/pitch(?) will be represented as either a small dot (lower amplitude) or a bigger dot (higher amplitude).

So if I had to look at a drum track, I should notably see big dots where the drum is hit, but smaller dots when a cymbal is hit.

From a technology stack perspective, I am using Python - and using a Library called Aubio (although I am not sure if there is a better library out there).

EDIT:

Forgive me on the lingo - very new at this audio stuff. Okay so the issue I have currently is that I have a waveform graph that shows the samples over time using a standard sampling technique.

But I found an article on Peak detection, which is exactly what I am looking for (I think).

The challenge I have now is pulling those peak values out via Python and Aubio and plotting them on a Graph.

meaning - いい versus よい? When do you use which?

What is the difference between いい and よい？

I notice that usually, いい is most commonly used, but sometimes, I get it wrong and よい is the correct answer. What is the situation to use each and what is the difference?

Thanks for the help.

Answer

They are quite the same except that よい sounds a bit more formal or contrived depending on the situation but that's all.

What you may already know is that いい only has a 連体形 and a 終止形 which are いい in both cases. For the others bases you have to use よい.

連用形　→　よく・よかっ; ex: よくない・よかった
未然形　→　よかろう

Some expressions explicitly call for よい but it is rare and most of the time rather archaic usage. (ex: 聞くが良い - You should listen)

sin - Why is misusing God's name so bad?

One is not allowed to take God's name in vain, and certainly not allowed to curse the name of God (chas v'shalom). I'd like to understand conceptually why these things are considered such grievous sins. Why is misusing God's name so bad?

My Orthodox Jewish co-worker invited me to his wedding. Anything I should know about?

My Orthodox Jewish co-worker invited me to his wedding, but I've never been to a Jewish wedding before. Is there anything I should be aware about if I plan to attend?

Answer

Yes, there is plenty that is worth knowing ahead of time about Orthodox weddings. First, I'll talk a little about what will or might be expected from you at the wedding and then I'll talk a little about what to expect at a Jewish wedding and how it's different from a non-Jewish or non-Orthodox wedding (I'm assuming since you say you've never been to a Jewish wedding that you have been to non-Jewish weddings). I am not going to go into details of the wedding ceremony itself. Rather, I will give some practical advice for you.

---

You won't have to worry too much about unexpectedly being asked to do something that you don't know how to do such as reading in Hebrew. The host of the wedding knows that you likely don't know how to do anything like that (and those honors are usually assigned ahead of time anyway).

One thing that you will want to take into consideration is your dress. Just like attendees of non-Jewish weddings, we dress up at Jewish weddings. The level of formality varies. If the wedding invitation doesn't mention "black tie" or anything like that, a nice suit or women's equivalent will suffice. This standard is the same as for a non-Jewish wedding. The one difference is that Jews do observe modesty laws. In order to show respect, you should do so as well. For men it's pretty simple. A regular suit will pretty much satisfy the requirements. Men should cover their heads with a kippah which will likely be available at the wedding venue. For women, dresses and skirts are to be preferred over pants and they should come down at least to the knee (possibly to the ankle, depending on the crowd) while shoulders should definitely be covered (no "strap" dresses) and in many communities arms should be covered down to the elbow. Tops or dresses that are cut low in the front or back should be avoided. How out-of-place you will feel if you don't follow these guidelines depends very much on the crowd. If the couple is newly religious, many of the guests (including family) may not be following them. On the other hand, if both spouses come from long religious lines and live in a religious neighborhood it is likely that everyone will follow them strictly. If you have any questions, your host undoubtedly be happy to give you more personally-tailored details.

Another point to note is that certain parts of the wedding may be separated by gender. It is very likely that the wedding dancing will be separate by gender, and the wedding ceremony itself may be as well. There are probably not going to be signs telling you where to go; just follow what everybody else is doing. If men and women are separating, go to the appropriate area.

---

In some ways Jewish weddings are similar to non-Jewish weddings, but in other ways they are very different. Usually the wedding will start with some time where the bride and groom are sitting in separate rooms and there is food in both. Where the guests go during this time varies; just do what everyone else is doing. In some cases, all of the men will be in the room with the groom while all the women will be in the room with the bride. In other cases, the room with the groom will have all of his close male friends and relatives while everyone else will be in the room with the bride. Again, just follow the crowd. If there's a large group of people of both genders hanging out and eating somewhere, that is definitely an appropriate place for you to be. Otherwise, find the place with people of your gender and help yourself to food. During this time, both spouses' parents will likely meet in the room with the groom and sign some documents. Then some other people will sign some documents. One last thing to note about this time: it usually lasts for quite a while... often an hour or more. It is not expected that you arrive at the very beginning of this time.

After some time has passed, the groom will go see the bride and then everybody will move on to the place where the wedding ceremony itself will take place. For this, just follow the crowd. If people are sitting separately by gender at the ceremony, do so as well.

Jewish wedding ceremonies are actually quite short. Often no more than 20 minutes or so. Some prayers and blessings will be said, a couple of songs will be sung, and someone might say a few words of Torah. Then the groom will step on and break a glass and that will be it. You don't have to do anything in particular during this time. Just sit and watch.

Finally, the meal and dancing part of the wedding will occur. The bride and groom will be in seclusion for a few minutes together during which time an appetizer course is often served to the guests. Once the bride and groom come back into the room, the dancing will begin! Dancing will likely be separated by genders with a curtain or free-standing wall separating them. Go to the appropriate side and have fun! Dancing at Orthodox Jewish weddings is quite different from dancing at non-Jewish weddings. It is fast and frenetic and there is no slow-dancing. You definitely want to be wearing comfortable shoes. Jackets and ties often come off for this part and you can expect to sweat significantly if you participate. During a part of the dancing, there will be a moment when the bride and groom are brought to sit next to each other and people take turns doing silly things to entertain them. You can participate in this if you want if you are a man, though in many communities women do not participate. This is another one of those cases where you just see what others are doing.

At some point during the wedding, an announcement might be made that people are going to take a break to pray. This could be at any of the transition points or possibly during the meal. The announcement might mention the words "mincha," "ma'ariv," or "daven." If you aren't Jewish, you can ignore this announcement. If you are Jewish, you might want to join in the prayer. You can ask if someone has an extra prayer book (with an English translation, if you need it). Occasionally the prayer service might take place in the main room with everyone, though in my experience this is rare. If you are not Jewish and this happens, it's best to stand when people stand and sit when they sit. The prayer probably won't take more than 10 minutes.

Once everything is done and the meal and dancing are over, everyone will say the Grace After Meals. There are a few special blessings at the end of this that are special for weddings. Usually these are assigned ahead of time, but in some cases they aren't. If someone asks you if you want to say one of the blessings but you are not Jewish or simply cannot read Hebrew, you can simply politely decline. Nobody will be offended.

Typically the entire wedding will last somewhere between 3 and 6 hours.

All of the above is typical of an Ashkenazi wedding in the United States. Ashkenazi weddings in Israel are likely to be similar though the dress is likely to be less formal if the families are not American immigrants to Israel (and possibly even if they are). In Israel it is relatively common for people who weren't invited to the wedding to show up after the meal to participate in the dancing. Some people might also be specifically invited to this part. If someone verbally invites you to "come dance at my wedding," but doesn't send you a wedding invitation, this is likely what they mean.

Finally, Sefardi weddings are quite different from Ashkenazi weddings. They are more likely to start late and much more likely to last much longer. In general, though, if you follow the rule of "do what everyone else is doing," you will be able to get through any Jewish wedding and hopefully have a great time!

terminology - Is there a lingustic term for okurigana omission?

Is there a (Japanese) linguistic term for okurigana omission (cases when 問い合わせ is written as 問合せ, etc.)? If not then what would be a concise way to refer to the phenomena (in Japanese)?

Answer

Being a non-linguist, I have no idea if this term is used in linguistics, but our 文化庁{ぶんかちょう} (Agency for Cultural Affairs) calls it 「許容{きょよう}」 ("tolerance").

http://www.bunka.go.jp/kokugo_nihongo/sisaku/joho/joho/kakuki/10/tosin01/02.html

To refer to the phenomenon, you could use a phrase like:

「誤読{ごどく}の可能性{かのうせい}が低{ひく}い（単{たん}）語{ご}の送{おく}り仮名{がな}の省略{しょうりゃく}」

That would be understood by all native-speakers, I promise.

brit milah - How does one become a Mohel?

I want to be a Mohel.

I learned the Tur - Shulchan Aruch (YD 260-266).

Now what?

What should be my next step?

P.S. I live in Brooklyn.

Answer

Probably the best option is to learn from a mohel or get good advice from a good mohel. The best and most friendliest Mohel I know is Rav Paysach Krohn, this web site has his number and email. I know that he's busy doing britot and lecturing, but, at worst, if he can't train you, I'm quite certain he will advise and, if appropriate, recommend you to the right person. (He may also try to sell you one of his many books. At least you may get them autographed :-)

Another possibility is to contact his son in law, Rav Ephra'im Perlstein, who is also a mohel, info here.

If you do, eventually become a mohel, I may ask you for some "tips" :-( :-(

shabbat - Bigdei Shabbos on Erev Pesach

It says in SA OC Siman 471 in the Rema Sif 3 that it's a mitzvah to take shower/bath and cut ones hair Erev Yom Tov. As well to wear "Bigadim Noim" (nice clothing) "c'mo Shabbos" (like on Shabbos.)

However the clothing of Yom Tov should be nicer than those of Shabbos (SA OC Siman 529). So why is the Rema saying to get ready and put on Bigadim Noim like one does on Shabbos. It could be that "c'mo b'Shabbos" means that one should get dressed nicely now just like one does for Shabbos (and not that the begadim themselves will be "c'mo", "like", those of Shabbos and rather like the ones of yom tov.

Or perhaps it could be understood like this, that the clothing (Shabbos clothing) that one should wear on davka Erev Pesach because it is more than just a normal Erev Yom Tov. Then the opposite, I would say to wear Yom Tov clothing itself.

An answer to this question could be either addressing my difficulty (which is why the Rema is seemingly telling us to get dressed with Bigdei Shabbos for Yom Tov which is in contradiction to the Shulchan Aruch in Siman 529) or perhaps correcting my understanding of the words of the Rema with a proper source or explanation (which in itself would answer the difficulty.)

FFT plot in Matlab, accuracy

I have a small input signal of 60Hz sine wave from signal generator, which is corrupted with 50Hz mains supply frequency. I want to measure the amplitude of the 60Hz signal using FFT because it is very small to see in the oscilloscope.
The Matlab FFT code:

y = data;    
Fs = 2048;
[r, L] = size(y);
NFFT = 2^nextpow2(L); % Next power of 2 from length of y
Y = fft(y,NFFT)/L;
f = Fs/2*linspace(0,1,NFFT/2+1);

% Plot single-sided amplitude spectrum.
plot(f,2*abs(Y(1:NFFT/2+1))) 

But the FFT plot doesn't give a sharp peak at 50 and 60Hz. The plot looks like this: . The consecutive points have high and low amplitude alternatively which gives a saw-tooth like plot. Why is it so? Is the amplitude of 60Hz affected by this?

Answer

The phenomenon you see is called "window effect" or also "spectral leakage". It occurs because ideally you would like to analyze an infinitely long signal (which would give you ideal peaks in the frequency domain), but actually you analyze a truncated (windowed) signal. In fact you multiply your signal with a window function - in your case a simple rectangular window - which in the frequency domain corresponds to a convolution with the frequency response of the window. This gives you the effect that you see. You can try different window functions, but you will not get rid of the basic effect.

BTW, for the plot you could try using values in dB, i.e. use $20\log (|Y|)$ instead of a linear plot; this will make things look a bit better.

chasidut hasidism - Relationship between Chabad and the Malachim today

These days, what is the relationship between Chabad and the Malachim? How close are they -- do members of the groups marry each other, participate in each other's mosdos at all, etc.? Do Chabad consider the Malachim "their own," or members of a totally different group?

tefilin - Why do Tefillin have filler material in the base of the batim?

Mikshah tefillin are tefillin battim which have no filler material in the titurah (base). Why is filler material even necessary?

The photo below illustrates the thickness with a piece of filler (roughly a third of the titurah).

Photos credit of R' Melech Michaels

publications - אגרת הרמב״ן versus חרם דרבנו גרשם

Rabbeinu Gershom (also known as Me'or Hagolah, the "Light of the Diaspora" - a Rishon who lived approximately 1000 years ago) issued a Cherem (ban) on unauthorized reading of private letters. This prohibition applies even if the reader does not take the letter to his own domain. However, if the owner of the letter threw it into the trash, it is permissible to read it.

This Cherem is still effective today, and must be considered with the same gravity as any other Torah prohibition. It was embraced and accepted at the time that it was issued by all Jewish communities throughout the world. There was no time limitation placed on this ban.

— from http://www.torah.org/advanced/business-halacha/5757/vol2no17.html with internal footnotes omitted

---

Many a sidur includes a copy of a letter that the Ramban (Nachmanides) wrote to his son, including exhortations on character improvement. Similarly, people sometimes republish unearthed halachic or other responsa of long-dead rabbis without the permission of either party to the communication and (I assume) without knowing that the recipient discarded the letter.

How are such practices allowed?

Answer

First some background from here

[In 1997, there was a significant controversy when] Dr Marc Shapiro published an article called Scholars and Friends: R' Yechiel Ya'akov Weinberg and Prof. Samuel Atlas. The piece included private correspondence between the Seridei Esh (R Weinberg) and his friend Prof. Samuel Atlas of Hebrew Union College. A lot of people were upset that this private correspondence was published, both because of what it was in itself: letters between a גדול and his friend who was a professor at a Reform university, but also because of the content of those letters. Of course other people felt that this is the truth, and the truth is not upsetting, but just true.

In the next volume, journal editor R Dr. J.J. Schachter published a piece called Facing the Truths of History in which he basically questioned his decision to publish Shapiro's article, but also defended it.

Starting on p. 242 R Schachter discusses the herem of R Gershom and specifically various caveats that would enable one to publish letters. See the full article for details but here is a summary of some of the caveats

• 
  

  some formulations of the original herem are phrased "if [the recipient] threw away the letter it is permitted [to read it]"

  
  


• 
  

  R Hayim Palaggi states the herem only applies if the letter includes a prohibition to further broadcast it

  
  


• 
  

  R Moshe ben Habib felt the sender needed in addition to verbally articulate that the herem applies to his letter, in addition he felt the herem applied only to the one opening the letter, not to one who reads an already opened one -- and so write the Shiltei ha-Gibborim and the Birkei Yosef

  
  


• 
  
  

  on p. 245, R Schachter brings arguments showing the herem wouldn't apply to a deceased person

  
  

He concludes by writing

Finally, my most significant proof for the inapplicability of this herem to our context and the permissibility of generally printing divrei Torah after their author’s death is simply ma‘aseh rav. Significant precedent is, indeed, available for both these activities. What is the essential content of Torah journals like Moriah and Kerem Shlomoh, for example, and countless memorial volumes for deceased gedolim if not precisely this, publishing private letters and divrei Torah of gedolei Yisrael after their deaths when neither they nor members of their family are available to grant permission? Furthermore, dozens of collections of letters of gedolei Yisrael—including much personal material as well—have been published without permission.

grammar - How is あっての used to define something?

I've previously asked about あっての, but now it seems to me that I've run into an additional usage of it (or perhaps the same usage I just can't wrap my head around it...).

When the sentence is simply AあってのB, it seems pretty straightforward. For example:

あなたあっての私なんです。

I think means: "I wouldn't be here without you" This sentence, however is more confusing to me:

子供あっての我が家である。

Does this mean:

• "Our family wouldn't be here without the children/if not for the children"?

Or is it more like:

• "Our family exists for the (benefit of the) children"?

Or even:

• "If we never had children, we wouldn't be a family"?

Answer

I sometimes have this problem with あっての　too so I looked it up (Reference: 日本語表現文型辞典　p25). To my surprise the English explanation was contradictory but the Japanese explanation works.

I'll start with the English definition:

「N１あってのN２」is an　emphatic expression meaning N1 is realized because there is N2.

This fits

「子供あっての我が家である。」

which I take to mean "We would not be the family we are without our children"(see note 3), but seems contra to the more familiar:

「あなたあっての私なんです。 / "I wouldn't be here without you"

However the Japanese explanation uses the expression:

「N１があるからN２が成立する」

which works for both examples.

Notes

1. 
   

   FWIW: The book also give alternative English equivalents as "comprised of" or "indispensable to".

   
   
   


2. 
   

   The full Japanese definition was:

   
   

   「N１あってのN２」の形で、「N１があるからN２が成立する」と強調するときの表現。

   
   


3. 
   

   This translation is closest to your first meaning, which also seems quite acceptable. The others might also work in the right context?

   
   

physical chemistry - Compound with a bright green emission when electrically excited

I rolled back the edit because I really am looking for the following:

I am looking for an element or compound that would have a bright green emission when electrically excited and is a gas at between 1 torr and 4 torr. If such a compound could be nontoxic, that would be beneficial.

The pressure range is important.

I'm familiar with the emissions spectra of all the noble gases, but none of them work for me. I want to find such a compound to use in a Geissler tube, which will be excited with about 50kVac at 300 to 500kHz. I am capable of pulling a vacuum down to 0.2 torr, and I normally work between 1 torr and 4 torr.

I know of a Xenon/nitrogen mix that produces the desired color, but it's too fussy for me to achieve, and Xenon is too expensive for this purpose.

Relatedly, I was wondering why the Xenon/nitrogen mixture emits a green light. Neither Xenon or Nitrogen has much green at the appropriate pressure, but somehow the combination, within a narrow range of Nitrogen partial pressure, produces a bright green. What causes this color when the two compounds are mixed together, and how can I predict the color of a given mixture of gases at a given pressure?

I know of the bohr model and balmer series etc, but I don't understand how to apply that to compounds or mixtures of compounds. Is there some other way to predict the spectra produced by mixtures of gases?

It's not easy gettin' green! (Apologies to Kermit)

physical chemistry - In a molecular dynamics context, is the methyl rotation in propene a symmetric or asymmetric internal rotor?

In a prior question, I asked about the (a)symmetry of the potential energy surface of the methyl rotation of propene. In that context, the kinetic energy of the nuclear motions is of course assumed to be negligible, and thus nuclear inertial effects are irrelevant.

Here, I want to ask about the (a)symmetry of this same internal rotation, but instead in the context of molecular dynamics (MD), where the Born-Oppenheimer approximation still applies but the kinetic energy of the nuclei is non-negligible compared to the variations in the potential energy over the course of the motion of the system. For the sake of argument, assume that the propene is in a sufficiently high rovibrational energy state for the methyl rotation that it behaves as a hindered internal rotor, and thus the nuclear motion is not "trapped" in one of the wells of the potential energy surface.

---

Depending on how one imagines the methyl rotation of propene to occur, it seems like it could behave as either a symmetric or an asymmetric internal rotor in an MD context. If the $\ce{H2C=CH\! -}$ portion were held fixed, the rotating methyl would be inertially symmetric due to the local $\mathrm C_3$ axis:

On the other hand, if the methyl group were held fixed, the rotating $\ce{C=C}$ portion would be highly inertially asymmetric:

Obviously this rotation can't simultaneously be both inertially symmetric and inertially asymmetric. So which is it, and why?

My inclination is to assume that the internal rotor is asymmetrical, since the overall system does not have any axes of three-fold or higher symmetry. However, I don't know a good mathematical or group theoretic 'language' in which to define such internal rotor (a)symmetry, and so I'm unable to prove this to my own satisfaction.

---

The best qualitative argument I've thought of in favor of it being an asymmetric internal rotor is that the axis of the rotation (green bar) does not pass through the center of mass of the system (purple sphere / orange bar):

FWIW, I calculate the skew angle between the two colored bars in the above geometry to be about $18^\circ$. Anyways, as a consequence of this skewed orientiation, I think the methyl hydrogens would oscillate parallel to the axis of internal rotation while they rotate around the methyl carbon. Simultaneously, I would expect a sort of corresponding "waggle" of the ethenyl fragment.

Thus, directly related to the "why" question above: If this qualitative argument is correct, how can I express it quantitatively?

usage - What is the meaning of 〜たりして?

I've just come across "〜していたりして" at the end of a sentence in a post on Facebook, so it's probably very casual. Does anyone know the correct meaning and typical usage?

Answer

たりして is used to posit some event as a possibility but something you are not sure about. For example, about the future:

10年後に大金持ちになっていたりして。

From the nature of this expression meaning "not being sure", it is also used as a hedge when you want to be modest and a bit comical:

ひょっとして、さっきのことでまだ怒ってたりして。

clothing - Did G-d and angels appeared dressed or naked to Adam in Eden?

1. 
   

   First, we know that Adam and Eve were naked in Eden and didn't feel ashamed (Ber 2.25).

   
   

   
   

   "וַיִּהְיוּ שְׁנֵיהֶם עֲרוּמִּים הָאָדָם וְאִשְׁתּוֹ וְלֹא יִתְבֹּשָׁשׁוּ׃

   
   

   The two of them were naked, the man and his wife, yet they felt no shame.

   
   

   
   
   


2. 
   

   Second, once they ate the fruit they revealed their nakedness and were ashamed and got dressed (Ber 3.7).

   
   

   
   

   וַתִּפָּקַחְנָה עֵינֵי שְׁנֵיהֶם וַיֵּדְעוּ כִּי עֵירֻמִּם הֵם וַיִּתְפְּרוּ עֲלֵה תְאֵנָה וַיַּעֲשׂוּ לָהֶם חֲגֹרֹת׃

   
   

   Then the eyes of both of them were opened and they perceived that they were naked, and they sewed together fig leaves and made themselves loincloths.

   
   

   
   

Heres how the Midrash pictures the interaction between them (Avot_D'Rabbi_Natan.1.8 thanks DonielF)

ר' יהודה בן בתירה אומר אדם הראשון היה מיסב בג״ע ומלאכי השרת עומדין בגן עדן לקראתו וצולין לו בשר ומצננין לו יין בא נחש וראה אותו והציץ בכבודו ונתקנא בו.

I'm confused - if G-d and the angels appeared clothed from the beginning, Adam would feel like second graded and animal-like before the sin; if they did appear naked as Adam was, why would he feel ashamed after eating the fruit?

So how did they appeared before Adam before and after the sin?

---

Note: According to what the Torah specifies later about Aharon's cloths - לכבוד ולתפארת, dressing had nothing to do with modesty - it was the sign of respect and dignity.

minhag - Keeping your own community's dinim vs. yuhara

My chosen community--like every community, I suppose--has its own body of distinctive minhagim, horaos, chumras, hiddurim, and normative halachas. All, including the hiddurim, are observed with a high degree of commitment by a substantial cohort who see this as a matter of loyalty and love. People do not tend to deviate from them because of travel, convenience, or the minhag hamakom.

But I am trying to learn more about the halachos of yuhara, according to which it seems that it may be forbidden to go above and beyond the basic halacha in public if others are not doing the same.

From here it seems that in at least one case, a non-Torah-scholar may do an "extra" practice in public as long as all the Torah scholars and some of the balabatim are doing it. And from the Rema cited here, he may do an "extra" something if he is involved in "prishus and chassidus" in general. Of course, he may (must?) do what is correct l'chatchila even if others are doing only b'dieved or less. Other deviations from the norm, however, would seem to be discouraged.

• 
  

  Is it really yuhara to keep, say, your kashrus standards all the time? I read a source saying that not drinking cholov stam is not yuhara, perhaps because this "act" is completely passive. But when it's a matter of requiring CY keilim--or, very complicated, refusing the meat of your Satmar Shabbos hosts--you are going to stick out. And yet I can't imagine allowing or requiring yeridah in a matter like kashrus just because "other people are doing it."

  
  


• 
  

  What is a general guideline for what types of practices are doche and not doche hilchos yuhara? (Personal hachlatos/nedarim/chazakos? Things that you have genuine spiritual pleasure from, or a strong spiritual need to do? Communal and family minhagim? Explicit directives of the religious leader(s) of your community? Rulings of the poskim of your community? Chumras which everyone in your community keeps?) I'd appreciate "canonical" sources if they exist.

  
  

Related: When should one change one's Minhag with one's Makom (and when should one not)?

Chaba''d doesn't follow minhag hamakom?

writing printing - Three letters at the end of the parasha

What are the three letters either samechs or pe's which are at the end of the parasha in the Chumash?

Answer

See the article on parashah in Wikipedia .

Some extracts from it:

A parashah formally means a section of a biblical book in the masoretic text of the Tanakh (Hebrew Bible).[1] In the masoretic text, parashah sections are designated by various types of spacing between them, as found in Torah scrolls, scrolls of the books of Nevi'im or Ketuvim (especially megillot), masoretic codices from the Middle Ages and printed editions of the masoretic text.

You have used the word "parasha" which does not fit this definition. What I think you mean is "sedrah".

In most modern Torah scrolls and Jewish editions of the Bible, there are two types of parashot, an "open portion" (parashah petuhah) and a "closed portion" (parashah setumah). An "open portion" is roughly similar to a modern paragraph: The text of the previous portion ends before the end of the column (leaving a space at the end of the line), and the new "open" portion starts at the beginning of the next line (but with no indentation). A "closed portion", on the other hand, leaves a space in the middle of the line of text, where the previous portion ends before the space, and the next portion starts after it, towards the end of the line of text.

In some manuscripts and in many printed editions, an "open portion" (petuhah) is abbreviated with the Hebrew letter "פ" (peh), and a "closed portion" (setumah) with the Hebrew letter "ס" (samekh), often in place of the visual gap in the line.[8]

The five books of the Torah have been broken down into their weekly Torah readings for convenience. The weekly Torah readings always begin at a parashah break, with the single exception of Vayechi (Genesis 47:28).

This parashah break is signified by three "פ"s at the end of the sedrah. Eg here.

The end of the sedrah ויגש which is the sedrah before ויחי looks like this.

grammar - versus +と versus +に

I often see adverbs used in one of three ways:

1) Adverb appears in isolation in a sentence:

あまり 好きじゃないんですが。

2) Adverb is followed by に

別々に お願いします。

1970年代後半、多くの罪もない日本の一般市民が 次々に 失踪した。

3) Adverb is followed by と

鮮明な花火が夜空に 次々と 揚がった。

Notice that in 2b), and 3), it's even the same adverb and the meaning appears identical. So suppose for a minute we wrote sentence 3) in each of the three different ways:

鮮明な花火が夜空に 次々 揚がった。

鮮明な花火が夜空に 次々に 揚がった。

鮮明な花火が夜空に 次々と 揚がった。

Is there any difference between these?

I suspect that the first one is wrong, but the second two are identical and both correct. But I don't know what rule governs this. And I think (although I don't have an example handy) that the first ( adv only) and second ( adv + に) patterns can also be used interchangeably in certain situations, which would suggest that maybe all 3 can be used interchangeably in some situations, but not others.

Can anyone explain how this works?

Answer

I think what's really going on here can be traced back to the two different ways 形容動詞 (けいようどうし: adjectival nouns or "な-adjectives") were inflected. If we look under the 連用形 (れんようけい: the "adverbial inflection", for lack of a better term) column under the first table on this Wikibooks page detailing Classical Japanese inflection patterns, we find the following two patterns:

ナリ活用 (the ナリ inflection), such as with 静か【しずか】: 静かなり or 静かに

タリ活用 (the タリ inflection), such as with 堂々【どうどう】: 堂々たり or 堂々と

(The Wikipedia page on 形容動詞 mentions that these inflections were derived from the ～にあり and ～とあり forms, respectively, in Classical Japanese.) For the most part the old styles of inflection have fallen out of use, but there are many examples fossilized in Modern Japanese:

聖なる夜 holy night (also used as the Japanese title of "Silent Night")

暗澹【あんたん】たる時期 a dark period

So without getting into the entire class of words that is used as adverbs without any special と or に appendages, we can see that from early on 形容動詞 were split in that some took なり／に to become adverbs, while some took たり／と.

Generally speaking:

• If a word is more commonly used as a な-adjective (that is, if its 連体形 (れんたいけい), the form by which it connects to a noun, is な), the adverbial form will have に.


• If a word typically does not connect to nouns or is more commonly used as an adverb, the adverbial form will usually have と or nothing at all (excepting common forms such as ～になる or ～にする).

These are general rules (and not very good rules at that), and so exceptions, such as 次々, aren't hard to find.

静か｛○に／×と／×∅｝話す speak quietly

きれい｛○に／×と／×∅｝整える arrange neatly

ゆっくり｛△に／○と／○∅｝歩く walk slowly

きっぱり｛△に／○と／○∅｝言う say flatly

はっきり｛△に／○と／○∅｝見える [be able to] see clearly

Unfortunately there are no pretty dividing lines between に and と here. This is probably because に and と have both retained their role of "adverbializer" throughout the evolution of Japanese, and neither form succeeded in displacing the other. Boaz Yaniv mentions this phenomenon in his answer for why some adjectives use な and some use の.