halacha - Bracha after an earthquake

Per the Artscroll Siddur after an earthquake we make a Bracha "Oseh Maaseh Breishis". Up to how long after the earthquake can you make this Bracha? (sources please)

Answer

Piskei Teshuvos (227:2) cites Bircas HaBayis who says that the blessing can only be recited during the quake or within 2-3 seconds (תוך כדי דיבור) after it's over.

He also says (from Teshuvos Shevet HaKehasi) that even mild quakes warrant this blessing, and (from Shaarei Teshuvah in the name of Maharam Chaviv) that if another quake occurs even that same day, the blessing is repeated, as long as some time has passed and the person is no longer thinking about it.

halacha - Benefiting from work done by a non-observant Jew after Shabbat

Observant Jews do not resume doing melacha after Shabbat until after Havdalah. But not all Jews do this. So may you benefit from work done by a non-observant Jew after Shabbat ends, even if he did not "end" Shabbat with Havdalah? Let's say, should you not call them on the phone on Saturday Night?

Answer

The short answer is that this is allowed. There are two issues here

1. Is work forbidden before havdala?


2. Can you benefit from work done by a Jew after shabbat if he hasn't done havdala?

The answer to the first question is that indeed work is forbidden before havdala (see Mishna Brura 299:10), the Rema says one might be lenient for non full-fledged labor work but apparently the Magen Avraham disagrees. So for all practical purposes one has to say Barukh Hamavdil ben kodesh le hol before doing any work. See here for a related MY discussion

Now when you are calling someone who didn't make havdala, he is not transgressing a melacha (forbidden Shabbat work) of Shabbat because Shabbat has ended for him even if he didn't do havdala. He is "only" transgressing the interdiction of not doing work before hadvala. The Shmirat Shabat Kehilchata (59:8 in vol 3, p. 938) explicitly allows this

One is allowed to benefit when somebody who is not shomer mitzvot and does not make Havdalah performs, after Shabbat, an activity forbidden on Shabbat, e.g., traveling on a bus with a Jewish driver who did not make Havdalah

He brings an interesting idea to wish that person "Shavua tov" with the intent he might reply the same and so perhaps fulfill at least his basic obligation to make Havdala (i.e., acknowledging Shabbat has ended).

R Ari Enkin in Da'at v'din (p. 52) brings additional sources saying the same, e.g., Tzitz Eliezer 11:34, 14:34, Rivevot Ephraim 8:118:9

Remains the question whether you can "actively trigger" that interdiction by calling someone after shabbat when you know he hasn't done havdala. It might be a case of lifnei iver lo titen michshol ("do not put an obstacle in front of the blind"). However if there was such an interdiction, practically, an observant Jew couldn't interact with any non-observant Jew. The Shmirat Shabat Kehilchata is not disturbed by this as he allows delivering work to be done after Shabat by someone who did not make havdalah.

matlab - Image processing coding

I was wondering which is the best language for image processing? I know MATLAB has a good library and user community for it. I havent checked it out, its there for python as well.

What is the most efficient language for this?

organic chemistry - Why do some nucleophiles attack at the carbonyl group while others at an alpha-carbon in ketones?

I was reading about the iodoform reaction and it stated that $\ce{OH^-}$ attacks at the $\alpha$-carbon and makes a substitution reaction possible. But there is also the possibility of attacking the carbonyl group directly and forming a gem-diol. Why doesn't that happen?

organic chemistry - SN1, SN2 or acid-base reaction

I am asked to give the type of reaction (S_N1, S_N2 or acid-base reaction) for the following reactions. I know that both $\ce{MeOH}$ and $\ce{EtOH}$ polar protic solvents, so because the first is an S_N2 reaction shouldn't the second reaction be that as well? It says that it is an acid-base reaction as $\ce{MeO-}$ reacts with the $\ce{EtOH}$ to from 1-bromopropane, $\ce{MeOH}$ and $\ce{EtO-}$ and then goes on to from a S_N2 reaction.

I would appreciate if someone could explain why the second reaction would be an acid-base reaction at first instead of a S_N2 reaction.

korban - What do we learn from Miriam's demise being juxtaposed to the Red Heifer?

What precisely does the demise of righteous people atone for, and who gets the atonement?

Background:

In Parshat Chukath - במדבר פרק-כ - we learn from Rashi that the demise of the prophetess Miriam was juxtaposed to the chapter of the Red Heifer to teach us that both of these atone.

The Pasuk says:

וַתָּמָת שָׁם מִרְיָם וַתִּקָּבֵר שָׁם

Rashi:

ותמת שם מרים. למה נסמכה מיתת מרים (ל) לפרשת פרה אדומה, לומר לך, מה קרבנות (מ) מכפרין, (ס"א כמו שפרה אדומה מכפרת) אף מיתת צדיקים (נ) מכפרת (מועד קטן כח.):‏

Why was Miriam's death juxtaposed to the Red Heifer? To teach us that just as sacrifices atone (alternate reading: just as the Red Heifer atones) so too does the demise of the righteous atone.

Rashi is quoting the Gemara in Mo'ed Katan 28a - which has the alternate reading's text.

Tosafos there explains - מה פרה אדומה מכפרת פירוש על מעשה העגל וכדאמרינן במדרש משל לבן השפחה שטינף פלטירין של מלך - that the Red Heifer atones for the sin of the Golden Calf, as per the Medrash that the maidservant (Heifer) is expected to clean up her child's (Calf's) mess in the palace.

The שפתי חכמים elaborates:

ל) פירוש דאין כאן מקומו שהרי בשנה ראשונה ליציאת מצרים עשו העגל ובשנה שנייה שרפו פרה אדומה ומיתת מרים היתה בסוף מ' שנה ליציאת מצרים:‏

That is: The first RedHeifer was done soon after the Mishkan was erected - it should be in the Chumash around Tazria-Metzora. Miriam's demise happened 38 years later; the Red Heifer is put here - some 38 years after it happened - to teach us something.

He continues:

מ) ואם תאמר וכי קרבן היתה הפרה אדומה והלא לא היו מקריבין ממנה כלום. ויש לומר לפי דבר אחר שפירש"י לעיל שקראה הכתוב חטאת לומר שהיא כקדשים ליאסר בהנאה שמע מינה שהיא כקרבן: ‏

That is: Even though the Red Heifer was not a real sacrifice, (it was done outside the Temple and no part of it was brought on the altar), Rashi already explained that it has some of the laws of a sacrifice, as it's called a חַטָּאת (ibid 19:9) ולפי הלכותיו קראה הכתוב חטאת, לומר שהיא כקדשים להאסר בהנאה - in that one is forbidden to derive personal benefit from it, [besides for its stated purpose. (As per שפתי חכמים there- ויש מפרשים כקדשים שבאין לכפרה כך האפר בא לטהר מי שצריך ואין שום הנאה אחרת ממנה).]

He concludes:

נ) ואם תאמר לפי זה היה לו לסמוך גבי קרבנות ממש. ויש לומר לכך נסמכה לפרה לפי שהם דומים להדדי לפי שמיתת צדיקים אינן קרבנות וגם הפרה אינה קרבן ממש ולמדנו מהדדי כמו שזה מכפר גם זה מכפר:‏

That is: Miriam's demise was juxtaposed to the Red Heifer, and not to a regular sacrifice, to highlight that neither are real sacrifices, yet they both atone.

Question:

What precisely does the demise of righteous people atone for, and who gets the atonement?

I'm asking, as the concept the death of the righteous atones is often quoted at funerals, implying that it's a Korban Tzibur - a general atonement for the public.

Sources and novel ideas are welcome.

Answer

According to R' Samson Raphael Hirsch's commentary on these sections of the Torah,¹ the Red Heifer and the death of the righteous both accomplish the same spiritually educational mission: curing people of the illusion that they are solely physical beings without free will.

R' Hirsch explains his understanding of the meaning of every aspect of the Red Heifer procedure in an extended comment following Numbers 19:22. This comment is an interpretive masterpiece that will reward the reader who studies it in full with a wealth of insight. I'll do my best to summarize some of the main pertinent points here.

The Problem of Contact with Death

The point of the Red Heifer process is to cure people of the טומאה‎² that comes from contact with death. According to R' Hirsch, this טומאה is a sort of moral depression that comes from contemplating a dead human body and drawing the mistaken conclusion that the whole human being ends with death. The person in the thrall of this materialistic idea has trouble believing in human free will - if humans are just matter, then human behavior is compelled by the laws of physics just like the behavior of all matter is. This person is then unfit to participate in the service of God, which requires free-willed devotion of oneself.

... then altogether nowhere is there place for the moral "thou shalt" next to the physical "thou must".

The Red Heifer Solution

The Red Heifer process teaches that the essence of humanity is that the physical body, which is indeed bound by the laws of physics, is joined with an immortal soul, which has the Godly ability to freely choose between good and evil and the charge from God to choose good. The heifer itself represents the uncontrolled physicality, in that it is fully grown, red like blood, and has never in its life been bent to a higher purpose. When the heifer is burnt to ashes, we see the physical body returning to the dust whence it came. But before it's burnt, the heifer is slaughtered by a kohen opposite the Temple, and the life-blood that comes out is sprinkled toward the Temple, representing the one aspect of a person that does not return to dust, the immortal soul. Later, the ashes, representing pure physicality, are combined with "living water," another representation of the free-willed soul. When people are sprinkled with this mixture, they are reminded of the true, dual nature of humanity and enjoy restored confidence in their freedom to choose service over sin.

... although thou art "earthly ashes" nevertheless thou art מים חיים, life drawn from the source of immortality.

The Death of the Righteous

At the end of his comment on Numbers 20:1, R' Hirsch cites the same explanation in Mo'ed Katan that Rashi does for the juxtaposition of the laws of the Red Heifer with the stories of the deaths of Miriam and Aharon, and uses what he has taught us about the former to show a lesson for us in the latter.

... just as the [Red Heifer] institution teaches immortality and the moral freedom of will of the godlike nature of Man, so does the death of the righteous directly teach both.

Anyone who sees the physical remains of a righteous person can see, intuitively, that they do not comprise the totality of the individual who, until now, was constantly making free-willed choices to do good. It is clear that

Just as their work here below lives on in immortality in all the succeeding generations of the nation, so their own real selves did not die, but went back out of earthly transience into eternity to God, the source of all life.

Like one who has been sprinkled with the lesson in free-willed humanity that is the Red Heifer water, one who sees the death of the righteous returns from the spiritual depression that regular human death brings, newly empowered to choose dedication to the service of God.³

---

<sup>1. Fourteen pages in the Isaac Levy translation.
2. Often translated as "impurity." Its meaning according to R' Hirsch is summarized here.

3. This answer was posted soon after the death of R' Dr. Aharon Lichtenstein, ZT"L. May we contemplate this exemplary man and his immortal legacy of myriad students and teachings, and be inspired to attempt to emulate his "towering goodness."</sup>

hebrew - Relationship between Samekh and Sin

What is the relationship between the letters samekh and sin? Did they ever have distinct sounds? Why do they exist as separate letters?

Answer

"A sin is just a samech with three branches."

-- A contemporary American ראש ישיבה

The idea here is that in modern usage they are both actually interchangeable with samech.

For an illustration of this interchangeability see the 15th line of the alphabetical acrostic א-ל אדון, in which a sin appears where we would expect a samech, or the common root א.ר.ס used by חז"ל in place of the Torah's synonymous root א.ר.ש.

The difference in sound between the samech, a voiceless alveolar fricative ([s]) and sin, a putative voiceless lateral fricative ([ɬ]), is hypothesized to have been lost as early as Biblical Hebrew, with its remnants still evident in transliterations like "Chaldean" for "כשדי" and "balsam" for "בושם". In each case, the sin that we would conventionally pronounce as [s] was ostensibly closer to [ɬ], which is, in a way, halfway between /s/ and /l/.

There is a complicated diachronic explanation of exactly how and why this shift took place, which is summarized very briefly on page 73 of this paper, by Biblical Hebraicist Gary Rendsburg.

Contractions in やんなっちゃう

A person is comparing herself to some disreputable school mates, thinking that she might be similar to them, and says:

やんなっちゃうなぁ

Is this a contraction of (い)やになっちゃうなぁ meaning "I ended up becoming unlikeable"?

I'm coming across more and more of these contractions as I read more, and they keep tripping me up. Are there any general rules I should know that will help me figure this stuff out on my own?

Answer

Yes, やんなっちゃう is short for いやになっちゃう, which is short for いやになってしまう.

いやになる is a fixed phrase meaning "to be fed up / sick / disgusted". So やんなっちゃうなあ is something like "Now I'm starting to feel disgusted", "I can't help being sick".

grammar - What is the meaning of 「ため」 in the following sentence?

I understand that ため means "in order to" or "goal".

I don't understand how it works in this sentence though. Could someone please explain.

バスの事故が続いているため出発前に警察などが調べ

This is how I interpret it:

The bus accident | in order to continue being | before the departure | Police etc investigate

marriage - Multiple wives in Chazal

Is anyone aware of any of the Tanaim or Amoraim who had more than one wife (at the same time)? Not just technically married, but actually living together as husband and wife (or wives). I was once told that you will not find any that did.

Answer

Hebrew Wikipedia says that

לא ידוע על תנאים או על אמוראים שהיו נשואים לשתי נשים יחד. על פי זה, הסיק הרב ראובן מרגליות שריבוי נשים, גם אם הוא מותר - איננו מומלץ, ואף מגונה.‏

We do not find any Tanaim or Amoraim married to two wives together and Rav Reuven Margulies concludes that multiple wives even if permitted is not advised and is even unpleasant.

This is cited to "עוללות, מוסד הרב קוק, תש"ז עמ' 13."

He does not mention the Yerushalmi Yevomos mentioned here and in several of the comments.

megillat esther - How did Haman think he could get away with murdering Mordechai?

Haman persuaded Ahashverosh to sign a decree enabling the genocide of the Jews in the Persian empire. This much is clear from the text. But in between Esther's parties, Haman constructs a gallows 50 cubits tall, at his own home, specifically to hang Mordechai. I'm a little befuddled by how he could think he could get away with this. True, he lurked in the king's courtyard that night, probably rehearsing his speech and/or waiting for the king to wake up, so he could request permission for Mordechai's hanging. But wouldn't Ahashverosh find it a little bit odd that Haman had already built the gallows at his own home to hang Mordechai?

Under what kind of system of laws were the Persians operating that Haman could conceive of this as somehow legitimate - or legitimate enough to avoid some kind of inquiry by the king's court into what the heck he had planned and for how long?

halacha - When is the latest that one can have coffee before reciting the kiddush on Shabbat morning?

One is not allowed to partake of any food or drink before reciting or hearing the kiddush of the day. However, because coffee helps with concentration during prayers, there's a leniency to allow one to drink coffee before the morning prayer.

Until when does this leniency extend? Is it only before the beginning of shacharit? What about before mussaf or during the Torah reading?

What is the difference between continuous, discrete, analog and digital signal?

It's my first time studying DSP and I've faced a problem finding a convenient definition.

Are the following definitions correct? And if so why there are some resources defining it in other terms such as "Digital signal: is a signal with discrete time and discrete amplitude"

1. 
   

   Discrete time signal: X-axis (time) is discrete and Y-axis (amplitude) may be continuous or discrete.

   
   
   


2. 
   

   Continuous time signal: X-axis (time) is continuous and Y-axis (amplitude) may be continuous or discrete.

   
   


3. 
   

   Digital signal: Y-axis (amplitude) is discrete and X-axis (time) may be continuous or discrete.

   
   


4. 
   

   Analog signal: Y-axis (amplitude) is continuous and X-axis (time) may be continuous or discrete.

   
   

Answer

A signal is indeed a function. Given a signal $f(x)$, according to whether continuous or discrete for both the variable $x$ and the function $f(x)$, there are four types of combinations:

(1) $\mathbf{continuous}$ $x$ and $\mathbf{continuous}$ $f(x)$

This is the most common $\mathbf{analog}$ signal.

(2) $\mathbf{continuous}$ $x$ and $\mathbf{discrete}$ $f(x)$

For this one, we can imagine the ideal base-band waveform used in digital communication. As this one:

(3) $\mathbf{discrete}$ $x$ and $\mathbf{continuous}$ $f(x)$

This is indeed the signal in most the "digital signal processing" textbooks. An example, as others have pointed out, is the output of the CCD sensor.

(4) $\mathbf{discrete}$ $x$ and $\mathbf{discrete}$ $f(x)$

This is the $\mathbf{digital}$ signal. Digital signals are used in practical implementation aspects, and they actually exist in a conceptual manner.

If we concern the discrete feature of the function, the problem will be more complex, therefore, in most "digital signal processing" textbooks, the signals are $\mathbf{not}$ digital indeed. An interesting fact is that, for the the classical textbook by A. V. Oppenheim, the name was "digital signal processing" in the 1st edition, but the name was changed to "discrete-time signal processing" for the later editions.

shema - Can a rabbinical mitzvah (that is currently being done) override a biblical mitzvah?

There's a principle of Osek Ba-Mitzva Patur Min Ha-Mitzva that says that if one is in the midst of doing one mitzvah he is exempt from performing other mitzvot.

Do both mitzvot have to be of the same type (biblical or rabbinical)? Or does any mitzvah count towards this principle.

A common application of this happens daily: You have 5 minutes until sof zman kriat shema (a biblical obligation) and you're in the middle of reciting pesukey dizimra (a rabbinical mitzvah). Should you interrupt pesukey dizimra to say shema on time? Or does reciting the pesukey dizimra exempt you from saying shema on time?

Stam viYesh Halacha k'.....?

This question is a followup to these comments

When the Shulchan Aruch brings two opinions as to what the halacha in a given situation is, the first is brought without a name, and the second is brought as a "yesh (omrim, osrim, matirim)," and does not specify which opinion he prefers (like by writing ונראין דבריהם or וכן נוהגין or some similar wording), which opinion should be followed?

Nuance between でいい and でもいい

Follow up question to this one :

Sentence structure and meaning

About this sentence :

「ただしお前達の相手は私一人でいい。」

It seemed to me that in Tokyo Nagoya's answer, でいい sounded a lot like でもいい :

" Meaning-wise, however, 「でいい」 adds much more [than だ]. It expresses the speaker's agreement to the fighting rules that could possibly be disadvantageous to him. In other words, the speaker is already very confident of his victory as he speaks. "

So I did a bit of research and found these :

Is 「でいい」 the same as 「でもいい」?

http://www.guidetojapanese.org/learn/grammar/must

The first link says that でもいい has a sense of "something is better out there, but you settle for less" that でいい doesn't have.

The second link says that "In casual speech, 「～てもいい」 sometimes get shortened to just 「～ていい」."

So is でいい just the familiar abbreviation of でもいい or are they 2 distinct (though similar) structures with different nuances?

Answer

The same as "also" in English. The word "も" implies the existence of another option.

「お前達の相手は私一人でいい。」 is natural. Simply, the speaker must be very confident about the fight against many opponents in front of him.

「お前達の相手は私一人でもいい。」 sounds weird, but it seems that the speaker implies another person stronger than him is standing by.

カレーライスでいい。 = Curry and rice is acceptable / enough / OK.

カレーライスでもいい。 = Curry and rice is also acceptable (but implies the speaker has other choices in his mind.)

words - Questions about ありたい

心がいつも美しくありたいです

I want my heart to always be beautiful.

心がいつも美しくして欲しいです (Incorrect)

心がいつも美しくなりたいです

I want my heart to always be beautiful.(?)

My Japanese friend wrote the first sentence, while I wrote it over attempting to use 欲しい instead. I am unfamiliar with this use of ある, and have a few questions about it.

Is it derived from the same "existence" verb, ある -- 在る ?

My other question is how personal is the nuance when expressing a wish or desire, compared to 欲しい? If the second version that I wrote with 欲しい is acceptable, how do the two sentences differ in tone, politeness, meaning and expression?

I am wondering if ありたい expresses a more, or less personal desire than 欲しい.

Furthermore, can one rewrite the original sentence using another verb, while retaining the same meaning? Lastly, is my translation correct? Or should it read "I want my heart to always be beautiful."? I had thought that the original sentence corresponded to something like "I always want the person on the inside to be beautiful (just like how I am on the outside)," but maybe I am wrong. Thank you.

Answer

• たい is used when the expected change is on the subject or it is about the subject's action.

お菓子を食べたい
'I want to eat some/the snack.'

• ほしい is used when it is about something other than the subject.

お菓子を食べてほしい
'I want someone to eat some/the snack.'

Your second sentence is ungrammatical because 心 is the object. It should be:

心をいつも美しくして欲しいです

But this sentence cannot be interpreted as describing your own mind. It has to mean the mind of someone else. The same thing can be said about your third sentence.

A possible rewrite of the first example is:

心がいつも美しくなりたいです

organic chemistry - Is an SN1 reaction possible in halobenzene?

Is an SN1 reaction possible in halobenzene?

Will the phenyl carbocation be stabilized via resonance? Suppose the leaving group is very electronegative and the environment is protic. What then would be a suitable nucleophile?

Answer

Yes, that reaction occurs, but generation of the phenyl carbocation was much more difficult than anyone might have guessed. Here is a drawing of the phenyl carbocation. First note that the 6 p orbitals making up the aromatic pi system are all still intact and overlapping - the aromatic nature of the benzene ring has not been tampered with. Then notice that the cationic center exists as an empty $\ce{sp^2}$ orbital where the

$\ce{C-H}$ bond used to be. The empty (cationic) $\ce{sp^2}$ orbital is orthogonal to the aromatic pi system; as a consequence there is no resonance interaction or stabilization of any sort between the two systems. Further, being constrained by the 6-membered ring, the cationic $\ce{sp^2}$ orbital cannot rehybridize. This results in considerable (low energy) s-character being used to stabilize an empty orbital, and is not available to stabilize other orbitals that do contain electrons! The vinylic carbocation, the ethylenic analogue of the phenyl cation, is much more stable and common (it can even be observed by nmr) because it is not constrained by a ring and can rehybridrize, thereby lowering its energy. It is both this total lack of stabilization and relatively high (higher than need be if rehybridization could occur) energy of the molecule that has made the phenyl carbocation such an elusive target.

To stack the deck in their favor, investigators have run experiments using extremely good leaving groups such as nitrogen and the triflate anion. Magic acid and its variations, a very powerful acid that stabilizes carbocations, was often employed as well. The nitrogen leaving group route, using thermal decomposition of aryl diazonium cations has been one of the few methods that has allowed access to this transient intermediate.

A few references if anyone would like to read more:

spelling - How does one transcribe the romaji "ō"?

I use The Kodansha Kanji Learner's Dictionary, which describes pronunciation in romaji instead of kana. I never learned romaji in a classroom, and generally only use it when reading this dictionary.

When "ō" is not proceeded by a consonant (like "tō" is), how does one know how transcribe it into kana?

I first used "おう" (such as "tō": "とう"); however, through trial and error, I came to realize that "おお" is more accurate. Then, I came across the kanji 扇 in my dictionary as "ōgi", and realized that, if I typed "おおぎ" or "おうぎ", both displayed the option of 扇.

It's quite possible this is a "spellcheck" type safeguard (the Japanese equivalent of "the" being typed out when "teh" is entered) because I have checked around various online dictionaries (Wiktionary, Yahoo!dict) and it turns out that in this case, 「おうぎ」 is indeed the correct transcription. Is there a definitive way of knowing in other cases, solely by reading the romaji?

Answer

It depends. In most cases it is おう. But is some words, the "おお" form is retained, such as "大【おお】きい", "多【おお】い", "遠【とお】い", etc.

For 扇, I'd believe if the dictionary doesn't have おおぎ, it should be incorrect.

(btw, from the transcription of おうぎ in classic Japanese (あふぎ) which is shown in the dictionary, the transcription now can only be おうぎ.)

grammar - Meaning of こともあるもんです

How should I translate こともある in this sentence (response to '何それ?'):

あなたが辞書を使うなんて、はなはだ珍妙なこともあるもんです

Literal translation of はなはだ珍妙なこともある would be 'there are also really odd things', but that makes no sense.

One suggestion seems to be that it means 'among other things' so I get:

Because (もん), among other things (こともある), it's really odd that (なんて) you use a dictionary

Is this a correct translation? If so can anyone offer a suggestion as to how we arrive at that from the literal translation? (and why do I have to keep reaching for my advanced grammar book to read a children's story? It's really dispiriting.)

Answer

The latter part is in line with: "wow, strange things happen!"

もん (ものだ) is used here emphatically to indicate emotion (hence I decided for "wow").

こともある literally stands for occasionally, but as the English verb to happen already covers the occasional aspect the meaning can be expressed just with "things happen".

halacha theory - The meaning of "האב שמחל על כבדו כבדו מחול"?

This is a follow-up question to "does-mechilah-invalidate-kibud-av".

The Gemmorah in Kiddushin 32 states:

"א"ר יצחק בר שילא א"ר מתנה אמר רב חסדא האב שמחל על כבודו כבודו מחול"

Translating מחילה into English is tricky, it could mean "forgiveness" or "absolution". The difference it like דחויה or הותרה, in other words, it can mean that the כבוד exists but the father only "frees the son from the punishment" or that the father's כבוד is annulated by him so no Mitzvah of Kibbud can exist.

The first approach is backed by Radva"z and Sefer Chassidim, see Chortkov's answer, the other is backed by Rashb"A (1:18), see David's answer.

We use the term מחילה in various other situations, e.g. in monetary conducts (מחילת חוב) or as forgiveness for misdeeds.

What is the Halacha considering the מחילה - is it "total" or "partial"?

halacha - Are Shiros considered one parshah or several?

The two Shiros, Shiras HaYam and Shiras Ha’azinu, are both written slightly differently from one another, but are both written in a “brickwork” format, rather than the typical paragraph format (YD 275:3-5). From observing Sifrei Torah, the gist of it seems to be a layering of text, wherein the words are broken up into several word phrases, which are then layered line by line, with gaps in the middle.

What are considered the parshah breaks for these? Both songs are preceded by and followed by a Pesuchah - are those the bounds of the parshah, and one could start an aliyah in the fourth passuk of either song? Or are the breaks in the middle of the lines considered a new parshah each time?

When a ba’al korei reads a parshah, he may not begin an aliyah within three pesukim of the beginning of a parsha, nor may he end one within three pesukim of the end of a parsha (OC 138). To that end, I am aware that the practice is to have several parshah breaks during Shiras Ha’azinu, but none in Shiras HaYam (at least among Ashkenazim). Does this mean that the Shiros are a single parshah? If so, is this limited to Ha’azinu, but the breaks in Beshalach are Parshah breaks? Or does this in theory apply to Beshalach as well, just that in practice it wouldn’t occur without adding aliyos according to our minhag?

In the event that the gaps during a Shirah are not considered Parshah breaks, I would like an explanation as to why that is the case. In the event that Shiras HaYam and Shiras Ha’azinu are different, I would also like an explanation of that as well.

electronic configuration - Plutonium having more oxidation states than samarium?

Why does plutonium have more oxidation states than samarium?

Electron configuration of Pu: $\ce{[Rn] 5f^6 7s^2}$

Electron configuration of Sm: $\ce{[Xe] 4f^6 6s^2}$

I thought that only the valence electrons affected the oxidation states, so why does plutonium have more oxidation states (6,5,4,3) than samarium (2,3) whilst they both have the same valence electrons (including f-orbitals): ..$\ce{f^6}$..$\ce{s^2}$ ?

Elements such as scandium (Sc),Yttrium (Y) and Lanthanum (La) all have the same valence electrons (including d-orbitals): ..$\ce{d^1}$..$\ce{s^2}$ , but these elements have the same oxidation state : 3 and that doesn't change, even when going down that group and looking at actinium.

Does this have to do with the ionization energy, or the energy level or ....?

Answer

This is yet another interesting effect of the anomalous compactness of orbitals in the first appearance of each type of subshell ($1s$, $2p$, $3d$, $4f$, $5g$, etc). The solutions to the Schrödinger equation for electron wavefunctions in hydrogen-like atoms are such that these subshells are composed of orbitals with no radial nodes. This means the electrons in these subshells are closer to the nucleus than you might expect, and therefore they are more strongly bound.

The striking chemical similarity of the lanthanides comes from the fact that the $4f$ subshell is both anomalously compact and subjected to a high effective nuclear charge. The electrons end up being held so closely to the nucleus that they effective behave as core electrons, and participate very little in chemical interactions; lanthanides do not form coordination compounds using their $4f$ orbitals, and it is very difficult to go past an oxidation state of +3 in most because few conditions can compensate the large energy required to ionize a fourth electron coupled with the relatively weakly bound compounds they would form.

In the actinides, the $5f$ orbitals do not suffer from the same lack of radial node, and therefore are more chemically available. The first half of the actinides show many compounds with high oxidation numbers, and have significant coordination chemistry using $f$ orbitals. Curiously, as you go form curium to berkelium, there is a sudden increase in reluctance to display high oxidation numbers, and the actinides beyond curium tend to behave similarly (though of course exploration of their chemical properties is significantly hindered by their rarity and instability). This is likely because even though the $5f$ orbitals have a radial node, in the second half of the actinides they are subjected to such a high effective nuclear charge that become too strongly bound to display significant participation in chemistry.

This same effect explains why the metals in the first row of transition metals do not display as many stable compounds with high oxidation states compared to the second and third rows, as the $3d$ orbitals are much smaller than $4d$ or $5d$ orbitals.

mfcc - Cepstral Mean Normalization

Can anyone please explain about Cepstral Mean Normalization, how the equivalence property of convolution affect this? Is it must to do CMN in MFCC Based Speaker Recognition? Why the property of convolution is the fundamental need for MFCC?

I am very new to this signal processing. Please help

Answer

Just to make things clear - this property is not fundamental but important. It is the fundamental difference when it comes to using DCT instead of DFT for spectrum calculation.

Why do we do Cepstral Mean Normalisation

In speaker recognition we want to remove any channel effects (impulse response of vocal tract, audio path, room, etc.). Providing that input signal is $x[n]$ and channel impulse response is given by $h[n]$, the recorded signal is linear convolution of both:

$$y[n] = x[n] \star h[n]$$

By taking the Fourier Transform we get:

$$Y[f] = X[f]\cdot H[f] $$

due to convolution-multiplication equivalence property of FT - that is why it's so important property of FFT at this step.

Next step in calculation of cepstrum is taking the logarithm of spectrum:

$$Y[q] = \log Y[f] = \log \left( X[f] \cdot H[f]\right) = X[q] + H[q]$$

because: $\log(ab) = \log a +\log b $. Obviously, $q$ is the quefrency. As one might notice, by taking the cepstrum of convolution in time domain we end up with the addition in cepstral (quefrency) domain.

What is the Cepstral Mean Normalisation?

Now we know that in cepstral domain any convolutional distortions are represented by addition. Let's assume that all of them are stationary (which is a strong assumption as a vocal tract and channel response are not changing) and the stationary part of speech is negligible. We can observe that for every i-th frame true is:

$$Y_i[q] = H[q] + X_i[q] $$

By taking the average over all frames we get

$$\dfrac{1}{N}\sum_{i} Y_i[q] = H[q] + \dfrac{1}{N}\sum_{i} X_i[q]$$

Defining the difference:

$$\begin{array} &R_i[q] &= Y_i[q] - \dfrac{1}{N}\sum_{j} Y_j[q]\\ & = H[q] + X_i[q] - \left(H[q] + \dfrac{1}{N}\sum_{j} X_j[q]\right) \\ & = X_i[q] - \dfrac{1}{N}\sum_{j} X_j[q]\\ \end{array}$$

We ending up with our signal with channel distortions removed. Putting all above equations into simple English:

• Calculate cepstrum



• Subtract the average from each coefficient


• Optionally divide by variance to perform Cepstral Mean Normalisation as opposed to Subtraction.

Is Cepstral Mean Normalisation necessary?

It's not mandatory, especially when you are trying to recognise one speaker in a single environment. In fact, it can even deteriorate your results, as it's prone to errors due to additive noise:

$$y[n] = x[n] \star h[n] + w[n] $$

$$Y[f] = X[f]\cdot H[f] + W[f] $$

$$\log Y[f] = \log \left[X[f]\left(H[f]+\dfrac{W[f]}{X[f]} \right) \right] = \log X[f] +\log \left(H[f]+\color{red}{\dfrac{W[f]}{X[f]}} \right)$$

In poor SNR conditions marked term can overtake the estimation.

Although when CMS is performed, you can usually gain few extra percent. If you add to that performance gain from derivatives of coefficients then you get a real boost of your recognition rate. The final decision is up to you, especially that there are plenty of other methods used for the improvement of speech recognition systems.

food - What type of Maror?

For Maror there are those that use lettuce, those that use endives, those that use fresh grated horseradish, or maybe something else. Is there a difference in what you use for Maror and what you use for Koraich?

organic chemistry - How there are 7 enolizable hydrogens in 2‐methylcyclohex‐2‐en‐1‐one?

49. How many enolizable hydrogens are there in the following compound?

(a) 2
(b) 4
(c) 5
(d) 7

I know that enolate ion is the anion formed when an α-hydrogen in the molecule of an aldehyde or ketone is removed as a hydrogen ion.

In the above question I find only two α-hydrogens which can participate (denoted with red color):

But the answer is (d) 7. Where am I getting wrong?

Nomenclature of methyl groups in an alkanol

I'm having trouble with this question since I'm getting (A), when the answer says its (B).

My logic was that there is a methyl group on the first carbon, and a hydroxide functional group on the second carbon, hence the name 1-methyl-2-pentanol.

Could someone please explain why I am wrong?

Answer

Don't let the graphical layout of the molecule deceive you! There are no branches in the carbon chain. (That is, no carbon atom is bound to more than two carbon atoms.) The molecule ethane is not called "methylmethane", so calling your molecule a methylpentane derivative would similarly be an error.

With no branches (and no rings and no double bonds etc.), and with six carbon atoms, we must be dealing with a hexane derivative. Once you know that, you just need to apply IUPAC rules that minimize the numbering of atoms to which substituents are bound. So answer B makes more sense than C, for that reason.

tamei tahor ritual purity - Two supports for a stove: which one "counts"?

The mishnah in Keilim 6:1 describes a stove made in two ways: a pot resting on three metal^* pegs that are either (1) attached at the ground via clay, or (2) stuck into the ground. In the first case, the clay gives the stove the status of a "clay stove", which is susceptible to tumah, whereas in the second case, there is no susceptibility to tumah.

‮העושה שלושה פטפוטין בארץ, וחיברן בטיט להיות שופת עליהן את הקדירה: טמאה. קבע שלושה מסמרין בארץ להיות שופת עליהן את הקדירה: אף על פי שעשה בראשן מקום שתהא הקדירה יושבת, טהורה.

If he put three props into the ground and joined them [to the ground] with clay so that a pot could be set on them, [the structure] is susceptible to impurity. If he set three nails in the ground so that a pot could be set on them, even though a place was made on the top for the pot to rest, [the structure] is not susceptible to impurity. (translation from Sefaria)

What is the rule when the pegs are both stuck in the ground and also connected to the ground via clay? Does the order make a difference?

If it's relevant: imagine the case such that if the ground where the pegs are stuck were removed/looser, the clay would hold up the pegs, and if the clay were removed, the pegs would stand due to being stuck in the ground.

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See also this question.

^* I know that some commentaries read the initial sentence as referring to clay props, but I'm asking according to those who don't (or according to everyone, if the material doesn't matter). See also the tosefta Keilim BK 5:1 which seems to support a read of metal props.

meaning - What does んだけど mean here?

「……さすがにそれはちょっと、あまりオススメできないっていうか……」

優には悪いけど、恥ずかしい……。

俺があのベッドで寝るのも恥ずかしいし、自分の部屋にあるのも恥ずかしい……。

……というか根本的な問題として置けるのか、アレは。

「なんで？　私と寝るのイヤなの？」


「いや……そういうことは全くもってない**んだけど**……」

「じゃあ問題ない、いい生活にはいい睡眠が大事」

Can anyone help me understand what it means?

In dictionaries it says that the definition for this usage of けど is 言い切りを避け、婉曲に表現する気持ちを表す but I don't understand what is being left unsaid.

Edit : Unfortunately the suggested duplicate question doesn't answer my question. The answer there literally says the same as the definition I provided. If that definition answered my question then I wouldn't have posted this question. My question is more about what is left unsaid and the function of けど in this case. Is what's left unsaid something like "けど　いやなのはそのベッドで寝ること” or is it him expressing his confusion as to why she would think that he wouldn't want to sleep together.

Answer

This sentence can translate to:

いや……そういうことは全くもってないんだけど……
No... I don't mean it, but...

Regarding the grammatical function, the けど in question is basically the same as けど described in this question: けど at the end of the sentence?

Without けど, the sentence would become 「そういうことは全くもってないよ」, which is almost equal to accepting the girl's proposal in this context (I don't know what her proposal is, but it seems to be something very embarrassing to the boy). So he hedged by adding けど. He weakened his statement by saying けど, and implied he still wanted to refuse her proposal in some way or other.

This type of けど/が/ですが/だが happens all the time in Japanese, much more frequently than in English. You don't usually have to fill "the unsaid part" because even the speaker himself is often unaware of what he wants to say after けど. It's basically just the sign of hedging. It's not always possible to fill the "unsaid part" in one way, and we can only guess from the context. That said, judging from the excerpt, my guess is that "the unsaid part" is something like 「やっぱり恥ずかしい」「それでもオススメできない」「置けるかどうかも分からない」.

Which one is the best notation for sodium acetate

I have seen two different notations for sodium acetate. The first one is:

$$\text{NaCH}_3\text{COO}$$

The second one is:

$$\text{CH}_3\text{COONa}$$

Now I'm confused, which one is the best to use?

Answer

There is nothing wrong with either formula. And you can use even more:

• $\ce{NaC2H3O2}$



• $\ce{C2H3NaO2}$

It really depends on which point you want to bring across.

$$\ce{NaCH3COO}$$

This formula, being analogous to formulae like $\ce{NaCl}$ stresses the inorganic salt view more. It shows that there is a cation ($\ce{Na+}$) and an anion ($\ce{CH3COO-}$) which form a salt crystal together much like the anion $\ce{Cl-}$ would do with the same cation. Inorganic nomenclature prefers cations to be written first.

$$\ce{NaC2H3O2}$$

Is basically the same except for saying ‘I don’t care how those seven atoms combine to form the anion, all I care for is what’s in there.’

$$\ce{CH3COONa}$$

This one stresses a more organic-chemical point of view where it’s relevant where the cation is actually bound to within the molecule. Oftentimes, organic chemists would even write structural formulae with a bond between oxygen and sodium as if it were hydrogen. The reasoning behind this is ‘I don’t care if the structure ends up being a salt, all I need to know is that the sodium somehow connects to the carboxyl group.’

Note that you can combine the first’s and the third’s idea to give $\ce{NaOOCCH3}$ which works, but is a lot less used than either of them.

$$\ce{C2H3NaO2}$$

This is the Beilstein-type lookup formula. You just know the elemental composition of your compound and now want to look it up — you can’t know whether it’s sodium acetate or sodium hydroxyethanalate (if that name is even correct). Or maybe you just don’t care. The reasoning behind this is $\ce{C}$ first, $\ce{H}$ second, the remaining elements following in alphabetic order.

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Finally, there are also shortened formulae. The most common (the one I actually use most) would be $\ce{NaOAc}$. Here, $\ce{Ac}$ is an abbreviation for $\ce{H3C-C=O}$ where whatever follows or precedes is bound to the carbonyl carbon. Note that this formula is not considered standard, and would need to be included in a list of abbreviations or defined otherwise if you decide to use it.

repentance teshuvah - What's the point of Jeremiah 13:18–27?

In Jeremiah 13:18–27, Jeremiah is told to address the king and queen, telling them of the trouble that will come (using the prophetic past). Unlike many of the preceding chapters, where he tells the Jews to repent of their wrongdoing and change their ways, he here says that they cannot:

הֲיַהֲפֹךְ כּוּשִׁי עוֹרוֹ וְנָמֵר חֲבַרְבֻּרֹתָיו גַּם אַתֶּם תּוּכְלוּ לְהֵיטִיב לִמֻּדֵי הָרֵעַ.‏

Can the Ethiopian change his skin, or the leopard his spots? Then may ye also do good, that are accustomed to do evil. (JPS)

M'tzudas David explains this as an exaggeration: it would be difficult, but not literally impossible, for the sinners to change their ways. But I'm asking according to view that it would be impossible: Radak explains "the evil won't be able to turn from you, as if it is natural in you"; Mahari Kara says "it is impossible for you that you'll be able to do good".

What purpose did this prophecy serve?

• If the prophecy was true — it would be impossible to repent — then why the prophecy at all? What's the point of telling people they can't repent?


• And if it was false, then (besides the philosophical difficulty in the existence of a false prophecy, which I don't want to get into) how would relaying this (false) prophecy urge the people to repent? Surely if they heard "you can't repent", they wouldn't!

pronunciation - How to pronounce the name of the last letter in the Hebrew alphabet?

I have heard mixed answers as to how to pronounce the letter תּ

Is it taf or tav?

(I'm referring to the halachic pronunciation not the common street way.)

Is there a difference between Ashkenazi or Sefardi in this matter?

Answer

The Talmud (Shabbat 104a) spells it out as תיו. So anything from Taw to Tau to Tav is probably in the right ballpark. The unvoicing of the 'v' to make 'f' in common parlance is a common feature of speech (see also this parallel question).

grammar - How to understand 余りと and 以降最も多くなった。

For full context: https://www3.nhk.or.jp/news/html/20180127/k10011304581000.html

The sentence in question: 日本で働く外国人労働者は去年１２７万人余りと、統計を取り始めた平成２０年以降最も多くなったことが厚生労働省のまとめでわかりました。

My attempt at translation: "Concerning the foreigner employees who work in japan, through the conclusion of the ministry of health, labour and welfare we know that last year it became more than 1270000 since 20 years heisei era where they began taking the statistics."

So I basically ignored the と in 余りと because I didnt know how to interprete it. The entry on jisho didnt seem to fit either http://jisho.org/search/amarito .

Im also not sure if I resolved the nominal phrase 統計を取り始めた平成２０年以降最 correctly by making 統計を取り始めた a relative attribute.

I think that 余り and 多くなった are somehow related, since the foreigners "became more than...". However, the more semantics already is in the word あまり, which is why it seems like a doublette if 多くなった follows.

Ultimately, Im very skeptical about my interpretation of まとめで. I interpreted で as a particle indicating a means because it fit my interpretation well, but since my interpretation had a lot of guesses, I feel like this is probably not right xD

Answer

The と is a quotative particle. Here it continues to （最も）多くなった.

『日本で働く外国人労働者は去年１２７万人余り』と、（統計を取り始めた平成２０年以降）最も多くなった

It can be roughly understood as 「～というふうに・というように・のように、多くなった」.

Similar examples:

• 参加者は200名と多くなった。 The number of participants grew to 200.


• 数値は80％と、今までで最も高かった。 The number was the highest ever, being 80%.


• 結果は５対０と、初出場ながら健闘しました。 The team did well with a score of 5 to 0, even though it was their first appearance in the tournament.

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As the other posters said...

余り means "a little more than [a phrase with a number]".

あまり【余り】

🈪（造）《数を表す語に付いて》それより少し多い意を表す。[余]{よ}。
「二百余りの申し込みがあった」「ひと月余りが経過した」
(明鏡国語辞典)

and まとめ is "summary" (or "conclusion" or "report", depending on the context.)

As for the other part and a full translation, please refer to the other posters' answers...

words - What do つれて and いくと mean here?

ある日、アリババがロバをつれて森へいくと、たくさんの馬の足音が聞こえてきました。

Can anyone explain to me what つれて and いくと mean in this sentence, I'm having a hard time understanding..

Thanks

Answer

つれて is just the て-form of the verb 連{つ}れる whose meanning is "to lead (people)", "to take people (from one place) to another one".

And, いくと is the verb 行{い}く + the と particle. In this case と means "when".

If you still can figure out the meaning of your sentence, there is a translation in a spoiler.

Therefore, your sentence (ある日、アリババがロバをつれて森へいくと、たくさんの馬の足音が聞こえてきました。) translates into: Once, Alibaba led the donkeys, when they came close to the forest, a great sound of hooves could be heard.

spoken language - In real life, do Japanese speakers exclaim things like 熱っ！ or 痛たた… or 寒！?

In anime and Japanese television and so forth, I've noticed that people confronted with a sudden undesired stimulus, like heat or pain or cold, will often utter something like 熱っ【あつっ】！ or 痛たた【いたたた】… or 寒【さむ】！, all of which follow the pattern of taking a word that describes the undesired stimulus and then modifying it in some way, like clipping it or extending it.

To my English ear, this sounds a little bit unusual, since in English, the things people exclaim when presented with an undesired stimulus are generally non-words (e.g. "Aaaah!" or "Ouch!" or "Brrrr") or profanities, rather than something like "Hot!" or "Painful!". This is the case even in works of fiction, though of course the exclamations might be more articulate or exaggerated than one would expect from real life.

Do Japanese speakers exclaim these sorts of things in real life?

Answer

Yes, saying those as the very first word after the stimulus is very common even in real life.

• 痛【いた】っ！　痛たたた…　いててて…


• 寒【さむ】っ！



• 臭【くさ】っ！


• 熱【あつ】っ！　熱つつつ…　あちちち…


• うるさっ！


• 汚【きたな】っ！


• 痒【かゆ】っ！


• 旨【うま】っ！

We don't say 寒むむむむ or 臭ささささ for some reason... perhaps because they're difficult to pronounce? And as you can see in the last example, you can sometimes use this kind of expressions for pleasant but unexpected stimuli.

image - Blending Artifacts in Photo Stitching

I am working on a photo stitching application that uses multi-band blending. I need to get rid of unpleasant edges appearing at some places:

Here is the area of overlap (left - new image added to the mosaic, right - current mosaic contaning pixels of new image on background pixels to improve blending, middle - blending mask):

If I just compute weighted average between left and right image according to mask, the result is of course OK. However, this would leave a visible seam as two images have usually slightly different exposure.

So all three images need to be successively blurred to build a Gaussian pyramid - here is how one level of the pyramid looks like:

You can see that the top part of blending mask "touches" the border. The Gaussian blurring filter reflects on image borders and this causes inaccuracy in lower band.

I colored the images to make the problem more visible:

I am not sure about how to blur the mask so that it would deal with overlap area edges nicely.

Few suggestions:

• change behavior of the blurring filter (how?)


• extend area of blending mask so that one part never "touches" the border


• update weighting masks so that resulting blend mask is more "edge-aware"

Any other suggestions/hints?

Answer

I have solved this problem by adding certain padding to overlap area.

There are pixels belonging to image1, image2, background and overlap. A pixels in overlap are successively relabeled to either image1 or image2 depending on neighborhood.

This padding will make some space for the blurring so that sharp edges of the overlap have no change of appearing.

Another treat is photometric calibration, i.e. gain compensation and vignetting removal. This minimizes or even eliminates the differences in low frequency band.

Finally, the blurring have to avoid background pixels (usually black) from bleeding into the image. This can be done by alpha blending or using binary mask as described here.

It is also possible to reduce amount of blurring near edges and corners of the overlap. This, unfortunately, reduces performance of the blending algorithm and the results are somewhat uncontrolled (as the blurring is non-uniform).

Finally, a gradient domain blending improves the quality near edges as it does not rely on Gaussian blurs of fixed sizes.

grammar - N+にわたって/にわたり/にわたる

Can someone explain me the exact meaning of にわたって when used in describing time/ duration? I understand it's use for range when we describe space. And I know it can mean something like "over a period of", but I saw it also means prolongation of time.Also, isn't 間 alone for duration? Why we need にわたって? So, what is the difference here:

私は ３時間 勉強しました。
私は ３時間にわたって 勉強しました。

Hope you'll understand what I want to say. I'm confused because for one moment I understand it and poof it's gone.

Could a DCT be used for an audio magnitude spectrum rather than DFT?

From what I understand, the DCT has half the bin size as a DFT of the same size N. The DFT also includes phase information, but often this is not needed when only the magnitude spectrum is desired.

• Could the DCT be used to provide a magnitude spectrum with twice the density (half the bin spacing) of the DFT or would out of phase information be lost?


• How about with a 50% overlap?

Answer

Yes, DCT can be used to provide a magnitude spectrum with twice the density. I do not quite understand overlap, but I am assuming that since DCT covers less, you thought there would be an overlap. To provide an eligible answer to the question, let me make a quick review for usage of DCT in mainly image processing.

First, we need to make some assumptions. In order to use DCT, you need to have a real signal. This is by definition. While you are saying, DCT has half the bin size comparing to DFT in size N, you are assuming that the signal is low frequency signal. Otherwise, not so much.

For usage of DCT in compression, since DFT of image will be symmetric, it produces redundant information (one side mirror will be enough to reproduce the signal). Therefore, kernel of DCT is used in order to produce denser information comparing to DFT. This is also true for low frequency audio signals, it can be used in the same way. While it makes it denser, coefficients gets bigger, since kernel of DCT covers both sides(real and imaginary parts) of the signal.

My major is image processing, so I tried to map DCT and DFT concepts and explanations in image processing. One difference between image and audio could be sizes, though. In image processing, you know the sizes(row and columns for FFT and other purpose of processing). I guess that you need to divide the vector of audio data somehow in order to further process. Without knowing the data, this could be troublesome(I am not sure).

Here is an image taken from web, but I did not write it down where I took it, could be wikipedia.;

As you can see, transformed image is represented in DCT by magnitude spectrum with no problem. In a more compact and denser way, and look at the magnitude of coefficients. It is bigger than two times of DFT. DFT is symmetric, you could just divide it into two. One part is redundant. And one more thing, DCT can store the information is not just half of DFT but nearly quarter of DFT. That is generally the case of DCT overcoming to DFT in images.

What's the literal and natural translation of たるもの?

子{こ}たる者{もの}すべからく親{おや}の命{めい}に従{したが}うべし。

Children should obey their parents

What I got from ALC is that a child isn't fit, unqualified, to be one's child if it disobeys its parents. Or is it just "Those who are children..."?

Answer

H'm, I dunno. たる is actually not the classic form of the copula である; it is most likely from とある (quotative particle + aru). なる describes what someone/-thing is (essential nature), but たる describes how someone/-thing appears, or acts, or should act (assigned role, etc.). There is often an implied judgment (nowadays it is often paired with 〜すべきである or 〜てはならない, etc., and used to prescribe behavior to people in certain positions). I would say that Louis's sample sentence does indeed imply that a child who disobeys their parents is in that way unfit to be their child -- it's not an uncommon idea at all in Confucian thought.

So, as sawa says below, you might say that a more "literal" translation would be "Whoever is supposed to be a child should obey their parents," or "A person in the position of a child should obey all of their parents' commands," etc. For a more natural translation, just "Children" might work in many cases (especially if you believed that たる者 was just being used to add archaic flavor), or you might say "All children" to emphasize that you are prescribing behavior required of anyone meeting the description "child", not just suggesting a general rule. You might even use a word like "duty" to bring the prescriptiveness out: "Obeying one's parents is one's duty as a child." There are many possible translations that would be more or less appropriate depending on context, translation philosophy, etc.

tractate brachot - Reciting the blessing of "Meshaneh Habriyos" ("who makes creatures different") on human beings

Based off the gemara on Berachos 58b, the Shulchan Aruch in Orach Chaim 225:8-9 writes:

for seeing a person with a dark, very red, or albino white complexion- or a person who is bent over because of obesity, a midget, a person with a lot of warts, a person with hair that clings to each other...

... for all these one should recite the blessing of "Meshaneh Habriyos" ("who makes creatures different").

Question:

As this beracha would seem to be offensive and could potentially cause pain to another human being, how can one understand such a beracha?

nuances - The difference between に and で when focusing on location vs. action

Consider these sentences (scenario 1):

1. 
   

   
   

   （私は）公園に花を植える。(I) plant flowers IN the park. (focus on the park)

   
   

   
   

vs

2. 
   

   
   

   （私は）公園で花を植える。(I) PLANT flowers in the park. (focus on planting)

   
   

   
   

First of all, I would like to know if this interpretation is accurate:

the first sentence emphasizes the location that is the park.

• This means that I will plant flowers in the park and in the park only. I won't plant anywhere else, and I won't take the flowers anywhere else. (But I could be doing other things like taking a walk, sitting on a bench etc.)

The second sentence emphasizes the action of planting.

• This means that I plant flowers at the park and I'm not doing anything else. (But I could be taking the flowers to plant somewhere else other than the park.)

---

Now, following that logic (if it is correct),

consider these next two sentences (scenario 2):

（私は）オフィスに電話をかける。

This can either be translated as:

• (I) telephone/call the office. ✔ correct


• (I) make a call INSIDE the office. (and nowhere else) ✘ wrong

（私は）オフィスで電話をかける。

This can only be translated as:

• (I) MAKE a phone call inside the office. (And I'm not doing anything else)

---

Now for my main question:

Why unlike the first scenario, I can use the に particle to say that I plant INSIDE the park but I can't use the に particle to indicate that I make a call INSIDE the office for the second case?

The only reason I could think of is because オフィス can only be treated as the object the verb (電話をかける） interacts with when using に and that takes priority over the に particle used as an indicator of location.

Is 電話をかける a special type of verb exclusive to this scenario or would there be other verbs that are similarly translated like that under a different context when using the に particle?

I have a very similar example to the second scenario that also uses the office:

オフィスに電話を設置する。

オフィスで電話を設置する。

They both mean (I) install the phone inside the office with different emphasis on location and action like the first scenario.

Can someone please explain the logic behind this use of particles?

Answer

I think you seem to be a little confused about the respective functions of に and で.

While it's true that their use in the sentences you provided could be seen as altering the emphasis in some of the ways you suggested, this is not because they have the function of providing the same meaning with different emphasis. Neither of them inherently add any notable emphasis to a sentence, but they do have fundamentally different meanings.

The particle で is straightforward; it indicates where someone is located when they perform an action. The particle に, on the other hand, does not indicate the location where an action takes place, but rather the location towards which an action is directed.

In the case of 花を植える, the distinction is somewhat awkward to express in English - in order to plant flowers into a specific spot you have to be in that spot yourself, so English would usually express both meanings using "in". But in essence 公園で花を植える indicates "I am in the park and I plant flowers", while 公園に花を植える indicates "I plant flowers into (the soil of) the park".

Using a more compact location makes the distinction clearer - 花を鉢に植える is a normal expression meaning "plant flowers into a plantpot", but 花を鉢で植える is strange - if we interpret it as a statement of location, it indicates that you are in the plantpot while planting the flowers, which is nonsensical, so we would have to interpret it as a different meaning of で, such as "plant flowers using a plantpot".

This same distinction in meaning is what separates the two 電話をかける sentences you described. オフィスで電話をかける indicates the location where you are going to be when you make the phone call. オフィスに電話をかける, on the other hand, indicates the target of the action of "calling on the phone", in other words the location of the person you're making the phone call to.

One natural outcome of this distinction is that while で can be used with any verb, に can only be used with verbs that have some kind of target location. You can't, for instance, say 部屋にドーナツを食べる, because the action of 食べる isn't directed towards any specific location - the only location that you would want to specify is your own location while performing it, in which case you would use で.

kanji - 決着 (keri or kecchaku)

This word 「決着」 (settlement/conclusion) is read as けっちゃく. Though lately, I've been digging into some more comics and noticed that there's another reading being used: ケリ.

For example:

• これが最後【さいご】だ。決着【ケリ】を付けよう【つけよう】じゃねぇか。


• いくぞ。ここで決着【ケリ】を付けて【つけて】やる。

Is this a new reading because I don't see it in any JAP to ENG dictionary I reference

Answer

It's 当て字. 決着{けっちゃく} does not have that reading and you won't find it in dictionaries. However, けりをつける is a saying in Japanese which does have an almost identical meaning.

Why do they use [当]{あ}て[字]{じ}?

This study divides the reason into 7 forms:

①
口語の読みを示す
②
外来語の読みを示す
③
英語の略表記の読みを示す

④
スポーツ用語
⑤
代名詞
⑥
言い換え表現
⑦
作品固有の表現

I would say けりをつける is a 口語 form※, i.e. you hear is used when speaking but not in writing. However, manga often depict colloquial conversations, which is why you see it's use here.

※You could also consider けりをつける to be 言い換え表現.

What is happening here, is by blending the spoken and written forms, you get full understanding, but also the reading portrays a real spoken conversation, so the manga doesn't feel very "stiff" like reading a long non-fiction novel.

Here is another study for people who want to read further about Ateji.

history - What is the source of hatred perceived by Jews in different parts of the world?

I don't know if this is off topic but a similar question is here at Christianity SE and I thought it would be interesting to ask the corresponding one here.

It intrigues me how people from other cultures like Hinduism, Confucianism, Buddhism or any of the isms are more readily accepted anywhere than the Jewish people.

What makes it all the more intriguing is the scope and age of the phenomenon. If it were an isolated thing confined to a single time and location, one could discount it as hand of fate or randomness of nature.

However to my knowledge it is much more pervasive than that. It seems to be present from the times of Haman and Mordecai to right until the present times in different parts of the world.

Is there a reason behind this? (Both religious and non-religious perspectives welcome.)

halacha - Bitcoin and Halakha

What are the halakhot that apply to bitcoin? Is it halakhickly money? What even is the halakhic definition of money? Can bitcoin transactions be made over shabbat? That sort of thing.

Answer

http://www.ou.org/torah/tt/5763/korach63/specialfeatures_mitzvot.htm

Jewish law distinguishes three categories of value: goods, which have inherent value; a note, which is a promise of value from a particular individual; and money, which is abstract value.

You might think that Gold and Silver coins have inherent not abstract value, but as the Chazon Ish said, Gold and Silver have no actual material use. People want them only because they are rare, and that means they have abstract value.

Bitcoin, and the balance in your electronic bank account, are the same: They have only abstract value, and are therefor money in halacha.

PS. It would be pretty hard to actually spend bitcoins on Shabbos since they are electronic only.

physical chemistry - Why is the enthalpy of vaporization greater than the enthalpy of fusion?

Why is the molar enthalpy of vaporization of a substance larger than its molar enthalpy of fusion (at constant pressure); for example, in the case of ice and water.

filters - Plot the frequency response of MTI delay line canceller using Octave

I try to plot the frequency response of the delay line canceller (FIR filter which used for MTI).

The delay line canceller has the following structure:

              +-----+
              |     |
x [k] >---+---|  T  |
          |   |     |
          |   +-----+

          |      |
          |   +-----+
          |   |     |
          |   |x -1 |
          |   |     |
          |   +-----+
          |      |
          |   +-----+
          |   | ___ |
          \---| \   |---> y [k]

              | /__ |
              +-----+

Its frequency response is well known (Pg 20) and equal:

$$H(\omega) = 2 \cdot \left|\sin (\frac{\omega \cdot T} {2})\right| \tag{1}$$

I also try obtain frequency response of the canceller using algorithm which described on this question:

$$y [k] = x [k] - x [k - 1] \tag{2}$$

$$Y (z) = X (z) - X (z) z ^{-1} \tag {3}$$

$$ H(z) = 1 - z^{-1} \tag{4}$$

Now I try to plot (using GNU Octave) both of responses (1) and (4).

w = linspace (0, 2 * pi, 100);
z = exp (-j .* w);

H_z = 1 - z .^ -1;
H_w = 2.0 * abs (sin (w / 2) );

hold ("on");
plot (w, H_z, "1", "linewidth", 2);
plot (w, H_w, "2", "linewidth", 2);
title ("Frequency response of the delay line canceler.");

set (gca, 'XTick',     0: pi / 2: 2 * pi)
set (gca, 'XTickLabel',{'0', 'pi / 2', 'pi', '3 pi / 2','2 pi'})
xlabel ("Angular frequency.");
ylabel ("Magnitude.");
legend ("H (z)", 'H (\omega)');

I expect that they will be the same, but they are different.

Where is my mistake?

P.S. If I add modulus for (4) (like: H_z = abs (1 - z .^ -1);) they will became the same.

Answer

Magnitude |H(z)| is always defined as an absolute value of your transfer function H(z) values which are complex. What you are plotting is the vector that contains complex numbers. You need to take their absolute value and that will give you magnitude.

If you call the angle function then you are going to get phase. Transfer function H(z) is always complex. Try to print values of real(H_z) and imag(H_z), then you will see real and imaginary values of $H(z)$. Now magnitude |H(z)| is sqrt(real * real + imag * imag) for every sample...

grammar dikduk - Plural of "Nafka Minah"

(Inspired by HodofHod's commment here: Four Holy Cities)

What is the proper plural for the common Aramaic phrase Nafka Minah נפקא מינה which means something along the line of "practical differences"?

As in "This distinction leads to multiple XXXXX XXXX."

Nafkot Minah? Nafkei Minah? Nafka Minam?

Answer

Grammatically, I guess "nafkei minah" would have to be the correct plural if there are two practical differences emerging from one distinction, or "nafkei minayhu" if they're completely disjoint. (See Avodah Zarah 28b and Shabbos 23b, respectively, although in neither place is the expression being used in the sense of "a practical difference or outcome.")

However, HodofHod is right: it's definitely not a noun in Aramaic - it's basically an adjectival phrase. So we might analogize it to words from Latin that have become nouns in English ("omnibus" and "virus," for example), which correctly use English plurals. So here, the plural would be "nafka minahs" (or for Israelis, I guess, "nafka minot").

halacha - Must the top of a sukkah be level?

I saw this question about a portable sukkah and I immediately thought of those pop-up canopies that you sometimes see at picnics and the like. The canopy has a metal or plastic frame that folds up and a (usually plastic) cover over the top. I've seen ones where the cover can be removed.

This seems like a reasonable basis for a portable sukkah except for one thing: these canopies have a peak in the center (to shed rain). That would make it difficult to have the s'chach level with the ground:

And that made me wonder:
Is the s'chach required to be level?

Or is a sukkah allowed to have a peaked or pointed roof?

Assume, for purposes of this question, kosher supporting materials and a means of attaching s'chach to a slanted frame; I'm just asking about the legality of the shape.

---

(A similar question arises with a palapa, a temporary structure with a convex roof but does not question the validity of the slanted roof rather the validity of the structure itself if perched in a place that will destroy the succcah e.g sea shore.)

Answer

This is addressed in Shulchan Aruch Orach Chaim 631,10:

סוכה שאין לה גג כגון שהיו ראשי הדפנות דבוקות זו בזו כמין צריף או שסמך ראש הדופן של סוכה לכותל פסולה ואם היה לה גג אפילו טפח או שהגביה הדופן הסמוך לכותל מן הקרקע טפח הרי זו כשרה. הגה: וצריך שיהיה בה שבעה טפחים על שבעה בגובה עשרה טפחים (טור)
A Succah without a flat roof at all e.g the entire walls slant and meet in the middle like a tent, alternatively one wall is slanted against a straight wall is Invalid. But if there was a section of roof flat roof even a Tefach (Hand-breadth )alternatively the slanted wall(s) rested on a vertical wall with a length of a tefach form the ground this is Kosher. Rema: But we need a volume of 7 by 7 tefachim with a height of 10 tefachim within these slanted walls (that have a tefach horizontal roof with sechach or vertical wall).

So yes your gazebo has straight walls much larger than 1 tefach (and the volume of a gazebo is much larger than 7x7x10), so putting the Sechach on the slanted sections of the roof makes it Kosher with 3 walls.

product recommendation - Where could an extreme ultra-orthodox baal t'shuva etc. realistically find a shidduch?

When it comes to shidduchim, the extreme ultra-orthodox (both chassidim and non-chassidim) often seem to discriminate against equally (or even more) religious (children of) baalei t'shuva, gerim, persons of color, b'nei niddah, and others of "lesser yichus".

Lev Tahor is an example of an extreme ultra-orthodox chassidic community that makes shidduchim regardless of yichus, etc. However that community is both controversial and remote.

Where could an extreme ultra-orthodox baal t'shuva realistically find a shidduch?

---

^{Note: This question is asked out of curiosity, as I am happily married, B"H.}

Answer

Generally with other ulta-orthodox baalei t'shuva or other people with similar backgrounds. That is a good idea, regardless, as the compatibility is more likely to be there. (The only exception to your list is persons of color - my observation is that they tend to find a person of a different color who doesn't have a hangup about it).

In addition, There are other members of the community that aren't on the "inside track" of shidduchim with which to make a shidduch, such as children of ba'alei Teshuva, etc. Compatibility has a lot to do with the age at which the person became a ba'al teshuva. If they started at 13/14 years old, and went through the regular school system at the end of their school years, it is very different than the 30 year old.

The main problem with this is that there is some view that those who are frum from birth from families with a long history of observance are somehow an inherently superior shidduch for a ba'al teshuva. In fact, compatibility in their life together is much more important.

In terms of where to find a Shadchan to make such a shidduch, the way to look is to find recently married people of similar circumstances and ask them how they made their shidduch, and follow those leads. You can also ask people who aren't married in a similar circumstance - perhaps they found a lead and are "in the parsha".

In the type of groups you are talking about, there are always people in the group who are very into knowing who is related to who and how they form the circle of the group (call it Olympic level Jewish geography). As such, some people always know who the Ba'al Teshuva is, so you can find out by asking around.

I am reminded of a story where a Ba'al Teshuva wrote to the Lubavitcher Rebbe that he was having a hard time finding a shidduch for his children. The Rebbe wrote him back that the other Chassidim he inherited from his father-in-law, the Ba'alei Teshuva he chose as Chassidim.

I'll tell you another story about someone I know who is in a Chabad community. He is not a Ba'al Teshuva at all (from a long line of non-Chabad Chassidim with many generations of Yichus) however he had a hard time with a Shidduch for his son because he kept the traditional clothing - streimel, etc. which was out of the norm for a Chabad family. So he looked for a Shidduch in Chassidic communities that demand large dowries from the girls (there is no such thing in Chabad circles). He found a good family that happened to be poor - and they were more than happy to make the Shidduch.

Anyway, the bottom line is that there are many such shidduchim made all the time, where people don't fit the pre-defined mold, and shadchanim who specialize in them. However, there does need to be an adjustment of expectations, which is a good thing for a happy marriage.

intermolecular forces - How do non-polar substances dissolve in non-polar solvents?

The case of polar solvents is clear to me - we get an attraction between opposite charges. However, how do non-polar substances dissolve in non-polar solvents? How could it be explained on a molecular level?

Answer

The electron density distribution in molecules (including nonpolar ones) is not static. Therefor, as a function of time, the electron density is not uniform. Occasionally, randomly, the electron density in a molecule will shift to produce a spontaneous dipole: part of the molecule now has more electron density ($\delta^-$) and part of the molecule now has less electron density ($\delta^+$). This spontaneous dipole is transient. The electron density will shift back to negate it and then shift again to create a new spontaneous dipole. In a vacuum, this behavior would be a curiosity.

In the presence of other molecules, these spontaneous dipoles have a propagating effect. If molecule A develops a spontaneous dipole, then the electron density in neighboring molecule B will by respond by developing a spontaneous (but opposite) dipole. The $\delta^+$ region of B will be close to the $\delta^-$ region of A. This new dipole in molecule B is an induced dipole. This induced dipole in B will then induce a new induced dipole in another neighboring molecule C. By this time the transient dipole in A is already fading, perhaps to be replaced by a new induced dipole from another molecule.

These random, transient, but continuously propagating dipoles have attractive forces associated with them. These forces are named London dispersion forces after the physicist who proposed them. The magnitude of these forces scales with increasing surface area of the molecule. Thus, larger molecules will overall have stronger London dispersion forces than smaller molecules. Linear rod-like molecules will have stronger forces than spherical molecules (spheres having the smallest surface area to volume ratio of the 3-dimensional solids).

More complex attractive forces also arise from nonpolar molecules. Benzene (and other aromatic molecules) can pi stack, which relies on the strong permanent electric quadrupole. Benzene also has a (weak but) permanent magnetic dipole due to its ring current, so some component of the attraction between benzene molecules may be magnetic and not coulombic. Or, the two attractions may be one and the same, as benzene's electric quadrupole may result from its having a magnetic dipole. As his part of the discussion is devolving into physics, I will end here.

historical figures - Did what David do to Batsheba and Uriah technically legal (not sin?)

David is a king.

Uriah is fighting for him.

As a King David has right to send any of his soldiers to any missions. Presumably that includes suicidal mission.

It is possible that Batsheba is not even technically Uriah's wife. I've heard about something called retroactive divorce.

Let's presume that Batsheba is not technically Uriah's wife at that time. Is what David do technically a sin?

This is discussed here: https://hermeneutics.stackexchange.com/questions/4587/to-what-extent-is-psalm-514-poetic-exaggeration

First, remember that David was king, and as king he answered to no one but G-d. He could have ordered Uriah killed on whatever pretext and then taken Bat-Sheva. He had that authority. Instead, what he did was rely on the fact that Jewish soldiers going into battle are required to give their wives conditional retroactive divorce papers which in effect say: "I divorce you effective today if I do not return from war by next month." Babyl. Talmud, Shab. 56a. As king, David could order any of his soldiers on a suicide mission without apology. And because of the retroactive divorce given to Bat-Sheva, David technically did not commit adultery with her as she was divorced. But, as Nathan pointed out, whether or not he was legally permitted to do all that he did, G-d had warned him to be better than that. Accordingly, he owed no apology to anyone (and could not apologize to the deceased Uriah) but G-d.

Now what about if Batsheba is indeed Uriah's wife? Why God demand such a light punishment against Dave? Shouldn't they both be stoned to death?

We probably have issue whether the sex is consensual or rape. Torah seems to punish married rape victim even if the sex is not consensual if the rape happens in town and the woman doesn't scream (reference needed). So Batsheba should be stoned too.

Some think David didn't commit any sin at all http://torahideals.com/essays-and-imaginings/david-and-bathsheba/

When Uriah was called before David, he made reference to his general as “my master, Joab” (2 Samuel 11:11). Although this form of address would have been proper in the presence of his commanding officer, referring to anyone other than the king as master in the presence of the king himself constituted an act of rebellion punishable by death.7 Uriah also disobeyed David’s order to return home to his wife.8 On two separate counts, therefore, Uriah placed himself in the category of mored b’malchus, a rebel against the king. As such, Uriah forfeited his life immediately since the extralegal powers of the monarch include the authority to invoke the death penalty upon rebels without the due process of law.9

We got two possibilities:

1. Either David, as king, commit a crime/sin and didn't get punished for it.


2. Or a jewish king (like pretty much any king at that time) can pretty much grab anyone's wife without even breaking the law.

Neither is good for the peasant. In any case, which one is right?

Answer

I think all commentaries agree that dovid did not actually technically commit the sin of adultery. As to why this is, either Uriah was actually divorced or conditionally divorced (which took effect retroactiy when he didn't come back). Uriah was mored bamolchus (either because he called yoav a "master" in front of dovid or because he didn't listen to dovid to go home) and so dovid had the right to have him killed. At the time that dovid and batsheva had relations Uriah was technically divorced. The question is SHOULD he have done what he did. Just for his being mored bamolchus he wouldn't have had Uriah killed it's only because he wanted his wife. While they were technically divorced, everyone understood that they weren't getting divorced because they wanted to seperated but as to not cause agunos. So when dovid and batsheva had relations was when Uriah was still alive and so dovid was in a ethical sense stealing his wife. Or according to the understanding that it was a retroactive divorce then batsheva was at that point in time still married to Uriah as only once Uriah was kille was it "revealed" that they had been divorced however long ago. So while dovid didn't technically sin according to the letter of the law he did commit some ethical crime.