history - How do we know that the civil Saturday is the correct Shabbat?

Disclaimer: I am not a religious Jew, this question is only out of curiosity.

I understand that observant Jews observe Shabbat from Friday night to Saturday. And from this question and this it seems that it is important that this happens on the correct and accurate time of week.

My question is, how do you know that the Saturday that everyone is using is correct (as in, exactly 7*x days after God's rest day)? Is there any record on who began declaring that Monday is Monday, etc. until it is used by today's civil calendar? And how can we know that the sequence is never broken? (for example, the sequence of calendar time of year was broken when there is a switch from the Julian calendar to Gregorian calendar)

halacha - Depicting a constellation

Assuming the intention is at least partly for educational purposes, Is it mutar to arrange star stickers in the form of actual constellations (say, on a ceiling) or is that included in the prohibition of depicting celestial bodies?

grammar - Meaning of pattern 「XがXなら、YもYだ」

While reading, I came across this sentence:

「上官が上官なら部下も部下だな」

What does this 「XがXなら、YもYだ」 pattern mean? "Like X, like Y"? "X will be X, and Y will be Y"?

Answer

“XがXならYもYだ” means that X is bad in some sense and it explains that Y is bad in the same way. Therefore 上官が上官なら部下も部下だ can be translated as “like officer, like his subordinate,” but it is only used to mean the similarity in something bad.

halacha - Can someone who takes out the Torah also get an Aliyah?

Can someone who gets the honor of taking out the Sefer Torah also get an Aliyah? I ask because perhaps there is an idea that someone should only get one Kavod by Sefer Torah.

grammar - ～ないでいる verb ending

This is dialogue from a book I have, where a doctor is talking about a patient:

気分が極端に変りやすくなっていて、自分で自分をコントロールできない。神を呪うかと思うと、神に祈る。呪う自分と祈る自分と、絶えず入れ替っていて、どっちが本当の自分か判断できないでいる。

My question is about the way the final verb is conjugated. I am familiar with the ている form for verbs that are not negated, like 「できている」, and I've also seen cases where でいる seems to be used similar to the copula である, for example 「好きでいる」.

In this sentence, is できないでいる just simply できない in the ている form (using できないで rather than できなくて)? Is there any connection with things such as 好きでいる, or is that different?

Answer

This usage of いる is unrelated to its usual function as a grammar element.

〜ている

食事を食べている
"I am eating my meal" (progressive)
"I eat meals" (habitual)
?? "I eat my meal and I am here (/I exist)" (conjunction)

Reading #3 is never used because no one would ever need to say that. I included it only to show that the て-form does normally perform a conjunction function, it's just very marginal here.

〜ていない

食事を食べていない
"I am not eating my meal" (progressive)

"I do not eat meals" (habitual)
?? "I eat my meal and I am here (/I exist)" (conjunction)

Again, reading #3 is a terrible way to read this sentence and is essentially wrong.

〜なくている

食事を食べなくている
?? "I do not eat my meal and I am here (/I exist)" (conjunction)

This form is never used because there's never a need to say this.

〜ないでいる

食事を食べないでいる
"I am here (/I exist) without eating my meal." (state adjunct)
"I am here (/I exist) by not eating my meal." (instrumental adjunct)

Reading #1 is Lit. "I am here, in the state of not eating my meal." (It's reminiscent of the stative function 〜ている often performs, but it's slightly different — here, いる is actually still a full-fledged verb and you can't drop the "exist" meaning.)

---

In the case of your sentence, context suggests that it's a state adjunct, not an instrumental adjunct; another way to write this form is できずにいる.

physical chemistry - Why is the relative atomic mass of carbon not exactly 12?

Relative atomic masses of atoms of all chemical elements are numbers without units, being the value of proportion compared to $\frac{1}{12}^\text{th}$ the mass of the carbon atom.

But the relative atomic mass of carbon is never 12! Instead, it is 12.01 or, more accurately, 12.011.

Why is this so?

Answer

Simply because the atomic mass is defined as 1/12 of the mass of ¹²C. Others isotopes of carbon (¹³C mostly, with an abundance of 1.1% approximately) account for an average atomic mass slightly above 12.

minor katan child - Why not focus on halacha in elementary education?

From the Mishna B'rura's introduction to the rules of Shabas:

…But by what means can we arrive at this level: that one keeps Shabas in all its details? The advice on this is that one urge himself to study the rules of Shabas and to review them always so he knows what's forbidden and what's permitted. Without that, even if he learns all the exhortatory things that urge one to keep Shabas properly, that won't help him.… [Rabbi Yonasan Eybeschutz] already assured us that it is utterly impossible in practice to be saved from committing a Shabas prohibition unless he learns all the rules very well.

I seem to recall a similar idea written about the rules of lashon hara — and, indeed, much the same can be said about many areas of halacha.

Considering that a twelve- or thirteen-year-old is obliged to follow all the details of halacha, it would seem, therefore, to behoove elementary-school teachers to focus on halacha to the extent that their students will retain it. Yet we don't find teachers doing so: halacha is relegated to perhaps four hours a week. Why is this?

kashrut kosher - Why doesn't Kellogg's print the symbol of their certifying agency on their boxes

^{I have separated my previous question about Kellogg's cereals into different posts based on the comments on that question.}

The cRc recommends Kellogg's cereals with only a k on the box. In my experience, I have not heard of anybody who disagrees with this. This is an unusual situation, though, since normally a plain k does not indicate reliable kashrut supervision. Apparently those cereals are under the supervision of the Rabbinical Council of New England (see linked question), but for some reason Kellogg's does not mark the boxes as being under their certification.

The Rabbinical Council of New England actually has its own logo which looks like this:

I have seen the KVH logo on restaurants in Boston such as Cafe Eilat which the Young Israel of Brookline lists as kosher. This in addition to the fact that well-known organizations stand by their certification of Kellogg's foods indicates to me that they seem to indeed be a reliable kashrut organization. So why doesn't their logo appear on Kellogg's cereal boxes?

I do not believe that the reason is simply because the symbol is less well-known (compared to OU or OK). A hechsher that some people would have to look up still seems better than something that is not a real hechsher at all.

I also don't believe that the reason is so that they can change at any time (as suggested in the comments on the other post). Kellogg's does print OU and OK on products certified by those organizations, and the same rule should apply. In any case, I just don't see what is gained by printing a K rather than KVH.

homework - Acidity In Organic Compounds

Why is the acidity order true? \[\ce{CH3COCH3 > CH3CO2CH3 > CH3CON(CH3)2}\]

I deduced that in second and third option there is a $-I$ effect of the methoxy group, $\ce{N(CH3)2}$ and a $+R$ effect, too so the attached keto-carbon develops a positive charge and the conjugate base becomes unstable due to the $+R$ effect of methoxy and $\ce{N(CH3)2}$ groups.

Is my logic right?

Please tell me any explanation you can think of.

quantum chemistry - Calculate the wavelength of the radiation released when an electron moves from n= 5 to n=2

Calculate the wavelength of the radiation released when an electron in a hydrogen atom moves from $n = 5$ to $n = 2$.

How can I find this wavelength?

history - If I wanted to sound more like a Samurai, what words and phrases should I learn?

Having watched jidai-geki for a long time, I have come across many Samurai-isms, but I can recall only a few. I would like to be able to do this more believably the next time I'm at the Izakaya.

What words and phrases are most commonly heard in jidai geki or period anime that would achieve this goal?

Answer

Well, there is indeed a stereotypical "Samurai way of talking" that you can see in Samurai films or in historical dramas (時代劇, Jidaigeki) on TV, but it's far from being authentic. In fact, Samurai talked in many different ways, depending on the era and their home province (after all, they were speaking in their dialect).

As far as I know, the stereotypical Samurai speech in Jidaigeki is actually based on the Edo dialect of late Edo period. Many of the mannerisms you'd find in this speech do not specifically represent Samurai, but rather a typical resident of Edo in that particular time.

The most striking feature of this speech is the complete absence of the modern ～ます forms, which are sometimes replaced by other polite forms, but very often find Keigo used with plain forms. The most noticeable alternative polite form of this Edo-jidai speech is probably the polite/humble copula で御座る which is often used wholesale instead of any other copula. Just note that is copula is considered humble, so usually when speaking about someone else (at least someone you'd want to respectful to :)), you'd use the honorific copula でいらっしゃる instead of で御座る. For instance:

拙者は侍でござる。

But when asking someone else for their name:

どなたでいらっしゃるか？

Note the first-person pronoun I used in the first example. 拙者 (せっしゃ) also highly identified with Samurai speech. It literally means something like "clumsy person", so it's a humble pronoun of course. In Jidaigeki, some Samurai use it, but the more haughty ones would probably use a different pronoun, such as おれ。

Another personal pronoun that's highly identified with Samurai speech is the second person pronoun お主. Again, you won't see every Jidaigeki Samurai using it, but it's highly stereotypical.

orthography - Are there rules for when 'e' becomes 'a' in compound words?

For example:

• て＋つな＝たづな（手綱）


• め＋ふた＝まぶた（瞼・目蓋）


• かね＋つち＝かなづち（金槌）

The only thing I can see for sure is that the second word becomes voiced, but that's more of an after-the-fact thing than a rule that dictates when the sound actually changes from e to a.

Is there a rule or pattern to it?

Answer

e does not become a. Rather, it is the other way around: a becomes e. More specifically, there are two forms of e: e₁ and e₂. (See 上代特殊仮名遣) The rule is a + i > e₂. Both e₁ and e₂ merge into e after Nara period.

For reference, these pairs are termed 被覆形 and 露出形. The form without the -i suffix is 被覆形 while the -i suffixed form is 露出形.

parshanut torah comment - (Neis) Miracle of Sarah giving birth at 90

We all know how in Parshas Vayeira the miracle of Sarah giving birth @ 90 takes place. In Mitzrayim Yocheved gave birth @ 130 yet there is no mention of this. Was it not a bigger miracle? Then why is it not mentioned?

Answer

Indeed, because of this Ibn Ezra (to Gen. 46:27) argues that Yocheved was not in fact born when they entered Egypt, but some time later, so that she bore Moshe at a normal age.

However, Ramban (ibid. v. 15) sharply disagrees with him (he goes so far as to use the semi-derogatory expression יוצק זהב רותח בפי החכם הזה!), and points out that since (a) Yocheved was the literal daughter of Levi (as per Num. 26:59), (b) 130 years passed from when they came to Egypt until Moshe was born, and (c) Levi was a grown man (in his forties) when they came down to Egypt - then there had to have been some kind of miracle here: either Levi fathered Yocheved, or Yocheved bore Moshe, at a very advanced age.

So he goes on to distinguish between miracles that Hashem performs (as sort of "standard operating procedure") to help righteous people or to destroy the wicked, which are not generally described explicitly in Tanach, versus those that are foretold by a prophet or an angel sent by G-d. Sarah's being able to bear children at 90 - and this, after decades of infertility - is a miracle of the latter type; Yocheved's bearing Moshe at 130 is of the former, and so it needn't be described in the Torah.

electronic configuration - How does radiation facilitate the formation of tetravalent iron?

In reading the article abstract What Oxidation State of Iron Determines the Amethyst Colour?, the author states that in regards to the gemstone amethyst, from clear quartz:

The crystal was transformed into violet amethyst by gamma-irradiation. The change in colour was accompanied by changes in the Mössbauer spectrum that can be interpreted as the conversion of trivalent iron into the tetravalent state: $\ce{Fe^{3+}→Fe^{4+}}$

How does gamma radiation facilitate the conversion of oxidation state of iron, from $\ce{Fe^{3+}}$ to $\ce{Fe^{4+}}$?

Answer

The ionization energy of $\ce{Fe^3+}$ to $\ce{Fe^4+}$ is 54.8 eV.
The energy of typical gamma radiation is much higher (in the order of roughly some keV to a few MeV). Depending on the energy, the interaction of average gamma radiation with the affected electron is mainly due to Compton scattering.

halacha - Does golel for first torah stand for second torah?

When there are two or three sifrei torah read on the same day, either the magbiah or golel holds the first sefer while the second is read. In this case should he stand for…

1. kadish after reading from the second sefer?


2. Hagbah for the second sefer?

I have no halachik reason to think he should/shouldn’t, I just think that I’ve seen most people sit through both and I can’t figure out why.

There have been a bunch of suggestions in the comments section that he doesn't stand out of respect to the second sefer (Why should one have to stand for the other?). I like the answer, but if some sort of authoritative source could be found that would be better.

Answer

The Chidah in Shu"t Chaim Sha'al 1:71:2 brings down that if one is sitting and holding a sefer Torah and a Rebbe passes by one should not get up.

Also, I believe if one sits with a Torah during hakafos it is fine.

halacha - Displaying Torah Fragments on a Wall

Assume the following: A Torah scroll has gone into such disrepair that it could not be made Kasher again. Rather than burying the remaining leaves that are still usable, they are sold off as art pieces. If someone were to display one of these leaves from an old retired Torah scroll, what things would need to be considered? Assume that the divine name is on the leaf or leaves.

There is another question similar to mine which asks what happens when a Torah's life ends, and that it is forbidden to use a Torah as art. However, that doesn't answer the question of it the Torah fragment is already being used as art, what precautions should one take?

Answer

I just received an email about a similar question from Yagdil Torah

Place: Lausanne, Switzerland. Date: 1963

The Swiss government once decided to put together an exhibition including various artifacts and items of interest which would be displayed before the public. One of the items they wanted to display was a sefer Torah, and they asked Rabbi Schwartz, a Rabbi in one of the local communities, for permission to borrow a sefer Torah from the shul. Was it permitted to hand over a sefer Torah to be displayed as an exhibit?

Rabbi Schwartz posed this question to R. Yechiel Yaakov Weinberg, from the nearby city of Montreaux. R. Weinberg confirmed Rabbi Schwartz's reservations about transporting a sefer Torah to another location where it will not be used for kriah purposes (see Shulchan Aruch, Orach Chaim 135:14 and commentaries ad loc.). In fact, there are two more halachic considerations as well: one may not give a sefer Torah to a non-Jew, and one may not leave a sefer Torah open, as would be done if it would be displayed as an exhibit (see Shach, Yoreh Dei'ah 277:1).

However, in this case, the government would take it as an insult if their request would be denied. Furthermore, this exhibit would create a kiddush Hashem, as it would give hundreds of non-Jews the chance to view and appreciate the sefer Torah. On these grounds, R. Weinberg ruled that it would be permitted to allow them to borrow a sefer Torah. He added that there are two reasons why there is room for leniency:

1. 
   

   It was once an accepted practice to take out a sefer Torah to honor a king (see Pischei Teshuvah, Yoreh Dei'ah 282:1). Nowadays, the government has the same status as the kings of old, and one may remove a sefer Torah from shul to heed their bidding.

   
   


2. 
   
   

   One may remove a sefer Torah from shul to show its beauty to others (see Shu"t Gur Aryeh Yehudah, Yoreh Dei'ah §24).

   
   

However, R. Weinberg adds a number of stipulations that should be kept. First of all, they should choose a sefer Torah that is possul to be displayed, and preferably one with a pessul that cannot be corrected. Second, Jews from Lausanne should visit the exhibit on a daily basis and read from the open portion of the sefer Torah without a berachah.

Shu"t Seridei Eish 2:79 (old print: 3:98)

---

Rabbi Schwartz posed this question to R. Yechiel Yaakov Weinberg, from the nearby city of Montreaux. R. Weinberg confirmed Rabbi Schwartz's reservations about transporting a sefer Torah to another location where it will not be used for kriah purposes (see Shulchan Aruch, Orach Chaim 135:14 and commentaries ad loc.). In fact, there are two more halachic considerations as well: one may not give a sefer Torah to a non-Jew, and one may not leave a sefer Torah open, as would be done if it would be displayed as an exhibit (see Shach, Yoreh Dei'ah 277:1).

• 1 and 3 still apply in this case, but 2 (giving the Torah to a non-Jew) may not

However, in this case, the government would take it as an insult if their request would be denied.

• In this case, the government isn't offended as it's not involved

Furthermore, this exhibit would create a kiddush Hashem, as it would give hundreds of non-Jews the chance to view and appreciate the sefer Torah.

*depends on who visits your house :)

On these grounds, R. Weinberg ruled that it would be permitted to allow them to borrow a sefer Torah. He added that there are two reasons why there is room for leniency:

It was once an accepted practice to take out a sefer Torah to honor a king (see Pischei Teshuvah, Yoreh Dei'ah 282:1). Nowadays, the government has the same status as the kings of old, and one may remove a sefer Torah from shul to heed their bidding.

• No king involved

One may remove a sefer Torah from shul to show its beauty to others (see Shu"t Gur Aryeh Yehudah, Yoreh Dei'ah §24).

• May still be true

minhag - Why do almost all Chabad shuls always use the same tunes for certain parts of davening?

I have noticed that at pretty much every Chabad shul I have ever attended, the same tunes were always used for certain parts of davening on Shabbos. For example, they all use the same tune for ha-aderet v'ha-emunah during psukei d'zimra as well as for the line in the kedusha for musaf that begins hu Elokeinu, hu avinu. They also all use the same tune for ata bechartanu during yamim tovim. Every Chabad shul also seems to sing al tira... at the end of davening, although I have noticed variations in the tune used.

Here are the tunes
- Hu Elokeinu
- Ata Bechartanu

Is there a reason why almost every Chabad shul seems to use these tunes for these parts of davening? What is the origin of the tunes? Were they favorite niggunim of one of the rebbes? How long have Chabad shuls used these uniform tunes?

Answer

Hu Elokeinu and Ato Vechartonu were introduced by the Rebbe and was always song in the Rebbe's presence. Hoaderes Vehoemuna -French National Anthem- was also introduced by the Rebbe but the other tune (the one that many Shuls use by Hakofos on Simchas Torah) was more common even during the Rebbe's presence.

Keily Attah (end of Hallel) was composed by the Alter Rebbe (first Chabad Rebbe).

Birkas Kohanim was composed by the Miteler Rebbe (second Chabad Rebbe)'s choir.

There are also Rosh Hashanah & Yom Kippur songs that they will sing in all Chabad Shuls like Hayom Teamtzeinu (which the Rebbe introduced as his father's Simchas Torah Niggun), Ovinu Malkeinu (composed by the Alter Rebbe), Mar'ei Kohen (Avodah YK) is not a "Rebbe song" but it was the song/tune used in the Rebbe's presence, Napolean March (sung at the very end of YK) was introduced by the Alter Rebbe. What it boilsdown to is either a Niggun introduced/composed by a Rebbe or was always the exclusive tune used the Rebbe's presence.

halacha - Is a child born to a kidnapper also considered kidnapped?

According to Torah law if a man kidnaps a woman and has a child with her is that child now considered kidnapped as well? The question being has the man now violated the prohibition of kidnapping twice.

halacha - sperm donation and p'ru ur'vu

Does donating sperm to a woman who is not your wife (who then goes on to bear children from it) fulfill the mitzvah of p'ru ur'vu?

Alternatively, is it a violation of halakha? Does it matter whose the egg is?

image processing - Gradient Domain Reconstruction - Scaling Problem

I am implementing reconstruction of image from gradient domain. This requires solving the following partial differential equation (a Poisson equation) on a 2D grid:

$$\nabla^{2}I=\mathbb{div} G$$

$\mathbb{div} G$ is divergence of a gradient field, which is simply an image with Laplacian operator applied (second-order derivative):

The original image have range of values 0 to 255 (8-bit image). The divergence image has values ranging from -341 to +318, which is expected.

However, when I solve the above equation for $I$, the result have very small scale. The values of reconstructed image range from -0.000038 to +0.000029.

I know the gradient domain stores information up to a constant. In this case however, the scale has been changed considerably.

When I stretch the reconstructed image to 0-255 interval, the correct result is obtained:

I am using Poisson solver based on the Full Multigrid Method (FMG) which works spectacularly in different application (HDR images). Here the values are stretched anyway so I never noticed the huge change of scale.

Is this scale change normal for gradient domain reconstruction or may there be

My ideas:

1. Some glitch in the numerical solution.


2. The $\mathbb{div} G$ image is padded with zeros so its size conforms with the solver - could this affect the scale?

Is acetate a weak base due to its resonance structure?

I just read that acetic acid is an exception to the general idea that the conjugate base to a weak acid is a strong base. The example says that the conjugate base of a weak acid will only be strong if the acid is a weaker acid than water.

What I'm curious about though, is if acetate is a weak base due to its resonance structure. Does the resonance cause acetate to be more stable than hydrogen acetate?

Is this true in the more general case where some substituent can bond to the atoms involved in the resonance?

Thanks.

Answer

Consider this generic acid-base reaction in water: $$\ce{HA <=>[K_\text{a}] A- + H+ }$$

The (thermodynamic) dissociation constant $K_\text{a}$ depends mainly on two things:

• The stability of the product $\ce{A-}$


• The instability of the starting material $\ce{HA}$

The higher one of those factors is, the higher the dissociation constant. So in effect, what a chemist states is the following:

The carboxylate anion is the conjugated base of the carboxylic acid, whose strength is determined by the stability of said carboxylate ion and the instability of the acid. It may be reasoned that carboxylic acids would be much less strong if it was not for the additional stability via conjugation.

grammar - What is this と?

芸術家は芸術を仕事としている人。

Concerning an artist, it is a person who does art for a living (=as a job).

I didn't encounter と in this kind of function yet, or at least not often enough to remember it. Did I translate this correctly?

Answer

「Noun A + を + Noun B + と + する」

means:

"to regard A as B"

"to let A be B"

"to treat A as B", etc.

Thus, your translation is not bad at all.

translation - How do I translate 「コロッと転がってたりする」 to english?

I've encountered the following sentence in a game:

時には後ろを振り返ると案外役に立つ事がコロッと転がってたりするもんだ。

First, I'd like to understand why the "to" in コロッと isn't in katakana like the rest of the word, why the dictionary writes it all in hiragana (http://jisho.org/search/korotto). Maybe I got the wrong word?
But regardless of that, how do I put that part of the sentence into words? I seem to have it in my mind, but can't quite say it in english.

Answer

This コロッと isn't really describing the quality of the thing itself, I mean, it is, but much more reflecting the speaker's impression or observation.

In your example, 転がっている alone can fully depict the situation, "it's lying on the ground". The remainder, コロッと and ～たりする both represent the speaker's mood.

コロッと implies (of course not round or rolling-ness here) something exists there as casually, unattendedly as a roadside pebble. In other word, it's actually a rhetoric attributing one's failure to notice to that innocent thing.

たりする is a worth learning colloquial idiom that derives from たり of probability or exemplification. It means "sometimes could happen/do", "do — or something" or "things such like — happen".

bond - Why isn't water an ionic compound?

If two alkali metal atoms join with an oxygen atom, an ionic bond forms. Since hydrogen has the same number of valence electrons as alkali metals, why can't water be ionic?

This is what I'm thinking:

$$ \ce{(H^+)_2O^{2-}} $$

Thank you

Answer

First of all, the difference between ionic and covalent bonds is not sharp. As electronegativity differences increase, you move away from covalent and towards ionic bonds. There are "in between" states like polar covalent, where one side of the bond is stronger but not fully ionic. And this I think is the main reason: hydrogen has fairly high Pauling electronegativity (2.20), rather close to oxygen (3.44), which seems polar covalent overall (and why we get hydrogen bonding with water). In contrast, the alkali metals all have electronegativity less than 1.00, a much bigger difference versus oxygen and thus a more ionic bond.

yom tov - Should a man say Shehecheyanu when lighting Yom Tov candles?

In a situation when a man will both be lighting the Yom Tov candles and making Kiddush, when should he make Shehecheyanu?

Do we say only when lighting candles, since that is when the women say it when they light candles (and perhaps because that is the earliest possible opportunity)?

Do we say that they should only say it when making Kiddush, since that is when it would normally be said?

Or, are there certain times when men would say the blessing both times, such as when the Shehecheyanu in Kiddush also applies to another Mitzvah of the day. For example, would the man say Shehechyanu both when lighting the candles on the second day of Rosh Hashana, and during Kiddush when we are supposed to have in mind a new fruit or garment when saying the Shehecheyanu (Orach Chaim 600:2)?

And, assuming the man is supposed to say it twice, what does he do if already said it when he lit the candles and he doesn't have a new fruit or garment? (Normally Shulchan Aruch says to say it anyway, but in this case he has already said it when he lit the candles)

Take Sukkot as an example. The Shulchan Aruch (Orach Chaim 641:1) tells us that the Shehecheyanu we say on the first night of Sukkot is also being said for the Sukkah. If for some reason you said Shehecheyanu on the first night of Sukkot outside the Sukkah you repeat it the first time you sit in the Sukkah. If so, it would stand to reason that if the man said it when he lit candles he would still repeat it when making Kiddush in the Sukkah. In such a situation, should the man skip it when he lights candles and only say it in Kiddush, or should he say it twice?

Answer

Say it only during kiddush. The women too should only say it during kiddush. Why would one assume the two would be any different? They are both obligated in kiddush and both obligated to have the lights lit. The Talmud in Sukkah (47b) implies already that the shehechiyanu is said with the kiddush. (The Tur OC 519 deems it an "enactment of [the sages] to say it [then].") I see no reason to distinguish between genders.

Some more discussion: The Mishna Brurah (263:23) and Rav Moshe Feinstein (Igros Moshe OC 4:101) both point out that the custom of some women to say shehechiyanu when lighting has no basis, but one does not need to protest against women who do so. Moreover, Rav Ovadiah Yosef (Yechavveh Da'at 3:34) actually recommends stopping the practice because it is preferable to say the shehechiyanu on kiddush (and quotes a slew of opinions who agree with him, as he is wont to do). The only reason it seems that no one has fully condemned the practice is because everyone agrees that the bracha is not levattala: the gemara referenced above explicitly permits one to say shehechiyanu while standing in the market and this is indeed what most men do on Yom Kippur. But it is clear that the ideal time is to say it with kiddush.

I'm not sure why one would continue to teach their daughters this minhag. But all the more so why a man who happens to be lighting candles one yom tov would give up the shehechiyanu on kiddush for candles when there is no reason for him to do so!

grammar - What exactly does the grammatical form NがNなだけに mean?

In my JLPT textbook, it has a section explaining the verb form [Noun]が[Noun]なだけに. By way of explanation, it says that this means, "unlike other things, [Noun] is special, so..."

I'm having a hard time reconciling this explanation with the examples given.

Here is one example provided:

A : 部長{ぶちょう}に連絡{れんらく}しなきゃいけないんだけど、時間{じかん}が時間{じかん}なだけに電話{でんわ}はまずいよね。

B : そうね。とりあえずメールだけ送{おく}っておいて、明日{あした}の朝{あさ}報告{ほうこく}したら？

So... on A's sentence, we need to contact the department head, but "unlike other things", time is "special", and so it would bad to call? It's just kind of nonsensical to me. B's sentence only confuses me more, because apparently we can email tomorrow and that's fine... so it's bad to call now because it's too soon, and better to wait and send an email? To soon how?

Another example given:

状況{じょうきょう}が状況{じょうきょう}なだけに、家族{かぞく}の許可{きょか}をとっている暇{ひま}がない。とにかく手術{しゅじゅつ}を始{はじ}めよう。

In this situation I at least understand what's going on. We don't have time to wait for permission from the family, we should start operating. Okay, but why? Because the circumstances are "unlike other things"? What other things are we comparing to? Other options for trying to help the patient? Other circumstances the patient might have been in?

Intuitively, to me it seems like in this case the way to think of 状況{じょうきょう}が状況{じょうきょう}なだけに is that it conveys an idea similar to, "the circumstances are what they are." In other words, we've got what we've got, so there are no other ways of dealing with it. But that's just my feeling and I've let my intuitions on Japanese grammar mislead me before.

What exactly does [Noun]が[Noun]なだけに mean?

Answer

This may be a weird thing to say but if one already knew what 「[Noun]が[Noun]なだけに」 meant, that explanation in your book would make pretty good sense with minor alterations.

"unlike other things, [Noun] is special, so..."

↓

"unlike other [Noun]s, this particular [Noun] is so special that..."　

「[Noun]が[Noun]なだけに」 describes a special kind of situation requiring an equally special kind of action or treatment.

From the sentence:

「部長に連絡しなきゃいけないんだけど、時間が時間だけに電話はまずいよね。」

One would know that an unexpected event occured very late at night, so it would not be a good idea to call the boss immediately. It does not say "too soon" as you stated. It is saying "too late at night". How do I know? I know from the last part of B's reply --- 「明日の朝報告したら？」 = "Why don't we report to him tomorrow morning?".

To repeat, it is saying:

"unlike other times (of the day) this time (of the day) is special, so ~~"

It is NOT saying:

"unlike other things, this time (of the day) is special, so ~~"

gentiles - Is hamsa allowed?

Does the Halacha allow the use of a hamsa as a good luck charm, considering that it originated as a Muslim symbol?

Answer

Ben Ish Hai (Shana Bet Parashat Pinehas sim. 13) actually endorses the Hamsa.

A few months ago, I asked HaGaon HaRav Meir Elyiahu Shelit"a this question (question 108 on RabiMeir.com):

שמעתי שקדן גדול בהיסטוריה, כי חמסה היא מן התרבות המוסלמית, ולכן החלטתי לתפוס לדעת כי היא, שאסור להשתמש בהם. האם זה נכון

He answered:

צורת החמסה אכן לקוחה מאגדה ערבית ישנה אולם מצינו הרבה מחכמי המערב שהיו משתתפים בצורה זו ואין פוצה פה ומצפצף ופשוט שאין פה משום חוקת הגוים.‏

He admits that it is taken from the Muslims, but since a lot of big rabbis didn't protest but actually promoted it, it is simple to him that there is no Hukot HaGoyim involved.

inorganic chemistry - How is Persian blue rock salt made?

How is Persian blue rock salt made and what does it contain that makes it look blue?

frequency spectrum - "Complex sampling" can break Nyquist?

I have heard anecdotaly that sampling complex signals need not follow Nyquist sampling rates but can actually be gotten away with half Nyquist sampling rates. I am wondering if there is any truth to this?

From Nyquist, we know that to unambiguously sample a signal, we need to sample at least higher than double the bandwidth of that signal. (I am defining bandwidth here as they do in the wiki link, aka, the occupancy of the positive frequency). In other words, if my signal exists from -B to B, I need to sample at least > 2*B to satisfy nyquist. If I mixed this signal up to fc, and wished to do bandpass sampling, I would need to sample at least > 4*B.

This is all great for real signals.

My question is, is there any truth to the statement that a complex baseband signal (aka, one that only exists on one side of the frequency spectrum) need not be sampled at a rate of at least > 2*B, but can in fact be adequately sampled at a rate of at least > B?

(I tend to think that if this is the case this is simply semantics, because you still have to take two samples (one real and one imaginary) per sample time in order to completely represent the rotating phasor, thereby strictly still following Nyquist...)

What are your thoughts?

Answer

Your understanding is correct. If you sample at rate $f_s$, then with real samples only, you can unambiguously represent frequency content in the region $[0, \frac{f_s}{2})$ (although the caveat that allows bandpass sampling still applies). No additional information can be held in the other half of the spectrum when the samples are real, because real signals exhibit conjugate symmetry in the frequency domain; if your signal is real and you know its spectrum from $0$ to $\frac{f_s}{2}$, then you can trivially conclude what the other half of its spectrum is.

There is no such restriction for complex signals, so a complex signal sampled at rate $f_s$ can unambiguously contain content from $-\frac{f_s}{2}$ to $\frac{f_s}{2}$ (for a total bandwidth of $f_s$). As you noted, however, there's not an inherent efficiency improvement to be made here, as each complex sample contains two components (real and imaginary), so while you require half as many samples, each requires twice the amount of data storage, which cancels out any immediate benefit. Complex signals are often used in signal processing, however, where you have problems that map well to that structure (such as in quadrature communications systems).

physical chemistry - Ground state electron configuration of chromium

What is the ground state electron configuration of chromium?

Is it $\ce{[Ar]}4s^23d^4$ or

Is it $\ce{[Ar]}4s^13d^5$

word choice - What's the difference between 値段 and 価格

They're both "price", but I don't see the difference. Even the Kanji appear to suggest similar meanings. Thanks for any advice!

Answer

"値段" (mixed kun-on compound) is a rather colloquial word, used in most part of our daily life. In most cases, 値段 refers to "how much we/you have to pay" in individual transactions, from the viewpoint of those who buy or sell the item.

慌てて買う前に、値段をよく確かめよう。

あのお店でレアなグッズを見つけたけど、値段が高すぎて買えなかったよ。

Using 価格 in casual conversations like these is not incorrect, but sounds a bit unnatural to me.

On the other hand, the usage of "価格" is that of typical 漢語. In serious written articles or business conversations, we mainly use 価格:

原油産出量の増加に伴い、ここ数年、石油の価格は緩徐な下落傾向にある。

「需要」と「供給」という2つの要素が、小売市場における商品の価格を決定づける。

価格 can construct many longer compound words, such as 希望小売価格, 市場価格, 価格調査. I can't think of similar compounds which contain 値段.

meaning - Help with translation, 綺麗事 and 奴の方

Context: Person A has been talking about how they will spend their life making better some wrong by dedicating their life to helping others. In fact it's not really A's fault but something their subordinates did without their knowledge, but A is still accepting responsibility for it. In the course of the incident in question B also did bad things to A as part of trying to stop what A is now taking the blame for.

Person B is, I think, not impressed with it, and might think A is dishonest. So B says:

そんな綺麗事、通じない奴の方が多いぞ。 大人の社会にはな。

As far as I can figure out this means more or less:

Such whitewashing. There are so many people who simply aren't open. In the world of the adults.

But I'm not sure about this at all. For one, the A is really young and could not be considered adult. So I'm not sure what that part is supposed to indicate? That there are people who are dishonest in the adult world too?

Also I'm not sure what the 奴{やつ}の方 construct is supposed to mean. Right now I consider 方 to be used here in it's "side of argument/group" type of meaning. So "other group of people" would be the meant meaning here. Possibly indicating that the speaker is not one of these people. But I'm not sure at all.

And I assume 綺麗事 is just B saying to A that they are whitewashing events, that is they aren't being honest.

Answer

「そんな綺麗事{きれいごと}、通{つう}じない奴{やつ}の方{ほう}が多{おお}いぞ。 大人{おとな}の社会{しゃかい}にはな。」

And your TL of that is:

"Such whitewashing. There are so many people who simply aren't open. In the world of the adults."

The first thing I would like to point out is the possibility that you might not be parsing the 「通じない奴の方が多いぞ」 part. Your translation of "open" kind of worries me. It is saying that:

"there are more people who would not understand or practice such whitewashing/lip service than those who would.

「Aの方が多い」 means "A outnumbers (the other group)." 「方」 is used for comparison between two items.

That is to say that 「そんな綺麗事が通じない奴」 outnumber「そんな綺麗事が通じる奴」.

So, the entire quote means:

"There would be more guys who would not understand or practice such whitewashing than those who would. In the adult world, that is."

Regarding your questions:

"A is really young and could not be considered adult. So I'm not sure what that part is supposed to indicate? That there are people who are dishonest in the adult world too?"

B is not saying or implying A is an adult. B is simply trying to explain to A what happens in the adult world. In fact, it sounds like B is actually implying that A is not thinking like an adult.

organic chemistry - Dichloromethane solubility in water

I heard dichloromethane is soluble in water 1:50, but I also heard it is not because it can't form hydrogen bonds. I'm confused. Is there a way to extract it? Would putting the water to $40~\mathrm{^\circ C}$ make it evaporate trough water?

particles - この道をまっすぐ行ってください。 Why を and not で?

In a quiz, I got a question where one had to complete with に、を、で or が the following sentence:

この道（？）まっすぐ行ってください。

The correct answer being:

この道をまっすぐ行ってください。

It always seems more natural to me to put で here instead of を as 道 describes where the action will take place.

Could anyone please give me the reason behind this choice in Japanese?

Answer

There are basically four choices with motion verbs in Japanese. Each has a slightly different implication.

• に - "to" indicates the final goal of the travel. If chosen in your sentence it would be slightly nonsensical due to the この "Go directly to the street right here"


• で - "in or around" tends to indicate meandering inside of the boundaries of a location. In other words, で treats the street not as a path to travel along, but as a place to move around inside of. This might be appropriate if you were at a street-fair or similar event (although this would probably be better with a verb other than 行く). In this case, however, the まっすぐ contradicts the implication of で, so it's not appropriate here. (EDIT: As several commentators have pointed out, で is a reasonable choice if there is a discussion of which way to travel. But this requires a context in which the conversants are discussing different options: "this road", "that sidewalk", "hang-gliding")


• を - "across/along" indicates traveling the length (or a significant portion thereof) of the road/mountain/sky/(distance). More details are at this question


• へ - "to" - very similar to に, and へ can be replaced with に in pretty much all situations involving movement verbs. There is a slight emphasis on the "direction" with へ, such that へ is often called the "direction particle", as opposed to the "destination particle" に.

There are, of course, other possible particles for marking destinations, such as まで, までで, までに, the catch-all topic marker は, and even simple omission.

organic chemistry - Rates of solvolysis of p-dimethylamino benzyl halides

What will be the order of $\mathrm{S_N1}$ solvolysis rates for these?

I'm confused between the second and third options. $\ce{I-}$ is a better leaving group than $\ce{Br-}$, but the carbocation formed in 2 is more stable than 3. So how are we supposed to decide between them?

Answer

In the second compound, steric repulsions (denoted by the curly lines) between the N-methyl groups and the methyl groups on the ring occur:

This forces the $\ce{-NMe2}$ group to rotate such that the nitrogen lone pair is no longer parallel to the ring's $\pi$ system. As a result, the nitrogen lone pair can no longer contribute to the mesomeric stabilisation of the second carbocation.

The rate of solvolysis therefore increases in the order: $2 < 1 < 3$. The effect described above is called "steric inhibition of resonance".

A similar effect is observed in azo coupling:

In the second reaction, the nitrogen lone pair is not delocalised into the ring and the ring is therefore not nucleophilic enough to attack the diazonium ion.

physical chemistry - Room-conditions supercritical fluids?

Are there any reasonably obtainable supercritical fluids that I could, say, run my hand through? Wikipedia makes it sound like there are plenty of room-temperature ones, but no room-pressure fluids.

Answer

If exceeding the "liquid–liquid critical point" for a solution suffices, then perhaps you could survive contact with methane hydrate for a short while. Though He is supercritical at ~two atmospheres, running you hand through it would be a chilly experience at about 5 K.

tefilla - Peirush on Lecha Dodi

I’m looking for an in depth explanation of the Lecha Dodi we say on Friday night. Is there any peirush out there that does this?

Answer

Here are a few that contain running commentaries on this hymn:

1. The controversial book Hemdat Ha-yamim (vol 1 p. 43).


2. R. Moshe [Austrer] of Zamość (Arugat Ha-bosem, 62ff.)


3. R. Avenr Afjin (Divrei Shalom vol. 4, 391ff.) Note: some of his commentary is from #1.

I have aslo seen referenced in numerous places a collection entitled 'Tikkunei Shabbat' (pub. 1641) by R. Raphael b. Yaakov of Posen which contains a commentary too, however, I have not seen the book myself.

tefilla - Importance of Minyan

How far must I go out of my way to pray with a minyan (quorum)? Does it matter if it's longer one direction than the other (ie I have ride back but not there or vice-versa)?

Answer

One must travel 1 mil (or kilometer) to daven with a minyan, (or 4 mil, if its on his way anyways). I assume that describes the amount of time one must spend travelling rather than the distance. I think we mainly look at the time to travel there,* but probably both are a factor. See Shulchan Aruch OHC #90:

סעיף ט ישתדל אדם להתפלל בבית הכנסת עם הצבור ואם הוא אנוס שאינו יכול לבוא לבית הכנסת יכוין להתפלל בשעה שהצבור מתפללים (והוא הדין בני אדם הדרים בישובים ואין להם מנין מכל מקום יתפללו שחרית וערבית בזמן שהצבור מתפללים. סמ"ג). וכן אם נאנס ולא התפלל בשעה שהתפללו הצבור והוא מתפלל ביחיד אף על פי כן יתפלל בבית הכנסת:

סעיף יא מי שיש לו בית הכנסת בעירו ואינו נכנס בו להתפלל נקרא שכן רע וגורם גלות לו ולבניו:

סעיף טז ההולך בדרך והגיע לעיר ורוצה ללון בה אם לפניו עד ד' מילין מקום שמתפללים בי' צריך לילך שם ולאחריו צריך לחזור עד מיל כדי להתפלל בי':

organic chemistry - Precedence of 1,2 carbocation rearrangement

How can one choose which group has more shifting tendency in 1,2 carbocation rearrangement? The obvious order is via the stability of the carbocation of the group. But, phenylic groups have high shifting tendency--and a phenylic carbocation is unstable.

Is there a way of predicting these? I was thinking that it will be related to the delocalization in the triangular intermediate formed.

Update: I'm talking about comparing "migratory aptitude" of the $R$ groups in a system similar to $>C(+)-C(R_1R_2R_3)$

Answer

The obvious order is via the stability of the carbocation of the group.

I think you meant the migrating groups stability?
This is not what textbooks say.
Reactions are ruled by the $ΔG$ of the activated complex. This may be close to educts, or to products, or some halfway state or a real intermediate minimum is on the reaction path. So, in some cases the model of a separate carbenium ion (in a ionic pair maybe) is useful, sometimes you need to think of a three-center bond state.

organic chemistry - What is the geometry of an alkyl radical?

I encountered this question which asks how many possible radicals are formed when $\ce{CH3CH2C(CH3)3}$ is monosubstituted by $\ce{Br2}$. The answer given is 3 while I think it should be 4, reasoning that there is a "chiral" carbon if the radical is formed on carbon 3. While arguing with my tutor two questions came to my mind:

1. What is the geometry of the $\ce{CH3\dot{\ce{C}}HC(CH3)3}$ radical?


2. If the radical is trigonal pyramidal, does it transition quickly between the two possible states? If so are they considered two radicals?

---

My findings so far:

This answer on SE hints that the exact shape depends on the substituents on the alkyl radical.

Modern Physical Organic Chemistry states that all other (non-methyl) localized radicals are not planar.

Organic Reaction Mechanisms states that the geometry of free radicals is still controversial.

halacha - Why do plastic bags and not fuselages protect against impurity?

In a picture on this article, we see a kohen who has enclosed himself in a plastic bag so as to avoid becoming impure as a result of flying over a cemetery. Why is it that a pressurized fuselage does not protect against this impurity, but a plastic bag with a hole in it does? What factors specify what barriers appropriately protect against this impurity?

EDIT - In light of some answers I consider incomplete, I'd like to make something clear: a proper answer should explain the logic behind why metal is an ineffective barrier but plastic is not. Also, I thought of something else relevant: if plastic is an effective barrier, then would this plastic bag not be necessary in a 787, which is made of carbon-fiber reinforced plastic?

Answer

Anything which can contract impurity cannot block impurity from passing through it (Megillah 26b, Shulchan Aruch YD 371:1). A vessel can only contract impurity if it is made from cloth, sackcloth, leather, bone, wood, metal, or earthenware (Rambam Keilim 1:1, see Leviticus 11:32-33 and Numbers 31:22). Plastic therefore cannot contract impurity, so it can block effectively. The metal of the plane very possibly can contract impurity (depending if "metal utensils" means any kind of metal or just the six listed in the verse (gold, silver, copper, iron, tin, and lead)), so it can't block effectively. I note that even a vessel which ordinarily does not contract impurity can sometimes become susceptible if some metal is present and essential to its function, but these laws are quite complicated and beyond the scope of this answer.

everyday chemistry - Melting ice with salt - how does it start?

I know that salt reduces the melting point of ice. I can see how a little bit of salty water can melt ice to water which can dissolve even more salt. But how does it even start? There is ice, which is hard. There are grains of salt, which are hard. So how does the salt enter the ice, to begin with?

Answer

I believe that Ivan's comments are on the right track. Generally any melting phenomenon to do with ice begins with the fact that the surface of ice is disordered. By this I mean that ice on the whole is a periodic crystal like other solids, but at the surface there are imperfections, primarily due to the extra conformational freedom afforded to the surface molecules. This distortion then propagates down quite a few layers [1]. Ref. [1] discusses the properties of this surface layer which is liquid-like, and points out that this layer exists even down to quite low temperatures.

If these surface molecules "see" something charged (each ion that is) like $\ce{NaCl}$, then the surface molecules already have the conformational freedom to solvate the ions. Additionally, there is an energetic benefit to this because the hydrogen bonds between these ions and water are stronger than the water-water hydrogen bonds.

In general, melting phenomena are extremely complicated and the question of how melting "begins" is has not really been answered completely or satisfactorily (can provide refs. later if you want). This case is a bit different though because it is really a solvation phenomenon, which is adequately explained by the liquid-like layer at the surface.

---

[1]: Beaglehole, D., & Nason, D. (1980). Transition layer on the surface on ice. Surface science, 96(1-3), 357-363.

homonyms - ambiguity of どうこう

Perhaps one of the more interesting/infuriating things i've found is how どうこう is seemingly always written without kanji...

the obvious ones with する default to 同行 I assume

だからと言って今すぐどうこうするって話でもないけど。-just cuz i said that doesn't mean i saying i want to go out with her

同好

一概にどうこう言えない気がするんだけど…… - I feel like you can’t say all (girls ) have the same tastes (when it comes to guy's heights)

"どうのこうの"

「なんでせっかく好きな人と結ばれたのに、他人がどうこう言って間に割り込んでこようとするわけ……？　関係ないじゃん……」- how come even though i'm finally with a guy i like, other people keep disturbing us and saying all this crap, what we're doing has nothing to do with them.

and the stuff I'm not so sure of

どうのこうの or 動向？

俺が殴られるどうこうはもう関係ない。- your ("tendency" to assault me/this and that sort of beating me up) is already irrelevant ?

動向?

お前がどうこうじゃなく俺が決めたんだ。(context is "っ…入れてくださいっ！ 　私なら大丈夫です。これしき耐えられます" 🙄) - I , who "doesn't have the same "tendencies" as you, has already made up my mind. - really not sure about the last one.

Appreciate any clarifications and further insight

Answer

In all your five example sentences, どうこう is this どうこう meaning "this and that", "something", "blah-blah", etc. It's used to contract the unimportant part of the sentence. It's interchangeable with どうのこうの.

どうこう can work as an adverb, "(like) this or that":

今すぐどうこうするって話でもないけど。
That does not mean I'll do something (about the problem) right away.

一概にどうこう言えない気がする。
I feel we cannot say something sweepingly. / It's not a black-and-white situation.

どうこう also can colloquially form a noun clause (i.e., どうこう can be followed by particles like が, を, の):

[俺が殴られるどうこう]はもう関係ない。
I'll be beaten, or this, or that...they're no longer relevant.

[お前がどうこう]じゃなく俺が決めたんだ。
This is not a you-think-this-or-that kind of problem; I decided it.

彼とどうのこうのの前に自分を磨きなさい。
Before thinking about doing something with him, you must make yourself a better person.

^{(Forgive me if my English translations are unnatural; I'm bad at this type of colloquial sentences)}

Unsurprisingly, 動向, 同行 and 同好 are normally written in kanji. These words are simply not used in your examples.

frequency spectrum - How to perform a Rubberband-Correction on spectroscopic data?

I basicaly understood how the Rubberband/Baseline-correction works.

1. The given spectrum is divided into (N) ranges.


2. The lowest points in every range are determined.


3. The initial baseline is built out of those points.


4. Now all the points on the spectrum are drawn down by the difference between the lowest point in the current range and the lowest point on the baseline.

There are some nuances, though, that I do not know how to handle. E.g., what if one of the points is exactly on the border between two ranges, etc.

Plus, I have to be able to prove that the algorithm that I am writing is a solid one and can be referenced by other works or scientific papers.

If anyone could give me some reference I would be very pleased.

Answer

This can be easily done in R or Python. There are well-tested functions available, so you don't have to worry about any boundaries or nuances. Moreover, both are free and popular among scientists.

There is a special package to handle spectral data, called hyperSpec. The rubberband baseline correction is already implemented there (function spc.rubberband). All details are highlighted in the documentation. The usage is pretty simple:

require(hyperSpec)
spc <- read.spe("paracetamol.SPE")
baseline <- spc.rubberband(spc)

corrected <- spc - baseline

There is no (to the best of my knowledge) out-of-the box solution for python, but you can use scipy.spatial.ConvexHull function to find indices of all points that form a convex hull around your spectrum. Suppose that the spectrum is contained in x and y arrays:

import numpy as np
from scipy.spatial import ConvexHull

def rubberband(x, y):
    # Find the convex hull
    v = ConvexHull(np.array(zip(x, y))).vertices

Array v contains indices of the vertex points, arranged in the CCW direction, e.g. [892, 125, 93, 0, 4, 89, 701, 1023]. We have to extract part where v is ascending, e.g. 0–1023.

    # Rotate convex hull vertices until they start from the lowest one
    v = np.roll(v, -v.argmin())
    # Leave only the ascending part
    v = v[:v.argmax()]

    # Create baseline using linear interpolation between vertices
    return np.interp(x, x[v], y[v])

Now the baseline is corrected like this:

y = y - rubberband(x, y)

torah study - If you can only choose one which way should you learn, bekiyus or beiyun?

If you can only choose one, which way should you learn, bekiyus (learning quickly on a more superficial level to cover ground) or beiyun (slower, more in depth study)?

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As a reminder, answers on this site should be supported by facts, references, or specific expertise: please cite your arguments or sources!

translation - What is the も in 今年も used for ? What does 雨が少なく mean here, and why isn't it followed by a て?

I have the following translation for class.

今年も、
トゥーソンは、
雨が少なく、
水が不足して、

困るかもしれません。

So far, I have the following.

This year also
Tucson
rain is little
water has become insufficient and
it might be a problem.

I have a few questions.

1. Why is there that も on 今年? Is it just signifying that the absence of rain is "also" like other years?


2. I am confused by the 雨が少なく. I am not sure how to relate it to Tucson. "As for Tucson, the rain is little"? Also, I would expect a て at the end (少なくて). But is it somehow an adverb instead of て form?

Answer

1. 
   

   The drought in Arizona has been going on for about fifteen years. So it's "this year too".

   
   



2. 
   

   The 連用形{れんようけい} ("continuative form") of a verb or adjective can be used like a conjunction without adding て. For an adjective, that is the 〜く form, and for a verb, it's the stem you add 〜ます to.

   
   

   Here you have the 連用形 of an adjective, not an adverb. It acts like a conjunction, joining two predicates together. You can think of it like 少ない, except that the sentence continues with something like an "and".

   
   

   We have some questions already where people talk about this usage:

   
   
   

   But if you wait, perhaps someone will write another answer talking about it.

   
   

history - Prior to the Men of the Great Assembly (and after Moses, our teacher), could halacha be decided by prophecy?

I think that I remember hearing that during the times of the Men of the Great Assembly, it was decided that prophecy would no longer be used to determine halachic rulings, i.e that before then it was acceptable.

Does anyone have a source for that?

This link (without a source) says that " The Great Assembly included the last of the prophets. One couldn’t “feel for” the right answer as reliably, and halachic reasoning came to the fore."

Update: It seems like the Rambam spoke on this in Yesodei HaTorah 9:4, namely that a prophet cannot change the oral law or decide based upon his prophecy. It seems as though he is including the period before the Great Assembly. This link also discusses similar ideas. I'm leaving the question open in case someone can provide specific information.

Answer

" Although the Jewish people demanded of the prophets and priests that followed - Yehoshua, Shmu'el, Pinhas and Elazar - that they ask for Heavenly direction with regard to the questions that arose, each of them replies lo ba-shamyim he - "The Torah is not in Heaven" (see Devarim 30:12). Once the Torah was given at Mount Sinai it is incumbent on the Sages of every generation to establish the meaning of the Torah; whose meaning cannot be established by prophetic communication with God." (Temurah 16)

http://steinsaltz.org/learning.php?pg=daf_yomi&articleId=2637

software implementation - Removing Glare from Image

Disclaimer: I am in NO way engaged in signal processing. Just very curious...

Ny question is, very simply: is it possible to apply software processing to an image to remove or reduce headlight glare?

It would be a picture such as this:

If this IS possible, is there a software library available for this? I don't care which language, I just want the capabilities. Slash does anyone know if there is current research on this?

Answer

The problem you might have is that when bright lights are present, the camera will be using a fast shutter speed to keep the image from saturating too much. All the detail you are interested in is in the bottom few bits of the data.

So even if you remove the glare and then try and pull the rest of the image up in level, it's very noisy. For example, if you take your image and play with the levels to pull up the darker sections and just allow the glare to clip, this is the result:

If that's OK for onward processing (I don't know what you have in mind) then you could maybe remove the glare by looking at distributions of saturated pixels, and expand into the "glow" around them.

A better solution (if you have the option) can be to use a high-dynamic range camera which has an non-linear response in the pixels, and also often 10 or 12 bits per pixel of usable resolution, which means you can keep 7-8 bits for the darker sections.

prefixes - a few words have an honorific 「お」or「ご」 as a necessary prefix, right?

I just came a across the word 「お巡りさん」。While 「お巡り」 is a word, 「巡り」 is not. Likewise, 「ご飯」 is a word, but while 「飯」is a word, the reading changes to the 訓読み (めし)。This means that the 「ご」in「ご飯」is not window-dressing 美化語. The「ご」in「ご飯」is a necessary part of the word. In my opinion, 「お茶」 is in limbo. I've never heard 「茶」 spoken without an honorific 「お」、but 「茶」alone is officially in my dictionary。

Over time, 「お」or「ご」can become a necessary part of some words, right? Is this a documented part of Japanese grammar? (reference links would be welcomed). What are a few more words that have an honorific prefix, 「お」or「ご」, as a necessary part?

Answer

In language, a process is said to be productive if it can produce new words (or phrases, etc.). For example, in English, you can add un- to lots of words, so we say that un- affixation is a productive process. And in Japanese, affixing go- and o- to words is relatively productive.

But when a word can no longer be formed via a productive process in the modern language with a predictable meaning, we say that it's become lexicalized. In other words, it's become a single word, and it needs its own dictionary entry. You need a dictionary entry for disgruntled because you can't figure it out from dis- and gruntled in the modern language. Likewise, you need a dictionary entry for おやすみ, ごはん, and おにぎり because they've become single lexical words.

So yes, o- and go- can become a necessary part of a word, and the name for this process is lexicalization.

electrons - Why do atoms generally become smaller as one moves left to right across a period?

It seems to me that the addition of electrons and protons as you move across a period would cause an atom to become larger. However, I'm told it gets smaller. Why is this?

Answer

As you move from left to right across a period, the number of protons in the nucleus increases. The electrons are thus attracted to the nucleus more strongly, and the atomic radius is smaller (this attraction is much stronger than the relatively weak repulsion between electrons).

As you move down a column, there are more protons, but there are also more complete energy levels below the valence electrons. These lower energy levels shield the valence electrons from the attractive effects of the atom's nucleus, so the atomic radius gets larger.

organic chemistry - Migratory preference in a rearrangement involving carbocations

I just read about the Pinacol rearrangement and the following reaction was presented just after it. The book (Clayden) shows path 1 being taken.

My question is why is the second path not taken? I know that migratory aptitude of $\ce{Ph>H}$ but all we want is stability, so why can't the $\ce{H}$ migrate?

books generally - Citation format for G'mara

If one is citing a g'mara in a scholarly article, what is the proper publication information to use, including title, etc.? I can't seem to find reliable examples in either English or Hebrew.

This question extends (and becomes even less clear to me) when it comes to citing m'farshim whose comments appear in the back of the same volume.

The "editor" of the particular volume is almost completely irrelevant, considering how minimally one would alter the standard page, including text, format, notation, etc. Authorship is a bit fishy in terms of accurately pinning down an individual whose naming would truly portray their contribution to the volume in question. But it doesn't seem right or correct to skip all of the (publishing, printing, editing) middlemen and only name the original author because sometimes variation does occur and it could be significant and irresponsible to leave that information out.

Answer

Let's assume MLA style.

eHow has this:

Lastly, if your source is a sacred text, such as the Bible or Talmud, cite the edition, book, chapter, and verse. This may vary according to each text.

([Edition], [Book]. [Chapter].[Verse])

So treat Talmud like Bible.

Purdue University's writing lab has this:

Citing the Bible

In your first parenthetical citation, you want to make clear which Bible you're using (and underline or italicize the title), as each version varies in its translation, followed by book (do not italicize or underline), chapter and verse. For example: Ezekiel saw "what seemed to be four living creatures," each with faces of a man, a lion, an ox, and an eagle (New Jerusalem Bible, Ezek. 1.5-10).

If future references employ the same edition of the Bible you’re using, list only the book, chapter, and verse in the parenthetical citation.

I would thus assume your in-line citations would look like this:

The obligation to pay one's taxes is made clear by the Talmudic sage Shmuel (Mechon Mamre Talmud Bavli, Ned. 28a). The later sage Rav Safra was said to exemplify truthfulness (Mak. 24a).

My sense is for sacred texts, you don't list Ravina and Rav Ashi from 1500 years ago as its editors in your Works Cited section; just whatever information about the edition you were using. (See a bit more here.)

reference request - Is there a database on chemical reactions, similar to NIST, but far more complete?

The only thing I'm interested in is to be able to search all reactions involving that compound in the database. Equilibrium constant, reaction rate and energy of activation would all be very welcome, but in case these data are absent it's no big deal.

Doesn't need to be an online database either, I can download a software if it contains such data.

Answer

The best known databases are Beilstein and Chemical Abstracts with around 22 millions reactions each since the end of the 19th century but they are commercial.

Organic Syntheses has made available its database for free and it covers 6000 reactions. One of the greatest advantages is that each step is described in depth and each reaction has been thoroughly tested prior to publication.

Have a look here for a list of databases.

everyday chemistry - Is toothpaste solid or liquid?

My teacher didn't answer this properly:

Is toothpaste solid or liquid?

You can't say toothpaste is a solid because solid material have a fixed shape but toothpaste doesn't. However, you can't say it's a liquid because liquids flow easily but toothpaste needs a certain force to push it out of the tube. So is it a solid or liquid? And are there any other example just like toothpaste?

Answer

Toothpaste is what is called a non-newtonian fluid, more specifically toothpaste is a Bingham plastic. This means that the viscosity of the fluid is linearly dependent on the shear stress, but with an offset called the yield stress (see figure below). This yield stress is what makes it hard to say whether it is liquid or solid. The fact that toothpaste is viscous alone is not sufficient to explain this, because water is also viscous, but doesn't behave like a solid (unless frozen, but that's another phenomenon).

What the yield stress does is the following. Below a certain shear threshold the fluid responds as if it where a solid, as you can see happening when you have put toothpaste on your toothbrush, it just sits there without flowing away. A highly viscous but newtonian fluid would flow away (although slowly as pointed out by @ron in his comment to the answer of @freddy).

Now if you put sufficient shear stress on the toothpaste, when you squeeze the tube of paste, it will start flowing and respond as a liquid.

Other examples, as mentioned in the Wikipedia link in my first sentence, are e.g. mayonnaise and mustard. Another example is silly putty.

kinetics - Rate and order of a reaction

The rate of reaction can be measured from a concentration vs time graph of a particular reactant in a reaction.

But, if in your reaction you have different reactants of different orders surely they will each give a different concentration vs time graph and so different rate at any time t. This implies that the rate of reaction can have multiple values depending on which reactant you follow.

number - Can someone have more than one potential soulmate simultaneously?

I have been told from several different people that it is possible for one person to have multiple Besherts (divinely intended marriage partners, soulmates if you will) to choose from. He may only choose one at the end, but there are several possible options. A quick search online will bring you claims like, "it says that every person has 7 zivuggim", but no source to back it up.

This is usually told to people who have never been married, (which seems to indicate they are referring to the first marriage, and not to subsequent marriages).

Is this true? Is there a source for this statement? And if so, is it universally applicable, as everyone who quotes it seems to think, or is it limited (perhaps to a second marriage)?

avodah zarah - Do not worship any graven image? Or do not worship any created image/being

God makes it clear that we are not to make and worship/bow down to an image of anything in heaven or on earth. God is very careful in even revealing himself to Israel, to point out that they heard only a voice, but saw NO image.

12The Lord spoke to you out of the midst of the fire; you heard the sound of the words, but saw no image, just a voice.

יבוַיְדַבֵּר יְהֹוָה אֲלֵיכֶם מִתּוֹךְ הָאֵשׁ קוֹל דְּבָרִים אַתֶּם שֹׁמְעִים וּתְמוּנָה אֵינְכֶם רֹאִים זוּלָתִי קוֹל:

...

15And you shall watch yourselves very well, for you did not see any image on the day that the Lord spoke to you at Horeb from the midst of the fire.

טווְנִשְׁמַרְתֶּם מְאֹד לְנַפְשֹׁתֵיכֶם כִּי לֹא רְאִיתֶם כָּל תְּמוּנָה בְּיוֹם דִּבֶּר יְהֹוָה אֲלֵיכֶם בְּחֹרֵב מִתּוֹךְ הָאֵשׁ:

16 Lest you become corrupt and make for yourselves a graven image, the representation of any form, the likeness of male or female,

טזפֶּן תַּשְׁחִתוּן וַעֲשִׂיתֶם לָכֶם פֶּסֶל תְּמוּנַת כָּל סָמֶל תַּבְנִית זָכָר אוֹ נְקֵבָה:

Rashi: form: Heb. סָמֶל, meaning “form.” סמל: צורה:

17the likeness of any beast that is on the earth, the likeness of any winged bird that flies in the heaven,

יזתַּבְנִית כָּל בְּהֵמָה אֲשֶׁר בָּאָרֶץ תַּבְנִית כָּל צִפּוֹר כָּנָף אֲשֶׁר תָּעוּף בַּשָּׁמָיִם:

18the likeness of anything that crawls on the ground, the likeness of any fish that is in the waters, beneath the earth.

יחתַּבְנִית כָּל רֹמֵשׂ בַּאֲדָמָה תַּבְנִית כָּל דָּגָה אֲשֶׁר בַּמַּיִם מִתַּחַת לָאָרֶץ:

19And lest you lift up your eyes to heaven, and see the sun, and the moon, and the stars, all the host of heaven, which the Lord your God assigned to all peoples under the entire heaven, and be drawn away to prostrate yourselves before them and worship them.

יטוּפֶן תִּשָּׂא עֵינֶיךָ הַשָּׁמַיְמָה וְרָאִיתָ אֶת הַשֶּׁמֶשׁ וְאֶת הַיָּרֵחַ וְאֶת הַכּוֹכָבִים כֹּל צְבָא הַשָּׁמַיִם וְנִדַּחְתָּ וְהִשְׁתַּחֲוִיתָ לָהֶם וַעֲבַדְתָּם אֲשֶׁר חָלַק יְהֹוָה אֱלֹהֶיךָ אֹתָם לְכֹל הָעַמִּים תַּחַת כָּל הַשָּׁמָיִם:

1. Does He also somewhere say not to bow down to created beings (angels, mankind, creatures).

organic chemistry - Can 1,3,5-trihydroxybenzene perform haloform reaction?

As far as I know it's not possible for 1,3,5-trihydroxybenzene to give the haloform reaction.

The prerequisites(that I know) for the haloform reaction are:

Only those organic compounds which can be converted to a methyl ketone or acetaldehyde by means of oxidation (by $\ce{NaOX}$ ($\ce{NaOH + X2}$) type agents which are present in the reaction mixture) give this reaction. And obviously a methyl ketone or acetaldehyde would give this reaction too.

So the problem is I don't see how 1,3,5-trihydroxybenzene meet those prerequisites. Is there any way out because in a recent practice test I came to know that 1,3,5-trihydroxybenzene does give the haloform reaction.

sukkot - Can too many decorations render a sukkah invalid?

I've seen some sukkahs (especially ones where they've had big "make sukkah decorations" kids' projects) where there are tons and tons and tons of decorations hanging down from the schach. At what point would that invalidate the sukkah? Are there other decoration issues that are problematic?

orthography - Why is マシ written using katakana?

Does マシ come from English? Or is it a semantic emphasis?

tefilla - Why are Ashre and Alenu considered communal prayers?

Shulchan Aruch (OC 65) says to say "Sh'ma" with the congregation when they say it, and Mishna B'rura 9 there says the same is true of other things recited as a congregation such as "Ashre" and "Alenu". (Indeed, it is common practice that one recites "Alenu" when the congregation does even if he is not at that point in the service or is not praying at all.) In what sense are the latter two considered prayers that are recited communally (more so than most of the rest of the prayer service), that the Mishna B'rura mentions them as communally-recited prayers? That is, what makes them communal, whereas other prayers aren't necessarily so considered?

grammar - Proper use of ため to thank someone for doing x？

I know ため can be translated into English as "for" such-and-such.

But is it appropriate to use it to thank some one for doing something?

For example, "Thank you for your email address." Would it be grammatically accurate to say: メールアドレスためありがとうございます。

Google translate seems to understand the sentence perfectly fine. But would a native speaker scratch their head at that use of ため in this manner?

Answer

Using ため as the 'for' in 'thank you for' is strange.

Off the top of my head I can think of 4 ways we normally use ありがとう to say thanks for something.

1. 
   

   masu-stem of the verb + ありがとう (this one's particularly formal)
   メールアドレスを教えていただき有難う御座います。
   Thank you for telling me your email address.

   
   


2. 
   

   te-form of the verb + ありがとう
   
   メールアドレスを教えてくれてありがとう。
   Thanks for telling me your email address.

   
   


3. 
   

   noun + ありがとう
   メアドありがとう！
   Thanks for your email address!

   
   


4. 
   

   noun + を + ありがとう
   
   メッセージをありがとう
   Thanks for your message

   
   

There's lots of other expressions which don't use ありがとう like:

～についてお礼を申し上げます
～に対し感謝します

ため is 'for' as in for the benefit or purpose of someone/something.

私のためにこんなすてきなパーティーを開いてくれてありがとう。
Thank you for throwing such a splendid party for me.

organic chemistry - Fehling's test arrow pushing mechanism

I am currently attempting to generate an arrow pushing mechanism for the oxidation of glucose to gluconic acid using Fehling's solution. My original thought was to go the route of alcohol oxidation using acidified dichromate where the alcohol attacks in and loses the H using a E2 mechanism.

In the aldehyde oxidation, I would have a hydroxide ion attack prior to the H bond collapse leaving an extra electron on the Cu from the $\ce{C-\mathbf{O-Cu}}$ bond resulting in reduction of $\ce{Cu^2+ -> Cu+}$. Which would satisfy the observed empirical data. After an attempt I googled the mechanism finding very little real information.

A post on this very site suggested the mechanism proceeds via enolate formation followed by single electron transfer with $\ce{Cu^2+}$. Unfortunately, there is no elaboration on this or a source, I also can't find a source online which corroborates this mechanism. Does anyone have a good source for this?

song lyrics - What does できる mean in this context?

こん。ちょっと質問があります。
★ Hello. I've got a quick question.

この曲、「僕に彼女ができたんだ」と呼んでいますが、タイトルの意味が分からない。
★ Even though the song is called 「僕に彼女ができたんだ」, I don't know what the title means.

暇があったら、手伝ってください。日本語と英語、どっちでもいい。
★ If you've got some time help me out. Japanese, English - whatever is cool.

よろしく！
★ Thanks!

Answer

This できる means "to come into existence".

「僕に彼女ができたんだ」 therefore means "I've got a girlfriend now." since it would not be natural to say in English the literal translation version "A girlfriend has come into existence for me."

More examples:

「今日新しい友だちができた。」

「もうすぐここにラーメン屋ができるらしい。」= "I hear there will be a ramen shop here soon."

「OMG, こどもができちゃった！」= "I/She got pregnant!" I am sure some of you have heard the word 「できちゃった婚」 or 「できちゃった結婚」 ("shotgun marriage"). It comes from this ｛できる｝.

Why does the DFT assume the transformed signal is periodic?

In many signal processing books, it is claimed that the DFT assumes the transformed signal to be periodic (and that this is the reason why spectral leakage for example may occur).

Now, if you look at the definition of the DFT, there is simply no that kind of assumption. However, in the Wikipedia article about the discrete-time Fourier transform (DTFT), it is stated that

When the input data sequence $x[n]$ is $N$-periodic, Eq.2 can be computationally reduced to a discrete Fourier transform (DFT)

• So, does this assumption stems from the DTFT?


• Actually, when calculating the DFT, am I in fact calculating the DTFT with the assumption that the signal is periodic?

fuel - Production of hydrogen through the reaction of aluminium metal and sodium hydroxide

If I have a solution of 25% $\ce{NaOH}$, and I simply add a cut-up aluminium can or some aluminium foil, will it react into hydrogen and sodium aluminate?

In principle this reaction should happen, but it didn't work when I attempted it. Perhaps an oxide layer prevented it, or a protective layer of sodium aluminate was formed. (Perhaps my experiment was faulty.) Should this happen, and what can I do to fix it? (My goal is to generate hydrogen gas.)

Answer

Oxide layer would not hold against the strong alkali, and sodium aluminate does not form protective layer either. I suppose cans and foil may be covered by some coating, to make them suitable for food grade applications. Try burning it off, or rather use other sorts of aluminium (cut-up wire, maybe). Normally it would react quite vigorously.

organic chemistry - Why unsaturated fats are usually cis?

I've been studying organic chemistry and I think trans fats are actually more stable than cis fats. This is because the steric hindrance (for trans) would be lower and the molecule energy would be lower too (more stable).

Why are unsaturated fats usually cis at room temperature if the steric hindrance is higher?

Is that because the room temperature provides enough energy to break the pi bond in the double covalent bond (for example) making the molecule rotate and have a isomer of higher energy?

Answer

Nature produces cis fats exclusively (someone may prove me wrong with some weird example.) This is why unsaturated fats such as vegetable oil have lower melting point than saturated fats of the same MW (the cis double bonds lead to a more compact molecule which gets less tangled with its neighbours.)

The reason nature produces cis bonds is due to the enzymatic mechanism in which these bonds are produced. Therefore this is down to reaction kinetics, and as often happens the product which is not the most thermodynamically stable of all possible products is produced. It just has to be more stable than the reactants.

When fat is artificially hydrogenated with a metal catalyst (for example nickel) to increase its viscosity/raise its melting point (to turn vegetable oil into margarine) some of the cis double bonds that escape being hydrogenated are able to change from cis to the more thermodynamically stable trans. These trans fats are unnatural and are therefore widely claimed to be unhealthy.

grammar - Do I have a good grasp on the basics of what the continuative form is?

I'm doing some research as to what continuative forms are, due to naruto's previous answer to a earlier question of mine. To make sure I understand correctly; roughly; the "continuative form" is what results when you have dictionary verbs, attach a suru verb in dictionary form to the end of the dictionary form verb, then conjugate the verb stems as you would via te form; WITHOUT ADDING THE TE.

I.E. for Taberu (to eat);

1. 
   

   drop the ru (to make the stem form);

   
   


2. 
   

   add suru to the end of tabe (now tabesuru)

   
   


3. Conjugate the suru to its te form equivalent (i.e. shi, thereby forming tabeshi)

I don't think I was really taught the continuative form as the continuative form when we were going over te form in my Japanese class, it was just something I did and subconsciously understood then picked up without recognizing it for what it was.

If you want to say how I am wrong or minorly correct but still wrong when my idea is applied to non ru verbs, by all means, I appreciate the corrective... constructive criticism; or whatever its called, as its early morning and I need some sleep.

Answer

連用形 (usually translated as "continuative form") is one of "the basic 6 conjugation forms" of Japanese verbs/adjectives. For the ichidan verb 食べる, its 連用形 is 食べ. For godan verbs, many of them have two different 連用形. For example, 書く has two 連用形, namely 書き and 書い.

How can we make a 連用形? Simply, remove ます from the masu-form. For godan verbs, you can create the other 連用形 by removing て/で from the te-form.

Why do the two different forms have the same name? Isn't it confusing? Because they were historically the same. For example, the te-form 書いて was originally 書きて. See this chart for the actual euphonic changes. The term 連用形 is indeed somewhat confusing for learners, and that is probably why you did not learn about 連用形 in your Japanese classes. 連用形 is mainly taught in Japanese classes at Japanese schools.

What does the kanji 用 mean here? This 用 stands for 用言, which is a term that basically refers to Japanese "predicative" words. You can think of it roughly as "Japanese verbs and adjectives".

What are the other names of 連用形? 連用形 is translated variously as "continuative form", "conjunctive form", or "combining form". Specifically, the "masu-form minus masu" version of 連用形 has various alternative names, including "pre-masu form", "masu-stem", "stem" and "i-form". As far as I know, there is no specific name for the "te-form minus te/de" type of 連用形. See: Does "te-form" of a verb always include て/で? Why?

Why do we have to learn 連用形? Beginners may not need this term because they tend to learn 連用形 as part of longer "forms". They learn so-called "te-forms" and "ta-forms" even without knowing they include 連用形. But once you start learning Japanese using monolingual dictionaries, understanding the concept of 連用形 and 助動詞 (auxiliaries) is a must. In addition, many native Japanese speakers post answers here using the term 連用形 because this is how they learned Japanese grammar. Lastly, it may help you understand and memorize long rare "forms".

How is 連用形 used?

1. It connects to some auxiliaries and particles including ます, て/で, たい, に and たり/だり.
   
   


2. Masu-stems can directly connect to another clause/verb, just like te-forms can. For example, 声に出し言う and 声に出して言う mean the same thing ("say it out loud"), although the former sounds stiffer.
   
   


3. Likewise, a masu-stem appears as part of tons of compound verbs. For example 食べ切る, 走り出す, 受け取る.


4. You can form honorific verbs from a masu-stem. (お待ちになる, etc)


5. Interestingly, some masu-stems work as a noun.