electrochemistry - Why do Electrons leave the Zinc in a Galvanic Cell

What induces electrons to leave the atoms around the part of the zinc metal in a solution to travel up along that zinc metal and above the solution, through the wire and to the copper metal and reduce the copper ions in that solution.

Is it a result of the positive metal ions in a 'sea of electrons' being attracted to the negative ions of the solution making the electrons surrounding them leave, are the electrons repelled by the electrons in the solution or do these electrons 'sense' the copper ions on the other side waiting to be reduced and flows towards them?

I'm just not sure what prompts them to leave in the first place if the positive copper ions are not directly in contact with the zinc.

pronunciation - Pronouncing ない as ねい / ねえ (also ~oi to ~ei)

I noticed that in anime and other Japanese shows, people often pronounce 「ない」 as 「ねい」. For example, instead of saying 「使わない」, the person will say 「使わねい」, but the translation is the same.

I have many questions about this.

• Is there any nuanced difference in meaning between 〜ない and 〜ねい?


• Is it a colloquialism? Is it from a specific region or used mostly by one gender?


• When written, is it spelled 〜ねい or 〜ねえ? And do people often use it in writing, or only in speech?



• I've also noticed that 「すごい」 sometimes gets pronounced 「すげい」. Is this the same phenomenon? Are there other non-ない examples?


• Does this transformation have a name? I'd like to read more about it but I don't know what to search.

Answer

1. I see it most often spelled out as ねー as in 使わねー etc.


2. For me it has a rough, slightly negative, rude connotation (e.g. used by ruffians and ヤンキー, or the older generation that speak their opinions freely). It is also more prevalent in males than females.


3. I've seen ねー、ねえ、ねぇ but not ねい.


4. Can be used in the positive to show emphasis (also used by above) e.g. やりてぇー、食べてーetc etc.


5. If there is a name, I don't know it..

hebrew - How do Jews understand this idiom in Psalm 40:7

Inspired by https://christianity.stackexchange.com/questions/1294/hebrew-ot-translation-to-greek-nt, I wonder what Jews interpret this idiom, "אָזְנַיִם כָּרִיתָ לִּי," to mean.

The English Standard Version of the Bible translates the phrase in question as "you have given me an open ear", and notes that literally the phrase means "ears you have dug for me".

So my question is, are we just talking about an open ear in the sense of a willingness to listen to HaShem? Or is there more to it? An alternative translation I've seen reads "my ears you have pierced". Is this valid, and if so, does it lend some more context?

Answer

Rashi, Radak, ibn Ezra and the M'tzudos all seem to say it means "you have caused me to hear" your command, i.e. informed me of it, though literally, yes, it means "you have dug me ears".

matlab - Filter is too large

Hi I'm trying to separate sound from music using wfilters and heard each part separately using its name scale3 function

function s = scale3(q,n)
   p = length(q);
    if p==n 
       s = q;
      else 
      s = resample(q,n,p);
     end

the program

 s = wavread('K:\Khaleel_3aaza (1).wav'); % whatever here
 [l,h] = wfilters('sym2','d');
 [z.x]=wavedec(s,2,l,h);

 -> p = scale3(z.x(25000:40000),45000);

And the function in the program I apply with wfilters and filter works well until approximately 20,000 but the values ​​of the file that I'm working it the larger, and the music begins approximately 3,000 when I ues more than 30000 or more give me this error

??? Error using ==> upfirdnmex
  Filter length is too large - reduce problem complexity.


 Error in ==> upfirdn at 86
 Y = upfirdnmex(x,h,p,q,Lx,Lh,hCols,nChans);

 Error in ==> resample at 106
  y = upfirdn(x,h,p,q);

 Error in ==> scale3 at 6
  s = resample(q,n,p);


  Error in ==> Untitled2 at 7
  p = scale3(z.x(25000:40000),45000);

I don't understand what that means ? ang how I can fix it thank you for help

history - Critical Jewish analysis of the Ipuwer papyrus

I just stumbled across information about the Ipuwer papyrus, and I was wondering how many Jewish Egyptologists have had an opportunity to review and study it at length. Other than this very brief analysis by R' Mordechai Becher, and the article cited therein, are there any more recent, and more comprehensive, analyses of the document and its (possible) relationship to the Exodus?

mezuzah - Source that every room in the house needs a mezuza

What are the source(s) that every room needs a mezuzah and not just the front door?

In the Torah and Talmud.

Answer

There does not appear to be a Talmudic source that explicitly states that every room in a house requires it's own mezuzah. Rambam, however, does explicitly state this:

Hilchot Mezuzah 6:10

חדר שבבית אפילו חדר בחדר חייב לעשות מזוזה על שער החדר הפנימי ועל שער החדר החיצון ועל שער הבית שכולן עשויין לדירה וקבועין

When there is a separate room in a house, or even one room which leads to another room, it is necessary to affix a mezuzah on the doorway to the innermost room, the doorway to the outer room, and the doorway to the house, since all of them are used for the purpose of dwelling and are permanent structures. (Touger translation)

The subsequent major codes all adopt Rambam's ruling (Tur Y.D. 286, Shulchan Aruch Y.D. 286:16, Levush Y.D. 286:16, Aruch Hashulchan Y.D. 286:37. The respective commentaries that provide the sources for those codes send the reader right back to the statement of Rambam quoted above.

The question then is, what was Rambam's source?

R. Yosef Karo in his commentary thereto wonders why Rambam had to include this rule at all, since it is already covered by a previous rule. He does not tell us which previous rule he is referring to, but the other commentaries appear to assume that he is referring to the following:

Hilchot Mezuzah 6:8

לפיכך אחד שערי חצרות ואחד שערי מבואות ואחד שערי מדינות ועיירות הכל חייבים במזוזה שהרי הבתים החייבין במזוזה פתוחין לתוכן אפילו עשרה בתים זה פתוח לזה וזה פתוח לזה הואיל והפנימי חייב במזוזה כולן חייבין ומפני זה אמרו שער הפתוח מן הגינה לחצר חייב במזוזה

Accordingly, gates to courtyards, gates to alleys, and gates to cities and towns, all require a mezuzah, since houses which require a mezuzah open up to them. Even when there are ten structures leading one to each other, should the innermost one require a mezuzah, they all require [mezuzot]. Therefore, [our Sages] stated: A gate which opens up from a garden to a courtyard requires a mezuzah. (Touger translation)

In his commentary to that ruling, R. Karo traces the law back to the following Talmudic statement:

Menachot 33b

אמר רחבה אמר רב יהודה בי הרזיקי חייב בשתי מזוזות מאי בי הרזיקי אמר רב פפא סבא משמיה דרב בית שער הפתוח לחצר ובתים פתוחין לבית שער

Rehabah said in the name of Rab Judah, An entrance-lodge requires two mezuzoth. What is meant by ‘an entrance-lodge’? — R. Papa the Elder said in the name of Rab, It is a lodge, with one door opening on to the courtyard and another leading to the dwelling-houses. (Soncino translation)

Thus according to R. Karo, the source that every room in a house requires a mezuzah is a bit of a leap. We start with a Talmudic statement that when there is an entrance structure between the main structure and the courtyard, the entrance structure requires a mezuzah in addition to the main structure's mezuzah. This is then expanded to include even a chain of ten such structures, which in turn is taken to mean that any room within a structure requires a mezuzah.

That this is a bit of a leap is noted by some of the commentaries. R. Yedidya Shmuel Tarika argues that the cases in 6:8 and 6:10 are not necessarily analogous. In the former, all the outer structures require a mezuzah because they are the entrance structures to an inner structure that requires a mezuzah. In the latter case, though, each room is just another room of the house so it should be covered under the mezuzah by the entrance to the house:

Ben Yedid Hichot Mezuzah 6:10

ואפשר דהו"א דוקא עשרה בתים זה פתוח לזה הואיל והפנימי חייב כולן חייבים אבל בית שיש בתוך הבית עצמו חדר וחדר לפנים ממנו שהכל בית אחד תסגי במזוזה אחת

Somewhat similarly, R. Massoud Chai Rakkah points out that in the former case the outer structures require a mezuzah because they are necessary to get to the inner structure; in the latter case it is the reverse – we would be requiring a mezuzah on an inner room on account of the rest of the house:

Maaseh Rokeach Hilchot Mezuzah 6:10

אפשר לומר דהתם שאני שאף ששאר הבתים החיצונים אין חייבים מצד עצמם מ"מ כיון שהפנימית חייבת והוא צריך ליכנס בה דרך שאר הבתים להכי מחייבו כולם אבל הכא הוי איפכא

Both of them ultimately conclude that the reason why even an inner room would require a mezuzah is simply because it is used for living. Indeed, that is what Rambam himself said at the end of 6:10 – "since all of them are used for the purpose of dwelling and are permanent structures":

Ben Yedid

יהיב טעמא מדעת עצמו שכולן עשויין לדירה וקבועין

Maaseh Rokeach

דכיון שכל החדרים עשוים לדירה אין לחלק בהכי

According to this, then, the rule that every room in a house requires a mezuzah is apparently based on the assumption that the Talmudic ruling which states that the Torah specifically refers to structures that are used for living means that anything used for living, even an individual room that is part of an overall living structure, requires a mezuzah:

Yoma 11b

ת"ל בית מה בית מיוחד לדירה יצאו אלו שאין מיוחדין לדירה

therefore the text reads, ‘house’ — [meaning] just as ‘house’ means a building appointed for a dwelling it thus excludes all other buildings not appointed for a dwelling. (Soncino translation)

halacha - Difference between eiver min hachai for Jews and Noahides

Both Jews and Noahides are forbidden to eat aiver min hachai (a limb torn from a live animal).

Is there any difference between the prohibitions for Jews and non-Jews?

Answer

Yes there are many differences.

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• Jews are allowed to eat pieces taken from the animal immediately after shechita is performed, even while the animal is still moving מפרכס (blood must still be removed -- which is harder to do compared to regular meat, because it was taken alive-ish). Shechita kills the animal, even if it is still convulsing. (Simla Chadasha 27:1)
  Before digging in, one should wait until the animal stops moving, which is possibly a biblical prohibition of לא תאכלו על הדם (literally, "do not eat on the blood").


• However, a Noahide has to wait until the animal stops moving in order to be allowed to eat it (27:2).
  
  

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This leads to an interesting paradox -- after an animal was killed, while it is still moving, it is permitted to Jews and forbidden to non-Jews.
Therefore, based on the principle "ליכא מידי דלישראל מותר ולעכו"ם אסור" ("there is nothing that is permitted to Jews but forbidden to non-Jews") the convulsing animal would be permitted to Noahides if it's a kosher animal that had a good shechita (i.e. not neveila) and was killed by a Jew, even though it would be forbidden if a non-Jew killed it. (ibid., Shach 27:2)

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Rambam (Melachim 9:10) also says that while a Jew is only culpable for a shiur (kezayis) of eiver min hachai, the non-Jew is culpable for any amount of eiver min hachai. (see later in this answer for more from the Rambam on this topic)

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Chasam Sofer (Tshuva 19, brought by Pischei Tshuva 62:1) says that since eggs are really eiver min hachai (see this answer), and only became מותר to Jews from a דרשה in a פסוק, since the non-Jews never got the Torah, they never got the allowance to eat eggs. Now, because of ליכא מידי, eggs that Jews are allowed to eat are also permitted to non-Jews [ignoring the רמב"ם, who doesn't hold of ליכא מידי (he writes that even if a Jew killed it, it would still be forbidden to non-Jews), and therefore all would be אסור].

However, this means that those eggs that are not לישראל מותר, would still be forbidden to non-Jews. This includes ביצי טריפה [the eggs of kosher animals that have certain bodily defects such as torn lung, broken leg/wing in certain locations etc.], and ביצי טמאה [non-kosher animals, such as hawks or snakes] (those are his examples, I would add the eggs of a chicken that you hit, that is eiver min hachai [see here again], as well as fertilized eggs [the ones with blood spots]).
These eggs may not be sold to גויים by Jews due to לפני עור, but since eggs are common מצוי it's fine. All the same, they should not be gifted freely, unless there is room to say that they will be used for a non-food purpose, such as for glue or to be incubated/raised by his chickens. If it is clearly for food, such as if it is already cooked, then it is אסור. If there is a food that was cooked with eggs, it is still אסור, because גויים do not have ביטול, even in 1,000 (see this question, which leaves it unresolved whether or not ביטול may be used for גויים, the Chasam Sofer assumes that it may not), and even if it is a נותן טעם לפגם.

[We do not פסקן like the Rambam that does not hold of ליכא מידי due to the Simla Chadasha mentioned above, but all the same, according to Chasam Sofer one would not be allowed to sell ביצי טריפה\טמאה, and one might argue that when he is the only egg vendor (=not מצוי) it would be אסור as well]

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Credit for the Rambam, Shach and Chasam Sofer go to Yoni. Thanks! :)