What is the difference between べんきょう する and べんきょうを する?
Answer
勉強{べんきょう}する is one verb. 勉強をする is a phrase.
They don't seem to have any difference in meaning, but the usage may differ.
For 勉強する, an objective can be added:
日本語{にほんご}を勉強する learn Japanese
日本語を勉強をするis wrong
For 勉強をする, adjectives (or words or phrases that can be used as adjectives) can be used before 勉強:
しばらく医者{いしゃ}になるための勉強をする study for a while to become a doctor
While 勉強する cannot be used in this way.
According to my calculations, the reaction $\ce{H2O + O3 -> H2O2 + O2}$ should be favourable under standard conditions. However, I am told that the reaction is probably very slow in solution since ozone is poorly soluble in water and the reaction occurs through a radical mechanism.
Water can be ignited in a fluorine atmosphere. Can water also be ignited in an ozone atmosphere? Can this be done at 1 atm?
Answer
We are basically talking about a derivation of the $\ce{H2/O2}$ system, which involves a radical mechanism. You maybe want to have a look at this answer of mine going a bit more into detail.
The reaction you are interested about is only a total sum of reactions and is most likely not to occur as other reactions will be favourable. Ozone itself is not a very stable compound and many other molecules may actively catalyse decomposition. There are various publications[1-3] on the mechanism of this reaction: \begin{align}\ce{ M + O3 &<=> M + O2 + O\\ O + O3 &<=> 2O2\tag1 }\end{align}
The range of $\ce{M}$ is in $\ce{O3, O2, CO2, N2, He, etc}$.[1] Although not stated explicitly, there should basically no reason why water is not be able to accomplish the same. Hence the driving force of the total reaction would be entropy, giving the overall equation: $$\ce{2 O3 ->[\ce{H2O}] 3 O2}\tag2$$
It is most likely that the reaction will start with the formation of oxygen radicals in the gas phase ($\ce{O}$ atom transfer).$$\ce{O3 + O3 -> O3 + O2 + O}\tag3$$
In presence of Hydrogen donors ($\ce{RH}$ apparently any kind will do) a chain reaction will be initiated.[1] $$\ce{O + RH -> OH + R}\tag4$$
The main chain carriers will be $\ce{HO, HO2}$. \begin{align}\ce{ HO + O3 &-> HO2 + O2\\ HO2 + O3 &-> HO + 2O2\tag5 }\end{align}
The process will be terminated by this (quite unspecific) reaction. This may then also involve $\ce{H2O2}$, which "is expected to be an excellent $\ce{H}$ donor."[1] $$\ce{2HO2 ->}\text{stable products}\tag6$$
In aqueous solution the decomposition is highly pH dependent, but may always work because of autoprotolysis. $$\ce{2H2O <=> H3+O + {}^{-}OH}\tag7$$
Steahelin and Hoigné propose several hypothesis in which way ozone will be decomposed, but I will not go into absurd detail.[4] The core assumptions involve $\ce{{}^{-}OH}$ as initiator of a radical chain. \begin{align}\ce{ O3 + {}^{-}OH &-> .O2- + HO2. & HO2. &<=> H+ + .O2-\\ O3 + {}^{-}OH &-> HO2- + O2 & H2O2 &<=> HO2- + H+\\ && O3 + HO2- &-> .OH + .O2- + O2\\ O3 + {}^{-}OH &-> .O3- + .OH\tag8 }\end{align}
Which is basically followed by another set of radical chain reactions. \begin{align}\ce{ O3 + .O2- &-> .O3- + O2\\ .O3- + H2O &-> .OH + {}^{-}OH + O2\tag9 }\end{align}
Which is all again resulting in $(2)$ again.
In summary the proposed reaction might occur, but will immediately be followed by another set of reactions resulting in the formation of biatomic oxygen.
References
What is with the different Holocaust Remembrance Days?
When I was a kid, my entire community observed Yom HaShoah. This came about approximately one week after Pesaḥ. Although I'm not totally sure, I think they must have followed the date observed in Israel, which is 27 Nisan. The particular date was of extreme importance to the organizers, however, because it was essential that all the various Jewish organizations joined together as one community to observe this solemn day, and the March of the Living was also scheduled around that date.
In college, or more precisely, in Yeshivah, I learned that there was some early opposition from religious groups to establish a date for Yom HaShoah, since the fast of the Tenth of Teveth was considered the catch-all for Jewish national tragedies, as is the Sefirah period*.
Nowadays, though, it seems that there are several other, non-religious, internationally recognized dates for Holocaust Remembrance.
So what's going on exactly? What's the history of these divergent observances, and who actually observes them? It still seems to me that Yom HaShoah is the dominant date observed by most people, but is that really true? Recently there was some controversy over an offensive (allegedly antisemitic) cartoon published on one of these dates. It made waves because of the double impact of resembling a blood-libel cartoon from the Nazi era and being published on "Holocaust Remembrance Day" (I think the UN-sanctioned date). But other than its own distastefulness and offensiveness, was this really an issue for most people? I mean, did anyone who is not in tune with internationally-recognized holidays make this connection because they personally observe that date?
*(As explained to me, the Three Weeks, etc., are regarded as unique dates of suffering, not to be associated with general tragedies that didn't befall the Jewish people on those specific dates.)
Answer
January 27th is probably the most universally accepted non-Jewish holocaust remembrance day. It is the anniversary of the day that Soviet Troop liberated Auschwitz-Birkenau in 1945. It was designated by the UN in 2005 and as of 2004 at least 12 countries have some type of official observance on this day. Israel has designated this day, not as a holocaust remembrance day, but as a day to mark the struggle against anti-semitism. Ceremonies are held at the United States Holocaust Museum in Washington DC and in Israel's Yad VaShem. This date has a specifically non-religious character.
Nissan 27 is the most universally accepted Jewish holocaust remembrance day. The date is tied to the Warsaw Ghetto uprising, but is not the actual anniversary. The actual anniversary takes place on the 14th of Nissan, but due to its proximity to Passover the date was moved to the 27th of Nissan. It was officially established by Israel's Prime Minister and President in 1953. Most communities that have a dedicated Holocaust memorial service (generally "Modern" Orthodox) will do so on Yom HaShoah (27 Nissan), while those who remember the Holocaust together with other national tragedies (generally "Yeshivish" Orthodox) will do so on Tisha B'Av or Asara B'Tevet. Some communities will also hold educational events (but not specifically religious services) on Yom HaShoah.
Many Jewish communities will hold educational and other non-religious events on the days designated by their host-countries as "Holocaust Memorial Day" or other days which may be locally designated as such or on the International Holocaust Remembrance Day (Janaury 27th).
I am told that carbon dioxide is IR inactive.
This somehow strikes me as untrue or at best oversimplified, because yes, it is overall symmetrical, but can't $\ce{CO2}$ be induced to show asymmetric stretching patterns?
So this leads me to the question: in a simplified presentation of IR, why might someone present symmetrical, non-polar molecules as IR "inactive"? Could we be relying on a simpler definition of IR inactive?
Answer
I am told that carbon dioxide is IR inactive.
You're right, that's not true. Since carbon dioxide is linear it has $3n-5 = 4$ vibrations and they are pictured below.
We expected 4 vibrations and I've only listed 3. This is because the "bend" (let's start by placing the molecule along the x-axis) can occur in the y direction and the z direction. But these two motions are the same, just deforming in different directions, the bend is said to be degenerate, accounting for the "fourth" vibration.
To sum up, carbon dioxide has 2 ir-active vibrations.
Edit - response to example added (question d) by OP
Question d is incorrect. Either the author 1) inadvertently switched the column headings (IR active, IR inactive) or 2) meant to use some molecule other than carbon dioxide.
The first 3 rules you learn for interpreting IR and Raman spectra are
Here's a link to a recent SE Chem question: How can I deduce the linearity of XeF2 from the IR spectrum? where these rules were used to determine the structure of a molecule.
I am working on an audio system where I need to implement an equal power crossfade between two signals over a specified number of samples. Initially I implemented a linear fade but this creates a dip in the middle of the crossfade which I don't want. I tried a few other methods that I found on Google but they either make a dip in another part of the curve or even make the sound louder.
If I have float samples ranging from -1.0 to 1.0 and I want to crossfade between them over the course of x samples, keeping the perceived volume the same over the entire crossfade, what would be the correct formula for calculating the curve? Preferably I want to have a value like 0.001 represent the minimum level that the fade in starts at and the fade out goes to. 1.0 should be the maximum. Thanks in advance for any advice!
My teacher told - "To reduce carboxylic acid to alcohol, $\ce{LiAlH4}$ is used. But since $\ce{LiAlH4}$ is an expensive reagent, it is commercially reduced by forming an ester and then to alcohol". I asked that we can also use $\ce{NaBH4}$ as it also contains 4 hydrogen bonds. He said that $\ce{LiAlH4}$ is a strong reducing agent that $\ce{NaBH4}$. I was not satisfied by his answer. I want an answer in terms of a reaction mechanism.
Answer
The answer is polarity.
Consider the two ions $\ce{AlH4-}$ and $\ce{BH4-}$ (as they exist as ions in a solution).
Now the electro-negativity of $\ce{Al}$ is $1.5$, and that of $\ce{B}$ is $2$, and that of $\ce{H}$ is $2.1$.
So the electro-negativity difference ($\Delta\mathrm{EN}$) between $\ce{Al-H}$ bond is $0.6$ and that of $\ce{B-H}$ bond is $0.1$. It is clearly visible that the $\Delta\mathrm{EN}$ of the $\ce{Al-H}$ bond is greater than that of the $\ce{B-H}$ bond.
Now considering the mechanism, due to the small polarity induced by the carbonyl group of the carboxylic acid, the $\ce{H}$ atom in $\ce{Al-H}$ bond is readily broken due to its high polarity, while the $\ce{H}$ in $\ce{B-H}$ can't do the same because it has a low polarity.
This is the reason why $\ce{NaBH4}$ cannot be used instead of $\ce{LiAlH4}$ for reducing carboxylic acids to alcohols.
I am working on a project that needs a lowpass filter with a -7.5 dB/Octave rolloff. This is somewhere between the rolloff of a one-pole and two-pole filter, so I wanted to ask what some standard methods are for generating this type of response.
Is it appropriate to have a two pole filter (or two one-pole filters in series) and do a wet/dry mix? Or would is there a more robust method I should try instead?
I am hoping I am able to accomplish this using a simple IIR filter like a biquad.
Propose a mechanism for the following reaction showing the relevant stereochemistry of intermediates and the final product.
I am confused as to what is going on here. I guess there's some sort of neighboring group participation after the formation of the bromonium intermediate. From the molecular formula of the product, I deduce the mechanism seems to proceed via an addition and subsequent elimination. But then again I'm not very sure.
Answer
As you already know, treatment of an alkene with aqueous bromine leads to halohydrin formation. This results when the intermediate bromonium ion is trapped by the solvent, water:
Generally, water is a lousy nucleophile, but this process can happen because there is simply so much water around. In our case, the alcohol in the same molecule acts as the nucleophile, instead of water which may or may not be present. Alcohols aren't great nucleophiles, but what this has going for it is that the process (called bromoetherification, because you form a bromo+ether) is intramolecular.
As you can see in the scheme above, there are two possibilities in the formation of the bromonium ion: either on the top face of the alkene, or on the bottom face. There is probably a slight bias because of the presence of the substituent on the ring, but it turns out that this probably does not matter.
When the alcohol attacks the bromonium, it is an $\mathrm{S_N2}$ process, which requires the oxygen to attack carbon from behind the C–Br bond. Now, if the bromonium ion forms on the top face, this can't happen, because it's tough for the oxygen to loop all the way to below the plane of the alkene. Only if the bromonium ion is formed on the bottom face can the oxygen attack. Thankfully, bromonium formation is pretty much reversible, so even if the bromonium ion is initially formed on the top face, it can revert to starting material.
Extra
This bromoetherification reaction doesn't seem to have been carried out on this particular substrate - perhaps it's too simple - but it is a thing. Here's a more impressive example (Org. Lett. 2004, 6, 2961):
It also has a somewhat more popular cousin, called bromolactonisation, where the nucleophile is a carboxylate instead of an alcohol. Here's an example, taken from E. J. Corey's prostaglandin synthesis. The halogen used is different ($\ce{KI3}$ acts as a source of $\ce{I2}$, so this is an iodolactonisation) and the nucleophile is different, but the mechanism is generally the same - except that $\ce{NaHCO3}$ deprotonates the carboxylic acid before it attacks the bromonium. Can you work it out?
See also: Facial selectivity of iodonium formation in an iodolactonisation for a related question on iodolactonisation.
How do we fulfill the positive commandment in Devarim 28:34 which commands us to be crazy:
וְהָיִיתָ, מְשֻׁגָּע
Can one in theory achieve as high accuracy as needed by sampling a sinusoidal signal over n Periods? Is there a formula that connects the signal frequency (f), sampling frequency (fs), periods (P) and accuracy (Acc) or can someone explain how accuracy rise with number of periods? Let's say I want to know the signals amplitude with an error of less than 0.1%.
Lets say I want to sample a signal with a sampling frequency exactly four times that of the signal frequency. Let's say the first sample hit the sinusoidal signal at it's peak, the second at a zero-crossing, the third at it's negative peak and the fourth at a zero-crossing. This average will yield (1 + 0 + abs(-1) + 0)/4 = 1/2. Averaging over n periods would not change this average value in theory. Let's say the first value hits 45 degrees off the peak and the next 3 samples follows with 90 degree phase difference. The average would now be: (0,71 + abs(-0,71) + abs(-0,71) + 0,71)/4 = 0,71. Averaging over n periods would not change this average value either.
But I have been thinking.
If one introduces a small phase shift of let's say 1 degree per period based on the difference between the signal frequency and the sampling frequency, one could over 360 periods have sampled along the "whole" sinus with samples at 360 different points on a sinusoidal signal. This of course assumes the signal is periodically (and it is in this case). This would give a pretty good estimate of the sinusoidal signals amplitude, but how much is the error here? Is this something that can be calculated easily with some sort of formula or do I have to use MATLAB?
And what happens in "real" situations when the sampling frequency can't be exactly 1 degree off per period, but maybe 0,9384283437 and we have to sample e.g., 324986234 (just a big number to prove the point that an unrealistic number of periods have to be sampled) periods to be able to sample an integer number of periods. I understand that here there will be a trade-off between needed accuracy and number of periods needed to be sampled, but how can I calculate this?
If what I have written above makes sense and is correct, it seems doable to obtain the wanted accuracy by adjusting the phase shift and number of periods to sample over.
Other: I can understand how some would think of this long text as more of an explanation or help to calculate different things. And this is mostly true as I have no experience or academic background in digital signal processing and therefor need to get confirmation on my idea, thought and understanding of the subject. Things I ask here are things I have not found the answers to by any text book or by googling, even though they for sure are available a lot of places, none of them have been able to completely show me or make me understand this topic and I am therefor asking by writing this text above. Hopefully others may benefit from this questions and the answers provided. Thanks! =)
How many names of Tannaim do we know?
How many names of Ammoraim do we know?
(I am asking about the names and not simply asking "how many were there" because I don't know if there were people that were considered a Tanna or Ammora that we don't know of [whatever that would mean])
So I started watching the movie あかひげ the other night and intrigued by the title I looked it up in the dictionary where one of the definitions was:
Westerner (derogatory)
Does it really contain this meaning?
How is this used (if it is indeed used?!?) in modern Japanese?
If it's not used what word can be used to express "Westerner (derogatory)" in modern Japanese?
Answer
Born in Japan and raised in Japan for more than 30 years, I have never seen "赤ひげ" used as a derogatory term of "westerner".
Before I write this, I did find an entry 赤髭 in a Japanese derogatory terms glossary, and it does say it's "Westerner (derogatory)." However, more than 90% of the words in that list were totally unfamiliar to me. So I believe it's safe to say there's no derogatory nuance in "赤ひげ" in modern Japanese. Maybe it was a derogatory term in the Edo period.
Today, "赤ひげ" reminds Japanese (not younger than 30) of what you've just watched in the movie; a humane doctor who sacrifices himself and willingly helps weak people. It is a stereotype of "ideal doctor" in Japan, just like "黒ひげ" or Blackbeard is the symbol of pirates. There is Akahige Prize for doctors.
(However, its original novel, 赤ひげ診療譚, published in 1958, is full of discriminatory terms and acts by today's standards...)
Say I have a pot that I used for beef soup. Then an hour later I forgot I used the pot for meat and I decide to make soup with cheese. I throw the cheese in it and put it on the fire. About 5 seconds later I remember I used it for meat. What is the Halacha, does the pot need to be kashered, and what is the Halacha regarding the cheese.
Romaji is somewhat of a conversion from kanji and kana to the Roman alphabet.
What are the disadvantages of learning only or mostly romaji aside from being unable to read/write in kanji? I don't think there are many advantages.
Answer
Your question body contradicts the title, so I'll answer both questions:
Advantages of roomaji (I never thought I'd say this!):
Disadvantages of roomaji:
In our engineering academics, there is one subject named "signals and systems". In this subject only LTI system is discussed.
I want to know what are the advantages of LTI systems over other combinations like system which is stable and causal or system which is Linear and stable ? Also,don't they have any disadvantages?
Why is $\ce{CrCl3}$ acidic? I know that it has a high charge density given that it is a transition metal ion, and can hence polarize neighbouring water molecules, resulting in hydrolysis and formation of $\ce{H+}$. However, I am a little confused over how this happens? Is the water molecule that it polarizes the ones that have formed a coordinate bond with it, or simply any water molecule? Also, with the high charge density, it should be attracting electrons from the water molecule. But does it mean that it attracts the 2 electrons forming the bond between $\ce{O}$ and $\ce{H}$? And if it attracts them to itself, why doesn't it form an extra coordinate bond? Why is there still only 1 coordinate bond? Another thing that I don't understand is that $\ce{OH-}$ has a lower d-orbital splitting ability than $\ce{H2O}$, doesn't that mean coordinate bonds with $\ce{H2O}$ are preferred? Why do they still polarize $\ce{H2O}$ to get $\ce{OH-}$ instead?
I am machmir on only listening to music that was performed by a Jew, but i don't really understand it. Does anyone know what is the source for this? Does Matisyahu perform with only Jews?
Answer
See Igros Moshe YD 2:111 where he raises issue of church influence which relate to the players' intentions, the words, and the instruments. Jews presumably would not have suspicious (regarding idol worship) intentions.
Here on Mi Yodeya, one can earn the "Fanatic" badge for visiting the site for 100 consecutive days.
Is it halachically possible to earn the fanatic badge in the Diaspora?
が早{はや}いか and や否{いな}や both seem to mean "as soon as". They describe a relation between two actions, where one action occurs when another does.
I'm a little fuzzy on the difference, though. I think, from reading examples in my N1 practise book that が早{はや}いか is more momentary. Action A is something that is more or less instantaneous, triggering B to happen in a mere moment.
や否{いな}や, on the other hand, can be a little more overlapping. While action A is in the process of completing, B happens.
Here are some example sentences which seem to support that difference:
時計{とけい}が10時{じ}を告{つ}げるが早いか、いっせいに問{と}い合{あ}わせの電話{でんわ}が鳴{な}り出{だ}した。
The clock hitting ten is an instantaneous occurrence.
母{はは}の足音{あしおと}が聞{き}こえるや否{いな}や、愛犬{いあけん}のチロは玄関{げんかん}までダッシュした。
Footsteps continue over a small amount of time, so there is a bit of overlap between them being heard by the dog, and it running toward the front door.
However, this example sentence doesn't fit the mould:
電車{でんしゃ}のドアが開{ひら}くや否{いな}や、どっと乗客{じょうかきゃく}が降{お}りてきた。
A train door opening, to me, seems more of an instantaneous occurrence than not. Though maybe that's just my take on it. I could see how some might argue that it is a point in time more than a section of time.
Am I correct in that they a differentiated by how instantaneous event A is? Is there anything else that differentiates them?
Answer
"Japanese Core Words and Phrases" by Kakuko Shoji has a little bit about ~が早いか. The book contrasts it with ~たと思ったら instead of with ~や否や, saying that "the focus here is on what actually happened rather than on what the speaker perceived". Unfortunately, the book doesn't have anything on ~や否や.
Looking at the sample sentences for ~や否や on this JLPT practice site, the examples aren't necessarily consistent with the idea that in Aや否やB, the two events can be overlapping in time. For instance, the two events in the below example should be instantaneous:
その部屋に入るやいなや彼らは話をやめた。
The minute I entered the room, they stopped talking.
The description on this grammar site suggests the two are essentially the same.
This Chiebukuro answer suggests the same thing, but adds that ~や否や has the additional meaning ~かどうか, and clearly cannot in this capacity be substituted with ~が早いか.
It is established the dipole moment is a result of multiplication of the magnitude of charges (Q) and the distance between them (r). What I understand is that when an electron and a proton get closer (bond length decreases), polarity decreases hence the dipole decreases. When they move further away from each other(bond length increases), the polarity increases and hence the dipole moment increases. However, in case of halides (H-X), let's take for example HF and HI, HF has a bigger dipole moment than HI, it is stated that the bond length of HF is smaller than HI. Why do I find this contradictory? Can you help me with What I am missing here?
Everyone knows that Sephardics and Ashkenazis wrap tefillin differently. But how did/do Romaniotes (from parts of Greece, mainly Ioannina) wrap it?
I have a little karaoke-style app where a user sings 4 lines of a song, with a one second gap between each line. There is no backing music, so it's voice only, hopefully making the problem easier to solve.
I am looking for the most robust way to detect exactly where in my recording the user starts and ends singing line 1, starts and ends singing line 2, etc.
I have cobbled together a simple-minded algorithm that works when there is very little background noise in the recording (like when does that happen?), but it falls to pieces in the presence of the smallest noise.
Can anybody point me towards something more robust?
Of course there is a set order in the Siddur, but is there a hierarchy in ברכות השחר? If, for example, someone did not wash his hands or use the bathroom when he woke up, can he say Elokai Neshamah or ברכות התורה?
What is the formula on this cup representing?
Are we commanded to love an Apikores as a fellow Jew, or are the regarded as something else?
My question is: does the Mitzva of Viahavta Lereiacha Kamocha apply to an Apikores?
Answer
This seems to be addressed Sefer Chafetz Chaim 8:5
(Source provided from Sefaria.org)
And this entire issur of lashon hara applies only [when spoken] against the man who is in the category of "your neighbor" [amitecha], "am she'techa", i.e. "a people who is with you" in Torah and in mitzvoth. But those people whom he knows to have "apikorsoth" [heresy] among them, it is a mitzvah to demean and to shame, both in their presence and not in their presence, in everything that he sees or hears about them. For it is written (Vayikra 25:17): "And you shall not wrong, one man, his fellow [amito]" and (Vayikra 19:16): "You shall not go talebearing among your people [be'amecha]." And they are not in this category, for they do not act as Your people. And it is written (Tehillim 139:21): "Do I not hate your haters, O L-rd? And against those who rise up against You do I strive." And one who denies the Torah and prophecy of Israel, both the written and the oral Law, is called an apikoress [heretic], even if he says all the Torah is from Heaven, except for one verse, or one kal vachomer [a fortiori argument], or one gezeirah shavah [identity deduction], or one dikduk [inference].
Hope this helps.
Most of us here would know that flames can be colored by adding an appropriate salt to the 'fuel' or by simply introducing it into a flame. Boron and Barium salts give the flame a green tinge, Strontium colors it red, Sodium does gold, copper a bluish-green, etc, etc.
Now from my (not-so-in-depth) high-schooler level of understanding, the energy released by whatever is being burnt to produce the flame in the first place (as is usually the case), excites electrons in metal ions in the salt to higher energy levels. And when these electrons 'de-excite' and drop back to the original energy levels, they emit that extra energy as photons (whose frequencies are determined by the Planck equation $E = h\nu$ ) and these photons are what we perceive as the colored flame.
If I'm not mistaken the book Harry Potter and the Philosopher's stone mentions a 'black flame' of sorts, being one of the obstacles Harry has to circumvent in order to reach the Stone. (Artist's depiction)
Now, as I understand it, for something to be 'black', it must absorb all ( or at least a fairly significant amount of) visible light, encompassing a wide range of frequencies.
Going back to colored flames, I mentioned that the ions must emit light energy, not absorb it, in order to color the flame.
Armed with all this information, would anyone know if it really is possible to create 'black colored flames'? Has it ever been achieved?
[I tried thinking it out myself.....just gave me a headache]
Edit 1: And yes, I've made note of what @Mithoron mentioned, but what I mentioned was just conventional logic, it isn't universal though.
...Newtonian mechanics was 'conventional logic', but we all saw how that failed in relativistic scenarios. So I didn't want to take the risk, hence I've asked If it actually is possible...
Edit 2: Just because someone mentioned otherwise in an answer... I emphasise that by black flames I don't mean invisible flames.
Answer
If black means that the flame does not emit light that is visible to the human eye then there is a certain chance that black flames might exist.
Since hot flames emit black body radiation and the spectrum of visible light reaches from about $\pu{400nm}$ to $\pu{800nm}$, a black flame had to be cool enough to not emit too high intensities of light below $\pu{800nm}$. So we're searching for a cool flame.
While cool flames are hardly visible in daylight, it might be difficult to find one that is invisible in a dark environment. Here is a report of a cool flame that could only made visible in the dark by long photographic lighting.
How do these two verbs differ?
Answer
More or less like "I love you" and "I love thee" differ. 愛す is an older form with basically the same meaning. Same with other す/する pairs like 略す／略する、座す／座する etc.
Tehillim is plural of Tehilla (תהלה). Tehilla looks like a feminine noun, which is why there's a word called תהלות.
So why is the sefer called Sefer Tehillim?
How can I derive the fourier transform of
g1(t) = {A cos(2πfc t),−T/2 < t
and;
g2(t) = cos(t), −∞ < t < ∞
my answer for g1 is;
∫ g(t)exp(-j*2*pi*f*t)dt = ∫ Acos(2*pi*fc*t)exp(-j*2*pi*f*t)dt
=∫ 1/2A (exp(j*2*pi*fc*t)+exp(-j*2*pi*fc*t))exp(-j*2*pi*f*t)dt
=∫1/2A(exp(j*2*pi*fc*t)exp(-j*2*pi*fc*t)+∫1/2A(exp (-j*2*pi*fc*t)exp(-j*2*pi*fc*t))
=1/2A∫exp(-j*2*pi(f-fc)t) + 1/2A ∫exp(-j*2*pi(f+fc)t)dt
=1/2A(f-fc)+1/2A(f+fc)
I was trying to draw the Lewis structure of $\ce{HSO5-}$ (peroxymonosulfate), so I came up the structure on the left that satisfies the octet rule. Then, I saw that the correct structure is the one on the right. Why is the structure on the right favored over the one on the left? They both have the same formal charges. So shouldn't the one that satisfies the octet rule be favored over the one with an extended octet?
$\hspace{15 mm}$
Answer
The structure on the left is less favored because of the presence of too many peroxide bonds. You must have come across a few peroxides like $\ce{H_2O_2}$. Have you ever noticed why we handle these compounds with great care, like storing them away from sunlight in a dark bottle? It is because the peroxide bond is quite weak when compared to other bonds. So, more the number of less energetic bonds, less stable is the compund
$\ce{S=O}$ has a bond energy of around $\pu{128 kcal/mol}$, but $\ce{O-O}$ has a measly bond energy of $\pu{35 kcal/mol}$. So, in future, if you are asked to draw Lewis structure for compounds, avoid using multiple peroxide linkages. There can be a maximum of one* in your structure.
Some compounds with many $\ce{O-O}$ bonds exist. But in general, such compounds are highly reactive in nature. There could be exceptions as well, since it is not possible to give a single set of rules to determine stability for all compounds.
As pointed out here, it is not required and widely common for a boy under Bar Mitzva to lead the congregation in the singing of Shir Hakavd.
My question: is it acceptable for a girl under Bat Mitzva to lead the congregation for Shir Hakavod as well?
I do not know if a realistic or abstract freestanding or hanging sculpture of any creature as art (for a museum or store) is permitted me to create or for Jews to view, or whether it would be confused for an idol. What are the restrictions on Jews to create sculpture?
Consider the following experiment:
Questions
in order of importance
Notes: Analytical methods would be appreciated instead of 'heavy' computer simulations.
Answer
Such questions are relatively standard in discussing transport phenomena, so I'll suggest Bird, Stewart, and Lightfoot's Transport Phenomena as a good reference.
We assume a flat plane of contact infinite in extent. We assume that the bulk atmosphere has a constant concentration $c_A$ of some species of interest, and that the bulk liquid has a constant concentration $c_B$ of that species. The species is only allowed to mix between the two bulk phases for times $t > 0$. Then the problem reduces to the one-dimensional diffusion equation (Fick's first and second laws) $$\partial_t c(z,t) = D\,\partial_z^2 c(z,t)$$ subject to the initial condition $$c(z,0) = \frac{c_A+c_B}{2} + \frac{c_B-c_A}{2}\text{sgn}(z),$$ and the boundary conditions $$c(-\infty, t) = c_A, \quad c(+\infty, t) = c_B,$$ where $D$ is the species' diffusion constant and $\text{sgn}(z)$ is the signum function.
For ease of solution, make the substitutions $$\bar{c}(z,t) := c(z,t) - \frac{c_A+c_B}{2}, \quad \Delta c := \frac{c_B-c_A}{2}, \quad \phi(z,t) := \frac{\bar{c}(z,t)}{\Delta c},$$ which yields $$\partial_t\phi(z,t) = D\,\partial_z^2 \phi(z,t), \quad \phi(z,0) = \text{sgn}(z), \quad \phi(\pm\infty, t) = \pm1.$$ By definition $\phi$ is a dimensionless quantity, so it must depend on the variables relevant in the problem in a dimensionless form, for otherwise $\phi$ would have units. The relevant variables in our problem are the diffusion constant $D$, the length $z$, and the time $t$.
The only dimensionless variable that arises from this set of quantities is $\eta := z/\sqrt{Dt}$, so we know $\phi(z,t) = \phi(\eta)$. Substituting this result into our diffusion equation and applying the chain rule yields the ordinary differential equation $$-\frac{\eta}{2}\phi'(\eta) = \phi''(\eta).$$ Integrating twice yields the result $$\phi(\eta) = \alpha + \beta\int_0^\eta\text{d}\eta'\,\exp\left(-\frac{\eta'^2}{4}\right),$$ and it remains to determine the constants $\alpha$ and $\beta$ from our boundary conditions. Actually, for standardization, we will first take $\eta' \to 2\eta'$ and $2\eta \to \eta$, so $$\phi(\eta) = \alpha + 2\beta\int_0^\eta\text{d}\eta'\,\exp(-\eta'^2).$$ By symmetry $\alpha = 0$, and by explicit evaluation $\beta = 1/\sqrt{\pi}$, and hence we have $$\phi(\eta) = \text{erf}(\eta), \quad \text{or} \quad \phi(z,t) = \text{erf}\left(\frac{z}{\sqrt{4Dt}}\right).$$ Going back and untangling all our substitutions, we end up with $$c(z,t) = \frac{c_A+c_B}{2}+\frac{c_B-c_A}{2}\text{erf}\left(\frac{z}{\sqrt{4Dt}}\right).$$ The flux then follows as $$J(z,t) = -D\,\partial_zc(z,t) = -D\,\frac{c_B-c_A}{\sqrt{4\pi Dt}}\exp\left(-\frac{z^2}{4Dt}\right),$$ and we are done.
Regarding your second question, I don't believe the movement of one phase relative to the other will have any effect. As we've seen above, the xy-plane essentially drops out of the picture, and you won't be introducing any further gradients in chemical potential by translating one phase relative to the other, since the concentration of each phase is a function of $z$ only. Of course, if you had a finite area of contact, then things would be different. Perhaps see BSL 18.5, in this case.
In addition, keep in mind that there's important chemistry that's being neglected in this simplistic model. For example, the dissolution of carbon dioxide in water follows not just from diffusion but also from reaction with water, forming bicarbonate ion and related species in solution. This model doesn't account for that.
So, I need a method of estimating the influence of a surface (rate constant would do for a start), the idea is to estimate just Reactant + Surface -> Product in a turbulent liquid flow.
Now I am aware of the book "The properties of gases and liquids" by Poling and Prausnitz which gives me two terms for estimating diffusion in a liquid, one general formula from 1975 and a formula specific to hydrocarbons (applicable in my case) from 1982, namely:
Tyn and Calus, 1975:
$$D(AB) = \frac{7.4\,10^{-4} (\phi M(B))^{1/2}T}{\eta(B) V(A)^{0.6}}$$
Hayduk and Minhas, 1982:
$$D(AB) = \frac{13.3\,10^{-8}T^{1.47} \eta(B)^{\epsilon}}{V(A)^{0.71}}$$ where $\epsilon = \frac{10.2}{V(A)}-0.791$
The other variables are
Given that in my special case I am looking at a liquid in a turbulent flow, I can use the kinetic theory of gases to estimate a surface collision rate - and include surface efficiency using the work on Baldwin and Howarth from 1982.
For a cylindrical pipe with the solute tending to zero, an upper limit for my rate constant for a surface reaction would be: $k(s) = \frac{8D}{r^2}$
Now there is one big problem with this: The diffusion estimate is not for a turbulent flow (I might be able to get get a diffusion term from Fluent to get a more accurate estimate).
Secondly, at best this would give me an upper limit.
So my question is, do you know of any better more accurate methods of estimating (at least limits) a rate constant for surface reactions? (Or at least the collision rate with the surface.)
Anyone have an idea of how I can implement autocorrelation of power spectrum of one image? I tried using:
autocorrel = ifft( | fft(power spectrum) | ^ 2 );
but it's not working. Do you have any idea why or some other way?
We're trying to implement a "simple" speech recognition application in MATLAB (isolated words from a very limited dictionary). We've been trying the following methods:
All three of these methods didn't work well (and gave almost everything wrong results). We don't know what the problem is.. A few questions that arose, but we don't know the answers, are:
We would appreciate any help, or references to good sources. We thought about using HMMs, but it seems much more difficult and not really possible in our time-frame..
Thanks.
Answer
What finally worked for me:
Calculate the DTW between the MFCC vectors of each of the training samples.
Classify in pairs (i.e. check if the word $w$ is in {class1, class2}. If the decision is class1, then $w\notin$class2. Then check {class1, class3}, etc...).
Generate for each word $w$ and pair of classes {class1, class2} a 2D feature vector, $p$, as follows: $p_i$ = mean of the DTW between $w$ and all the training words of class-i.
Now I generated the feature vectors for every word of the training set (and for every class-pair), and used them to train $n \choose 2$ SVM classifiers ($n$ - number of different classes).
For the classification, we need to make $n$ tests (to rule out $n-1$ classes).
Notes:
Isn't it better to daven in your first language rather than davening in Hebrew and only knowing part of what you're sayig?
Why is 味わわせる often pronounced as 味あわせる? What makes the former form unnatural, and what is the mechanism that changes it to the latter form? In the first place, what it the -waw- attached to aji (besides the obvious answer that it is an affix that derives a verb)? Are there other words (inside or outside of Japanese) that follow the same phonological pattern?
Answer
Why is 味わわせる often pronounced as 味あわせる?
I can only speculate that this is a kind of onbin to ease pronunciation. The two medial approximates /w/ are only separated by a vowel. Approximates, also known as semi-vowels, share some similarities with vowels. The reduction of one in rapid speech is small while still understandable. The reduction of the first rather than the second is similar to baai <> bawai, which tries to avoid repeating the same vowel twice.
What makes the former form unnatural, and what is the mechanism that changes it to the latter form?
I would not say that the former is necessarily unnatural. Rather that in spoken language the former takes more effort to say and as such sounds stiff or formal. See above for speculation for the mechanism.
If the first place, what it the -waw- attached to aji (besides the obvious answer that it is an affix that derives a verb)?
As you already said, it is just an affix that attaches to nouns to derive verbs. Etymologically it is suggested to be 這う・延う, but evidence is minimal. There are both yodan and shimo nidan versions.
Are there other words (inside or outside of Japanese) that follow the same phonological pattern?
If you are asking for other words with the same affix waw-, then yes.
And then there is the nominal forms (cf ajiwai), though the corresponding verbal forms do not seem to exist:
These are more verbal than affix, but for reference, there is also:
My understanding of the purpose of the trope (cantillation) notes is that they were initially (Massorah) meant for the purposes of grammar and pronunciation. I've hunted a few web sites, and I couldn't locate anything that states that by Massorah (I.e. when given at Mt. Sinai) these notes had music to them.
I did locate in Talmud Megillah 32a:
ואמר ר' שפטיה אמר ר' יוחנן כל הקורא בלא נעימה ושונה בלא זמרה עליו הכתוב אומר (יחזקאל כ, כה) וגם אני נתתי להם חוקים לא טובים וגו'
R. Sheftiah further said in the name of R. Yohanan: If one reads [Scripture] without a melody or recites the Mishnah without a tune, of him the verse says, “For I gave them also statutes that were not good.” (Ezekiel 20:25).
(Note: I am aware that immediately afterwards, Abaye disputes this statement.)
By making this statement, R. Sheftiah seems to imply that one should sing the Torah reading (See Rashi's explanation, there) stating that he means using ta'amei hamikrah - cantillation notes).
What's unclear from the Gemara's statement are these areas:
Answer
- Is a person obligated ever to sing the notes whether he is reading Torah aloud individually or a congregational setting?
In a congregational setting one is obligated to sing the notes, and according to some the congregation does not fulfill their obligation if the notes are not sung. (See Beis Yosef 142)
In a private setting:
Magen Avraham (285:1) writes that one who is familiar with the ta'amim should read "shnayim mikrah" from a Torah Scroll.
According to the Tur (61:24), there is an obligation to read the Shema with the notes (also see Beis Yosef there) This ruling is also brought in Shulchan Aruch (61:24).
In casual speech what does ja na mean?
As in this example:
葉人をつかまえたんじゃな
Googling for it only turns up results for じゃない。
Why would a hydrogen atom "donate" to fluorine in an ionic bond but not in $\ce{HCl}$? Why would $\ce{H}$ and chlorine share instead of $\ce{Cl}$ just stripping it away like $\ce{F}$ does?
When considering these sentences
- 食べる前に宿題をする。
- 食べるより先に宿題をする。
They both mean I will do my homework before I eat.
If I had to guess, the nuance would be for 先に means "I will do homework ahead of eating" and 前に focuses more doing the action of eating before doing the homework. But I'm not so sure about my interpretation.
Can someone explain the difference and in which particular contexts they can only be used with some examples?
Answer
食べる前に宿題をする。
食べるより先に宿題をする。
You're right that they both mean "(I will) do my homework before I eat", both 前に and (より)先に can mean "before" or "earlier" and these can be used interchangeably in most situations where you describe one action occurring before another.
The only difference that I can see in your specific examples is... 先に can have a nuance of order of priority/precedence (優先順位), so I think 食べるより先に宿題をする can have a slight nuance that 宿題 has priority/precedence over 食べる, is more important and should be done earlier than 食べる, whereas 食べる前に宿題をする just neutrally means "to do homework before eating".
And ～する前に can often mean "right before".
A few examples using 前に or 先に (when used in the sense "before/earlier"):
お先にどうぞ。（× 前に） After you.
先に行くよ。（× 前に） I (will) go/leave first.
何よりも先に First of all / before anything else
お先に失礼します。（× 前に） I'm going home (before you). → Good-bye. (at the office etc.)
３月３日より前に返事をください。 Give your answer before March 3.
(～より先に返事を下さい might sound like you want the answer after March 3.)
彼より先に着く / 彼の前に着く / 彼より早く着く arrive before/earlier than him
(前に can mean "right before".)
Is there a Halachah that forbids eating while learning? One of my friends told me it was forbidden.
I did some calculations, based on the following measures:
I arrived at approximately 4 metric tons. Is this reasonable?
Answer
I go through the math here. Admittedly I use a lot of very rough estimation. I caught some mistakes in my math in the video which I have edited here, as well as adding a section below regarding the contents of the Aron.
It's important to note that according to R' Meir, the amos used are 6 tefachim each, while according to R' Yehudah, the amos used are 5 tefachim each. (All sources used to justify these and other numbers later are cited at the bottom.)
Making these conversions, according to R' Meir:
All of the above was made of gold, yielding a total of 344.43 cubic tefachim of gold according to R' Meir.
According to R' Yehudah:
For a total of 245.5 cubic tefachim of gold according to R' Yehudah.
The poles and middle box were both made of wood.
According to R' Meir:
Totaling 293.5 cubic tefachim of wood.
According to R' Yehudah:
Totaling 188.66 cubic tefachim of wood.
According to Rav Moshe, a cubic tefach is equivalent to 751.83 cubic centimeters. Since the density of gold is 19.32 g/cm3, R' Meir's 344.43 cubic tefachim (258,952.81 cubic centimeters) of gold weighs 5,002.97 kilograms, and R' Yehudah's 245.5 cubic tefachim (184,574.265 cubic centimeters) of gold weighs 3,565.97 kilograms.
The wood used was specifically cedar wood, which has a density of 0.58 g/cm3. R' Meir's 293.5 cubic tefachim of wood weighs 127.98 kilograms, and R' Yehudah's 173.66 cubic tefachim of wood weighs 109.42 kilograms.
Adding these together yields that:
As I noted, I discuss an empty Aron, whereas you include the Luchos in your calculations. The following additions are not discussed in the linked video.
Four metric tons (=4000 kilograms) isn't a bad estimate...for an empty Aron. For a full one, you're waaaay off.
I have heard some rumors that drinking milk prevents chemical poisoning. I have done a bit research and some sources confirm that.
Corrosive Poisons
The best first aid is to dilute the poison as quickly as possible. For acids or alkalis (bases), give the patient water or preferably milk or ice cream — one (1) cup for victims under five (5) years; or one (1) to two (2) glasses for patients over five (5) years. Milk or ice cream is better than water because it dilutes and helps neutralize the poison. Water only dilutes the poison. Cornell University
In Case of Poison Ingestion: Drink Milk?
As @Jan pointed out in the case of chemical poisoning the paramedics are immediately called.
So my question is, does milk helps chemical poisoning, e.g., for people that daily work with chemicals or are working in chemical facilities (working with or be in the presence of $\ce{HCl}$, $\ce{HF}$, $\ce{NaOH}$, $\ce{HNO3}$, $\ce{H3PO4}$, etc.)? Or what would be beneficial? And I mean long-term exposure and not immediately threat to life or health.
Answer
This post only concerns chronic poisoning, i.e. exposure to a harmful chemical in low amounts for an extended period of time. The answer is not applicable to acute poisoning; in that case a doctor should immediately be called.
Basically there are three types of chemicals that have a harmfulness threshold to which one can be exposed over extended periods of time.
Type one includes substances such as mercury that are primarily aggregated in the body rather than excreted. In rare cases, drinking milk may enhance excretion thereby decontaminating the body. I haven’t heard of any such examples, though, and I would assume it to be a very rare case so neglegible.
Type two includes those substances that the body can actually metabolise to harmless products. This would include most protein poisons. However, the metabolism shouldn’t be enhanced by drinking milk so it will likely have a non-effect.
Type three includes those that, while they aren’t metabolised, just don’t do enough damage at low concentrations. That would basically include your list of acidic and basic substances but also non-aggregating metals at low concentrations. For these, excretion is not significantly enhanced or reduced by drinking milk so again no effect is expected.
Comparing the acute exposure to acids to the chronic one, in the former giving a person milk to drink is actively encouraged. This is because milk contains a lot of proteins that can act as buffers, increasing the body’s buffering potential and reducing the effects of the acid. The body does have more than enough buffering capabilities to cope with chronic cases though, so even there regularly drinking milk would not help.
Tl;dr: Milk is a great drink but cannot act as a type of preventive antidote.
It is true that Adam and Eve didn’t die the exact day they ate, as some seem to think Genesis 2:17 implies. The Hebrew is die-die (muwth-muwth), which is often translated as “surely die” or literally as “dying you shall die,” which indicates the beginning of dying (i.e. an ingressive sense). At that point, Adam and Eve began to die and would return to dust. If they were meant to have died right then, the text should have used muwth only once, as is used in the Hebrew meaning “dead, died, or die” and not “beginning to die” or “surely die.”
Is such an interpretation of בְּיוֹם אֲכָלְךָ מִמֶּנּוּ מוֹת תָּמוּת valid in the context of this verse?
The "sixth chapter" of Avot lists forty-eight qualities with which Torah is acquired.
גדולה תורה יותר מן הכהונה ומן המלכות, שהמלכות נקנית בשלשים מעלות, והכהנה בעשרים וארבע, והתורה נקנית בארבעים ושמונה דברים, ואלו הן: בתלמוד, בשמיעת האזן, בעריכת שפתים, בבינת הלב, באימה, ביראה, בענוה, בשמחה, בטהרה, בשמוש חכמים, בדקדוק חברים, בפלפול התלמידים, בישוב, במקרא, במשנה, במעוט סחורה, במעוט דרך ארץ, במעוט תענוג, במעוט שנה, במעוט שיחה, במעוט שחוק, בארך אפים, בלב טוב, באמונת חכמים, בקבלת היסורין, המכיר את מקומו, והשמח בחלקו, והעושה סיג לדבריו, ואינו מחזיק טובה לעצמו, אהוב, אוהב את המקום, אוהב את הבריות, אוהב את הצדקות, אוהב את המישרים, אוהב את התוכחות, ומתרחק מן הכבוד, ולא מגיס לבו בתלמודו, ואינו שמח בהוראה, נושא בעל עם חברו, ומכריעו לכף זכות, ומעמידו על האמת, ומעמידו על השלום, ומתישב לבו בתלמודו, שואל ומשיב, שומע ומוסיף, הלומד על מנת ללמד והלומד על מנת לעשות, המחכים את רבו, והמכון את שמועתו, והאומר דבר בשם אומרו
Greater is Torah than priesthood and kingship, for kingship is obtained with thirty levels, and priesthood with twenty-four, and Torah is obtained with forty-eight things. And these are them: learning, listening of the ear, preparation of speech, understanding of the heart, intellect of the heart, reverence, awe, humility, happiness, purity, service of sages, care of friends, debate of the students, clarification, scripture, mishnah, minimization of merchandise, minimization of worldly occupation, minimization of pleasure, minimization of sleep, minimization of conversation, minimization of laughter, patience, generosity, trust of the sages, acceptance of afflictions, knowing one's place, gladness in one's portion, erection of a fence to one's words, lack of self-aggrandizement, lovableness, love of God, love of the creatures, love of the righteous, love of the upright, love of rebuke, distancing from honor, lack of arrogance in learning, lack of joy in issuing legal decisions, lifting of a burden with one's friend, judging him with the benefit of the doubt, placing him with the truth, placing him with peace, deliberation in study, questioning and responding, hearing and adding, learning in order to teach and learning in order to act, making one's master wiser, focusing one's teaching, saying [a thing] in the name of the one who said it.
Are there any other sources, earlier in composition than this version, which list the qualities any differently?
Answer
Commonly known by their appearance in the “sixth chapter” of Avot, this list of virtuous attainments of Torah, along with the rest of the chapter, are actually an emended version of Baraitot from earlier sources, which were supplemented to the weekly Avot study cycle in the Geonic period to provide sufficient reading material for a six-week Shabbat learning session between Pesach and Shavuot. The version which appears in most Siddurim actually differs substantially from earlier versions of the text found in Talmudic and post-Talmudic manuscripts.
There are four ways in which the versions differentiate from each other:
Content - Each list offers its' own unique qualities (some of which may be due to textual variances over time and transcription; I merely present the facts as they are).
Order - Even when listing similar qualities, the order differs substantially from list to list. This can be significant for those who attempt to glean insight into a particular progression that the list sketches for the reader.
I have highlighted qualities which are unique to each version in the texts provided below.
What appears to be the earliest rendition of this Baraita can be found in the 8th chapter of Mesechet Kallah Rabbati, an early anthology of Baraitot with Talmudic discussions which can usually be found printed after Mesechet Avodah Zara. Some editions have this as the 6th or 7th chapter:
גדולה תורה מן הכהונה ומן המלכות, שהמלכות בשלשים מעלות, וכהונה בעשרים וארבעה, והתורה בארבעים ושמונה דברים: בישיבה, במקרא, בדרך ארץ, במיעוט שינה, במיעוט שיחה, במיעוט סחורה,במיעוט שחוק, במיעוט תענוג, במיעוט דרך ארץ, בארך אפים, ולב טוב, באמונת חכמים, ובקבלת היסורין בתלמוד, בשמיעת אזן, בעריכת שפתים, בבינת הלב, בשכלות הלב, בקימה, ביראה, בחכמה, בענוה, בשמוש חכמים, ובדקדוק חברים, ובפלפול התלמידים, המכיר את מקומו, השמח בחלקו, העושה סיג לדבריו, ואין מחזיק טובה לעצמו, ואוהב את המקום, אוהב את התוכחות, אוהב את הצדקות, אוהב את המישרים, מתרחק מן הכבוד, ולא רודף אחר הכבוד, ולא מגיס לבו בתלמודו, ולא שמח בהוראה, הנושא בעול עם חברו, והמכריעו לכף זכות, מעמידו על האמת, מעמידו על השלום, מתישב בתלמודו, שואל ומשיב, שומע ומוסיף, המחכם את רבו, המכוין את שמועתו, והאומר דבר בשם אומרו
Midrash Mishlei, an exegetical commentary on the book of Proverbs written before the beginning of the 11th century (as quoted by R. Chananel; Buber finds content references going back to the 8th century), records a version of the forty-eight qualities (Parasha 19:14) which differs substantially from all other authoritative versions of the text. Of significance is this work being the only one which attributes specific authorship to this Baraita - namely, R. Yishmael.
אמר ר' ישמעאל: גדולה היא התורה שהיא גדולה יותר מן הכהונה ומן המלכות, שהמלכות נקנית בשלשים מעלות, והכהונה בעשרים וארבע, והתורה נקנית בארבעים ושמונה דברים, ואלו הן: בישוב הלב, בשמיעת האוזן, בעריכות שפתים, ובהטבת פנים, ולב טוב, בדעה, ובחכמה, מכיר את מקומו, וקונה לו חבר, ומדקדק בתלמודו, ומעין בשמועתו, ואומר על הטמא טמא, ועל הטהור טהור, ועל הן הן, ועל לאו לאו, ואומר דבר בשם אומרו, ונושא בעול עם חבירו, ומכריעו לכף זכות, ומקבל פני חכמים, ואוהב פלפול חכמים, ושמח בתלמודו, ואין גס לבו בהוראה, ואין מורה הלכה בפני רבי, ולא יושב במקום מי שהוא גדול ממנו, ואוהב את הבריות, ואוהב את התוכחות, ומודה על האמת, ונושא ונותן בשמועתו, ומייסר בנו לתלמוד תורה
Seder Eliyahu Zuta, in chapter 17 (which itself is a supplementary addition to the book proper) records a similar formulation but with significant differences. This Midrashic work dates back to at least 1136 CE, and shares the name of an earlier work written by R. Anan containing teachings from Eliyahu HaNavi (Cf. B. Ketuvot 106a).
גדולה תורה מן הכהונה ומן המלכות, שהמלכות בשלשים מעלות, וכהונה בעשרים וארבע, והתורה נקנית בארבעים ושמונה דברים, ואלו הן: בתלמוד, בשמיעת האוזן, בעריכת שפתיים, בבינת שפתיים, בבינת הלב, בשכל, באימה, ויראה, בענוה, בשמחה, בשימוש חכמים, בדיבוק חברים, בישיבה, במקרא, ובמשנה, בדרך ארץ, במיעוט שינה, במיעוט תענוג, במיעוט דרך ארץ, במיעוט סחורה, בארך אפים, בלב טוב, באמונת חכמים, ובקבלת היסורין, והמכיר את מקומו, והשמח בחלקו, והעושה סייג לדבריו, ואינו מחזיק טובה לעצמו, אוהב את המקום, אוהב את הבריות, אוהב את התוכחות, אוהב את המישרים, ומתרחק מן הכבוד, ואינו רודף אחר הכבוד, ואינו מגיס לבו בלימודו, ואינו שמח בהוראה, הנושא בעול עם חבירו, ומכריעו לכף זכות, ומעמידו על האמת ועל השלום, ומתישב בלמודו, שואל ומשיב, הלומד על מנת ללמד, והלומד על מנת לעשות, והמחכים את רבו, והמכוון את שמועתו, והאומר דבר בשם אומרו
As regarding the “sixth chapter” of Avot itself, the text of this chapter, also known as Perek Kinyan Torah, was critically evaluated by Michael Higger (in Chorev II:2, 1936) based primarily on three early manuscripts of the text. This, too, differs substantially from the popular version found in Siddurim today.
גדולה תורה מן הכהונה ומן המלכות, שהמלכות בשלשים מעלות, והכהונה בעשרים וארבעה מעלות, ותורה נקנית בארבעים ושמונה מעלות: בישוב, במקרא, במשנה, בתלמוד, בדרך ארץ, במיעוט שינה, במיעוט סחורה, במיעוט שחוק, במיעוט תענוג, במיעוט דרך ארץ, בארך אפים, בלב טוב, באומנות חכמים, ובקבלת יסורין, בשמיעת האוזן, בעריכות שפתים, בבינת הלב, בשכלות הלב, באימה, ביראה, בחכמה, בענוה, בשמחה, בשמוש חכמים, בדבוק התלמידים, ובפלפול התלמידים, המכיר את מקומו, השמח בחלקו, והעושה סיג לדברו, ואינו מחזיק טובה לעצמו, אוהב את המקום, אוהב את הבריות, אוהב את הצדקות, אוהב את התוכחות, אוהב את המישרים, ומתרחק מן הכיבוד, ולא רודף אחר הכבוד, ולא מגיס לבו בתלמוד, ולא שמח בהוראה, הנושא בעול עם חבירו, ומכריעו לזכות, ומעמידו על השלום, המתישב בתלמודו, ושואל ומשיב, שומע ומוסיף, ואינו נכנס לתוך דברי חבירו, המחכה את רבו, והמכוין את שמועתו, והאומר דבר בשם אומרו
There are also significant differences in the closing words of each version, but that goes beyond the scope of this question.
In conclusion, each of the versions has some qualities which are unique to its’ version, while sharing others in common with other versions. As well, there are minor textual variations between each version, including additional or missing Vav’s and spelling differences, which can impact the meaning and grammatical breakdown of the list.
The question asks us to select the compound with the smallest heat of hydrogenation per mole out of the following:
a) 1-butene
b) trans-2-butene
c) cis-2-butene
d) 1,3-butadiene
Since all four compounds form the same product (butane), a comparison without actual data should be possible. 1,3-butadiene is conjugated so it is the most stable compound and therefore its heat of hydrogenation should be the smallest.
But it requires 2 moles of hydrogen for complete conversion to butane. And the answer is actually trans-2-butene.
So would we consider each heat of hydrogenation "per mole of hydrogen" or "per mole of the given compound"? The question isn't clear about this and also, if we do consider it as "per mole of hydrogen" then is it correct to simply half the value heat of hydrogenation for 2 moles?
Answer
a comparison without actual data should be possible. 1,3-butadiene is conjugated so it is the most stable compound and therefore its heat of hydrogenation should be the smallest
No, 1,3-butadiene is not the most stable of these compounds, either for the whole molecule or on a per double bond basis (see below). The actual numbers (see table below) are too close, we need to look at some data in order to answer the question correctly.
The question asks us to select the compound with the smallest heat of hydrogenation per mole out of the following:
So would we consider each heat of hydrogenation "per mole of hydrogen" or "per mole of the given compound"?
Here is some data that will help answer the question.
On a "per mole of given compound", trans-2-butene has the lowest heat of hydrogenation, 27.6 kcal/mole.
On a "per mole of hydrogen", 1,3-butadiene has a heat of hydrogenation between 28.2 (56.5/2) and 28.6 (57.1/2) kcal/mole, so trans-2-butene still has the lowest heat of hydrogenation at 27.6 kcal/mole.
So in this particular list of compounds, it doesn't matter whether the question is asking per mole of hydrogen or per mole of given compound, the answer is the same, trans-2-butene.
At first I thought "trick question", but then later thought, not really. The questioner did his homework and wanted the student to work out the answer both ways and see that since the you get the same answer whether you answer on a per mole compound or per mole hydrogen, you don't need to know whether the question is being asked on a per mole compound or per mole hydrogen basis.
This may have some things in common with beginner's seder advice, but it's different enough that I'm asking separately.
For family-obligation reasons, I sometimes find myself at a seder where most of the people are not interested in the religious content -- the seder to them is a family reuinion with traditional elements. (I've already tried "let's get together on day 3 instead"; won't fly.) These are people who identify culturally but not religiously -- but they value home-based rituals for the sake of the ritual itself. All of the attendees are teens or adults.
I have already (mostly) found ways to fulfill my own halachic obligations in such a setting (helped by long-running meals). What, if anything, can I do to liven up this kind of seder and pique others' interest?
Should I bring midrashim that aren't in the haggadah (maybe people like stories)? Should I ask questions (that I'm prepared to then answer if needed) about the haggadah? Can I somehow make the theme of redemption more personal, in a way they could relate to? (How?)
I don't want to be seen as "preaching" but I would like to find a way to improve the situation.
Answer
Report
This "answer" records what I did this year and how it worked out. I drew from several suggestions in other answers here.
Some context: the two seders had different but overlapping groups of attendees. One has always been a "when do we eat?" seder; the other spends more time but replaces a lot of the traditional content with other readings and songs (mostly Zionist). It was hard to get the leaaders of the former to pause for any discussion, though we had some brief conversations farther down the table and a little during the meal. The other one ended up having better prospects.
Eytan Yammer suggested: Go around the table and have everyone finish a sentence "slavery is..." "freedom is..."
This idea really appeals to me. It makes it personal. I recast this as: Pesach is about freedom. We can be free from things and we can be free to do things. How are we free this year?"
What I learned: I think this would work well for a seder with friends, but the idea fell flat with a group of relatives who are there because you're expected to be there. This idea felt awkward to the people I proposed it to before the seder and I did not pursue it further. I will use this idea in other seder settings in the future.
Jake suggested: Get into "round-table" discussions related to the Exodus somehow, in which everyone is encouraged to voice their opinions on the subject at hand.
This worked, albeit not in the way I anticipated. I went prepared with ideas to throw out for discussion and people didn't much take the bait -- but it led to them asking questions, and once it wasn't coming from the most religious person at the table it worked well. The conversations were not necessarily deep, but people asked questions and offered answers -- score. (During the hurried seder when I saw somebody trying to speak I directly encouraged that person to ask his question -- if not then, then the following night. This happened.)
Seth J suggested (in a comment): have everyone go around the room reading and following the Haggadah for as long as everyone seems willing/able to pay attention.
This practice naturally arose at one seder (the latter one) and had to be pushed a little harder with the other. Sharing the reading increased participation (and that's a keeper); some people, however, read as quickly as they could to get it over with. Perhaps an explicit invitation to pass if you must (but we'd really like you to read) would address this.
Seth also suggested good wine: check. :-)
Eytan said: when you prepare think of questions more than answers.
Yes. Questions invited discussion, and a lot of them came back to people looking to me for answers but that has a very different dynamic than offering a d'var up front. (And none of my answers were long.)
Jake suggested more singing. One of the two seders is usually fairly musical and the other not; I was able to help both of them do more music by the simple expedient of just started to sing (rather than waiting for consensus to arise). It probably helps that I have a pretty good voice (at least according to the other attendees).
I did not get to try Eytan's suggestions about art or personalized readings, nor Jake's and Gershon's suggestions about table toys/puzzles.
To summarize:
Anything I could do to prompt other people to ask questions -- planting ideas, reaching out to hesitant people, helping side/dinner conversations happen -- worked well. Asking questions about the text, the haggadah, etc worked; asking people to personalize it did not work in this setting (but would in others).
Coming prepared to present material was not needed, or helpful. People didn't want unsolicited teaching, but answers to their questions are completely different.
Sharing the reading among willing participants worked; pushing people who don't want to read to read led to rushed, mumbled reading, not engagement.
Singing worked well, and it was ok to just jump in and not wait for permission.
In the future I hope to build on this foundation.
I have the following dilemma with my father in law. I'm stating that assuming that both men have given their 10% if a rich man gives $1000 he makes a bigger mitzva than if a poor man gives $999. My take is that Judaism is about actions and general world improvement more than intentions. So that extra $1 makes another child eat then the rich man made the world better than the poor man even with the extra effort that he endured.
Is there any direct reference in texts about bigger mitzvot being accounted on results instead of intentions?
Do the texts specifically say what would be the bigger mitzva? To elaborate further, which action is better looked in the eyes of Hashem (Which action has the bigger reward)?
Inspired by this interesting question, I wonder if the principle of תינוק שנשבה (a child taken captive) can be applied to non-Jews who grew up in cultures antithetical to those that the mitzvot bnei noach require of them to adopt? In the same way that a Jew who was raised in an environment antithetical to rabbinic Judaism might be forgiven for not observing the mitzvot required of him, can we make the same argument as regards non-Jews?
Answer
In Noahide law, ignorance is no excuse (this, by the way, is true in secular law as well). The reason for this is, as the Rambam says (Hil. Melakhim, 10:1), היה לו ללמוד ולא למד--he should have learnt the law and he did not learn it:
אבל אם ידע שהוא אשת חבירו ולא ידע שהיא אסורה עליו. אלא עלה על לבו שדבר זה מותר לו. וכן אם הרג והוא לא ידע שאסור להרוג. הרי זה קרוב למזיד ונהרג. ולא תחשב זו להם שגגה מפני שהיה לו ללמוד ולא למד
See also: R. Chaim Hirschensohn, Malki ba-Kodesh, vol. 1 p. 21; Moreh Nevukhim, 1:36 (end); R. Nissim Gaon, introduction to the Talmud; R. J.D. Bleich, "Judaism and Natural Law."
However, R. Moshe Weiner in his Sheva Mitzvot Hashem (vol. 1, pp. 52-54) argues that the rule of היה לו ללמוד only applies in a society which observes sheva mitzvot:
ונראה לי דכל זה דוקא אם היה יכול ללמוד, כגון שהצבור בכללותו יודע אזהרת שבע מצוות בני נח, אבל בזמנים או מקומות שאין הצבור יודע כלל מהציווי, אין שייך לומר שהיה לו ללמוד, כי מנין ידע שעליו ללמוד כלל...במה דברים אמורים במצות ע"ז, גלוי עריות, ואבר מן החי [שאם לא למד לא ידע כלל שיש איסור בדבר], אבל איסור רציחה וגזל ומצוות דינים שגם אילולא נצטוו עליהם בני אדם מחוייבים בהם ע"פ המושכל לבד, אין לב"נ התנצלות שלא ידע שאסור לרצוח או לגזול.
R. Weiner distinguishes between murder, theft, birkat Hashem and dinim, in which one never has an excuse of ignorance, and the other laws. He bases this on the Avnei Nezer's comments in Orach Chaim 345. The Hit'orerut Teshuvah (4:186) similarly writes:
ונראה לי מה שכתב הרמב"ם בהל' מלכים (פ"י ה"א) דגוי שעובר על שבע מצות בחשבו שמותר הוא חייב, כי קרוב למזיד הוא שהיה לו ללמוד ולא למד...לענ"ד זה דווקא כשאנו שרוין בארצינו וידינו תקיפה...ובזה יש לומר שהי' לו ללמוד יען שרואה בכל יום כולם גירי תושבים ויש להם דת שבע מצות ויודע מכל זה ממעשים בכל יום ששומע ורואה, והיה לו ללמוד, אבל עתה בגלות שלא שמע ולא ראה ולא ידע מכל זה מאין יעלה על דעתו שיש לו ללמוד שבע מצות ולקיימם אשר לא שמע מעולם מכל זה, הגם שאין אנו רשאים להכשילו בהם משום לפני עור, אבל הוא שוגג גמור הוא יותר
I am not sure what is the right the expression to use when I want to include "can" in a Japanese sentence:
for example :
Can I buy a fruit?
is
Kudamono o kau koto wa dekimasu ka?
however
Can I ask you a question?
is
Shitsumon shite mo īdesu ka?
Isn't the expression "dekimasu ka" mean "can I" with the "I" part understood? Why is it not on the second sentence? Is there any grammar rule or is something to be memorized?
