Monday, June 28, 2010

Torah and science

"Our restricted minds see two realms, natural laws and man-made laws, the universe of physics and the universe of morals. But to God there is no distinction and both universes are one, because creation is an expression of divine chessed, an ethical performance. Since the world was created to share His existence with others, in essence a moral activity, the laws governing the cosmic processes are not just neutral laws; they rather express the absolute moral law. To deny this, and postulate two realms, would cause the whole monotheistic structure to crumble." -R' Soloveitchik, "The Rav Thinking Aloud", 87-88.

If asked, I would have said almost the opposite of this quote. But it makes a certain sense. It looks like I need to think more deeply about the subject.

Another interesting quote from the book:

"If you want to know what lashon hara is, whatever you enjoy when you talk about someone: that is lashon hara."

Thursday, June 24, 2010

The incense column

"These are remembered negatively... the house of Avtinas, who did not want to teach about the incense. The Rabbis taught: The house of Avtinas was skilled in the preparing of incense, but its members were unwilling to teach [their method]. The Sages sent for workers from Alexandria [to replace them]. These [workers] could prepare the incense, but could not make it so that the smoke would not bend [as it rose]. The smoke of the incense prepared by the house of Avtinas rose straight, like a rod, and the smoke of the others' incense bent this way and that." (Yoma 38a)

"The ‘ma’aleh ashan’ [herb?] would [cause the smoke from the burning incense] to rise straight up like a staff…" (Yoma 53a).

These sources discuss the smoke issuing from incense burning in the Temple. We see from both sources that the smoke was supposed to rise in a perfectly straight column.

This incense column is NOT the same smoke that Pirkei Avot 5:5 says was miraculously never dispersed by the wind. That smoke was from animal sacrifices burning on the large outdoor altar. We are talking about smoke from incense burned inside the Temple, where there was no wind. There is no need to assume that the vertical rising of incense smoke is miraculous. In fact, I will now provide a purely natural explanation for it.

Examine the following photograph of burning incense. At first, the smoke rises in a smooth vertical column. Then, past a certain point, the column collapses into a bunch of turbulent swirls. This is a common phenomenon, which I have seen with incense sticks and cigarettes, as well as in this picture.

It seems to me that the gemara is talking about this kind of smoke column and swirls. Smoke naturally begins as a straight column, and past a certain point becomes turbulent. Depending on the type of incense, the turbulence could begin sooner or later. The rabbis desired incense whose turbulence was delayed, so that the smoke column remained vertical for as long as possible.

I asked my father, a physics professor, to explain why this phenomenon occurs. Here is his response, (with the "bottom line" highlighted, in case you don't have patience for the technical details).

The rising column of hot air is unstable to shear instability (the simplest shear instability is Kelvin-Helmholtz instability that occurs between two half-spaces with relative velocity parallel to their boundary) that develops into turbulence. This can be stabilized by viscosity or density stratification (the latter is relevant to Kelvin-Helmholtz in the atmosphere, ocean, etc., but not to a rising column of hot air).

If the rise is slow and the column thin, viscosity will be more effective in stabilizing the flow. Very slow burning will then tend to produce a steady column. The burning rate will depend on how finely the incense is ground, what it is made of, moisture content, degree of packing, etc. The trick is to slow the burning without making it extinguish itself.

So there you go. Now you, too, know how to make perfectly rising incense, like the house of Avtinas did. Well, at least you know which factors to experiment with until by luck or skill you get it right. As I learned when my roommate did a class project on gas engine combustion chamber designs, the precise analysis of burning is very complicated and sometimes not fully predictable even by modern science.

Why was it desired that the smoke column rise straight upward? Possible reasons include: 1) It was simply more aesthetically pleasing. 2) It was cleaner – smoke concentrated at the ceiling rather than filling the entire room. 3) It was symbolic of the incense going directly to God and not getting "stuck" on the way there. 4) The rabbis noticed the link between vertical rising and slow burning; wanting the incense to last longer, they wanted to see vertical rising as an indication of this.

Whatever the reason, it seems this goal was not trivial to achieve. According to the gemara, a particular substance ("ma'aleh ashan") had to be mixed into the incense. But just the presence of that substance was not sufficient, and expert preparation was needed as well. The House of Avtinas were the experts, and the rabbis tried unsuccessfully to break their monopoly on the correct method.

One final word on the column of smoke from the outdoor altar. Pirkei Avot says that this smoke rose vertically as well, miraculously, despite the wind. What was the point of this vertical rising? Explanations 1), 2) and 3) from the incense column would also seem to apply here, with minor changes. 1) A vertical column of smoke would be more attractive, and like a skyscraper more visible to people far from the Temple. (Compare this to Akedat Yitzchak, where in the midrash Avraham saw a cloud over Mt. Moriah before arriving. Maybe he was prophetically envisioning smoke from sacrifices there?) 2) Anyone who has made a bonfire knows how annoying it is to stand downwind from the fire and get smoke blown in your face. With a vertical column that would not happen. 3) The burning sacrifices are supposed to provide a pleasing odor" to God (Bamidbar 28:1 and other verses). If the smoke is blown horizontally, then it never goes up to the heavens, giving the impression that God is literally pushing the sacrifice to the side and rejecting it.

Thursday, June 17, 2010

Hilchot Mundial

הלכות מונדיאל
גיל סלוביק

1. נהגו אומות העולם להיאבק זו בזו מדי ד' שנים בכיבוש שערים עד אשר יימצא זה אשר הגביע בידו, כדכתיב: ובשנה הרביעית יהיה לכדור קודש הילולים למונדיאל. וכיוון שהכיבוש משחית הוא, נוהגים ישראל להחמיר ולא לכבוש שערים כלל, ותחת להתחרות במונדיאל, מסתפקים בצפייה בו, בבחינת אותו תראה ושמה לא תשחק.

2. מצוות הצפייה במונדיאל מצוות עשה שהזמן גרמא היא, ועל כן נוהגת בגברים בלבד, וטוב שיתכוון הגבר להוציא אשתו מהבית בזמן המשחק.

3. יש לצאת בכל תוקף כנגד אותן נשים שעושות עצמן כמתעניינות בכדורגל, ותחת להניח לנפשם של הגברים, מציקות הן בקושיות סבוכות על חוקי המשחק בדיוק כשמסי פורץ לרחבה, וידוע מאמר חז"ל כי המלמד את אשתו כדורגל כאילו מלמדה תיפלות, שהוא מלמדה פרק בהלכות נבדל והיא שואלתו על שום מה נבדלים צבעי מדי הנבחרות אלה מאלה, ואינה מכירה בין תכלת של ארגנטינה ללבן של אנגליה.

4. נתייחדה מצוות הצפייה במונדיאל, שעל אף שמצוות עשה היא, יש בה משום שב ואל תעשה, שדי לו לאדם שירבץ בכורסתו אל מול המסך כדי לקיים המצווה. וכיוון שחביבות מצוות על ישראל נהגו להוסיף למצוות הרביצה גם פיצוח גרעינים קליות ואגוזים, לגימת בירה ומתן הוראות לשחקנים, ומתפללים שייעשה להם נס וישמעו השחקנים את הוראותיהם דרך המסך.

5. אין צופין במונדיאל אלא בחבורה, וממנים את הקטן שביניהם לסינג'ור והוא המוציא והמביא להם בירות מן המקרר, ומי שצופה לבדו אין לו חלק לעולם הבא וסופו שמפספס כל הגולים כשמביא בעצמו הבירה. בשעת הדחק יש להתיר לצפות ביחיד, אולם העושה כן יקפיד להתקשר מדי ח"י רגעים לחבריו כדי לשאול: "ראית את זה???".

6. מאימתי צופין? משלב הבתים ועד לגמר. ויש אומרים: משלב הבתים ועד שלב הרס הבתים, כשנוטשת אשתו את הבית ועוברת לגור אצל אמה. במקצת קהילות נהגו לצפות במשחקי הנוקאאוט בלבד, ולא טוב הם עושים, שככל שמתקדם המונדיאל הולכים ומשתעממים משחקיו, שרעדה אוחזת ברגלי השחקנים ותחת להיות כגיבורים הכובשים את גוליהם, עומדים הם כחומה בצורה ואין מבקיעין כלל (בונקער בלע"ז).

7. אין צופין במונדיאל לא מתוך שחוק ולא מתוך קלות ראש אלא מתוך כורסה של מצווה, וטוב שיכוון ליבו למשחק, יבטל עצמו כליל, ולא יתיק עיניו מהמסך לא ימין ולא שמאל, שאם לא כן עובר ב"לא תתורו". הנצרך לנקביו באמצע משחק טוב שיתאפק וימתין למחצית עת מלהגגים הפרשנים במילתא דבדיחותא וזורקים זה לזה קלישאות קלישאות חבוטות חבוטות.

8. משנתרתקו הגברים לכורסאותיהם ואינם נעים ואינם זעים מהן, יוצאות הנשים לפזז ולכרכר בקעניונים, בלא גברים שידחקו בהן לסיים השופינג, ומנהג זה הוא בבחינת זה נהנה שאשתו לא בבית וזה חסר בחשבון הבנק. ומכל מקום טוב שתקפיד האשה על קיום הלכות שופינג בכל דקדוקיהן ופרטיהן ותרי"ג שקיות התלויות בהן.

9. תחילה נהגו ישראל להתחלק בין אוהדי ברזיל, אנגליה והולנד (אחינו הכתומים). משנתמרמרו כל צבועי העולם על המרמריס, ונמצאו כל אומות העולם שונאות לישראל, אין זה חשוב את מי יאהד, ובלבד שינקוט צד מבעוד מועד וידבק בו, שלא יהיה כפוסח על שתי הסעיפים מדי משחק.

10. ר' כילי אומר: כל המסכים כשרים לצפייה, אפילו מסך שפופרת יד' אינץ' מתקופת האנטימחיקון התחתון. ר' סקאל אומר: לא יפחת ממסך מהודר עשוי פלעזמה בגודל לב' אינץ', שאותיות HD כסופות חקוקות בחזיתו. מנהג המפרסמים ליפות סחורתם ולהכתירה בשלל תכונות הכתובות בצופן עשויה צירופי אותיות משונים, ובמיוחד נהגו להרבות במספר היציאות שבגב המסך, כדכתיב: יציאות המסך שתיים שהן ארבע. ועוד נהגו לפרסם את ניגודיות המסך, ולא ידעתי עניין הניגודיות מהו עד שהתנגדה אשתי שאקנה המסך.

11. שלושים יום לפני המונדיאל מעלין את מחירי כורסאות הטלוויזיה, המסכים, ושאר תשמישי הקדושה של המונדיאל, ברמ"ח אחוזים, כדי להורידם לאחר מכן במבצע של "עד 50%". מנהג נאה נהגו לכתוב את ה "50%" באותיות קידוש לבנה בגודל 42 אינץ', ואת ה"עד" באותיות טל ומטר בגודל מחצית האינץ' בלבד. ייזהר הציבור מאוד מרכישת אותם מסכים המפארים עצמם כ"מותג מוכר" ונמכרים במחצית מדמיהם של מסכים בעלי יחוס, שחזקה היא שאם היה המותג מוכר למישהו מלבד לזה המוכרו, הרי שהיו מפרסמים את שמו.

12. שבת הקודמת לפרוץ המונדיאל היא שבת הגדול, ונהגו לפרסם בה מוספי ספורט מגודלים הסוקרים כל אחד ואחד מאחד-עשר כוכביא של נבחרות העולם, ועושין מי שברך לפצועים. גדולי פרשני הדור עוסקים במלאכת הניחוש, וכל נבחרות העולם עוברות לפניהם כבני מרון, וכותבים את גזר דינן: מי תעלה ומי תודח, מי בנגיחה ומי בבעיטה, מי בפנדלים ומי בשער זהב, וסופם שנמצאים ניחושיהם כחרס הנשבר וכצל עובר וכחלום בלהות יעוף.

13. מצווה מן המובחר שלא לשחק במונדיאל בכדור שרגילין לשחק בו בשאר ימות השנה, אלא לייחד מבעוד מועד
כדור חדש שלא עלה עליו עול, ורגל אדם לא בעטה בו, בבחינת וישן מפני חדש תוציאו. על כן נהגו גדולי ישיבת ההנהלה של אדידעס לברוא מדי מונדיאל, יש מאין, כדור חדש בתכלית החידוש (ג'אבולעני בלע"ז), ובכל מקום שדבר הכדור החדש מגיע אבל גדול לכדורגלנים ומתבכיינים בקול גדול, וטוענים שגדולי אדידעס שמים עליהם שלושה פסים.

14. מודים אנו לקב"ה ששם חלקנו מהבועטים נעלי הבית כשיושבין על הכורסא ולא שם חלקנו מבועטי קרנות. שאנו משכימים לצפות במשחק של צפון הונדורס נגד דרום ניגריה, והם משכימים לעוד אימון כושר, אנו רצים למקרר להביא עוד בירה, והם רצים כמשוגעים אחר הכדור, אנו עמלים לפצח הפיסטוקים והם עמלים לפצח ההגנה של היריב.

15. מייד כשיסתיים משחק הגמר, יכבה את הפלעזמה, יקום מכורסתו, ינער היטב קליפות הפיסטוקים, ויאמר: יהי רצון שכשם שזכינו לצפות במונדיאל זה, כן נזכה לשחק במונדיאל הבא בכדור מעורו של לוייתן.

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Tuesday, June 15, 2010


I once went to a Maccabi Haifa soccer game with a couple friends. (It was the infamous one where the Beitar fans cheered Yitzchak Rabin's assassination.) I expected the game to be boring - in 90 minutes of kicking the ball back and forth, a soccer game contains only a handful of scoring chances. But it was actually quite interesting to see the struggles for control of the ball, and the strategies for advancing it.

That said, I saw one big problem with that game - and with soccer in general. It often happens that one team clearly dominates the game from start to finish. But due to the extremely low scoring of soccer, chances are good that they don't actually score. And if the other team gets one lucky shot, or else a penalty shot, then the better team can easily end up losing 1-0.

A variation of that possibility has caused much controversy in the ongoing World Cup. A single momentary mistake by a "keeper" (apparently that's what they call goaltenders) results in a goal, dramatically changing the game and the team's entire fortunes in the World Cup. In the recent England-USA game, for example, from what I hear England clearly played better overall. But on one weak USA shot, the ball took an unusual bounce off the English keeper's hands and into the goal. (Some blame the bounce on problems with the ball.) Just like that, USA turned a predictable loss into a "stunning" tie against a much stronger team. A similar sequence occurred in the Slovenia-Algeria game. What is the value of 90 minutes of intense play when the game is really decided by half a second of random luck?

In other sports, it is certainly possible for luck to affect the outcome. Indeed, the two worst referee decisions in history went against teams from my home state. Each resulted in a win for the opposing team, which went on to win the national championship that year.

But as outrageous as these incidents were, they do not compare in impact to similar incidents occurring at soccer games. In both baseball and American football, it is normal for each team to score 5 or 6 times in a game. A bad call is unlikely to result in more than one undeserved score. If that score was enough to change the outcome, then the game was already quite close. If your team was clearly deserving of victory, it would not have failed in its previous chances to create a large lead that no single error could eliminate.

In soccer, that is not the case. One goal is all a team normally scores, and it is also the margin of error caused by unluckly circumstances such as referee mistakes. Thus, it is much more likely that undeserved circumstances will decide the outcome of the game. That cheapens the effort put forth by the players throughout the game. In my mind, this characteristic makes soccer a less compelling sport than many of its competitors.

Wednesday, June 09, 2010

Husband, wife, and shechina

"Husband and wife – if they merit, God's presence is found between them." (Sota 17a)

I can recall my parents occasionally having arguments, sometimes bitter, with each other when I was growing up. But personally, I almost never get into arguments with anyone. How is this? Am I really a better person than they are?

The more I learn about life, the clearer it is that the answer is not a quick and satisfying “yes”. The reason I do not argue is simple, and reflects my circumstances more than my character.

It is often hard to know what a single person is thinking. People have many reasons to keep their thoughts private. But in a marriage, much more so than any other relationship between individuals, thoughts do not remain private. They are shared verbally with one's partner.

The arguments which I occasionally witnessed in my family, and which are probably present in every family, are the result of frustration and anger. I certainly do experience these emotions sometimes. But I generally keep them to myself. If I were married, things would be different. I would much more readily express negative emotions to my wife than to other people. She might respond negatively, again more readily, and I might reciprocate. And just like that, we would get into a fight. The negative character traits which caused this fight were always part of each of us. But only when we were together would they express themselves in words and actions, immediately visible to anyone around us. Right now, I do easily not get into arguments and fights. But once I'm married (or in a sufficiently serious relationship), I can expect to do so more often.

What is true for negative character traits, like selfishness and cruelty, is also true for positive ones. With one's spouse, these positive traits too will be expressed more openly, and visibly to people other than the married couple.

In my opinion, this is the basis of the gemara saying that God's presence dwells between the husband and wife.

Apparently there is some set of Godly actions and attitudes – love, generosity, kindness, and so on – that wherever they are present, we say that the Divine presence is there as well. Each person, living by themselves, may possess these character traits, and thus we call them a holy or Godly person. But this Divine presence is private, as the character traits generally are. When husband and wife with these character traits are together, the traits are most strongly and visibly expressed, and the holiness become shared and evident between them.

There is a famous Romantic poem entitled “She walks in beauty”. It is not obvious whether a woman's beauty is part of her, or part of the mind of the man gazing at her. Either way, surely the beauty is present whenever he sees her. Therefore, he may speak of her walking “in” the beauty, it being part of the fabric of the situation in which they meet. We may speak the same way of God's presence dwelling between a married couple. When they interact with each other, treating each other with kindness and respect, the situation is one of Divine attributes and Divine presence. We cannot say that God is physically located anywhere, but when husband and wife treat each other this way, Godliness is surely an element of their interaction.

How much is a pruta?

The halachic pruta is equivalent to the value of 0.022 grams of silver. (0.025 grams according to a different opinion). (Source)

0.022 grams = 0.000776 ounces (Source)

0.000776 ounces silver = 5.5 agorot (Source)
0.000776 ounces silver = 1.4 cents (Source)

The price of silver, and thus the value of a pruta, may change with time. You should always be able to re-click the last two links to get an updated figure.

This was on my mind because of its relevance for maaser sheni.

Tuesday, June 01, 2010

The Gaza boat incident

Some thoughts:

1) Every IDF soldier should have a video camera mounted on their helmet. EVERY scene of conflict must be recorded, and immediately prepared and (if useful) released for publication by a PR crew on duty 24/7. (UPDATE: Apparently this kind of mechanism exists and just wasn't used.)

2) Right now Israel has "peace" (i.e. diplomatic relations) with several Muslim countries, including Egypt and Turkey. At the same time, both Egypt and Turkey are knowingly aiding military action against Israel. Egypt chooses not to stop arms smuggling into Gaza, and Turkey allowed boats containing weapons and hostile personnel to set out for Gaza. Once upon a time, before all the "peace" agreements, we could prevent this kind of action by threatening or using military force, both retaliatory and preventive. Now we can't. "Peace" means that we cannot do anything to prevent actual war which is being conducted against us. Perhaps we would be better off ending these "peace" agreements.

3) As isolated as Israel is now, historically it was much more isolated. The UN "Zionism is racism" resolution, for example, was only repealed in 1991. Israel has always been a pariah state, except from about 1991-2008. One important reason for this is obvious. The US, the only country ever willing to admit to being an Israeli ally, was the unchallenged single superpower during this period. Before 1991 it was balanced by the Soviet Union; now it is increasingly balanced by China and the rest of "BRIC". Israeli isolation is natural, since its existence is opposed by 60+ Muslim states who control the world's oil. So regardless of its policy choices, Israel will have to get used to being isolated. It survived isolation beforehand, and will again.

4) As usual, the IDF operation was labeled "disproportionate". That term is actually not a bad first reaction to the events. After all, when we killed 10 of them and they killed zero of us, isn't it obvious we were more aggressive? Shouldn't we have stopped and claimed victory once the body count was 8-0 or 9-0? We reply that the 10th casualty (like the 9th and 8th) was still a lethal threat to IDF soldiers, and could not be stopped in any other way. But that argument relies on facts, many of them unverifiable, which our enemies simply deny.

Another necessary approach may be to question the whole idea of disproportionality. Perhaps such an argument goes as follows. Supposedly a 10-0 body count is wrong because it is "disproportionate". If so, then if the body count were 10-10, the IDF would be morally justified. Effectively, the only way for IDF soldiers to be morally justified in their actions is to die. The only moral Israeli is a dead Israeli. The doctrine of disproportionality inherently leads to that conclusion, and a doctrine that implies obviously wrong conclusions cannot in itself be correct. This argument is emotional as well as logical, and must be presented as such. Hearing the rhetorical question "Must Israelis die in order for Israel to be considered moral?" from an Israeli leader could do a lot to reframe the debate in a more sensible direction.

5) As for general Israeli policy, this article presents my exact position, more elegantly than I could have.