233 —ניתוח אסטרונומיה בתורה, אור החמה, ושאלות הלכתיות

B"H, Friday, 22 Sivan 5706.

Brooklyn.

Shalom u'Vrachah!

In response to your letter, I received your sefer—Shu”t Bnei Tzion, first volume—and thank you for honoring me with this gift. I was pleased to see that you discuss topics related to the structure found in the words of our Sages regarding the calculation of years, etc., a field in our Torah with very few who engage in it and even fewer who truly understand it. Despite our Sages (Shabbos 75a) saying it is a mitzvah for a person (not just Beis Din—see Sefer Mitzvos Gadol positive commandment 47 and Sefer HaMitzvos of Rambam Shoresh Bet) to calculate seasons and constellations—and one who knows but does not calculate is forbidden to speak about it; about him it is said: "And the work of G‑d they do not regard," etc. Your above-mentioned sefer which you sent to my father-in-law the Rebbe shlita was received in due time. The list of participants in writing the Sefer Torah also arrived on time, including yourself and your family among them. Regarding the letter you wrote two years ago to my father-in-law the Rebbe admor shlita—I am unable to clarify after such a long time.

I would like to point out two or three places in your sefer as I read through quickly. Based on our Sages (Bava Metzia 84a): "It is difficult for me... thus the teaching is broadened," and you say: "A teaching supports you," but only where there is a question in my humble opinion. I chose the most surprising topic in your sefer—Kuntres Or Zayin HaYamim for your father shlita:

a) Page 26 left column: You compare three opinions regarding the sun’s light in the future (7, 49, 243). Based on our Sages in Bereishis Rabbah (10:4), before Adam sinned, the sun traveled a shorter path—which could mean that the sun’s sphere was seven times closer to earth; then its visible width would be seven times greater, its visible area forty-nine times greater, and its influence from the entire sun’s sphere would be 343 times greater. While you are correct regarding seven and forty-nine—what you wrote about 343 is unclear: since the actual size of the sun did not change but only its distance from earth decreased by seven times, all influences spreading over earth’s surface would strengthen forty-nine times. For example: gravitational force depends on mass and distance; if they come seven times closer (but mass remains unchanged), gravity increases forty-nine times—not 343—as is known and as you also write on page 28 right column. If we want to compare all three opinions as above, we can only do so by saying that the sun itself physically changed so its diameter increased sevenfold; then its area increases forty-nine times and its mass—and all influences depending on mass—increase by 343 times. Even though apparently light depends only on surface area and not thickness or mass—we find otherwise elsewhere; for example with a glowing metal coal—the heat depends on mass rather than area. Especially regarding sunlight—we do not currently know how its illumination works (see Shabbos 39a; Yerushalmi Rosh Hashanah ch.2 halacha 4; Rambam Yesodei HaTorah ch.2 halacha 3; etc.).

b) Page 28 left column: In your brief explanation of our Sages’ words: According to those knowledgeable in astronomy—on whom you base this section—if the sun’s distance were reduced by sevenfold, its orbital period would shorten by approximately eighteen-and-a-half times (not forty-nine as written), because orbital period depends not only on gravitational force but also other factors—the square of orbital period relates to cube of distance (the book Mehalech HaKochavim etc., which you cite—I haven’t seen but surely he brings this too). Certainly Midrash Rabbah needed to inform us about this because not everyone knows it (see Rambam Hilchos Shevuos ch.5), especially since this law was discovered only about three hundred years ago. Note also in this section: The beginning of your words and proofs suggest that speed increases by 343 times and besides that distance shortens sevenfold—so overall orbital period shortens by 343 times.

c) Page 31 right column: Section 26—you reconcile according to your approach what is stated in Braisa d’Shmuel chapter six: “The sun was created in Leo at fifteen degrees; moon in Cancer at fifteen degrees,” etc., explaining that according to Braisa d’Shmuel molad was at twenty-eight degrees Taurus and planetary motion began at fifteen degrees Leo; during the interval between these points planets traveled what now takes seventy-seven days (approx.), including seven days of rebuke/standing still—leaving seventy days traveled; thus if at twenty-eight degrees Taurus sun was at Libra twenty-three degrees then at fifteen degrees Leo it would be at fifteen degrees Leo—but what is unclear:

1) The rebuke occurred after moon’s complaint which happened at twenty-eight degrees Taurus per Tosafos Yom Tov—that is after seventy-seven days had already passed.

2) If at fifteen degrees Leo sun was there and moon at fifteen degrees Cancer—after both traveled what now takes seventy days—their positions per Braisa d’Shmuel ch.5 would have sun one hundred three degrees from moon—not matching molad position.

There are more comments on this kuntres but space does not allow further elaboration.

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What can simply be said to answer Aquilas’ statement to Hadrianus (Shemos Rabbah ch.30 sec.12) about Israel’s greatness—that even their youngest knows how many years have passed since creation—even though there are disagreements among Jews regarding counting years from creation as raised in your sefer—is that among non-Jews there is no knowledge or only conjecture about this matter with wide-ranging differences between their estimates (and so it remains today), whereas among Jews even children have knowledge—not mere conjecture—and any uncertainty over two or three years pales compared with non-Jews’ total lack of knowledge.

Alternatively—it can be said as follows: There are four main principles for calculating molados (new moons) and years—as you write—and based on what I’ll explain below perhaps a fifth principle too: They are—in order—twenty-eight degrees Taurus (“du kaf tet chet”), “beharad”, “vayad”, “gachav betat’u”. According to early authorities (and we are not responsible for reconciling every later authority with one view), their disagreement over when exactly these principles apply stems from four possible starting points: Rosh Hashanah when Adam was created; year before that when world itself was created; year after Adam’s creation which counted as a full year (unlike his birth year which lacked several hours—see Rambam Kiddush HaChodesh ch.6 halacha 8). Depending on whether constellations functioned during flood year (Bereishis Rabbah ch.25 sec.B), there will be another difference regarding one year—as discussed extensively in Masseches HaIbur and later authorities Choshen Mishpat siman 67; end of commentary to Braisa d’Shmuel by Maharal Lipkin etc.

Thus all these disputes concern calculation of years/new moons—but regarding number of moments since creation everyone agrees—and this explains Aquilas’ statement that even Jewish children know how much time has passed since creation.

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What I wrote above suggesting perhaps a fifth principle helps explain Braisa d’Shmuel based on Tosafos “LeTekufos” (Rosh Hashanah 8a): The principle “vayad” comes from our Sages (Sanhedrin 38b): "On ninth [hour] he was commanded [Adam], tenth he sinned." Some say he sinned halfway through day nine (see Sefer HaDorim beginning based on Bereishis Rabbah end ch.18); thus he was commanded start of sixth hour so principle becomes Friday eleven hours into day six.

This clarifies simply what Braisa d’Shmuel says—that at creation sun was at fifteen degrees Leo/moon at fifteen Cancer—and concludes “the new moon from start of planetary creation took two days plus a quarter day for moon’s path/two parts plus quarter for sun”—meaning until molad took two days eleven hours; according to Braisa planetary motion started beginning Wednesday night so molad fell Friday eleven hours—which matches our Sages above.

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This also explains why Braisa concludes “the new moon…” refers to first actual molad—not later ones taken as main reference point—which per your kuntres needs clarification why mention this if main molad used is not this one but third after it? Also actual revolution wasn’t two days etc., but rather occurred much faster—243 times faster—as explained earlier.

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In Pirkei D’Rabbi Eliezer ch.11 version says Adam commanded eighth hour—in which case principle would be Friday thirteen hours—but I haven’t found such a principle anywhere else whereas principle eleven fits simple meaning of Braisa d’Shmuel.

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If we accept Yaaros Devash’s explanation (“Beraisa says luminaries created Tu B’Av”—meaning their place/constellation Tu B’Av i.e., fifteen Leo—to explain opening words “sun created Leo fifteen degrees” as you write)—it seems questionable why such an interpretation is needed? On contrary—it could mislead people into thinking literally about time rather than place whereas opening phrase clearly means place where luminaries were created.

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Certainly you know that Ya’ad there writes molad occurred Friday twenty-one hours—I haven’t found anyone else saying so (in Drush Tu B’Av he holds principle vayad).

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d) Page 38 left column: You wish to resolve Admor Hazaken’s words in Shulchan Aruch Hilchos Shemirat Guf v'Nefesh end section seven concerning mixed drinks—that he means mixed for drinking rather than usual meaning mixed with water—but then why specify "not just water itself"? Also what does "itself" add? Admor Hazaken clarifies his view explicitly: "Do not drink mixed drinks left overnight after being mixed with water—even ours." By the way—the phrase "not just water itself…" appears within brackets—it is known that whenever he had doubts he put them in brackets intending later revision if his words proved correct (She’erit Yehuda Orach Chaim siman 363 cited Shaar HaKolel ch.1 sec.2).

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I am confident you will not take offense at my comments—and may mutual discussion bring benefit!

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Blessings for immediate teshuvah and immediate redemption!

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Rabbi Menachem Schneersohn

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Topic: "And the light of the moon will be like the light of the sun…" according to Chassidus—with two explanations:

• a) Then—the light of moon will equal present-day sunlight;
• b) Then—the sunlight will increase sevenfold etc., as explained by Gemara;

Also both explanations regarding "seven days": whether referring to current days or Seven Days of Creation—explained Likkutei Torah Parshas Tzav discourse VeHayah Or HaLevanah; also discourse Im Bechukosai from Rosh Hashanah series Tof Resh Samech Vav.
Perhaps based on these sources one can reconcile all three opinions regarding multiplication factors (7x,49x,243x).

I saw at end of your introduction reference to Rabbi Baruch Mordechai MiBabroisk—I found some say family name is Ettinga others Ettinger—do you have clarification? Surely you've seen Kuntres Bikur Chicago–(talks from my father-in-law Rebbe shlita)—second talk—from his biography. Perhaps your family has more information such as birth date, passing date etc.? Do you possess any manuscripts or novellae?

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SummaryThe Rebbe provides scholarly feedback on intricate astronomical topics discussed in Rabbi Shapira's sefer while highlighting Jewish tradition's unique precision in calendar calculations versus other nations' conjectures. He encourages respectful scholarly dialogue rooted deeply in Torah sources.