Friday, November 15, 2024
Witnesses to Sedom's Destruction
Thursday, September 12, 2024
A Very Low Moon
Did you have a very difficult time locating the moon for קידוש לבנה this past מוצאי שבת? It was extremely low and close to the horizon. I was discussing this with Rabbi Dovid Heber and he provided some very interesting findings, after noting that he doesn't recall ever having such difficulty seeing the moon for קידוש לבנה due to altitude.
First, a little background discussion on "moon mechanics" may be necessary to understand what was going on. I find it somewhat surprising but it seems there are many who are not aware that the moon rises in the east and sets in the west just like the sun. However, the precise location and times fluctuate much more erratically than that of the sun. Let's not worry for now about where it is but more about when it is.
At the beginning of the month, on the מולד, the moon sits between the earth and the sun. Therefore, it follows that the moon should rise and set at the same time as the sun, approximately. However, as the month goes on, the moon rotates around the earth and so its rise and set times will quickly deviate (later) from the sun's. How much should it deviate? That is relatively simple to calculate. While it spends the entire month rising and setting later and later, when we get back to the beginning of the next month, it's right back where it started. This means that the rise/set times have come around full circle - approximately 24 hours. Divide 24 by the average length of a month, approximately 29½ days and that yields...
If you want to avoid the math, skip here: the moon should rise and set close to 49 minutes later every day of the month. The מולד of אלול was on Tuesday afternoon. Four days later, the moon should be setting close to 3½ hours after sunset. That should leave it sufficiently high in the sky after מעריב to be seen by all. However, observe the moonset times here. (This is for Baltimore but the phenomenon is related to the moon's path and is evident no matter what city you look at.) Somehow, it is only advancing around 20 minutes - or even less - every day. Later in the month (starting tomorrow) the times seem to skew the other way such that everything more or less evens out by the time. So, the moon was still setting much closer to sundown than one would expect that many days in to the month and that is why it was so low.
Unfortunately, my ability to explain this even ends here. I can only illustrate that this was happening but I don't know exactly why. I have not done a full inspection but I assume if this happened once, it probably happens with some degree of frequency. But I haven't inspected moonset times on a greater scale yet to have any idea what that is. I hope this cleared up some things. And if you weren't able to say קדוש לבנה yet, you do have until... uh oh, there is a lunar eclipse coming up next week. See more
Tuesday, April 2, 2024
Eclipses in הלכה and מחשבה
Friday, June 30, 2017
Let's Face It
UPDATE: A reader has brought to my attention two sources which actually do discuss this practice.
I nevertheless still maintain that the source for this is obscure, at best. And certainly of note is the point made by יסוד ושורש העבודה to which I was מכוין, regarding those two phrases. If there is a concern related to gazing at the moon, I still do not feel that is reason to turn away. But at the very least, if that is to be the practice, everyone ought to get together and decide to face the same direction. In או"ח צ"ד, it is made very clear how careful one must be with the direction they face for שמונה עשרה, so as not to make the ציבור appear disjointed. While this is outside of the בית הכנסת, I think the same care should be taken. (Especially now considering the יסוד ושורש העבודה suggesting that one needs to stand in the same manner as in שמונה עשרה.)
Tuesday, March 9, 2010
Too Much Chiddush for Rosh Chodesh!
Wednesday, August 5, 2009
Superhuman Sight
I would also suggest one more point. It is clear from Rav Saadiah Gaon and Rabbeinu Chananel (and I would suggest, Rashi) that the commandment upon Beis Din to regulate a calendar is to do so via calculation and not eyewitness accounts. Therefore, the machlokes in R"H 24b - 25a between Rabban Gamliel and other Tanaim as to whether to trust certain suspect witnesses is clearly rooted in a machlokes of whether or not to follow calculation or witnesses. It is interesting to see that Rabban Gamliel invokes a tradition from his family to support his claim. A few lines later Rebbi seems to be expressing a similar claim. Rebbi was a descendant of Rabban Gamliel. It would seem that the household of the Nasi (Rabban Gamliel's family) was in charge with regulating the calendar.
Now, when looking at the famous Mishna later when witnesses came late in the day on Rosh Hashana and the Levi'im sang a weekday shir instead of a yom tov shir, we can see something fantastic! One could have asked why they were bothering with witnesses and not using calculations (according to Rav Saadiah Gaon, Rabbeinu Chananel and Rashi). The answer may be that the Nasi at the time (and posek for these matters, as mentioned in the Mishna) was Rabban Yochanan ben Zakai. He was a temporary Nasi. Rabban Shimon ben Gamliel I was horrifically murdered and his son Rabban Gamliel II was in hiding. The position of Nasi was therefore given to Rabban Yochanan ben Zakai until it could go back to Rabban Gamliel II. Clearly, Rabban Yochanan ben Zakai, not being from the family of the Nasi, did not have their tradition. He was of the opinion of those that argued with Rabban Gamliel (II) on 24b - 25a.