Wednesday, November 16, 2016

I Can't Believe Its Not Fresh

In the beginning of the Parsha we see that Avraham Avinu went to tremendous lengths in order to prepare feasts for the passersby that were lucky enough to be his guests. During the feast that he served the three angels that visited him after his bris, he had Sarah Imeinu make bread from three se'ah of fine flour, he had three oxen slaughtered to serve three separate tongues with mustard, and he had butter and milk brought to them. We see clearly how dedicated Avraham was in his hachnasas orchim. (See Bereishis 18 and Rashi's commentary.)

It is interesting to see that Avraham did not seem to have anything prepared for these wayfarers. We are taught that Avraham epitomized kindness. One would have thought that he would have had food prepared for the occasional guest that might accept an invitation. Nevertheless, in this week's storyline we see that Avraham clearly asked the visitors to rest for a bit while he went to prepare their food. Why would Avraham risk losing these guests by not having food ready for their possible arrival? The answer is simple, Avraham wanted evrything to be fresh. What sojourner could pass up a fresh meal filled with the choicest foods? Avraham knew that he would not lose guests if he asked them to relax while he prepared them a meal that was fit for a king. Therefore, he purposefully did not have food ready for their arrival. Additionally, while they rested Avraham would have ample time to strike up a conversation with them and teach them about Hashem.

It is so interesting to note that Avraham clearly wanted everything to be fresh so that he could serve his guests the finest delicacies. The meat was freshly slaughtered and the bread was freshly baked. Why then was the milk and butter only brought to the meal and not milked and churned that day? (See Bereishis 18:8) Perhaps, the answer lies in the date of this monumental feast, Pesach. (Rashi, Bereishis 18:10) It is prohibited to milk animals in order to drink their milk on Yom Tov, and it is also prohibited to churn butter on Yom Tov. (Shulchan Aruch Orach Chaim 505:1; and Rema 510:5) As such, Avraham would not want to be violate this holy day. Therefore, he had butter and milk prepared in anticipation that guest might arrive, but the rest of the meal was prepared on the spot.

A Scratch on the Wall

According to the Midrashim quoted by Rashi, Yitzchak was born precisely a year after the angels visited Avraham and Sarah, on the first day of Pesach. (According to the gemara Rosh HaShanah 11a the angels visited on Sukkos.) Rashi (21:2) writes that HaShem gave Avraham a sign. On the day the angels visited, HaShem made an etching in a wall and told Avraham, "When the sun reaches this point again next year, you will have a son." This sign requires some clarification. How exactly did this work?

An object that is standing upright in the path of the sun will form a shadow on the ground. The exact direction of the shadow depends on the position of the sun in the sky. As the sun moves through the eastern sky in the first half of the day, the shadow will be pointing westward and vice versa for the second half of the day. However, the exact direction of the shadow, i.e., its northerly or southerly bearing, will constantly change. As well, the size of the shadow is dependent on the north/south position of the sun as well. These are the principals behind the sundial. All of the factors change throughout the day and the daily patterns change throughout the year as a result of the change in direction of the earth's tilt. However, one thing is certain. At midday, the sun is not in the eastern sky or the western sky. Rather, it is either due north or due south, depending on where you are in the world. What is relevant to us is that since Eretz Yisroel, at approximately 31o North, is above the Tropic of Cancer (23.5o North), the sun will always be in the southern sky at midday. The size of the shadow depends on the angle of the sun in the sky which depends directly on the time of year.

Any sign involving a shadow would surely have been simplest to arrange at midday. It is therefore most noteworthy that the gemara (.ברכות כ"ז) infers from the words (18:2) "kechom hayom," in the heat of the day, that the angels visited in the sixth hour. After the food was prepared and served and the angels conversed with Avraham, it seems altogether plausible that it was exactly midday. It seems that the sign that was given was that at that moment, the southern wall (or other standing object) was casting a shadow on the northern wall. The scratch that was made on the wall indicated the end of the shadow. When the shadow reached the exact same point at midday sometime in the next year, it would indicate that a complete year had passed.

With all this considered the Midrash is quite troubling. All these details are specific to the solar year. However, Yitzchak was born precisely one year later by the lunar calendar, not the solar calendar. What significance could any sun-related sign have to the passing of a lunar year?

I particularly enjoyed the answer that Pi offered in the comments:
On pasuk 18:10, Seforno says: שוב אשוב אליך - למועד המילה כפעם בפעם.‏ This suggests that the time the angels would return a (solar) year later was not the exact day of Yitzchak's birth, but rather some time later. The book קונטרס די שמיא by Alexander Shutz on pages 18-19 claims that the ריב"א asks your question, and that ר' צבי יודא פריידמאן suggests the following answer: The angel Rephael would come back three days after Yitzchak's bris mila to heal him, which would be (about) 11 days after his birth, so that could have been the occasion when the sun reached the line that was marked on the wall.

Witnesses to Sedom's Destruction

Rashi on 19:24 notes that the destruction of Sedom happened at day break, when the sun and moon were in the sky at the same time. This was because they used to worship the sun and moon. HaShem therefore brought the destruction when both were out as a proof to all the sun and moon worshipers that the sun and moon are powerless. Had the destruction taken place when they were not in the sky, one could have argued that they were not "there" to save them. This is a rather simple statement by Rashi but the astronomical basis for it is quite interesting.

It is not always that the sun and moon are out together at day break. It is also not always that it is the only time that they are out together. The moon rises and sets approximately 49 minutes later each day. This is a result of the moon orbiting the earth. Just as the moon's position is reset at the end of every month, so are its rising and setting times. (The math is as follows: Every full moon cycle (month), moonrise and moonset make a full circle of 24 hours such that the times are as they were precisely one month previous. The figure of 49 minutes is achieved by dividing 24 hours by the duration of the lunar cycle, 29.5 days, 44 minutes, 3 and a third seconds. More precisely, the figure is 48 minutes, 45.5 seconds.)

At the beginning of the month, the moon follows a very similar schedule to the sun. The moon rises at the beginning of the day and sets at sundown. As the month progresses, the moon rises and sets later and later. At the middle of the month, the moon has virtually the opposite schedule to the sun. It rises when the sun sets and sets when the sun rises. As we enter the second half of the month, the moon begins to rise later in the night and thus, becomes visible at the beginning of the day.

The Midrash (Bereishis Rabba 50) teaches that Sedom was destroyed on the 16th of Nissan. As explained above, at that time of the month, the moon would have risen shortly after sunset and set very shortly after sunrise. Therefore, the only time in the entire day that both the sun and moon were out at the same time was very early in the morning and that is why the destruction took place specifically at the very beginning of the day. [Nevertheless, it is puzzling that Rashi uses the term "Alos HaShachar" which refers to a time before sunrise.]

Wednesday, November 2, 2016

The World's First Boat?

For 100 years Noach toiled and endured much ridicule from his neighbours as he built the ark. Sure enough, Noach had the last laugh when the flood finally came and wiped out everyone else on the planet. Having completely denigrated Noach and ignored his warnings, the people were completely unprepared. However, the ark was nothing more than a large boat. Didn’t anyone have a boat of their own to escape the destruction of the flood?

This fascinating question was asked of me by R’ Sander Goldberg of Baltimore and he followed it up with a fascinating answer from his sefer נחל חיים (Page 30.) There is some discussion regarding the general climate and environmental conditions before the flood and how they were changed forever by the flood. One of the principal catalysts for these theories is the first reference to seasons after the flood (8:22) which seems to imply that there were no seasons beforehand.

מלבי"ם writes that before the flood planet Earth was not on the 23.5 degree tilt on which it finds itself currently. The tilt was as direct consequence of the environmental havoc wreaked by the flood. When the earth is not tilted the climate conditions throughtout the world are at complete equilibrium. That is to say that weather conditions are completely uniform throughout the world and throughout the year. There is simply no reason for conditions to be any different in one place from another. Cloud cover as we know it did not exist either. After all, a partially cloudy sky means that there are clouds over one part of the land and not over the other. Rather, the skies slowly became saturated with moisture uniformly and once every forty years, writes מלבי"ם, the entire earth would be drenched with rain and the process would begin anew. (This explains why the people were not overly taken aback by the flood when it began.) מלבי"ם also attributes the longer lives lived before the flood to the consistency of the climate.

(Now THAT's climate change!)

Another condition that would result from a world climate in equilibrium is uniform atmospheric pressure. Without varying pressure, there can be no wind. Wind is a result of air moving from a high pressure area to a lower pressure area like the air flowing out of a balloon. Before the age of the motor, all large boats relied on wind to move. If there were no wind, there would have been no boats. This explains why Noach’s project appeared so strange and also explains why no one else had any means to survive the flood.

(He goes on to explain that due to this extreme difference in global climate fermentation was something that did not happen before the flood and that explains how Noach could go so terribly wrong afterwards getting drunk - alcohol hadn't existed either.)

Interesting Calendrical Facts About the Mabul

We are taught that the Mabul began at midday. (Bereishis 7:13) Rashi cites that the reason for this was to demonstrate that, with Hashem's protection, Noach was able to enter the Teivah in front of all the wicked people of his generation and none of them was able to harm him.

Rav Yehonasan Eibshitz zt"l offers an additional explanation that has to do with the way the calendar works. Rav Eibshitz mentions that the historic date which the dove found dry land in the year after the Mabul was the first of the first month and was a Shabbos. If so, then the year preceding this one, the year when the Mabul began, the first day of the first month was Tuesday. (Clearly Rav Eibshitz is using a regualry styled year in which half the months contain 30 days and the other half have 29. The months alternate with 30 then 29 and so forth throughout the year.) Since the first month was a Tuesday then the subsequent month, the month in which the Mabul started, started on a Thursday. Thus, the 17th of that month, the day which the Mabul started, was Shabbos. Since the Gemara teaches that rain on Friday night is a blessing, the rain, instead, began during the daytime as not to give the wicked people even one iota of blessing. (Taanis 23a) Rav Eibshitz continues that, additionally, the mazal of Shabbos daytime is Saturn which symbolizes mass destruction and that was befitting for the beginning of the Mabul. (See Rashi Berachos 59b and the Ibn Ezra's Reishis Chachma) (Tiferes Yehonasan Bereishis 7:13)