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 31^o North, is above the Tropic of Cancer (23.5^o 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.]

The Two Luminaries

Pasuk 16 refers to the sun and the moon as "shnei hame'oros hagedolim", the two large luminaries but concludes by referring to the sun as the "maor hagadol" and the moon as the "maor hakaton". On this pasuk there is the well-known Rashi, quoting the Midrash, that the moon and the sun were created equal but the moon complained that "two kings cannot share one crown". Therefore, it was reduced to a smaller luminary. However, this is certainly an allegorical understanding of the pasuk. What, then, is the simple understanding?

In In the Beginning: Biblical Creation and Science, a fascinating book reconciling the Biblical account of creation with modern science, Professor Nathan Aviezer offers an eye-opening interpretation. An astronomical body is measured both by its true size and by its apparent size or angular diameter. The apparent size specifies how large it appears to an observer on Earth. This figure is the ratio of the true size of the object to its distance from the Earth. This figure is expressed as the angle that the object subtends from the position of an observer on Earth. That means, if you were pointing to the bottom of the object, the apparent size is the number of degrees you must rotate your arm to be pointing at the top of the object. The sun is 400 times bigger than the moon. It is also exactly 400 times further away from Earth. As a result, the apparent size for the sun and moon are identical at 0.53 degrees! Now we can understand the pasuk as follows: The first part of the pasuk is referring to the point of view of an Earth observer. From our point of view, the sun and moon are the biggest heavenly bodies and in fact, appear identical in size. The second part of the pasuk refers to the true size of the sun and moon.

Please see Pi's comment below with some nice alternative understandings of this פסוק.

Eclipses in הלכה and מחשבה

In light of (no pun intended) the upcoming solar eclipse here in the USA, I thought I'd post a piece I wrote about eclipses a couple of years ago.

B’nei Yisrael are traditionally symbolized by the moon. The generations from Avraham are likened to the cycle of the moon. David and Shelomoh were the 14th and 15th generations from Avraham Avinu. It was during their reign that B’nei Yisrael was at its pinnacle. They conquered their enemies, stretched out their borders and built the beis hamikdash. This is just like the moon which is biggest on days 14 and 15. After Shelomoh, national stability began to deteriorate and B’nei Yisrael lost their splendour, just as the moon wanes after the 15th day.

There are many insights to be taken from this symbolism. The gemara (Rosh HaShanah 25a) quotes the pasuk (Tehillim 104:19) “shemesh yada mevo’o,” the sun knows its path. The gemara comments that the sun knows its path but the moon does not. The relative path of the sun as it changes from season to season is quite predictable and easy to figure out. The path of the moon, however, is erratic in nature and seems not to follow a specific pattern. We may understand this as analogous to the way in which the world is run. The nations of the world, traditionally symbolized by the sun, are governed, to a certain degree, by the laws of nature. There is a less focused Divine Providence that guides their everyday events. This is akin to the predictable path of the sun. One need not delve too deeply to realize that B’nei Yisrael are governed in quite a different manner. The great miracles that adorn our history, as well as the day-to-day twists and turns that befall our nation to this day are clear indications that there is nothing haphazard about the course of events that befall us. There are no patterns or laws of nature to rely on, just as the moon follows a seemingly unpredictable path.

The gemara (Sukkah 29a) tells us that when there is an eclipse of the sun, it is a bad sign for the gentiles. When there is an eclipse of the moon, it is a bad omen for B’nei Yisrael because we follow the lunar calendar and they follow the solar calendar. There is an intriguing insight that lies beneath the surface here as well. An eclipse of the moon happens when the moon moves into a position behind the earth such that the light of the sun cannot reach it. One might say that it is “the moon’s fault” that it was eclipsed. This is the way we must view calamities that befall us. We must search within for the causes and realize that it is our own deeds and actions that have brought them about.

An eclipse of the sun happens when the moon moves in front of the earth in such a way that it blocks the sun’s light from reaching certain spots on the earth. Here, too, we see that it is path of the moon that has caused the eclipse. The sun and earth are insignificant players in a solar eclipse. The lesson learned from this gemara is that everything that happens in this world is, in some way, connected to B’nei Yisrael. Despite our relatively insignificant size, like that of the moon to the sun, the world was created for us and continues to be governed according to our actions. This is not something to take advantage of but rather, a great responsibility that we must bear on our shoulders at all times.

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Every month, on the Shabbos before Rosh Chodesh, as part of "Birkas HaChodesh," the time of the molad is announced. This time refers to the birth of the new moon on which Rosh Chodesh is based. Astronomically, this is when the moon passes between the earth and the sun, thereby completing its monthly cycle. Although the time of the molad no longer determines the exact day of Rosh Chodesh since our calendars are set, we use this figure to determine when we may recite kiddush levanah. Based on the gemara (Sanhedrin 41b), we may only recite kiddush levanah when the moon is new, that is, when it is waxing. Knowing the midpoint between the two molados allows us to determine this exact time (Rema OC 426:3). Also, we do not begin to say kiddush levanah until three whole days after the molad, when the moon is big enough to see.

The period of time from molad to molad (synodic period) that we use for these calculations is 29 days, 12 hours, 44 minutes and 3 and a third seconds. However, this is not an exact, constant figure. Rather, it is the average length of a synodic period as indicated by Rambam (Hilchos Kiddush HaChodesh 6:3). The time we use for the molad may differ from the time of the actual molad, lunar conjunction, by a couple of hours one way or the other. In general, we don't really know when it does differ and we just rely on the average synodic period for all halachic calculations. However, nature can sometimes tell us that our calculations are off - with an eclipse.

An eclipse of the moon happens when the moon is in a position behind the earth such that the sun's rays cannot reach it. Clearly, this can only happen at the exact middle of the month, lunar opposition, when the moon is exactly behind the earth with respect to the sun. An eclipse of the sun is when the moon moves directly in front of the sun, obstructing the view of the sun from earth. This will only happen at the exact beginning of the month when the moon is exactly between the earth and the sun, i.e. the molad.

The issue of eclipses is discussed in Beis Yosef and Darchei Moshe OC 426. The consensus there is that if an eclipse of the moon is witnessed, then kiddush levanah may no longer be recited, even if this is before the prescribed time for sof zeman kiddush levanah, the halfway point between molados. [9/26/2015: This halachah was especially significant in this area of the world this month. The official time for sof zeman kiddush levanah was 12:47 am EDT on Thursday night (Friday morning, officially). However, there was a much anticipated full lunar eclipse that night. According to NASA, the time of mid-eclipse, essentially the official middle of the month was 11:40 pm EDT. Therefore, kiddush levanah should have been recited before that time, despite whatever is written in the calendars.]

A solar eclipse, however, is not as simple. Beis Yosef writes that a solar eclipse may not be used to determine the proper time after which one may not say kiddush levanah. However, there does not seem to be any discussion about beginning to say kiddush levanah. If the time of the molad were preceded by a solar eclipse, as the molad of Teves 5761 was by eight hours, would that allow us to recite kiddush levanah earlier? Conversely, if the molad were to precede the eclipse, would that move back the time at which we may recite kiddush levanah? For our upcoming solar eclipse, the peak time is actually around a full half day before the recorded time of the molad.

Perhaps, the reasoning behind Beis Yosef's ruling with regard to sof zeman kiddush levanah would not apply to techilas zeman kiddush levanah. When a lunar eclipse indicates that we may no longer recite kiddush levanah it is because we may not rely on an average when there is a clear indication that the average is incorrect. When it is an average against a clear natural indication, we dispense with the average. However, the calculation for sof zeman kiddush levanah is achieved by adding half of the average synodic period to the previous molad. To allow a solar eclipse to determine sof zeman would be to combine the clear evidence with an average. We must rely on one or the other but we may not combine the two.

To allow the solar eclipse to determine when we may begin to recite kiddush levanah is relying only on the clear evidence of the eclipse and not on any other averages. Therefore, it would seem that we may adjust the time based on a solar eclipse. Furthermore, the apparent source for the custom to wait three days is Talmidei Rabbeinu Yonah (End of Berachos 4.) But the specific wording used is that one should recite kiddush levanah when people derive benefit from the moon's light - after two or three days. In fact, Yad Ramah on Sanhedrin writes that it may be recited after one day. Therefore, to be lenient in this regard when there is sufficient astronomical evidence on our side does not seem so farfetched.

It should be noted that Darchei Moshe adds his own rationale - that a lunar eclipse is more widely viewed whereas a solar eclipse is only visible in a very limited area of the world. With that explanation, we wouldn't use the solar eclipse in any way to modify our average figures.

Ominous Eclipse Predictability

For those in the Western United States, you will be able to see a full lunar eclipse just before dawn this Shabbos!

Chazal tell us in Sukkah (quoted by Rashi in Bereishis) that eclipses are ominous signs. I have often been asked whether this is true with regard to contemporary times because we know how to predict eclipses. My answer has always been, "Yes." Even amongst the other ancient civilizations we find the ability to predict eclipses. The ability to predict eclipses was known as far back as the time of the Chaldeans. Even the Babylonians and Greeks were also very familiar with the necessary calculations.

The calculation required is knowledge of the Saros Cycle. The Saros Cycle is a duration of 18 years, 11 days and 8 hours. In each cycle, one will have eclipses at the same intervals as the one that preceded it. Every three cycles will have an eclipse at the same approximate location relative to Earth.

In fact, in the early 1900's an ancient Greek shipwreck was discovered. One of the items found was something that became known as the Antikythera Device (named for the location of the wreck). Its gearwork was so intricate that scientists were astounded. Something like this should not have been able to have been made in the time period this ship went down (approximately 100 years prior to the Churban Bayis Sheini). Not only was it clear that it had been made, it was clear that many prototypes had had to have been made prior to it, because this one was perfected. After much analysis, it became clear that the device was an ancient "calculator". It would display the movement of the Sun, Moon, stars and planets. It also would show when the next eclipse would happen.

This is more proof that they were able to calculate eclipses. They had even put the calculations into machines to do the dirty work for them. When Chazal made their statement, eclipses were already predictable events. If so, how could an eclipse be an ominous sign?

It seems that the answer is that when Hashem created the world He placed in it times that are naturally times of judgment (similar to Rosh Hashana). It was through His mercy that He shows us (and we can even predict) when these times will be, so the affected parties can repent.

THE BOOK (BEING PUBLISHED BY ISRAEL BOOK SHOP), THE SECRETS OF THE STARS, WILL BE IN STORES NEXT WEEK!!! KEEP YOUR EYES OPEN!

Hidden Summer Rainbows

The Midrash that discusses some of the meaning behind the names of the months explains that Tammuz is named for the idol that bears the same name. It was in this month that Klal Yisrael worshipped the Golden Calf and displayed their desires for idol worship. Therefore, it is befitting that the name of the month reflect this concept. (See Torah Sheleimah Parshas Bo Miluim 177)

Tammuz is also the beginning of the summer. The summer is when the sun is at its highest in the sky (for northern observers) and is certainly when its perceived power is felt the most. The sun is often utilized to express the forces of idol worship. In fact, the Rema mentions that Yirmiyahu HaNavi prophesied about the impending doom of the Beis HaMikdash and the kingdom of Yehuda which was to come from the Babylonian empire. Yirmiyahu describes this destruction as coming from the north. (Yirmiyahu 1:14; this week's Haftarah) The necessity of mentioning the direction of this foe, says the Rema, is because the destruction was a result of idol worship. The sun rises from the east, travels along the southern portion of the sky and sets in the west. It never truly resides on the northern portion of the sky. The sun, says the Rema, is the classic symbol of a deity served by ignorant people. The sun's path should have been a clear lesson to those that served other gods that their gods have no power just as the sun is forced to set. Had the people looked toward the north and understood that it shows the sun's impotence, they would have recognized the error of their ways and would have repented. Since, they did not, the destruction came from that very direction north. (Rema Toras HaOlah 1:16)

The summer, the sun's glorious months, has been a time of destruction for the Jewish people. We just fasted the 17 of Tammuz and historically 9 Av has been a day to mourn the horrific calamities of our past. The summer is currently bittered by the tears of tragedy. Rav Aharon Feldman shlita recently pointed out that the month's of summer, July and August, are the only two that bear the names of Roman emperors. (Mussar given in NIRC 6/2310) The Romans, considered to be the descendants of Eisav, are the nemesis of the Yisrael. Their glory is displayed in the time of destruction.

The Yerushalmi seems to tell over this same concept, but also shows that it is possible to change this time of year from its current destructive nature into a very positive time. (Chagigah 2:2) Rebbi Elazar ben Arach was able to elucidate the heavenly angelic court with such precision during the first day of summer, in Tammuz, that a rainbow was able to be seen in the sky. Rainbows, are not normally seen in the sky in the summer in Eretz Yisrael because it is the dry season and there are not usually clouds or rain. A rainbow is what Yechezkel HaNavi used to express Hashem's glorious heavenly court's beauty. (Yechezkel 1:28)

Perhaps, the Yerushalmi is telling us that normally Tammuz, and the summer, do not contain rainbows. Summer is not the time when Hashem's glory is naturally perceived. Nevertheless, through hard work and dedication, one can break through the veil that hides this glory and allow the glory to shine through. Zechariah HaNavi informs us that in the future these days of mourning will be transformed into festive days. (Zechariah 8:19) May we merit to those days very soon!

Goodnight Moon

The climactic moment of the Ten Plagues was the final one, the killing of the firstborns at midnight. Last year I posted about the star Sirius' connection to this event. This year I would like to add one more point to that post.

An entire lunar cycle (from our perspective) takes approximately 29 days, 12 hours, 44 minutes and 3 1/3 seconds. Since this tenth plague occurred on the 15th of the lunar month, that means that the moon was full.

Many notice that the moon is sometimes visible in the daytime and at other times at night. The basic overview of its rise and set times is that in the beginning of the lunar month it is visible in the afternoon and sets just after sunset. Every subsequent day it appears a little later in the day and sets a little later in the evening. In the middle of the month it rises at sunset and sets at sunrise and it then begins to rise after sunset and set in the morning until the cycle begins again.

When putting all this together, one can see that at midnight,the moment of the plague, the moon was full and at its peak. The sun, on the other, has its peak at midday and is at its lowest at midnight. The other nations of the world are compared to the sun (see Maharsha Yoma 20) and Klal Yisrael to the moon (see Midrash Tehillim 22). This was finally the moment when Klal Yisrael was shining and at its peak and their oppressors were at their lowest.

Can the Torah's South be North?

In this week’s Haftarah we are told (הושע יג:יב),
"צרור עון אפרים צפונה חטאתו."
"Ephraim’s iniquity is bound, his sin is hidden."
Earlier, the navi had made it known, clearly, that the sin of Ephraim was idolatry. Idolatry being "hidden" is something that actually refers to an astronomical fact. More specifically, that which is hidden shows that idolatry is ridiculous.

Rabbeinu Bachye (Bamidbar 2:2) informs us that the cardinal directions, east (מזרח), west (מערב), north (צפון) and south (דרום) are named such because of the sun’s perceived motion (also see Ramban Shemos 26:17). מזרח is the word for east because it comes from zarach meaning to shine. It is from this direction that the sun begins its journey every day. מערב is from erev which means nightfall because the sun’s journey ends here at nightfall. דרום is actually a contraction of two words, dar and rom, meaning dwells high.

The sun, to those at northern latitudes, rises from the east and travels on the southern portion of the sky and sets in the west. צפון also means hidden and that is why north is referred to as such. While the sun can definitely set and rise from a slightly northern direction, it NEVER travels on this side of the sky. The sun, the most commonly chosen idol, should have been rejected as a god for this reason. The fact that it has no power in this area, and that it sets, shows its impotence!!! The Rema (Toras HaOlah) tells us that this is why the pending destruction of the first Beis HaMikdash was described by the navi, Yirmiyahu, as coming from the north. This was to show the idol worshippers that they were horribly wrong. Perhaps, this is why Ephraim’s sin is depicted as being hidden, as well.

When describing these types of ideas, people sometimes ask why the Torah seems to totally disregard those in the southern hemisphere. For them, it is the northern side that the sun travels on and the southern side is "hidden". I am not 100% sure, but I feel that the answer is either that since the Torah was given in the northern hemisphere it is told from that perspective, OR that the Torah would have called north darom and south tzafon to these people!!! The idea is not the actual direction, but the solar movement. If so, then it is reasonable that this would be the case.

ברכת החמה and ערב פסח

One would have been hard pressed to escape all the "media hype" over the upcoming recitation of Birkas HaChamah. It's everywhere your turn. It's on various informational internet sites with explanatory videos and pictures. It is the subject of a number of worthy new publications as well as shiurim around the globe. And of course, let's not forget all of those tzedakah mailings. And it is with good reason. After all, this only happens once every 28 years. Of course, this year's recitation is yet more rare. We are required to recite the berachah amidst all of the hustle and bustle of Erev Pesach preparations. The last times this occurred were 1309 and 1925 and it won't happen again before the year 6000.So what is the significance of it all?

There are 13 individual beliefs that are delineated as the tenets of faith. However, there are two individual assertions of our belief in HaShem that are repeated in our daily and weekly routines at a much greater frequency. We are commanded to remember HaShem's deliverance of our forefathers from Mitzrayim every day of the year, at least twice a day. Additionally, the kiddush and tefillah for each Yom Tov incorporate a reference to the holiday as "zecher litziyas Mitzrayim."

The recalling of Yetzias Mitzrayim is so prevalent that many are troubled by the specific commandment to tell over the story on Pesach night. After all, how is this night different from all other nights? One thing is for certain, the mitzvah on Seder night takes on a different flavour from that which we find the rest of the year. Instead of a brief mention of Yetzias Mitzrayim, we are required to delve deeply into the story, to realize all of the wondrous miracles HaShem performed for us and to express our gratitude in many ways.

Another fundamental belief which appears nearly as frequently in our liturgy is the belief in HaShem as the Creator of the world. It is indeed the very essence of Shabbos which, although it only comes once a week, it is meant to be the focal point of our week. Our entire week is essentially a "zikaron le'maasei Bereishis." Interestingly, though, we find ourselves commemorating HaShem's day of rest without nearly as much attention given to the actual creation. Although Rosh HaShanah is meant to commemorate the creation of Man, it is so saturated with other various themes, it can easily get lost in the mix. Birkas HaChamah, recited when the sun begins a new cycle and the vernal equinox occurs at the same time in the week as it did during creation, demands of us to reflect on the creation itself and to give us renewed appreciation of the creator.

The timing of this year's Birkas HaChamah allows us to, in a matter of mere hours, take two of our most fundamental and basic assertions of faith in HaShem and elevate them and express them in new and special ways.

It is also worthy of note that in a year such as this, not only does the equinox occur at the same time of the week as it did when the sun was created, but the days of Pesach also fall out on the same days of the week as they did the year of Yetzias Mitzrayim.