Tuesday, March 17, 2015

Eclipses: Physics or Metaphysics?

This Friday, there will be a total eclipse of the sun. At the blog of The Biblical Museum of Natural History, I wrote a post about the spiritual significance of eclipses. The Talmud (Sukkah 29a) calls eclipses of the sun and moon unfavorable periods for the world. It further states that solar eclipses occur due to certain sins.

The question is clear: Many ancient peoples believed that eclipses were unpredictable events. But we know that they follow a set pattern and can be calculated in advance. Did the Talmud not know this? How can eclipses be a punishment for sins if they occur at predictable times?

Many years ago, Rav Aryeh Carmell ztz"l told me that the Sages simply did not know that eclipses are predictable events. I found two other approaches to this question.

One approach is that of Rabbi Yaakov Ettlinger (Aruch LeNer ad loc.). He argues that the Talmud clearly understood solar eclipses to be caused by the moon obscuring the sun. He also points out that the Talmud uses the seemingly superfluous wording, “at the time when the sun is eclipsed, it is an unfavorable period,” when it could have simply said “when the sun is eclipsed.” The word z’man, “time,” is related to the word “zamen,” prepared. Thus, he claims, the usage of this word shows that eclipses were known to be pre-arranged and predictable events. However, this does not present a contradiction to their indicting punishment for sin. Rabbi Ettlinger and Iyun Yaakov explain that during eclipses, God exacts retribution for certain sins. Certain periods are set aside for Divine justice to be meted out, and these are indicated in the physical universe by eclipses.

A different approach is taken by Rabbi Yonasan Eybeschitz (Ya’aros Devash 2:12). He explains the Talmud’s term likuy ha-chamah, literally “the striking of the sun,” to be referring not to solar eclipses but to sunspots. These are cool dark patches on the face of the sun caused by magnetic storms. These being events of unknown occurrence, R’ Eybeschitz explains sunspots to indicate God’s displeasure. Indeed, sunspots send vast amounts of charged protons into our atmosphere, and several studies have tentatively shown corresponding variations in animal populations and incidence of disease amongst people. R’ Eybeschitz argues that people of earlier times were more sensitive to such sunlight aberrations. A difficulty with this is that we now know that sunspots and solar storm disturbances occur in an approximately eleven-year cycle; however, this can vary from seven to sixteen year.

33 comments:

  1. How does Rabbi Yonasan Eybeschitz explain Likui Levanah?

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  2. Just speculating: maybe the Babylonian and Greek astronomers could predict the timing of solar eclipses but not the path of totality, so the Sages inferred that God made the path of totality cover the targets of His wrath.

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  3. Just speculating: maybe the Babylonian and Greek astronomers could predict the timing of solar eclipses but not the paths of totality, so the Sages inferred that God arranges the path of totality to cover the target of His wrath.

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  4. My understanding is that sunspots were discovered by Galileo when he first turned his telescope towards the sun, so they were not known about during the time of the Talmud, unless the Ya'arot Devash was claiming that HAZAl had some sort of special knowledge that they did exist.

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  5. The length of the lunar cycle was derived from the time between solar eclipses; it’s not plausible that the Sages did not know eclipses were predictable.

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    1. I am not sure the molad was calculated rather than revealed. We know it was in use in Bavel by the end of Galus Bavel. But we also know that due to the lengthening of the month and of the day over time, it was not as accurate then as it was in the 5th cent CE, when our current calendar was set up.

      It is an odd fact that we were using a number more correct when we most needed it than when there is the first evidence of anyone using it. It implies Divine Intervention. Whether in the measurements used in calculating the molad or in direct prophecy.

      Second, since the molad was used in Bavel, who did the calculation and therefore had to have known eclipses are predictable? Babylonian science? The prophets drafted into the Babylonian court in the days of Daniel? But in any case, Chazal could have known the measure without knowing how it was measured.

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    2. I am not sure the molad was calculated rather than revealed.

      Since our Molad corresponds to the one in the Almagest, it is likely calculated. From a "rationalist PoV" we were commanded to calculate it (or we were commanded to calculated the motions of the sun and moon and that was part of the calculation.)

      We know it was in use in Bavel by the end of Galus Bavel. But we also know that due to the lengthening of the month and of the day over time, it was not as accurate then as it was in the 5th cent CE, when our current calendar was set up.

      The evidence says that the calendar that we have today was instituted later. We have discussion in Geonic times of factor not relevant in our calendar, and dates that would not be used by our calendar.

      It is an odd fact that we were using a number more correct when we most needed it than when there is the first evidence of anyone using it. It implies Divine Intervention.

      It implies that when it was needed, it was calculated, to the extent possible by the people at the time and relying on whoever could supply the best number (given the Ptolemy had the number).

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  6. Quote: He also points out that the Talmud uses the seemingly superfluous wording, “at the time when the sun is eclipsed, it is an unfavorable period,”

    Here's my speculative explanation. It could well be that chazal knew of the obscuration of the sun by the moon as per Rabbi Yaakov Ettlinger. But, most likely, the majority of the world did not know that and it was a terrible and frightening sight to behold. Therefore, it was an "unfavorable period" just like Pesach was an unfavorable period for Jews during the Middle Ages. When something bad happens, blame the Jews. Obviously we caused the disappearance of the sun.

    An aside... for those of you living in the USA, keep August 21, 2017 in mind. It will be the first time since around 1978 that a total eclipse of the sun will be visible from within continental USA. It is an absolutely awesome thing to view. I saw the total eclipse in 1978 and am anxiously awaiting the next one in two years. You can learn more about it here: http://www.eclipse2017.org/

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  7. Or maybe the ancient to medieval Rabbis were superstitious just like many other cultures were. Many sages speak about the mystical and or real world influence of the planets on earthling history and possible events. Can anybody of sound mind believe in this nonsense. To laugh or cry.

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    1. It concerns me how the poetic eyes of Chazal are ignored by some. We are aware of the symbolic significance with which Chazal view the cycles of the moon. Waxing and waning represent the resilience of the Jewish People to fulfill it its role of reflecting the Light of all light. Good. But the routines of life and custom have had the unintended consequence of making us dependent upon those symbols for validation. When the natural cycles of the universe reveal it is just a symbol, we are faced with a "bad omen": Are we too attached to the symbols? If we are, THAT is a bad sign, and an indication that we need to re-evaluate our dependence on symbols.

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    2. I believe it and I have a sound mind.

      The sages were not superstitious and the Talmud speaks loudly against superstition.

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  8. I believe you are conflating sunspots which do not, as you wrote "send vast amounts of charged protons into our atmosphere" with coronal mass ejections (CMEs) which do, at least if they're launched in the right direction. There is some association of CMEs with sunspots but they are different phenomena. (self reference is gauche, but see http://time.com/93193/congress-hearing-solar-flares-electric-grid/). Also they would not really get into the sensible atmosphere at all but are rather trapped in the earth's ring current which is way higher up there. But I didn't know of RYE's susnspot chidush, so thank you.

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  9. Rabbi Ettlinger's explanation (that is, the last sentence of that paragraph) reminds me the explanation by Artscroll given in their siddur for "al shalosh aveiros nashim meisos bish'as leidasan...": "Punishments are most likely in time of danger."
    A question on Rabbi Ettlinger could be this: Do we empirically witness more bad news (or retribution) during an eclipse than during any other period?

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  10. Both lunar and solar eclipses were predictable (and often predicted) by Greek astronomers during the Bayit Sheni period. It is impossible that the sages of the Talmud were not aware of this.

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  11. It concerns me how the poetic eyes of Chazal are ignored by some. We are aware of the symbolic significance with which Chazal view the cycles of the moon. Waxing and waning represent the resilience of the Jewish People to fulfill it its role of reflecting the Light of all light. Good. But the routines of life and custom have had the unintended consequence of making us dependent upon those symbols for validation. When the natural cycles of the universe reveal it is just a symbol, we are faced with a "bad omen": Are we too attached to the symbols? If we are, THAT is a bad sign, and an indication that we need to re-evaluate our dependence on symbols.

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  12. Joe in Australia: Both lunar and solar eclipses were predictable (and often predicted) by Greek astronomers during the Bayit Sheni period. It is impossible that the sages of the Talmud were not aware of this.

    The sages were not a monolith. See Pesachim 94a which implies a flat earth model.

    Also, I don't think that solar eclipses were so predictable. They can only happen at certain times, but whether or not they would occur (and be visible) at that time was more difficult to ascertain. Someone here can correct my ignorance.

    The length of the lunar cycle was derived from the time between solar eclipses; it’s not plausible that the Sages did not know eclipses were predictable.

    All that means is that they used the eclipse to mark the conjunction of the sun and the moon. Eclipses don't have to be predictable to do that.

    Y. Ben-DavidMarch 17, 2015 at 9:56 PM
    My understanding is that sunspots were discovered by Galileo when he first turned his telescope towards the sun, so they were not known about during the time of the Talmud, unless the Ya'arot Devash was claiming that HAZAl had some sort of special knowledge that they did exist.


    As you point out, the Talmud is clearly talking about eclipses. However, sunspots were observed before the telescope. https://en.wikipedia.org/wiki/Sunspot#Early_observations.

    On the "rationalist" approach to such material: I used to try to puzzle out the "avoid bad luck" customs around Tisha B'Av in a rationalistic way. Then I found that Marc Shapiro in "Studies in Maimonides and His Interpreters" points out the following: The Rambam simply doesn't record those halachos.

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    1. David

      I do believe that solar eclipses were predictable during the Bayit Sheni period. One of the dials on the Antikythera mechanism was used for predicting solar eclipses. The Antikythera mechanism is generally dated to around 200 BCE, but in any event is from the pre-churban period.

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    2. As in, "today you will see one", or "today you might see one"?

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  13. I find the Maharal's explanation (https://books.google.com/books?id=Auaiwspdr9QC&lpg=PA71&ots=GdZHDdU9zz&dq=maharal%20eclipses&pg=PA70#v=onepage&q=maharal%20eclipses&f=false interesting (if not the original intent). He says that Chazal were explaining "why" it is that we have eclipses altogether. If the universe were designed "ideally", we would not. The reason is because of man's sin.

    So my thought was that if the universe was designed "ideally", the opposite might be the case. Maybe the planes of the orbits of the Moon and Sun would be perfectly aligned and we would have a solar and lunar eclipse every month! That would give the sighting of the new moon a whole different meaning.

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  14. The problem R. Slifkin raises was already acknowledged at least as far back as the fifteenth century, by R. Yitzhak Arama:

    http://seforim.blogspot.com/2010/03/woman-is-not-elephant.html

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  15. Mayan astronomers figured out the eclipse cycle.

    http://www.jstor.org/discover/10.2307/2742481?sid=21106155402123&uid=4&uid=2&uid=3739256

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    1. But if I understood the paper correctly, (and I didn't read it carefully at all), their cycle predicted lots of solar eclipses that they could not see. In fact most would not be seen by them. So if you wanted to (and I don't know that they did), you could still attribute see an occurrence as a bad omen.

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  16. Indeed, sunspots send vast amounts of charged protons into our atmosphere, and several studies have tentatively shown corresponding variations in animal populations and incidence of disease amongst people.

    These studies are at best problematic and most appear to emanate from the peripheries of science. They are not readily testable or falsifiable (too many subjective assessments involved) and cannot account for a mechanism which would convincingly explain specific behaviours of or effects on people or animals. The connection and surface effects of CMEs and solar winds to sunspot activity are, as Mechy Frankel above said, too tenuous.

    What's more, because there is an established, credible link between sunspot activity and weather and climate, it becomes nearly impossible to separate environmental effects on humans and animals ...such as low sunspot activity of the Maunder Minimum correlated to the Little Ice Age between mid 1600s and early 1700s... and any presumed physiological effects from sunspots.

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  17. The issue with solar eclipses is not so much what significance the sages attributed to it - which may have well been based on a misunderstanding, rather what significance the torah appears to ascribe. The significance of the appearance of the sun, moon, and stars is described as their becoming signs(otot) and designators as well as illuminants. What signs? Rashi, based on the sages, refers to eclipses of the sun as being 'bad signs'. Well, the eclipse of the sun by the moon or the moon by the earth is strictly a matter of orbital position and motions, i.e., the physics of the dynamics of the solar system. No special causation is needed. How, then, can an eclipse denote some sign? Perhaps it is just a reminder that life may not continue in its accustomed fashion. That there is a day of reckoning, and that GOD is not forever patient with human foibles and injustices. That evil doers and evil institutions will not hold sway for ever, but will be eradicated and overthrown.

    Y. Aharon

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  18. Aren't rainbows also predictable in advance, and yet they are also said to be indications that God is angry but recalling His promise with Noach? Doesn't Ramban address that? How does that differ or relate to this post?

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  19. David, does the Maharal really state that the 'non-ideal' arrangement of the solar system is due to man's sins? That would imply that a vast change in the earth-moon-sun configuration occurred subsequent to old Adam eating the 'apple'. That would carry implications for life on earth at the time for which there doesn't appear to be any indication in Genesis. Besides, I feel to see how a non-eclipsed sun is more ideal or even possible given the solar system configuration where the earth orbits the sun and the moon orbits the earth. Your scheme of monthly eclipses of the sun would happen if the moon's orbit was in the ecliptic plane (the plane of the earth's orbit) rather than being at an angle to it.

    Y. Aharon

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    1. Yes, you can see exactly what he says (well, translated into English) by following the link that I provided above. He basically says that since Chazal could not have meant that sin caused eclipse, that instead they meant that sins are the cause of God creating the universe in a manner which eclipse occur. I suppose that he viewed eclipse negatively because they detracts from otherwise "unchanging" and "perfect" nature of the heavens and also because they scare people.

      Your scheme of monthly eclipses of the sun would happen if the moon's orbit was in the ecliptic plane (the plane of the earth's orbit) rather than being at an angle to it.

      Yes, that is what I meant although I think that you stated it more clearly. Of course, I don't think that this has anything in reality to do with the statement of Chazal in question.

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    2. I don't know why I wrote "eclipse" 3 times above when I meant "eclipses", but I'm too lazy to fix it now :).

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  20. The significance of the appearance of the sun, moon, and stars is described as their becoming signs(otot) and designators as well as illuminants.

    The moon is a pretty darn good sign all by itself. It tells you the period of the tides and it's a calendar in the sky (at least for those following a lunar calendar). The Sun marks the seasons in its travel through the zodiac (besides marking the days). Do you need more than that?

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  21. David, the moon's gravity is, of course, the principal cause of ocean tides on earth (the sun is a secondary cause). However the timing of high and low tides is not a simple matter of the moon being directly above, or directly below, or just below the horizon of a given coastal location. it is also affected by the topography off-shore that location. Hence, the moon is not a particularly good indicator of the tidal periods, much less their timing. In terms of calendrical matters, I would fit that in the category of mo'adim mentioned in the verse. Of course, the sun is the primary determinant of the day and year (yamim veshanim in the verse). At least, that is why I cited Rashi's comment about solar eclipses being a sign of trouble - with my own spin, to account for the designation of otot in the verse.

    Y. Aharon

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    1. I certainly can't say that your d'rash is wrong. I just think that while we have become divorced from the heavens, in part because in the big cities we can't even see them, the movement of heavenly bodies have plenty of significance without any need for d'rash.

      David, the moon's gravity is, of course, the principal cause of ocean tides on earth (the sun is a secondary cause). However the timing of high and low tides is not a simple matter of the moon being directly above, or directly below, or just below the horizon of a given coastal location. it is also affected by the topography off-shore that location. Hence, the moon is not a particularly good indicator of the tidal periods, much less their timing.

      Yes, but an any given location, won't the high and low tides come at a given delay after the lunar midday at least on average. The reason that the moon-tide association was made is because the tidal period at a given location is half of the lunation. I believe that is true, although I don't have time right now to research how the delay might change.

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  22. Out of the 151 planetary systems, they now made an additional check on 31 planetary systems where they had already found planets in the habitable zone or where only a single extra planet was needed to meet the requirements.

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