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.