Bava Basra 74a ~ Where Heaven and Earth Touch

In honor of the birthday of my dear wife, Erica, who has taught me how to see the heavens and focus on the earth.

While discussing the legal technicalities involved in buying a boat, the Talmud digresses with a series of fantastic stories about boats, told by Rabbah bar bar Chanah.  And then it digresses again with a series of  fantastic stories about all kinds of things, also told by Rabbah bar bar Channah. In total he told fifteen stories. Here is the last one:

בבא בתרא עד, א

אמר לי תא אחוי לך היכא דנשקי ארעא ורקיעא אהדדי שקלתא לסילתאי אתנחתא בכוותא דרקיעא אדמצלינא בעיתיה ולא אשכחיתה אמינא ליה איכא גנבי הכא אמר לי האי גלגלא דרקיעא הוא דהדר נטר עד למחר הכא ומשכחת לה

An Arab also said to me: Come, I will show you the place where the earth and the heavens touch each other. I took my basket and placed it in a window of the heavens. After I finished praying, I searched for it but did not find it. I said to him: Are there thieves here? He said to me: This is the heavenly sphere that is turning around; wait here until tomorrow and you will find it again.

What should we make of this?  We should begin by considering its context, noting that it is part of a series of fantastic fables.  These include a man who pursued a demon on horseback, antelope the size of mountains, giant frogs ("the size of sixty houses") that are eaten by even more giant birds, a fish so large it took three days to sail between its fins, and scorpions the size of donkeys. You get the idea. Given this context, perhaps the tale of a place where heaven and earth touch as a description of reality should be taken with as much seriousness as the other stories. Which is to say, not very seriously at all. 

Other Talmudic descriptions of the Cosmos

Not so fast. There are other rabbis in Talmud who address the structure of the earth and the cosmos. Rabbi Natan noted that the stars do not seem to change in their positions overhead when walking far distances.  The assumption underlying his explanation for this observation was that the earth is flat. Covering the earth was an opaque cap referred to as the rakia, which is most commonly translated as the sky or firmament. Rava, a fourth-century Babylonian sage who lived on the banks of the river Tigris, determined this cap to be 1,000 parsa in width, while Rabbi Yehudah thought that he had over-estimated this thickness. There were others who added to the picture of the sky; Resh Lakish announced that it actually was made up of seven distinct layers. Given this model, there would have to be a place where the opaque cap touched the earth, a place that Rabbah bar Bar Channah claimed to have touched.  So even allowing for a degree of talmudic fantasy, this fable was clearly built on the model that was shared by other rabbis in the Talmud.

The Flammarion Engraving

In 1872, Camille Flammarion published L'atmosphère: météorologie populaire (The Atmosphere: Popular Meteorology). In the 1888 edition this engraving  appeared on page 163:

As you can see from the caption, the engraving is "A missionary of the Middle Ages tells that he had found the point where the sky and the Earth touch." The engraving appears to have been specially created for Flammarion's book. The text that precedes it reads as follows:

Whether the sky be clear or cloudy, it always seems to us to have the shape of an elliptic arch; far from having the form of a circular arch, it always seems flattened and depressed above our heads, and gradually to become farther removed toward the horizon. Our ancestors imagined that this blue vault was really what the eye would lead them to believe it to be; but, as Voltaire remarks, this is about as reasonable as if a silk-worm took his web for the limits of the universe. The Greek astronomers represented it as formed of a solid crystal substance; and so recently as Copernicus, a large number of astronomers thought it was as solid as plate-glass. The Latin poets placed the divinities of Olympus and the stately mythological court upon this vault, above the planets and the fixed stars. Previous to the knowledge that the earth was moving in space, and that space is everywhere, theologians had installed the Trinity in the empyrean, the glorified body of Jesus, that of the Virgin Mary, the angelic hierarchy, the saints, and all the heavenly host.... A naïve missionary of the Middle Ages even tells us that, in one of his voyages in search of the terrestrial paradise, he reached the horizon where the earth and the heavens met, and that he discovered a certain point where they were not joined together, and where, by stooping his shoulders, he passed under the roof of the heavens.

Flammarion does not reference his source for the missionary of the Middle Ages who, like Rabbah bar bar Channah, claimed to have found the place were the heavens and earth meet.  Despite this, his engraving has become very popular. A version of it appears on the cover of Daniel J. Boorstin's best selling work The Discoverers, and inside William Vollmann's Uncentering the Universe. And those are just the ones I know about from my own library. You can buy a color poster of it (where it is incorrectly described as a "medieval artwork") but if you are really dedicated you could always travel to San Fransisco where a tattoo parlor will create the image on your arm. 

We know that Rabbah bar bar Channah's model of the universe is not correct, but his suggestion of a place where heaven and earth touch is both endearing and enchanting.  (It is also the perfect name for an anthology of Midrash which was published back in 1983).  With Rosh Hashanah approaching, you may already be thinking about your wine list.  Perhaps you should consider a kosher wine whose label shows part of the Flammarion etching, and drink to the memory of Rabbah bar bar Channah. 

Talmudology on the Parsha Va'Etchanan~Jewish Astronomers

דברים 4:6

וּשְׁמַרְתֶּם וַעֲשִׂיתֶם כִּי הִוא חכְמַתְכֶם וּבִינַתְכֶם לְעֵינֵי הָעַמִּים אֲשֶׁר יִשְׁמְעוּן אֵת כל־הַחֻקִּים הָאֵלֶּה וְאָמְרוּ רַק עַם־חָכָם וְנָבוֹן הַגּוֹי הַגָּדוֹל הַזֶּה׃

Observe them faithfully, for that will be proof of your wisdom and discernment to other peoples, who on hearing of all these laws will say, “Surely, that great nation is a wise and discerning people.”

שבת עה,א

 אָמַר רַבִּי שְׁמוּאֵל בַּר נַחְמָנִי אָמַר רַבִּי יוֹחָנָן: מִנַּיִן שֶׁמִּצְוָה עַל הָאָדָם לְחַשֵּׁב תְּקוּפוֹת וּמַזָּלוֹת — שֶׁנֶּאֱמַר: ״וּשְׁמַרְתֶּם וַעֲשִׂיתֶם כִּי הִיא חכְמַתְכֶם וּבִינַתְכֶם לְעֵינֵי הָעַמִּים״, אֵיזוֹ חָכְמָה וּבִינָה שֶׁהִיא לְעֵינֵי הָעַמִּים — הֱוֵי אוֹמֵר: זֶה חִישּׁוּב תְּקוּפוֹת וּמַזָּלוֹת

And Rabbi Shmuel bar Nahmani said that Rabbi Yochanan said: From where is it derived that there is a mitzva incumbent upon a person to calculate astronomical seasons and the movement of constellations? As it was stated: “And you shall guard and perform, for it is your wisdom and understanding in the eyes of the nations”(Deuteronomy 4:6). What wisdom and understanding is there in the Torah that is in the eyes of the nations, i.e., appreciated and recognized by all?  It is the calculation of astronomical seasons and the movement of constellations, as the calculation of experts is witnessed by all.

According to the great Rabbi Yochanan (or more likely Rabbi Yonatan, since he was Rabbi Shmuel’s teacher) it is a mitzvah for every person to calculate for herself the positions of the planets and constellations. This is also the position of the important work Sefer Mitzvot Gagdol (#47) complied by Moses ben Jacob of Coucy and completed in 1247. Moses gave two reasons for this mitzvah. The first is that by understanding astronomy, farmers will gain insight into the planting cycle. And secondly, a knowledge of astronomy and the passage of the seasons will help determine when additional months must be intercalated into the calendar so as to allow Pesach to be celebrated in the Spring. But Rabbi Yochanan’s prooftext “for it is your wisdom and understanding in the eyes of the nations” suggests that it is not just about an understanding of astronomy. That knowledge must be demonstrated to those outside of Judaism. And there is, in fact, a long tradition of Jews being astronomers, and sharing their knowledge far beyond the Jewish community. It started with the very first Jew: Abraham.

THE THREE Abraham the Astronomers

According to David Gans, Abraham, the first Jew, was also the first Jewish astronomer. Gans, who wrote his compendium on astronomy around 1612, believed that Abraham had obtained his own knowledge of the stars from none other than the primordial human, Adam.

Adam was an outstanding astronomer . . . and Josephus has written that when Abraham went down to Egypt because of the famine he taught them astronomy and mathematics and was praised by the Egyptians for his outstanding wisdom in these two disciplines....Abraham passed this knowledge to his son Isaac and grandson Jacob.

And so began our long tradition of taking a special interest in astronomy. It would be hard to call the early medieval practitioners astronomers in the modern sense of the word, since almost none actually sat around and looked at the motions of the heavens. Instead they translated works of astronomy into Hebrew, or drew up tables and charts of where the planets could be located, called ephemerides. One of the earliest was Sahl ibn Bishr al-Israili (c. 786–c. 845), also known as Haya al-Yahudi (Haya the Jew) who is believed to have been the first person to translate Ptolemy’s Almagest into Arabic, though not everyone believes that he was actually Jewish.

There is no doubt though that the famous exegete, grammarian and poet Abraham ibn Ezra (d.1167) was Jewish. And he was also a bit of an astronomer too. Actually what he did was mostly astrology, but hey, that’s what everyone did in the twelfth century. He was, according to Bernard Goldstein, “one of the foremost transmitters of Arabic scientific knowledge to the West,” and since Ibn Ezra was one of the first scholars to write on scientific subjects in Hebrew, he had to invent or adapt many Hebrew terms to represent the technical terminology of Arabic. Sadly, some of his translations and original works are no longer extant, but among his most famous works are Sefer Ha’Ibbur (The Book of Intercalation), about the calendar, and Sefer HaMeorot, on medical astrology.

A third “Abraham the Astronomer” was the Spanish Abraham bar Hiyya (d. 1136) who was also an important mathematician. This Abraham wrote Tzurat Ha’aretz (The Form of the Earth) on the formation of the heavens and the earth, as well as Cheshbon Mahalach HaKochavim (Calculation of the Course of the Stars).

Levi ben Gershon

Measuring the height of a star with a Jacob's Staff. From John Sellers' Practical Navigation (1672).

Levi ben Gershon (d.1344) -the “Ralbag” - lived a century later and made an enormous contribution to astronomy. He is well known as a Jewish philosopher and the author of Sefer Milhamot Ha-Shem, (The Wars of the Lord), which took some twelve years to write. He also wrote Ma’aseh Choshev, a work on mathematics. It was not widely read outside of Jewish circles since it was never translated from the Hebrew, though it contains a number of very important theorems. But Levi was also an astronomer in the sense of the word used today. According to the late Yuval Ne’eman, “he personally remeasured everything, basing his models on his own observations only. In that, he is rather unique for that period. Levi writes "no argument can nullify the reality that is perceived by the senses, for true opinion must follow reality, but reality need not conform to opinion" - certainly not the usual position in the Middle Ages.” The Ralbag is also generally credited with the invention of an astronomical device called Jacob’s Staff. It measured the angles between heavenly bodies, and was also used by European sailors for navigation. Levi’s contributions to astronomy are recognized today; there is a crater on the moon named after him.

David Gans, Astronomer Extraordinaire

Another Jewish astronomer who actually did real astronomy was David Gans, who we mentioned above. Gans was born in 1541 in Germany though he spent most of his later life in Prague. While there, he frequented the observatory of Tycho Brahe and Johannes Kepler and learned his astronomy directly from what he saw. His description of the time he spent inside the observatory is perhaps the only one of its kind in rabbinic literature: It’s worth reading just for that:

I can recount how in the year 5360 (1600) our exalted lord Emperor Rudolf (may his glory be uplifted), a man of wisdom, full of general knowledge and expert in astronomy, who values and honors those who are learned, sent a mission to Denmark to invite the eminent scholar Tycho Brahe. He was a scientist and learned in astronomy, and a man who is a prince among his people. The Emperor installed him in a castle in Benatky (which is about five parsaot from the capital Prague), where he remained isolated. [Rudolf] gave him a yearly allowance of three thousand talars together with bread, wine and beer, not to mention other gifts. There he lived with twelve others, all of whom were experts in astrology [sic] and in the large instruments [for measuring,] the likes of which had never been seen. The Emperor Rudolf built thirteen consecutive rooms, and in each room were special instruments that enabled them to view the paths of the all the planets and most of the stars.

Throughout the year they would make and record daily observations of the Sun’s orbit, its latitude and longitude and its distance from the Earth. At night they would carefully do the same for each of the six planets and most of the stars, noting their latitude, longitude and distance from the Earth. I, your author, was there on three separate occasions, each lasting five consecutive days. I sat with them in their observatory, and I saw how they worked. They did amazing work, not just with the planets but also with the stars, recognizing each by its name. When each star would cross the meridian its position would be measured with three different instruments, each operated by two experts. This position would then immediately be transcribed into hours and minutes, for which purpose [Tycho] had an amazing clock. I can testify that none of our ancestors had ever seen or heard of such a device, and it has never been described in a book, whether written by a Jew or Gentile.

And a Famous Jewish Female Astronomer

There are dozens and dozens of other examples of famous medieval and modern astronomers that we cannot include because of space (though you can find a partial listing here). But let’s end with a Jewish astronomer who just had an observatory named in her honor - Vera Rubin (1928-2016). She was born to Jewish immigrants in Philadelphia, educated at Vassar, Cornell and Georgetown, and moved to the Carnegie Institution in Washington in the 1960s. She studied the rotation of galaxies, and discovered that something other than their matter must be holding them together. As her obituary in The New York Times noted, “her work helped usher in a Copernican-scale change in cosmic consciousness, namely the realization that what astronomers always saw and thought was the universe is just the visible tip of a lumbering iceberg of mystery.” Being a woman in a man’s field had tremendous challenges, and called for ingenuity:

…she still had to battle for access to a 200-inch telescope on Palomar Mountain in California jointly owned by Carnegie and Caltech. When she did get there, she found that there was no women’s restroom. …Dr. Rubin taped an outline of a woman’s skirt to the image of a man on a restroom door, making it a ladies’ room.

Vera Rubin was elected to the National Academy of Sciences, and in 2019 the Large Synoptic Survey Telescope was renamed the National Science Foundation Vera C. Rubin Observatory in recognition of her contributions to the study of dark matter and her outspoken advocacy for the equal treatment and representation of women in science. Despite her achievements she remained humble. “I’m sorry I know so little. I’m sorry we all know so little” she once said."But that’s kind of the fun, isn’t it?” Yes. It is.

The Vera C. Rubin Observatory and its target.

Bava Metzia 106b - Kimah, the Pleiades, and the Planting Season in Iraq

This post is for the page of Talmud to be studied on the Second Day of Shavuot (or Thursday, as it is called in Israel.)

Print it up now and enjoy (or wait till Thursday and read it then).

בבא מציעא קו, ב

ועד אימת אמר רב פפא עד דאתו אריסי מדברא וקיימא כימה ארישייהו 

Until when is it considered to be the planting season? Rav Pappa said until the season when sharecroppers come in from the field and Kimah is overhead. [Bava Metzia 106b]

In today's page of Talmud, Rav Pappa, who lived near the Iraqi town of Sura, used the presence of Kimah overhead as a marker of the planting season.  Which of course raises the question of what, precisely, he meant by the term Kimah.

A color-composite image of the Pleiades from the Digitized Sky Survey ...

...and now in Hebrew.

Just what, and where, is Kimah?

The term Kimah (כימה) appears three times in the Bible. Here they are, along with the JPS translation.

עמוס ה', ח

עֹשֵׂה כִימָה וּכְסִיל, וְהֹפֵךְ לַבֹּקֶר צַלְמָוֶת, וְיוֹם, לַיְלָה הֶחְשִׁיךְ

Him that maketh the Pleiades and Orion, And bringeth on the shadow of death in the morning, And darkeneth the day into night.

איוב ט', ט

עֹשֶׂה-עָשׁ, כְּסִיל וְכִימָה; וְחַדְרֵי תֵמָן

Who maketh the Bear, Orion, and the Pleiades, And the chambers of the south.
 

איוב ל"ח, ל"א-ל"ב

הַתְקַשֵּׁר, מַעֲדַנּוֹת כִּימָה; אוֹ-מֹשְׁכוֹת כְּסִיל תְּפַתֵּחַ 

Canst thou bind the chains of the Pleiades, Or loose the bands of Orion?
 

But none of these verses in their original help us understand where in the sky Kimah can be found. Back in 1982, Chaim Milikowski, now a professor of Talmud at Bar-Ilan University, published  a paper with the catchy title of Kima and the Flood in Seder 'Olam and B.T. Rosh Ha-Shana. Stellar Time-Reckoning and Uranography in Rabbinic Literature. Here's what he says about the word Kimah:

... there is no doubt that it refers to a star or configuration of stars. It is generally taken to be the Pleiades, but various scholars have also suggested Sirius, Scorpio and Draco. Unfortunately, in none of its occurrences can kima be identified on the basis of
its context, nor does it appear in any contemporaneous cognate language. The identification of kima as Pleiades is based upon two considerations,neither conclusive.The Septuagint to Job 38:31 translates kima as Pleiades, as does also Symmachus and the Vulgate. However, at Amos 5:8, while Symmachus and Theodotion have Pleiades, Aquila and the Vulgate have no material contemporaneous ...but it does occasionally appear in the Babylonian Talmud and in the midrashim. A number of these passages support the identification of kima as the Pleiades.

And here is what Prof. Melikowski says about the passage from today's daf yomi:

From the statement of R. Papa (fourth-century Babylonian Amora)in B.T. Baba Mesi'a' 106b it follows that the position of kima at nightfall around February or March is the middle of the sky: this is roughly true of all astral bodies from the Pleiades to Sirius.

Melikowski ultimately concludes that Kimah is indeed the Pleiades, (at least it was for the authors of Seder Olam Rabbah). Identifying Kimah with the Pleiades is fairly common. The JPS translation of the Bible did it.  The Artscroll Complete Tisha B'Av Service (page 63) does so, as does Rabbi Avraham Rosenfeld in his Tisha B'Av Compendium (page 38) and Feldman in his 1931 Rabbinic Mathematics and Astronomy  (page 77). Lazarus Goldschmidt (d. 1950) who translated the Talmud into German, uses the word Siebengestirn, or the Seven-Star, which is Pleaides. The Soncino English Talmud translates Kimah as...Kimah, which is not very helpful, but in a footnote point out that Jastrow does not identify Kimah with the Pleiades.  Marcus Jastrow (d.1903) was a lone voice who did not agree with the general consensus. In his famous dictionary he wrote that Kimah was probably Draco and not Pleiades - though he did not elaborate.  So let's follow the majority and move on.

The Pleiades

The Pleiades are a cluster of hundreds of stars all about 400 light years from earth. They are often called the Seven Sisters, after their six brightest stars (go figure).  With the naked eye on a clear night you can see about six of them; with a really good pair of eyes you might get to see eleven. In In 1769, Charles Messier included the Pleiades as number 45 in his first list of comet-like objects, published in 1771, which is why the group is also referred to a M45.  You may not have noticed them in the sky, but I'm fairly sure you've noticed them on the front of a Subaru.

Rashi places this group in the tail of the constellation of Aires, based on his understanding of the Talmud in Berachot 58b. Most modern astronomy books place them in the shoulder of the constellation Taurus, but as you can see from the diagram below, there's nothing to drive this decision one way or the other.

The Pleidas (M45) sits right in between Taurus and Aires...

“Samuel (third-centuryBabylonian Amora) gives an etymology of the name kima: like a hundred (keme’ah) stars. Though only six or seven stars are easily visible to the naked eye, the Pleiades consist of several hundred stars bunched closely together. Consequently, Samuel’s description is very applicable though it remains a question how he can have known this.”

— Chaim Milikowsky. "Kima" and the Flood in "Seder 'Olam" and B.T. Rosh Ha-Shana Stellar Time-Reckoning and Uranography in Rabbinic Literature. Proceedings of the American Academy for Jewish Research, Vol. 50 (1983), pp. 105-132

Rashi vs Tosafot on the Pleiades

Rav Pappa (c. 300-375 CE.) lived in Neharda which is very close to the modern Iraqi town of Sura.  So let's take a look at the sky around Sura on say, the 15th of Adar in the year 350 CE. According to Rashi, the workers would end at the end of the ninth hour of the day. On that day there would be about eleven hours of between sunrise and sunset. So around hour nine the sky in the southwest would look like this:

Of course you cannot see any stars in the sky, and the area where Kimah would be (shown in the crosshairs labelled M45) is also empty.  But if there was a total solar eclipse at that very moment, and the sun's light was extinguished, here's what you would see:

Without the light of the sun, Kimah is visible high in the sky, just like Rav Pappa said. Here is Rashi's explanantion:

עד זמן דכי אתא אריסא מדברא. ונכנס לבית בזמן שהן רגילין ליכנס דהיינו לאחר תשע שעות ביום קרוב לסוף העשירית קיימא כימה שהוא זנב טלה להדי רישייהו בראש כל אדם דהיינו באמצע הרקיע שנראה לכל אדם כאילו הוא על ראשו והן הן ימי אדר

Until the season when sharecroppers come in from the field, and go home. At the time they usually finish, namely after nine hours near to the end of the tenth hour. Then Kimah, which is located in the tail of Aires, is directly above the heads of the people, that is, it is in the zenith of the sky. It appears to all as if it is directly above, and this is during Adar...

There is of course one problem with Rashi's explanation. Barring a solar eclipse, no-one could ever see Kimah at the ninth hour of the day, because no stars are visible during the day. On the basis of this, Tosafot challenges the explanation of Rashi:

 ומה שפי' בקונטרס דביום ראשון של אדר בסוף שעה עשירית קיימא כימה באמצע הרקיע קשה דפועלים לא אתו מדברא עד צאת הכוכבים כדפי' בריש הפועלים (לעיל דף פג:) ותו דבסוף י' שעות הן עוד היום גדול ואין נראין הכוכבים ומשמע שבא ליתן סימן לאריסין להכיר שעה שיבאו מן השדה וזה דוחק לומר דה"ק כשיחשיך לילה אז רואין למפרע שבשעת הליכתן היתה כימה להדי רישייהו ונראה לפרש דאתו אריסי מדברא בתחילת הלילה וקיימא כימה להדי רישייהו היינו בתחילת שבט ואז כלה זמן הזרע והא דאמר בפ' כל הקרבנות (מנחות דף פה. ושם ד"ה וזורע) שהיו זורעים קודם הפסח ע' יום וזהו חמשה יומי בתוך שבט התם שקרקע חשובה היא שזורעין בה לצורך העומר נמשך שם ימי הזרע יותר א"נ דבתחילת שבט של חמה הוא דקיימא כימה להדי רישייהו ואין תחילת של שבט של חמה מתחיל ברוב שנים יותר מע' יום לפני הפסח

Rashi's explanation...is hard to accept. First, workers do not come in from the fields until nightfall...and furthermore, at the tenth hour it is clearly still daytime, and no stars can be seen. But the Talmud is giving a sign whereby the workers would know when to stop work. And it is far fetched to say that what is meant is that at nightfall it will become retroactively apparent that Kimah was at overhead when they stopped working...

Instead, Tosafot understands (1) workers finish at nightfall and (2) at this time Kimah must be overhead.  This turns out not to be in Adar, as posited by Rashi, but a month earlier, in Shevat, which coincides with December. If we go back to Sura in Shevat of 349, the Pleiades would indeed be seen after sunset, but rising in the east.

Pleiades (M45) rising one hour after sunset as seen from Sura, Iraq in 349 CE.

The upshot of all this is that according to Rashi the planting season in Iraq ends some time in March (Adar), whereas for Tosafot the season ends earlier, in early January (Shevat). Who is correct? If only we could find an Iraqi farmer willing to decide the matter for us.

Satellite Imagery from Iraq supports...Tosafot

I couldn't find a farmer, so I used a "Commodity Intelligence Report" from the US Department of Agriculture Foreign Agricultural Service. In a report from January 2015, they wrote that "wheat, the major winter grain, and barley are planted at the beginning of October until the end of November" which is close to Tosafot's opinion that the planting ends in Tevet.  Here are some satellite images to prove the point:

Image courtesy of the USDA from here.

Satellite imagery from December 2014 indicated fields of winter grain starting to emerge near Arbil in northern Iraq

Finally, a report published by Reuters in January 2015 notes that the Iraqi planting season ended the previous month - that is, in December. And so, assuming that the planting seasons have not changed much since the time of Rav Pappa, the explanation that is most likely to be correct is that of Tosafot, written by French and German medieval talmudists who were unlikely to ever have travelled to Iraq, or spent time planting there.  

“Many a night I saw the Pleiads, rising through the mellow shade,
Glitter like a swarm of fire-flies tangled in a silver braid.”

— Locksley Hall by Alfred Tennyson, 1835

Happy Birthday Tomorrow, Galileo

Galileo Galilei in a 1636 portrait by Justus Sustermans.

Tomorrow, February 15th, is a special day. It is the birthday of Galileo Galilei, who was born in Pisa on that day in 1564. Among his many achievements were his careful observations of the Earth’s moon, the identification of four of Jupiter’s moons, and the discovery that Venus, when observed through a telescope, has phases, just like that of our own moon. The only reasonable explanation of this was that Venus orbited the Sun, and not the Earth. And just like that, the geocentric model of the universe in which everything revolved around the Earth, came to a grinding halt.

Galileo’s Jewish Connection

Galileo taught astronomy to anyone who would listen, including Jews, and his most important Jewish student was Joseph Solomon Delmedigo who was born in Candia on the Island of Crete in 1591. At the age of fifteen Delmedigo left for Italy, where he enrolled in the University of Padua. For seven years there he studied astronomy, mathematics, natural science and medicine, and was taught by none other than Galileo Galilei, who was soon to become famous for both his observations of the planets and his clash with the Church.

When Delmedigo graduated he traveled to Lublin, Vilna, and Livona, where he spent much of his time working as a physician. He ultimately settled in Amsterdam where he published his Sefer Elim, a long book (it runs over four hundred pages) that deals with philosophy, science, mathematics, and astronomy.

“Galileo my Teacher” from Delmedigo, Sefer Elim, Amsterdam 1629. 148.

In this book Delmedigo outlined the reasons he accepted the Copernican model of the universe. In addition to explaining all of the theoretical support for the heliocentric model, he cited experimental evidence. If the planets revolved about the Sun and were illuminated by it, the amount of light that they reflect would depend on their location and distance from the Earth. And this is precisely what Delmedigo and his famous teacher had observed through the telescope. 

My teacher Galileo observed Mars when it lay close to the Earth. At this time its light was much brighter than that of Jupiter, even though Mars is much smaller. Indeed it appeared too bright to view through the telescope. I requested to look through the telescope, and Mars appeared to me to be elongated rather than round. (This is a result of its clarity and the movement of its rays of light.) In contrast, I found Jupiter to be round and Saturn to be egg-shaped.

This glorious passage reminds us that religiously observant Jews were sometimes at the very cutting edge of the new astronomy. How many could claim to have been instructed by the great Galileo himself?

But don’t get carried away

The historian Andre Neher (d. 1988) viewed Joseph Delmedigo as a fearless trailblazer whose goal was not only to influence his own community, but also the Catholic Church itself. In a paper published in 1977 he wrote:

When Delmedigo published Elim in 1629, he used the term “Rabbi” in speaking of his teacher Galileo. Rabbi Galileo! Was this not something of a challenge directed to the inquisitors in Rome who were then preoccupied with Galileo and who were not to let him go until his death in 1642? Free Galileo, Delmedigo seems to be saying, or release him to us; in the midst of our Jewish community, he will not be subjected to any trial, we shall not require him to make any retraction, we shall welcome him and honor him like a Rabbi in Israel!

Well, not quite. As I have written elsewhere, this account is linguistically, historically, and conjecturally incorrect. In the first place, although the term used by Delmedigo to describe Galileo was indeed the word rebbi, in this context, it means “my teacher,” and not “my rabbi.” By translating it in this way Neher was able to support his claim that the Jews were open, receptive, and respectful to new ideas emerging in astronomy; but the linguistic reality (and much else besides) does not bear this out.

Secondly, in the years prior to the publication of Sefer Elim in 1629, Galileo had not become the “preoccupation” of the Inquisition. The work that led to the trial by the Inquisition, Dialogue Concerning the Two Chief Systems of the World, was not published until 1632. And so Neher’s claim that Delmedigo was writing a message to release Galileo is chronologically incorrect. Finally, the notion that the Jewish community would not punish one of their own for expressing antinomian views is inaccurate. It was, after all, in Amsterdam itself, the city in which Delmedigo’s books were published, that the Jewish community excommunicated Spinoza in 1656 on account of “the horrible heresies which he practiced and taught.” Although Neher’s assessment of Delmedigo as challenging the Inquisition on behalf of Galileo was not accurate, it he was certainly correct in noting the important role that Galileo must surely have played in the education of the young Jew Joseph Delmedigo from Crete, who grew up and became the first Jewish Copernican.

A selection from the Talmudology Library Galileo Collection

Want more Galileo-related Talmudology posts? Try Jews and their Telescopes, available here.

[A repost, obviously, because it was also his birthday last year.]