YOSSI ARON

“And He [God] said [to Avraham] look to the heavens and count the stars if you are able to count them” (Bereshit 15:5).

“And lest you lift up your eyes to the heavens and you see the sun and the moon and the stars, all the hosts of the heavens” (Devarim 4:19).

“Rabban Gamliel had illustrations of the shapes of the moon on a tablet and on the upper wall of his chamber, which he showed to the potential witnesses [at the time of sanctification of the month] and he said ‘did you see like this or like this?‘“ (Mishnah Rosh Hashanah 2:8).

THE Jerusalem Post recently reported that in honour of the United Nations Educational, Scientific and Cultural Organisation’s (UNESCO) International Year of Astronomy, Israelis have an opportunity to vote for a Hebrew name for the further planets Uranus and Neptune.

The vote, to be conducted online, is being organised by the Hebrew Language Academy, which provides unique Hebrew terminology for those facets of life that for whatever reason are not specifically referred to in older texts.

Researchers and linguists have selected two names for each planet from 650 proposed alternatives, and voters will now decide the final name: Oron (small light) or Shahak (skies) for Uranus, and Rahav (the ruler of the seas) or Tarshish (the name for sea in Jewish literature) for Neptune.

Known by mankind since the earliest times, Mercury, Venus, Mars, Jupiter and Saturn bear the names of Greek and Roman gods. In Hebrew, they have long been named Hama (or Kochav), Noga, Ma’adim, Tzedek and Shabtai, respectively. These names already appear in talmudic literature. But in light of this new development, in the week when we read in the Torah of God’s command to Avraham cited above, a few comments on astronomy in Jewish sources are in order.

There can be no question as to the familiarity of the sages with the science of astronomy. True the Torah seems to be concerned with those who might seek to worship the heavenly bodies as so many of the ancients did. Nevertheless, astronomy was an essential part of practical Judaism. Despite the wording of the second commandment banning images of that which is in the heavens, Rabban Gamliel kept charts of the phases of the moon.

The fact that Hillel II was able to provide us with the basic framework of a calendar that to this day still has rosh chodesh coincidental with the new moon, indicates the extent to which he and his contemporaries were familiar with the intricacies of the lunar cycle.

But beyond that there are many references in talmudic literature to the stars. There was also some overlap between astronomy and astrology. The astrological signs that are based on constellations actually relate to the Hebrew months; they too were the subject of ancient Jewish art as evidenced by the famous mosaic floor of the synagogue at Beit Alpha. But the relationship with astrology does not detract from the sages’ astronomic knowledge, which extended even to knowledge of a comet that appeared once in 70 years (Halley’s comet; see tractate Horayot 10a).

Subsequent centuries saw a number of significant astronomers among great rabbis. The 12th century biblical commentator Abraham Ibn Ezra compiled astronomical tables on the movements of the then known planets; he also wrote a series of theoretical texts on astronomy, including Sefer HaIbbur, on the subjects of cycles, the new moon, seasons and signs of the zodiac. Ibn Ezra also explained the use of instruments such as the astrolabe.

The next century saw a series of further works by a group of 12 Jewish astronomers in Cordova. Jewish astronomical work continued throughout the Golden Era of Spanish Jewish life; the tables and almanac of Abraham Zacuto were used by Columbus on his voyages, which began at that very moment in history that the Jews were exiled from Spain. And centuries before Copernicus, the Zohar stated that: “The whole earth spins in a circle like a ball; the one part is up while the other part is down; the one part is light while the other is dark; it is day in the one part and night in the other.” Rabbi Moses Isserles, famous for his glosses on the Shulchan Aruch in accordance with European (Ashkenazi) custom, displayed in his writings a real knowledge of astronomy.

Indeed, if those voters in the current contest succeed in making a mark for perpetuity, they will be following in the footsteps of so many of our forebears whose knowledge extended beyond purely spiritual realms and contributed to the science and understanding of the vast universe that surrounds our insignificant planet.

Yossi Aron is The AJN‘s religious affairs editor.