Tel-Aviv University, Tel-Aviv, Israel
# Supported in part by the U.S.-Israel Binational Science Foundation
+ Wolfson Chair Extraordinary, Tel Aviv University
M. Livio and G.Shaviv (eds.) Cataclysmic Variables and Related Objects,
Copyright, 1983 by D. Reidel Publishing Company.
Colloquium IAU 72 is the first IAU-sponsored activity in this country,
and it therefore seemed appropriate to include a paper on Astronomy in Israel.
With the highly singular history of this nation, the scene will move
Prehistoric astronomical activity is represented by a Stonehengelike
megalithic circle and "Observatory" at Rujm-el-Hiri, near Yonathan
in the Golan, the Westernmost sector of the historical Bashan plateau
dating from the IIIrd Millenium BC. Star worship is mentioned
in the Old Testament  as beeing common among the
ASTRONOMY IN THE MISHNA
The Israelitis' abstract monotheism and their centering of intellectual
creativity on ethical issues were detrimental to a natural development
of observational science, as did happen in Sumeria or Greece.
However, the requirements of agriculture induced a cycle of holidays
that were incorporated in time into Judaism and were given Ethnical or
National religious significance. There thus developed a need for an
understanding of the recurrence of seasons and for a synchronized
calendar fitted to Solar, Lunar and Sidereal time
[4-6]. Several of the
This observation is generally interpreted as relating to Halley's Comet
with a period aproximating 76 years. Observing a comet's periodicity, with
such a long period, requires records covering many centuries; it is possible
that the Mishnaic scholars did inherit such records from the Great Knesset
scholars (before 300 BC) who received them during the Babylonian exile
(586-537 BC) from the "Chaldeans" (i.e. from Sumer, Akad etc. going back
to the IIIrd Millenium BC). Indeed, the Hebrew agricultural names of the
Philippe Veron has, however  , come up recently with a different identification of Rabbi Yehoshua's star, and argues that this was the variable Mira Ceti.
Mar Samuel, who became around 220 AD the Dean of the Talmudic Academy
of Nehardea in Babylonia, was an astronomer who could calculate
and adjust the calendar with great precision, intercalating an extra
month or reassigning the length of a month. The prescriptions for the
calendar adjustments were written down in a special Baraita
SPAIN AND PROVENCE 
Science spreads by convection. When Khushru Anushirvan, Sassanid Emperor of Persia, signed a ten year truce with Justinian of Byzance, he ensured the continuity of science by requesting that the teachers of the recently abolished Academy of Athens be transferred to Persia. In his fanaticism, Justinian was then trying hard to put an end to Judaism at the sametime eradicating Neo-Platonicism and what was left of Greek science. The Neo-Platonicists settled in Mesopotamia under Persian rule, and their school was already flourishing when Persia was conquered by Islam. Mathematics and Astronomy thrived (e.g. Omar Khayyam, whose Rubayat was just a hobby, his professional creativity having yielded methods for solving factorizable cubic equations etc.) and spread all over the new Mohammedon Empire. The Jews were active participants, and the first Arabic-languate treatise on the Astrolabe was written by the Jew Joel, known as Masha-Allah of Basra (Iraq) around the year 800. This is the treatise that was translated into English by Geoffrey Chaucer ("The Treatise on the Astrolabe") around 1380, from a prior Latin translation. Masha-Allah also wrote a book on Lunar and Solar Eclipses, that was later translated into Hebrew by Abraham Ibn Ezra ("Sefer be kadrut ha levana ve ha shemesh"")
Sind ben Ali, a heretic Jew, was the main contributor (~830) to the astronomical tables of the Caliph Maimum. The scene now shifts to Spain, where Abraham bar Hiyya Hanasi ("The Prince") of Barcelona (d. 1336) improved on these tables, using calculations performed by the Arab astronomer Al-Battani (d. 929). Abraham bar Hiyya was a prominent mathematician and astronomer, and wrote famous textboks in both fields. He introduced Europe to (Arab) trigonometry in his "Treatise on Mensuration and Calculations". The Hebrew was translated by Plast of Tivoli into Latin in 1145 and his book served as main source material for that later work of Leonardo Fibonacci of Pisa. In Astronomy, his book "The Shape of the Earth" is based upon the Ptolemaic system, contains a roughly correct estimate of the distance to the Moon (but the wrong distance to the Sun). The principles for Calender intercalation make up yet another book.)
His student, Abraham Ibn Ezra (1089-1164), poet, philosopher, Biblical commentator and Astronomer, spent the last part of this life travelling in Italy and France, ending up in Eretz-Israel. He continued the publication of tables, mostly on the movement of the planets. The "Toledo Tables" were compiled by 12 Jewish astronomers led by the Cordovan Arab astronomer Ibn Arzarkali ("Azarchel"). The Latin version (translated by John of Brescia and Jacob Ibn Tibbon) was further improved in 1272 by a group of astronomers led by Isaac Ibn Said, and is known as the "Alphonsine Tables".
Rabbi Moshe ben Maimon's (=Maimonides) main contribution to Astronomy in his complete rejection of Astrology (1194). He is is unique, throughout the Centuries, in making this clear-cut. Remember that Kepler was still drawing horoscopes! Perhaps this should justify a visit to Maimonides' tomb in Tiberias.......
Rabbi Levi ben Gershom ( = Gersonides, also Maestre Leo de Bagnols, Maestre Leo Hebraeus; 1288-1344), was one of the greatest of Medieval astronomers. He lived in Provence, mostly at Orange. As a mathematician, he rediscovered the law of sines and published a sine table, correct to the 5th decimal. As an astronomer (he wrote 136 "chapters"!), he is the first to have relied on his own observations (in his studies of eclipses) rather than on Ptolemy's. He invented "Jacob's staff", a navigational instrument which was widely used for 3 centuries, and was the first person kown to have used a Camera Obscura for his observations.
Rabbi Levi is also the first scientist to derive more realistice estimates of the distance to the fixed stars. Ptolemy's estimate was of the order of 10-5 light years ( a million times smaller than the distance to the nearest star), whereas Rabbi Levi reached a figure of about 105 light years, 10 times our present estimate for the distance to an average star in the Galaxy. Gersonides was also one of the greatest Medieval philosophers and published Commentaries to the Bible.
The Zohar, a compilation of Jewish mystic writings drawn in Spain in the XIIIth Century anticipates Copernicus by stating that "the whole earth spins in a circle like a ball; the one part is up when the other part is down; the one part is light when the other is dark; it is day in the one part and night in the other".
Jewish astronomers played a key role in the theoretical preparation of the great voyages of discovery in the XVth Century. Judah Cresques, forced to adopt Christianity in the massacres of 1391, later became the Director of the Prince Henry of Portugal's ("The Navigator") Nautical Academy of Sagres. Abraham Zacuto ("Zacut", 1452-1515) worked first at Salamanca but moved to Portugal after the expulsion from Spain. As Court Astronomer to Kings John II and Manuel I, he prepared the voyage of Vasco da Gama (1496) and supplied instumentation (include his newly perfected copper astrolabe), improved tables, charts, intruction and briefs. He developed the first copper astrolabe. His very precise predictions of eclipses were used by Columbus to threaten the natives at a dangerous moment. Like all Jews, Zacut had to flee Portugal in 1497 and went to Tunis. He died in Eretz-Israel.
The XVI-XVIIth Centuries were centuries of Jewish sufferings, and
contributions to Astronomy are less prominent, except perhaps for the
Herschel family, of Jewish origin. It was only when Alexander von Humboldt
became President of the Prussian Academy of Sciences, that he abolished
the requirement of a Christian Oath by a Professor at his ordination.
Karl-Gustav Jacobi was the first Jew who did not have to abjure his faith to become a Professor. The oath was re-establised by von Humbold successor, but it was no more in existence when Einstein, Minkowski and Schwarzschild were ordinated.
Until 1965, observational astronomy was entirely a matter of amateurs. In that year we started astronomical research at Tel-Aviv University, and by 1969 we had a Department of Physics and Astronomy, still the only one in the country in 1982. In 1971 we inaugurated, with the help of the Smithsonian Astrophysical Observatory, the Florence and George Wise Observatory  at Mizpe-Ramon (altitude 950m.) in the Negev. The telescope is a 40" Wide Angle Richtie-Chretien reflector. European astronomers have often used the instrument. The most important observations at the Wise Observatory have been:
We now have theoritical groups in almost all institutions in Israel. The late G. Racah was honoured by the IAU for his work in Spectroscopy by giving his name to a crater on the Moon, where he has thus joined the company of Ibn Ezra, Rabbi Levi, Zacut, Jacobi and Einstein.
The first Jewish Commenwealth lasted in various forms between 1700-586 BC. King David installed his capital in Jerusalem around 1000 BC. The second Commonwealth started as an autonomous province of the Persian Empire, Judea with Cyrus the Great's declaration in 437 BC. The Hashmonean (or Maccabean, then Herodian) independent state of Judea lasted from 167 BC to 44 AD (91 AD in the Golan), when it was replaced by the Roman province of Judea, of New Testament renown. After the Bar-Kochba rebellion of 135 AD, the Emperor Hadrian changed the name of the province to Palestine, to erase its connections with the Judean ( = Jewish ) nation. Palestine and Judea appear as synonims during the Crusades. Jewish autonomy in Galilee (the "Patriarchate" ) lasted till 425, when the Byzantine Emperor refused to recognize a successor to Gamliel VI. It was renewed for a short spell in 607-614. Galilee with its schools and religious leadership was again central to the Jewish world in the VII-Xth Centuries AD, and again in XVI Century. Modern Jewish resettlement started in 1777 and accelarated after 1870. Policital Zionism was created by Herzl in 1897 and received its Charter over the land in the Balfour Declaration (1917) and the League of Nations Mandate (1921). The Third Commonwealth became in 1948 the State of Israel.
|History of Jewish Astronomy|
Astronomy in Israel:|
From Og's Circle to the Wise Observatory
|Astronomy in Sefarad (Spain)|