Isaac Israeli ben Joseph or Yitzhak ben Yosef (often known as Isaac Israeli the Younger) was a Spanish-Jewish

astronomer An astronomer is a scientist in the field of astronomy who focuses on a specific question or field outside the scope of Earth. Astronomers observe astronomical objects, such as stars, planets, natural satellite, moons, comets and galaxy, galax ...

astrologer Astrology is a range of Divination, divinatory practices, recognized as pseudoscientific since the 18th century, that propose that information about human affairs and terrestrial events may be discerned by studying the apparent positions ...

who flourished at

Toledo Toledo most commonly refers to: * Toledo, Spain, a city in Spain * Province of Toledo, Spain * Toledo, Ohio, a city in the United States Toledo may also refer to: Places Belize * Toledo District * Toledo Settlement Bolivia * Toledo, Or ...

in the first half of the fourteenth century. He was a pupil of Asher ben Yehiel, at whose request (in 1310) he wrote the

astronomical Astronomy is a natural science that studies celestial objects and the phenomena that occur in the cosmos. It uses mathematics, physics, and chemistry in order to explain their origin and their overall evolution. Objects of interest include ...

work ''Yesod Olam''. The book includes chapters on:

geometry Geometry (; ) is a branch of mathematics concerned with properties of space such as the distance, shape, size, and relative position of figures. Geometry is, along with arithmetic, one of the oldest branches of mathematics. A mathematician w ...

and

trigonometry Trigonometry () is a branch of mathematics concerned with relationships between angles and side lengths of triangles. In particular, the trigonometric functions relate the angles of a right triangle with ratios of its side lengths. The fiel ...

; the structure and position of the globe; the number and movements of

celestial spheres The celestial spheres, or celestial orbs, were the fundamental entities of the cosmological models developed by Plato, Eudoxus, Aristotle, Ptolemy, Copernicus, and others. In these celestial models, the apparent motions of the fixed star ...

; the time differences in days and nights in various parts of the Earth; the movements of sun and moon;

solstice A solstice is the time when the Sun reaches its most northerly or southerly sun path, excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around 20–22 June and 20–22 December. In many countries ...

s, ''neomeniæ'',

eclipse An eclipse is an astronomical event which occurs when an astronomical object or spacecraft is temporarily obscured, by passing into the shadow of another body or by having another body pass between it and the viewer. This alignment of three ...

s, and leap-years. It also contains astronomical tables (

ephemeris In astronomy and celestial navigation, an ephemeris (; ; , ) is a book with tables that gives the trajectory of naturally occurring astronomical objects and artificial satellites in the sky, i.e., the position (and possibly velocity) over tim ...

) and a

perpetual calendar A perpetual calendar is a calendar valid for many years, usually designed to look up the day of the week for a given date in the past or future. For the Gregorian and Julian calendars, a perpetual calendar typically consists of one of three ...

. It also deals with the chronological systems of other nations and religions (iv, § 17), especially

Christianity Christianity is an Abrahamic monotheistic religion, which states that Jesus in Christianity, Jesus is the Son of God (Christianity), Son of God and Resurrection of Jesus, rose from the dead after his Crucifixion of Jesus, crucifixion, whose ...

, and lists notable personages of the

Biblical The Bible is a collection of religious texts that are central to Christianity and Judaism, and esteemed in other Abrahamic religions such as Islam. The Bible is an anthology (a compilation of texts of a variety of forms) biblical languages ...

Talmud The Talmud (; ) is the central text of Rabbinic Judaism and the primary source of Jewish religious law (''halakha'') and Jewish theology. Until the advent of Haskalah#Effects, modernity, in nearly all Jewish communities, the Talmud was the cen ...

ic, and

geonic ''Geonim'' (; ; also Romanization of Hebrew, transliterated Gaonim, singular Gaon) were the presidents of the two great Talmudic Academies in Babylonia, Babylonian Talmudic Academies of Sura Academy , Sura and Pumbedita Academy , Pumbedita, in t ...

periods, as per ''

Sefer ha-Qabbalah ''Sefer ha-Qabbalah'' () was written by Abraham ibn Daud around 1160–1161. The book is a response to Karaite attacks against the historical legitimacy of Rabbinic Judaism and contains, among other items, the controversial tale of the kidnappin ...

'' of

Abraham ibn Daud Abraham ibn Daud (; ) was a Spanish-Jewish astronomer, historian and philosopher; born in Córdoba, Spain about 1110; who was said to have been killed for his religious beliefs in Toledo, Spain, about 1180. He is sometimes known by the abbrevia ...

, in chronological order (iv, § 18). This last was included by

Zacuto Abraham Zacuto (, ; 12 August 1452 – ) was a Sephardic Jewish astronomer, astrologer, mathematician, rabbi and historian. Born in Castile, he served as Royal Astronomer to King John II of Portugal before fleeing to Tunis. His astrolabe of cop ...

in his ''Sefer ha-Yuḥasin.'' The ''Yesod Olam'' was first published in Berlin by Jacob Shklower in 1777. A more complete edition, with a preface by David Cassel, was published by B. Goldberg and L. Rosenkranz (1848). Israeli's work was much studied in the

Middle Ages In the history of Europe, the Middle Ages or medieval period lasted approximately from the 5th to the late 15th centuries, similarly to the post-classical period of global history. It began with the fall of the Western Roman Empire and ...

. Isaac al-Hadib, Judah Bassan, and Elijah Mizrahi annotated it, and an anonymous author wrote a commentary on it (Neubauer, ''Cat. Bodl. Hebr. MSS.'' Nos. 2044, 746, 5). An abridgment was made in

Arabic Arabic (, , or , ) is a Central Semitic languages, Central Semitic language of the Afroasiatic languages, Afroasiatic language family spoken primarily in the Arab world. The International Organization for Standardization (ISO) assigns lang ...

by the author's son Joseph Israeli ben Isaac, of which the Hebrew translation, ''Kitzur Yesod Olam'' is still extant (ib. No. 1319, 6). Israeli was also the author of two other astronomical works, ''Sha'ar ha-Shamayim'' and ''Sha'ar ha-Milu'im,'' both extant in manuscript (ib. No. 2046). Israeli apologizes for citing non-Jewish authors and claims that the ancient sages also possessed this knowledge before the destruction of the

First Temple Solomon's Temple, also known as the First Temple (), was a biblical Temple in Jerusalem believed to have existed between the 10th and 6th centuries BCE. Its description is largely based on narratives in the Hebrew Bible, in which it was commis ...

References

De Rossi De Rossi () is an Italian surname, and may refer to: Academics * Azariah dei Rossi, an Italian-Jewish physician and scholar * Bernardo de Rossi, (1687–1775), Italian theologian and historian * Elena De Rossi Filibeck (20th century), Italian wr ...

, Dizionario, p. 130; * Cassel, preface to Yesod 'Olam; *

Eliakim Carmoly Eliakim Carmoly (5 August 1802 in Soultz-Haut-Rhin, France – 15 February 1875 in Frankfurt) was a French scholar. He was born at Soultz-Haut-Rhin, then in the French department of Haut-Rhin. His real name was ''Goschel David Behr'' (or ''Ba ...

, Itinéraires, p. 224; *

Steinschneider Moritz Steinschneider (; 30 March 1816 – 24 January 1907) was a Moravian bibliographer and Orientalist, and an important figure in Jewish studies and Jewish history. He is credited as having invented the term ''antisemitism.'' Education Mo ...

, Cat. Bodl. col. 1124; *idem, Hebr. Uebers. p. 596; *idem, Die Arabische Litteratur der Juden, § 121; * Grätz, Gesch. vii. 249. * {{DEFAULTSORT:Israeli ben Joseph, Isaac Year of birth missing 14th-century deaths 14th-century Castilian Jews Medieval Jewish astronomers Medieval Spanish astronomers People from Toledo, Spain Medieval Jewish astrologers Medieval Spanish astrologers 14th-century astrologers 14th-century astronomers Jewish astronomers

See also

References