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 their studies on a specific question or field outside the scope of Earth. They observe astronomical objects such as stars, planets, natural satellite, moons, comets and galaxy, g ...

astrologer Astrology is a range of divinatory practices, recognized as pseudoscientific since the 18th century, that claim to discern information about human affairs and terrestrial events by studying the apparent positions of celestial objects. Dif ...

who flourished at Toledo 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 phenomena. It uses mathematics, physics, and chemistry in order to explain their origin and evolution. Objects of interest include planets, moons, stars, nebulae, galaxies ...

work ''Yesod Olam'', the finest contribution on the subject in

Hebrew literature Hebrew literature consists of ancient, medieval, and modern writings in the Hebrew language. It is one of the primary forms of Jewish literature, though there have been cases of literature written in Hebrew by non-Jews. Hebrew literature was pro ...

. The book includes chapters on:

geometry Geometry (; ) is, with arithmetic, one of the oldest branches of mathematics. It is concerned with properties of space such as the distance, shape, size, and relative position of figures. A mathematician who works in the field of geometry is c ...

and

trigonometry Trigonometry () is a branch of mathematics that studies relationships between side lengths and angles of triangles. The field emerged in the Hellenistic world during the 3rd century BC from applications of geometry to astronomical studies. T ...

; 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 cosmology, cosmological models developed by Plato, Eudoxus of Cnidus, Eudoxus, Aristotle, Ptolemy, Copernicus, and others. In these celestial models, the diurnal m ...

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

solstice A solstice is an event that occurs when the Sun appears to reach its most northerly or southerly excursion relative to the celestial equator on the celestial sphere. Two solstices occur annually, around June 21 and December 21. In many countr ...

s, ''neomeniæ'',

eclipse An eclipse is an astronomical event that 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 ce ...

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

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

) 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 based on the life and teachings of Jesus of Nazareth. It is the world's largest and most widespread religion with roughly 2.38 billion followers representing one-third of the global pop ...

, and lists notable personages of the

Biblical The Bible (from Koine Greek , , 'the books') is a collection of religious texts or scriptures that are held to be sacred in Christianity, Judaism, Samaritanism, and many other religions. The Bible is an anthologya compilation of texts of a ...

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

ic, and

geonic ''Geonim'' ( he, גאונים; ; also transliterated Gaonim, singular Gaon) were the presidents of the two great Babylonian Talmudic Academies of Sura and Pumbedita, in the Abbasid Caliphate, and were the generally accepted spiritual leaders of ...

periods, as per ''

Sefer ha-Qabbalah ''Sefer ha-Qabbalah'' (Hebrew: ספר הקבלה, "Book of Tradition") was a book written by Abraham ibn Daud around 1160–1161. The book is a response to Karaitic attacks against the historical legitimacy of Rabbinic Judaism, and contains, amon ...

'' of

Abraham ibn Daud Abraham ibn Daud ( he, אַבְרָהָם בֵּן דָּוִד הַלֵּוִי אִבְּן דָּאוּד; ar, ابراهيم بن داود) was a Spanish-Jewish astronomer, historian, and philosopher; born at Córdoba, Spain about 1110; di ...

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

Zacuto Abraham Zacuto ( he, , translit=Avraham ben Shmuel Zacut, pt, Abraão ben Samuel Zacuto; 12 August 1452 – ) was a Castilian astronomer, astrologer, mathematician, rabbi and historian who served as Royal Astronomer to King John II of Portugal. ...

in his ''Sefer ha-Yuḥasin.'' The ''Yesod Olam'' was first published in Berlin by

Jacob Shklower Jacob (; ; ar, يَعْقُوب, Jacob in Islam, Yaʿqūb; gr, Ἰακώβ, Iakṓb), later given the name Israel (name), Israel, is regarded as a Patriarchs (Bible), patriarch of the Israelites and is an important figure in Abrahamic religi ...

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 late 5th to the late 15th centuries, similar to the post-classical period of global history. It began with the fall of the Western Roman Empire a ...

. 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 Semitic languages, Semitic language spoken primarily across the Arab world.Semitic languages: an international handbook / edited by Stefan Weninger; in collaboration with Geoffrey Khan, Michael P. Streck, Janet C ...

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).

References

*De Rossi, 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 '' ...

, Itinéraires, p. 224; *

Steinschneider Moritz Steinschneider (30 March 1816, Prostějov, Moravia, Austrian Empire – 24 January 1907, Berlin) was a Moravian bibliographer and Orientalist. He received his early instruction in Hebrew from his father, Jacob Steinschneider ( 1782; ...

, 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