Alfonsine tables
Encyclopedia
The Alfonsine tables (sometimes spelled Alphonsine tables) provided data for computing the position of the Sun
Sun
The Sun is the star at the center of the Solar System. It is almost perfectly spherical and consists of hot plasma interwoven with magnetic fields...

, Moon
Moon
The Moon is Earth's only known natural satellite,There are a number of near-Earth asteroids including 3753 Cruithne that are co-orbital with Earth: their orbits bring them close to Earth for periods of time but then alter in the long term . These are quasi-satellites and not true moons. For more...

 and planet
Planet
A planet is a celestial body orbiting a star or stellar remnant that is massive enough to be rounded by its own gravity, is not massive enough to cause thermonuclear fusion, and has cleared its neighbouring region of planetesimals.The term planet is ancient, with ties to history, science,...

s relative to the fixed stars.

The tables were named after Alfonso X of Castile
Alfonso X of Castile
Alfonso X was a Castilian monarch who ruled as the King of Castile, León and Galicia from 1252 until his death...

, who sponsored its creation, and they were compiled in Toledo, Spain
Toledo, Spain
Toledo's Alcázar became renowned in the 19th and 20th centuries as a military academy. At the outbreak of the Spanish Civil War in 1936 its garrison was famously besieged by Republican forces.-Economy:...

. They contain astronomical data starting on January 1, 1252, the date of the coronation of the King.

Production

Alfonso X assembled a team of scholars, known as the Toledo School of Translators
Toledo School of Translators
The Toledo School of Translators is the name that commonly describes the group of scholars who worked together in the city of Toledo during the 12th and 13th centuries, to translate many of the philosophical and scientific works from classical Arabic, classical Greek, and ancient Hebrew.The School...

, who among other translating tasks, were commended to produce new tables that updated the Tables of Toledo
Tables of Toledo
The Toledan Tables, or Tables of Toledo, were astronomical tables which were used to predict the movements of the Sun, Moon and planets relative to the fixed stars...

. The new tables were based on earlier astronomical works and observations by Islamic astronomers and on added observations by astronomers Alfonso had gathered in Toledo, among them several Jewish scholars, like Yehuda ben Moshe
Yehuda ben Moshe
Yehuda ben Moshe ha-Kohen lived during the 13th century and became the personal physician of King Alfonso X of CastileHe also excelled as an astronomer and was a prominent translator and writer at the Toledo School of Translators where he translated important scientific works from Arabic and Hebrew...

 and Isaac ibn Sid
Isaac ibn Sid
Isaac ibn Sid was a Spanish-Jewish astronomer; he flourished at the Toledo School of Translators in the second half of the thirteenth century.From the surname "haḤazzan", given him by Isaac Israeli ben Joseph , it may be inferred that he was precentor at the synagogue.Isaac ibn Sid took a leading...

. He also brought Aben Raghel y Alquibicio and Aben Musio y Mohamat, from Seville, Joseph Aben Alí and Jacobo Abenvena, from Córdoba, and fifty more from Gascony and Paris.

The instructions for the Alfonsine tables were originally written in the Castilian Spanish
Castilian Spanish
Castilian Spanish is a term related to the Spanish language, but its exact meaning can vary even in that language. In English Castilian Spanish usually refers to the variety of European Spanish spoken in north and central Spain or as the language standard for radio and TV speakers...

. The first printed edition of the Alfonsine tables appeared in 1483, and a second edition in 1491.

Georg Purbach
Georg Purbach
Georg von Peuerbach was an Austrian astronomer, mathematician and instrument maker.-Biography:...

 used the Alfonsine tables for his book, Theoricae novae planetarum (New Theory of the Planets). Nicolaus Copernicus
Nicolaus Copernicus
Nicolaus Copernicus was a Renaissance astronomer and the first person to formulate a comprehensive heliocentric cosmology which displaced the Earth from the center of the universe....

 used the second edition in his work. One use of these and similar astronomical tables was to calculate ephemerides, which were in turn used by astrologers
Astrology
Astrology consists of a number of belief systems which hold that there is a relationship between astronomical phenomena and events in the human world...

 to cast horoscopes.

Methodology

The methods of Claudius Ptolemy were used to compute the table and they divided the year into 365 days, 5 hours, 49 minutes, 16 seconds - very close to the currently accepted figure. There is a famous (but apocryphal) quote attributed to Alfonso upon hearing an explanation of the extremely complicated mathematics required to demonstrate Ptolemy
Ptolemy
Claudius Ptolemy , was a Roman citizen of Egypt who wrote in Greek. He was a mathematician, astronomer, geographer, astrologer, and poet of a single epigram in the Greek Anthology. He lived in Egypt under Roman rule, and is believed to have been born in the town of Ptolemais Hermiou in the...

's geocentric model
Geocentric model
In astronomy, the geocentric model , is the superseded theory that the Earth is the center of the universe, and that all other objects orbit around it. This geocentric model served as the predominant cosmological system in many ancient civilizations such as ancient Greece...

 of the solar system - "If the Lord Almighty had consulted me before embarking on creation thus, I should have recommended something simpler." (The validity of this quotation is questioned by some historians.) This quotation has been used to illustrate the large number of additional epicycles introduced into the Ptolemaic system in an attempt to make it conform with observation. However, modern computations have concluded that the methodology used to derive the Alfonsine tables was Ptolemy's unmodified theory and that the original computations were correct.

Popularity

The Alfonsine tables were the most popular astronomical tables in Europe and updated versions were regularly produced for three hundred years. Copernicus himself owned a copy. In 1551, the Prutenic Tables
Prutenic Tables
The Prutenic Tables , were an ephemeris by the astronomer Erasmus Reinhold published in 1551. They are sometimes called the Prussian Tables after Albert I, Duke of Prussia, who supported Reinhold and financed the printing...

(or Prussian Tables) of Erasmus Reinhold
Erasmus Reinhold
Erasmus Reinhold was a German astronomer and mathematician, considered to be the most influential astronomical pedagogue of his generation. He was born and died in Saalfeld, Saxony....

's were published . These tables used the Copernican heliocentric
Copernican heliocentrism
Copernican heliocentrism is the name given to the astronomical model developed by Nicolaus Copernicus and published in 1543. It positioned the Sun near the center of the Universe, motionless, with Earth and the other planets rotating around it in circular paths modified by epicycles and at uniform...

 model of the solar system. Copernicus's publication—De revolutionibus—was not easy to use and the Prutenic tables were intended to make the heliocentric model more usable by astrologers and astronomers. However, the Prutenic tables were not widely adopted outside German speaking countries and new ephemerides based on the Alfonsine tables continued to be published until the publication of Johannes Kepler
Johannes Kepler
Johannes Kepler was a German mathematician, astronomer and astrologer. A key figure in the 17th century scientific revolution, he is best known for his eponymous laws of planetary motion, codified by later astronomers, based on his works Astronomia nova, Harmonices Mundi, and Epitome of Copernican...

's Rudolphine Tables
Rudolphine Tables
The Rudolphine Tables consist of a star catalogue and planetary tables published by Johannes Kepler in 1627 using data from Tycho Brahe's observations.-Previous tables:...

in 1627.
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