The Alfonsine tables (sometimes spelled Alphonsine tables) provided data for computing the position of the Sun, Moon and planets relative to the fixed stars. They are named for Alfonso X of Castile, upon whose order they were prepared in Toledo, Spain around 1252 to 1270.

Contents 1 Production 2 Methodology 3 Popularity 4 References 5 External links

[edit] Production

Alfonso X assembled a team of scholars, including both Jews and Moors, to produce new tables that updated the Tables of Toledo. The new tables were based on observations by Islamic astronomers and on earlier astronomical works preserved by Islamic scholars.^[1]

The instructions for the Alfonsine tables were originally written in the Castilian Spanish,^[2] but a version in Castilian has not survived. What are now called Alfonsine tables seem to have originated in Paris around 1320 in Latin.^[3][4] The first printed edition of the Alfonsine tables appeared in 1483, with a second edition in 1491.

Georg Purbach used the Alfonsine tables for his book, Theoricae novae planetarum (New Theory of the Planets). Nicolaus Copernicus 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 to cast horoscopes.^[5]

[edit] 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's geocentric model 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.^[6]) 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^[7] have concluded that the methodology used to derive the Alfonsine tables was Ptolemy's unmodified theory and that the original computations were correct.

[edit] 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 (or Prussian Tables) of Erasmus Reinhold's were published . These tables used the Copernican heliocentric 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 astologers and astromomers. However, the Prutenic tables were not widely adopted outside German speaking countries and new ephemerides based on the Alfonsine tables continued to be published^[8] until the publication of Johannes Kepler's Rudolphine Tables in 1627.

[edit] References

[edit] External links

• Astronomical Tables