Alfonsine tables facts for kids
The Alfonsine Tables were important books of numbers. They helped people figure out exactly where the Sun, Moon, and planets were in the sky. These tables were named after Alfonso X of Castile, a king from Spain who paid for them to be created. They were put together in Toledo, Spain. The information in the tables started from June 1, 1252, which was the day King Alfonso X became king.
How They Were Made
King Alfonso X brought together a group of smart people, known as the Toledo School of Translators. He asked them to create new tables that would update older ones, like the Tables of Toledo. These new tables used ideas and observations from earlier Islamic astronomers. They also included new observations from astronomers the King gathered in Toledo.
Some of these scholars were Jewish, like Yehuda ben Moshe and Isaac ibn Sid. Others came from different cities in Spain, like Seville and Córdoba, and even from France.
The instructions for using the Alfonsine Tables were first written in Castilian Spanish. The very first printed version of these tables came out in 1483. A second printed version followed in 1492.
Many famous astronomers used these tables. Georg Purbach used them for his book, New Theory of the Planets. Even Nicolaus Copernicus, a very important astronomer, used the second edition of the tables in his work. People used these tables to create ephemerides. These were like calendars that showed where planets would be on certain days. Astrologers then used these ephemerides to create horoscopes.
How They Worked
The Alfonsine Tables used methods from an ancient Greek astronomer named Claudius Ptolemy. They calculated the length of a year as 365 days, 5 hours, 49 minutes, and 16 seconds. This number is very close to what we know today.
Ptolemy's ideas were based on the geocentric model. This model said that the Earth was the center of the universe, and everything else orbited around it. Later, some astronomers thought that many extra circles were added to Ptolemy's system to make it match observations. However, modern calculations show that the original Alfonsine Tables could be made using Ptolemy's basic theory without many changes.
Why They Were Popular
The Alfonsine Tables were the most popular astronomy tables in Europe for a long time. Updated versions were made regularly for about 300 years!
Nicolaus Copernicus, who is often called the father of modern astronomy, bought a copy of these tables. He valued it so much that he had it specially bound with wood and leather. Some historians believe these tables helped Copernicus develop his idea of a heliocentric system. This system correctly showed that the Sun is the center of our solar system, not the Earth.
In 1551, new tables called the Prutenic Tables were published. These tables used Copernicus's idea of the Sun being the center. Copernicus's own book, De revolutionibus, was not easy to use. The Prutenic Tables were meant to make his heliocentric model easier for astronomers and astrologers to use. However, these new tables were not widely used outside of German-speaking countries. People continued to publish new ephemerides based on the Alfonsine Tables until Johannes Kepler published his Rudolphine Tables in 1627.
See Also
In Spanish: Tablas alfonsíes para niños
- Literature of Alfonso X
- Toledan tables
- Zij
- Regiomontanus
