Toledan Tables facts for kids

The Toledan Tables were special astronomical tables. People used them long ago to guess where the Sun, Moon, and planets would be in the sky. These tables helped predict how these space objects moved compared to the stars that seem to stay still. They were like a big collection of math charts that showed different things about the universe. This included predicting calendar dates, when cosmic events would happen, and how things moved in space.

How the Tables Started

The Toledan Tables were finished around the year 1080. A group of Arab astronomers in Toledo, Spain, created them. They started with older Arabic tables from other places. Then, they changed the numbers to make them work for the city of Toledo.

A famous astronomer named al-Zarqali helped create these tables. He was an Arab mathematician and astronomer who lived in Toledo. He also made tools for studying the stars. Most of the people who worked on the tables are not known today, except for al-Zarqali.

Toledo became part of Christian Spain in the mid-1080s. This was soon after the tables were finished. About 100 years later, a translator named Gerard of Cremona (1114–1187) worked in Toledo. He translated the Tables of Toledo from Arabic into Latin. At that time, these tables were the most accurate ones in Europe.

These tables were built on the work of older astronomers. They used ideas from tables by Ptolemy and al-Battānī. But the Toledan Tables also had new information. They had unique numbers for how fast planets moved. These numbers used a special way of measuring called "sidereal coordinates." This was different from other tables, like Ptolemy's.

Later, in the 1200s, a scholar named Campanus of Novara used the Toledan Tables. He made new tables for his city, Novara, based on al-Zarqali's work.

The original Arabic versions of the Toledan Tables are now lost. But over 100 copies of the Latin translation still exist. These Latin copies were even used to make a Greek translation. This Greek version was written in Cyprus in the 1330s. A Greek Cypriot scholar named George Lapithes likely wrote it.

The Toledan Tables had some mistakes in their calculations. Most of these tables were copies of other tables. So, many of the errors were probably just mistakes made during copying.

How the Tables Were Used

The Toledan Tables were updated in the 1270s. These new tables were called the Alfonsine tables. They were also made in Toledo, in Spanish and Latin. The Alfonsine Tables were based on the original Toledan Tables from two centuries before.

The updated Toledan Tables became the most popular astronomy tables in Europe during the late Middle Ages. The people who made these tables believed the Earth stayed still in the center of the universe. But the information in the tables was still very useful. Copernicus later used this data. He used it to develop his model where the Sun is at the center, not the Earth.

A man named Isaac ben Joseph Israeli of Toledo used the Toledan Tables. He combined different Toledan Tables with other sources. He used them to provide information about eclipses. He also used observations from R. Isaac ben Sid. This person was known for helping write the Castilian Alfonsine tables. Because of this, people thought Isaac ben Joseph would talk about the Alfonsine Tables. But he only mentioned the Toledan Tables.

Some Toledan Tables had a special feature. They listed the positions of planets in half-degrees. This made these tables twice as long as others. This was especially true for Saturn, Venus, and Mercury.

The Toledan Tables were organized into different sections, such as:

• Timelines of different historical periods
• Math for shapes and space (trigonometry and spherical astronomy)
• Average movements of the sun, moon, and planets
• How far north or south planets were (planetary latitudes)
• Eclipses
• Astrology (predicting the future using stars)

Today, tables that show how astronomical bodies move are called ephemerides. These modern tables build on the ideas of the Toledan Tables. They use computers to figure out where any space object will be at any time. NASA updates them every year. This makes sure they are very accurate for modern calculations. These modern tables are even more precise than the Alfonsine tables.

See also

• Zij (medieval Arabic astronomy tables)
• Alfonsine tables (produced at Toledo, mostly the original Toledan Tables)
• Prutenic Tables (first comprehensive heliocentric tables, year 1551)
• Rudolphine Tables (astronomy tables of Kepler, year 1627)

In Spanish: Tablas toledanas para niños

Images for kids

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  The 'Canones' are a translation of a diagram from the Toledan Tables by Gerardus Cremonensis.