The early history of Islam is called the Islamic Golden Age. It is rich because of scientific education, research and discoveries. During this period, Muslim scientists made startling contributions in the fields of innovation and exploration. Though most of the scientists were non-Arab, yet Al-Battani was the one who had been an Arab by origin. He was both an astronomer and mathematician, who refined existing values for the length of the year and of the seasons, for the annual precession of the equinoxes, and for the inclination of the ecliptic. His work laid the foundation for modern astronomy. His discoveries influenced scientists across cultures and centuries.

Who was Al-Battani?
Al-Battani was born around 858 in Harran city, now in Turkey. He spent much of his life in Raqqa, a city now in Syria. His father was also an astronomer. He studied mathematics and astronomy from his father, and read the books written by ancient scientists like Ptolemy. He learned about the methods that Greek and Indian astronomers used, but brought his own unique ideas to the field.
Education
His education included learning like how to make and use different types of astronomical tools. He became an expert in building and using instruments such as the astrolabe, which is a device that helps to measure the position of stars and planets. He calculated things more accurately than any other scientist had done before.
Astronomy
Al-Battani measured things in the sky with his own eyes and with the help of instruments. His calculations of the movement of planets were much more accurate than those of his predecessors. One of his major areas of focus was understanding the solar year — the time it takes for the earth to orbit the sun. Ptolemy had made calculations about this, but Al-Battani found a way to measure it even more precisely. His measurements of the length of the year and the angles of the planetary orbits were far more exact, and his corrections to the work of previous scholars were adopted widely in both the Islamic and Christian worlds.
Key Contributions
Here are a few of Battani’s contributions to science and mathematics:
1. Improved Length of the Solar Year
His measurements of the solar year — 365 days, 5 hours, 46 minutes, and 24 seconds — were incredibly accurate for his time. Although it’s not exact by today’s standards, yet it helped astronomers create better calendars.
2. Trigonometry Advancements
His work greatly influenced the field of trigonometry, which is a branch of mathematics that studies the relationships between the sides and angles of triangles. He made several important discoveries in trigonometry, including developing new trigonometric functions like cotangent, cosecant, and secant. These functions are still used in math and science. In his time, trigonometry was vital for understanding the movements of celestial bodies. His work allowed astronomers to make better predictions about the positions of the sun, moon, and planets, which helped in navigation and calendar-making.
3. Precession of the Equinoxes
He was one of the first astronomers to note that the positions of the equinoxes, which are the two points in the year when day and night are of equal length, change over time. This discovery known as the “Precession of the Equinoxes” was an important contribution to astronomy.

4. Corrections to Ptolemy’s “Almagest”
Ptolemy’s “Almagest” was the most famous book on astronomy during Al-Battani’s time, but it contained some errors. He worked hard to identify and correct those mistakes, and created his own version of the book with updated information. His work was so precise that it was studied by astronomers in Europe centuries later. In fact, Copernicus, the famous astronomer who developed the heliocentric model of the solar system, mentioned Al-Battani’s work as an inspiration.
5. Al-Battani’s “Zij”
He compiled a famous book called “Zij al-Sabi”, which means “the Astronomical Tables of Al-Battani”. In this book, he recorded his observations and mathematical calculations, including tables of planetary positions and the motions of the sun and moon. These tables helped the scientists calculate the positions of celestial bodies accurately for hundreds of years. The book became very popular and was translated into Latin, spreading his work across Europe.
Al-Battani’s Influence
His discoveries and methods were so valuable that his influence stretched far beyond his own time. His “Zij” was translated into Latin and used by European astronomers, including famous scientists like Johannes Kepler and Tycho Brahe. These astronomers admired his accuracy and used his methods and calculations to improve their own observations. His trigonometric advancements also helped in paving the way for the development of calculus and other advanced fields of mathematics. His contributions to science were respected in the Islamic world, but they also crossed into Europe, where scholars continued to study and expand upon his work.
Al-Battani’s Legacy
Al-Battani died in 929 near Samarra, Iraq. He is remembered as one of the pioneers of astronomy. He is considered one of the most important scientists of Islam’s Golden Age. In modern times, scientists honor his contributions. To honor him, a crater on the moon has been named “Albategnius” after him. His life teaches us that knowledge has no borders; it can be shared across cultures, religions, and languages. His story encourages us to look up at the sky, ask questions, and seek answers just like he did.