The Muslims' Contributions to Astronomy

Islam has had the most significant effect on the development of astronomy. A Muslim starts his day before sunrise in order to check for the break of dawn so he could perform the dawn Prayer. At the end of the day, a Muslim also checks the time of dusk in order to perform the Evening Prayer. Between dawn and the evening, a Muslim also follows the movement of the sun in order to determine the times of the Noon, Afternoon, and Sunset prayers and perform them on their due time.

A Muslim also fasts when he sees the new moon of Ramadhaan and he breaks the fast according to the end of the lunar month. If he prays anywhere, he is obliged to know the direction of the Ka`bah. This means that he should know his location, and be aware of the four directions: North, South, East and West.

When a Muslim recites the Holy Quran, he notices that its verses command him to contemplate the outer space and the creation of the heavens and the earth. The Holy Quran also mentions specific names of planets and stars, such as Allaah's saying:

And that He (Allaah) is the Lord of Sirius (the star which the pagan Arabs used to worship) (Quran 53: 49)

The first Muslim caliph to pay attention to astronomy was the Abbasid caliph, Abu Ja`far Al-Mansoor, who encouraged translators and gave them large amounts of money. During his era, he paid very generously for translators, and thus some astronomical books were translated into Arabic. The succeeding caliphs continued in the way of Abu Ja`far in the dissemination of knowledge, encouragement of the study of astronomy and mathematics, and in the translation of the works of Euclid, Archimedes, and Ptolemy as well as other Greek scientists.

Many Muslim scientists excelled in astronomy. Included were people such as Muhammad Al-Battaani who corrected some of Ptolemy's mistakes and reached new unprecedented results.

Also Muhammad Al-Farghaani, who lived in the fourth century A.H., made innovative researches on determining the accurate length of the year, the various lengths of day and night, and the movements of planets and stars.

Another scientist was Ibn Yoonus Al-Misri who lived during the reign of the Fatimid ruler Al-Haakim Bi-Amrillaah. He conducted some researches on the solar and lunar eclipses, determining the solar equinox, and longitudes. Ibn Yoonus' contemporary astronomer, Abu Al-Wafaa' Al-Boozjaani, who was famous for plotting tables for several new trigonometric functions.

Az-Zayj As-Saabi'ee as one of the most important references on astronomy.

Al-Battaani's Az-Zayj As-Saabi'ee is considered one of the most important references written by Muslim astronomers. It had a great effect on this science and was translated into Latin in the twelfth century. Many of its editions were published in Europe.

This book is an astronomical encyclopedia in which Al-Battaani pointed out the circle of the ephemeris, the altitude of the North pole, the altitudes of planets, the length of the solar year, the ephemeris of the moon and planets, the solar eclipse, the ascension of the zodiacs, and other important information supported by highly precise and clear mathematical tables.

Azyaaj – plural of Az-zayj (Almanacs) are numerical mathematical tables that determine the positions of planets, and the rules of knowing months, days and past dates, and detecting the altitudes, dip, declination, and motion of planets. These tables rely on highly precise mathematical rules and numerical laws.

Building observatories

In their astronomical researches, the Muslims made use of observatories. The first person to build observatories in Islamic history was the `Abbasid caliph Al-Ma`moon who loved knowledge and highly appreciated scientists and scientific research. He ordered that two observatories on Mount Qaasioon in Damascus and Ash-Shammaasiyyah in Baghdad be built. During his caliphate and after his death, several observatories were built in different areas throughout the Muslim world.

The sons of Moosaa Ibn Shaakir built an observatory in Baghdad where they calculated latitude. The Fatimids in Egypt also built an observatory on Mount Al-Muqattam and it was known as the Hakimite Observatory. Yet the largest and most famous one was Maraaghah Observatory in Persia and it was built by Naseerud-Deen At-Toosi. It was famous for its accurate instruments and the excellence of its scientists. The observations made by these observatories were extremely accurate and the European scientists, during and after the Renaissance, relied on them in their astronomical researches. In addition to these observatories, there were many others such as Ibn Ash-Shaatir's Observatory in Syria, Ad-Daynoori's Observatory in Esfahan, Aligh Beik's Observatory in Samarkand as well as other observatories in Andalusia (nowadays Spain and Portugal) and Morocco.

In these observatories, Muslim scientists used extremely accurate and well-designed instruments and devices in order to detect astronomical phenomena. Many of these instruments and devices were invented by Muslim scientists and were not known previously. They also used the devices developed by previous civilizations, such as

Astrolabe

Although it retained its Greek nomenclature, the Muslims developed it and even made several models that were amazingly accurate and elegant looking.

Many museums still have these models. The astrolabe was

used to determine the altitude of the planets and to define time.

The Muslims' Contribution to Astronomy

After the Muslims translated books on astronomy from the previous civilizations, they corrected, edited, and added to them. As far as this science is concerned, the Muslims were not only involved in theories, but they also made practical endeavors as represented in their observations.

Contemporary astronomers unanimously agree that the results found by Muslim astronomers were of great importance. Among such results are:

· The Muslims were the first to prove by experiment, observation, and calculation the fact that the earth is oval shaped.

· Some Muslim scientists such as Al-Farghaani and Ibn Rustah calculated the distance of the sun, the moon, Venus, Mars, Mercury, Saturn, and Jupiter from the center of the earth. Al-Battaani estimated that the distance of the sun, in its farthest ephemeris, equals 1,146 times the radius of the earth. When it is in its nearest position, it equals 1,070 times the radius of the earth. If it is in a middle position, it equals 1,108 times the radius of the earth. These numbers are surprisingly very close to the numbers estimated by contemporary scientists.

· Al-Hasan Ibn Al-Haytham invented the first camera in human history. He called it "The dark safe with a hole". It was a box coated from inside with the color black and it had a hole in one side and an external sanded plate on the other.

Muslim astronomers used this camera in their observatories as clear pictures of stars and planets appeared on the glass plate. This helped to determine their dimensions and discover new stars that still have Arabic nomenclatures until now.

· Muslim scientists drew colored maps of the sky. `Abdur-Rahmaan As-Soofi wrote a book entitled "Pictures of the Fixed Planets". The book covers the fixed stars and it contained colored maps. The book contains the positions of one thousand stars, all of which were observed by him personally. He also provided a precise description of these stars and accurately re-determined their dimensions in a way that is very close to modern estimations.

· Muslim scientists developed solar calendars that far excelled the previous ones as far as their precision is concerned. They calculated the days of the solar year as 365 days, six hours, nine minutes, and ten seconds. There are only two minutes and 22 seconds difference between this estimation and modern calculations.

· In addition to inventing the first airplane, the Andalusian scientist, `Abbaas Ibn Firnaas, was also the first person to invent the planetarium. In his house, he built a large dome in which the stars could be seen, as well as celestial bodies, meteors, thunder, and lightening. Princes, scientists, and high ranking people used to visit him and admire his invention.

Eighteen Muslim scientists on the moon

The clearest proof of the excellence of Muslim scientists in astronomy and their contributions, is that the World Astronomical Association has chosen eighteen Muslim scientists and decided to put their names on the geographical features of the moon as a way of giving credit to their researches on space and the role they played in assisting man to land on the moon. Some of these scientists are: Ibraaheem Al-Fazaari, Muhammad Al-Farghaani, Abu Rayhaan Al-Beerooni, Jaabir Ibn Hayyaan, Ibn Battootah, the famous explorer, and `Umar Al-Khayyaam who, in his observatory, made significant researches on the rotation of the planets around the sun.

The most famous Muslim astronomers

· Al-Battaani: Muhammad Ibn Jaabir Ibn Sinaan Al-Battaani was born in Battaan, Hurraan in 244 A.H. His title is derived from the town where he was born. Many scientists consider him to be one of the world geniuses who set important theories and made innovative researches in astronomy, algebra, and trigonometry. He was especially famous for observing the planets and celestial bodies although he did not have the precise instruments used by astronomers nowadays, yet he managed to make some observations that still draw the admiration and wonder of scientists. He died in 317 A.H., 929 A.C.

· Ibn Yoonus Al-Misri: His name is `Ali Ibn `Abdur-Rahmaan Ibn Ahmad Ibn Yoonus Al-Misri. He was one of the most famous mathematicians and astronomers who came after Al-Battaani. The Fatimids in Egypt held him in high esteem. They were very generous to him, and built him an observatory on Mount Muqattam and provided it with all the required instruments and devices. Ibn Yoonus invented the pendulum, although many people mistakenly believed that the famous Italian scientist Galileo (died in 1642) was its inventor. The fact that he was its inventor was actually proven by European scientists themselves.

· Al-Beerooni: His name is Muhammad Ibn Ahmad Abu Ar-Rayhaan Al-Beerooni. He was born in 362 Ah., 973 A.C. in Khuwaarazm. He was very intelligent. He mastered many sciences and conducted detailed researches. He made several inventions in mathematics, astronomy, and physics. He made great contributions to astronomy. He pointed out that the earth rotates on its axis and he wrote the most famous book on astronomy in the fifth Hijri century. He set a theory called "Al-Beerooni's Rule" for determining the axis of the earth. He wrote more than 120 books and some of them have been translated into English, French, and German. He died in 440 A.H. 1048 A.C.

Until now, astronomy has many terms of Arabic origin such as the names of planets and zodiacs. This proves the excellent contribution to this science by Muslim scientists. Examples of such names are:

الجدي Algedi