1. Islamic Civilization ALI110 Session three – March 15 th, 2006 Islam and Astronomy

2. The Holy Qur’an and Astronomy هُوَ الَّذِي جَعَلَ الشَّمْسَ ضِيَاء وَالْقَمَرَ نُورًا وَقَدَّرَهُ مَنَازِلَ لِتَعْلَمُواْ عَدَدَ السِّنِينَ وَالْحِسَابَ مَا خَلَقَ اللّهُ ذَلِكَ إِلاَّ بِالْحَقِّ يُفَصِّلُ الآيَاتِ لِقَوْمٍ يَعْلَمُونَ It is He Who made the sun to be a shining glory and the moon a light and measured out stages for it; that ye might know the number of years and the count (of time). Allah did not create this but in truth. (Thus) does He explain His Signs in detail, for those who understand. (10:5)

3. Holy Qur’an and Astronomy – cont. Sura Yasin, verses 38-40 وَآيَةٌ لَّهُمْ اللَّيْلُ نَسْلَخُ مِنْهُ النَّهَارَ فَإِذَا هُم مُّظْلِمُونَ And a Sign for them is the Night: We withdraw from it the Day, and behold they are plunged in darkness وَالشَّمْسُ تَجْرِي لِمُسْتَقَرٍّ لَّهَا ذَلِكَ تَقْدِيرُ الْعَزِيزِ الْعَلِيمِ And the sun runs its course for a period determined for him: that is the decree of (Him), the Exalted in Might, the All-Knowing وَالْقَمَرَ قَدَّرْنَاهُ مَنَازِلَ حَتَّى عَادَ كَالْعُرْجُونِ الْقَدِيمِ لَا الشَّمْسُ يَنبَغِي لَهَا أَن تُدْرِكَ الْقَمَرَ وَلَا اللَّيْلُ سَابِقُ النَّهَارِ وَكُلٌّ فِي فَلَكٍ يَسْبَحُونَ And the Moon, We have measured for it stages (to traverse) till it returns like the old withered part of a date-stalk. It is not permitted for the Sun to catch up the Moon, nor can the Night outstrip the Day: Each swims along in (its own) orbit

4. Imam Ja’far as-Sadiq (a) and Astronomy Imam taught astronomy and was the first to teach the following: Rotation of the earth on its axis Theory of the origin of the Universe Light of the stars Many existing worlds Expanding and contracting universe

5. Movement of the planets Ptolemy’s theory – He placed the earth as the earth at the center of the universe. According to him the sun moved around the earth. This was widely accepted at that time. Muslim astronomers made their own observations and contradicted this theory. They were the first to state that the sun was the center of the universe and the earth moved around it.

6. The Astrolabe The Muslim invented the Astrolabe, a tool used to show how the sky looks at a specific place at a given time. It is used to measure angles of the planets and stars above the horizon. In its simplest form it was a ring or disk with the degrees of a circle marked on it and had two pointing arms. Using the Astrolabe, Muslim astronomers plotted the movement of the stars and planets with amazing accuracy.

7. Muslim Observatories The Muslim established observatories where they studied the movement of the planets and the stars. They came up with the following: The Zij – an astronomical table that shows the position of the planets and stars. The invention of innovative astronomical instruments such as the sun-dial, new types of amillary spheres, and a huge quadrant.`

8. Muslim Observatories – cont. The following were also achieved in the observatories: discovering that the earth was round. It was widely believed at that time that the earth was flat. Muslims observed and stated that the earth was spherical. calculating the circumference of the earth. Earlier figures say it was 20,400 miles and later figures put it at 26,000 miles. Today scientists believe it to be 25,000 miles. The calendar of Omar Khayyam. He established a calendar which, to this day, allows the calculation of the Persian new year to the exact hour, minute, and second that the earth finishes its orbit to start its next solar revolution.

9. Al-Biruni Al Biruni was the most famous Muslim astronomer. He wrote more than 146 books on astronomy. By the age of 17 he calculated the latitude of Kath, the city he lived in, by observing the altitude of the sun. Al-Biruni wrote his famous book al-Qanun al-Masudi, fi al-Hai'a wa al- Nujum, which he dedicated to Sultan Masood. The book discusses several theorems of astronomy, trigonometry, solar, lunar, and planetary motions and relative topics He also wrote a comprehensive book on Shadows. This includes information on shade and shadows, applications of the shadow functions to the astrolabe and to other instruments, shadow observations for the solution of various astronomical problems, and the shadow-determined times of Muslim prayers. Shadows is an extremely important source for present day knowledge of the history of mathematics, astronomy, and physics.