Posts Tagged geographer

Muslim Matematician: Al-Khawarizmi

December 24, 2007 at 8:50 pm · Filed under Famous Muslims, Muslim History, Science ·Tagged , , , , , , , , , , , , ,

 Al-Khawarizmi 780-850 CE

Mathematician, astronomer, geographer and Father of Algebra 

Abu Abdullah Mohammad Ibn Musa al-Khawarizmi was born at Kath part of Khwarizm (modern day Kheva, Uzbekistan) south of the Aral Sea in Central Asia. Kath is now buried under sand. His last name Khawarizmi refers to where he was born Very little is know about his early life, and the exact dates of his birth and death remain unknown, but we know he was born around 780 CE.

Al Khawarizmi’s family migrated to a place south of Baghdad when summoned by the caliph Al-Ma’mun and was given the job of being the court astronomer. It is said that he flourished under Al-Ma’mun through 813-833. Al-Khawarizmi and his colleagues the Banu Musa were scholars at the House of Wisdom in Baghdad for most of their life. Their tasks included translating Greek manuscripts which they may have also studied and to write on algebra, geometry and astronomy.  

Al Khawarizmi’s Books

Al Khawarizmi was one of the greatest mathematicians, astronomers and geographers who ever lived. He was the founder of several basic principles of mathematics. In the words of Phillip Hitti about Al Khawarizmi, he said;“He influenced mathematics through to a greater extent than any other medieval writer.”

Under Al Khawarizmi, the development of mathematics went to a great extent like the fact that in his book Al-Jabr wa-al-Muqabilah  he gave some solutions to a few linear and quadratic equations such as x2 + 10x = 39, commonly used by later writers. Al-Jabr wa-al-Muqabilah (Book of Calculations, restoration and reduction) is where the word algebra (Al Jabr in Arabic) is derived from.Adelard of Bath’s book the “liber ysagogarum alchorismi in artem astronomicam a magistro A. (Adelard of Bath) compositus” includes within it things about arithmetic, geometry, music (a part of mathematics at that time) and astronomy. The book is more like or probably a summary of Al Khawarizmi’s work rather than original worksIn the twelfth century Gerard of Cremona and Roberts of Chester translated the algebra of Al Khawarizmi into Latin. Mathematicians and universities all over the world used Al Khawarizmi’s works until the sixteenth century. Several of Al Khawarizmi’s books were translated into Latin in the early twelfth century. One of those books on arithmetic Kitab al Jam’a wal –Tafreeq bil Hisaab al Hindi (“The Book of Addition and Subtraction According to the Hindu Calculation”)were lost in Arabic but remained preserved in Latin. Translations into European languages and Latin introduced a whole new science, completely unknown to the Europeans and the western world till then.                  

 Al Khawarizmi’s geographic book  Kitab Surat-al-Ard  (Book on the appearance of the                                                                        Earth) and his maps  were also translated into european languages.                                                                                                                                                                       

 Al Khawarizmi’s works

Al Khawarizmi explained the use of zero, which was developed by the Arabs and he also developed the decimal system. He introduced the Indian system of numerals, commonly known as the Arabic numeral system which through his work was introduced first to the Arabs then through translations, was introduced to the west. He perfected the representations of conic sections and developed the error of two sections which practically led him to the theory of differentiation.  He also developed at length several arithmetic procedures including procedures on fractions and developed the trigonometrical tables containing sine functions which were probably extended to tangent functions by Maslmah the son of the Umayyad caliph Abd al-Malik ibn Marwan.        

  Al Khawarizmi’s works on astronomy and geography  include original works on the sundial a book called Kitab al-Rukhmat that Al khawarizmi wrote but which has been lost, a book on the jewish calender called Istikraj Tarikh al-Yahud, two other books on the astrolobe and  original works on clocks.Al Khawarizmi revised and corrected Ptolmey’s theories on geography and corrected  Ptolmey’s map of the world.He also developed the astronomical tables, causing a significant development in the field of astronomy, on which he also wrote a book. These astronmoncal tables were translated into european languges then were later translated into chinese. Al Khawarizmi is well known for the collaboration in the degree measurements that was ordered by Ma’mun al-Rashid  directed for measuring the volume and circumference of the earth. The influence of Al Khawarizmi on the world of science and mathematics is very great, leaving behind a legacy that amazes the world even know. If it wasn’t for Al Khawarizmi’ mathematics would have never had flourished as greatly as it did under him. His contribution and systematic way of working has held high repute, through the centuries since then.

Abu Abdullah Mohammad Ibn Musa al Khawarizmi the great mathematician, astronomer and geographer died in 850.                                                                                                     

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Muslim Geographer: Al-Idrisi

December 24, 2007 at 6:26 pm · Filed under Famous Muslims, Muslim History, Science ·Tagged , , , , , , , , ,

Al-Idrisi 1099-1166 or 1180AD

Map of Al-Idrisi – Note: Muslims placed south at the top of their maps.

Geographer and Cartographer

 Abu Abdullah Muhammad Ibn Muhammad Ibn Abdullah Ibn Idrisi al-Qurtubi al-Hasani also known by his short name, Al-Sharif Al Idrisi Al Qurtubi, was born in Ceuta, Spain in 1099AD. Al-Idrisi received his education in Cordoba, Spain (Al Andalus). He flourished at the Norman Court of King Roger in Palermo, where he spent most of his life. He was also a direct descendant of the Prophet Muhammad (Peace and blessings be upon him).Al-Idrisi is regarded as the greatest geographer and cartographer of the middle ages.

As all Muslim geographers, Al-Idrisi traveled to many distant places, including Europe, to collect geographic data about the world.Geographers before Al-Idrisi correctly measured the surface of the earth, for example Al Hawqal, another geographer, in the late 11th century produced a map of the world, while other maps were also available. Arab manuscripts were also available and much older Greek charts and sailing manuscripts as well. This, Al-Idrisi combined with his own information gained from his personal experience. From this, Al-Idrisi became famous for his knowledge, especially attracting attention from sea navigators and military planners because their ships and navigators from the north sea’s, Atlantic and Mediterranean all passed through the Mediterranean passing Sicily, where Al-Idrisi spent most of his life.  

  Al-Idrisi’s fame soon reached the court of King Roger, the Norman of Sicily, who invited him to produce an up-to-date map of the world. It should be mentioned that Sicily was under Muslim control before King Roger, and Muslim works were freely available to transport to Europe through Latin West.One of Al-Idrisi’s most famous works was composed of a circular world map of pure silver weighing approximately 400 kilograms and precisely on it recorded the seven continents with trade routes, lakes, rivers, major plains and mountains. His map can be seen on the next page.

Al-Idrisi’s Work and Books

It took several centuries for Europe to make use for  Al-Idrisi’s work, and Christopher Columbus probably wouldn’t have found America if he hadn’t used Al-Idrisi’s maps. Al-Idrisi was totally convinced that earth was round, and for some people who said that water of the oceans cannot remain on a curved surface, he gave an answer saying,

 “An equilibrium which experiences no variation, keeps these bodies of water in place.”

Using all the information compiled by himself, Al-Idrisi wrote his most famous book, Al-Kitab al-Rujari” (Roger’s Book) in 1154 in honour of his patron King Roger, which is also entitled “Mushtaq fi Ikhtiraq al-Afaq” (The delight of him who desires to journey through the climates). This is the name that King Roger gave to the book. It is virtually an encyclopedia containing geographical information on Asia, Africa and also Europe.

Al-Idrisi also compiled another geographical encyclopedia, larger than his previous one, named “Rawd-Unnas wa-Nuzhat al-Nafs” (Pleasure of men and delight of souls) also known as “Kitab al- Mamalik wa al-Masalik.” It contained knowledge on the Niger, Sudan and he also named the precise location of the head waters of the Nile to be in East Africa in the “Jibaal al-Qamar” (Mountains of the moon), which can be clearly seen on his map.

 It is amazing that the precise location of the head waters of the River Nile were not discovered by the Europeans until the 19th century and it is remarkable of the accuracy of the location given by Al Idrisi.                                                                                                                                

In addition to geography, he also contributed to the science  of medical plants. His major contribution in this field lies in his medicinal plants as presented in his books, especially Kitab al-Jami-li-Sifat Ashtat al-Nabatat. Al-Idrisi reviewed and made all the material available on the subject of plants, and also associated drugs available to him from Muslim scientists and added it to his collection of research from his travels.Al-Idrisi contributed his knowledge to the subject of botany and gave the names of the drugs in Syriac, Greek, Persian, Hindi, Latin and Berber. 

Al-Idrisi-besides botany and geography- also wrote on fauna, zoology and therapeutic aspects.Al-Idrisi’s work was soon translated into Latin and his books remained popular in the east and west for many centuries. His maps                                                                       remained available in libraries remained available in libraries of European schools of navigation, and the Portuguese and  Spanish made use of them before setting out to the Atlantic Ocean (The Sea of darkness).

One of Al-Idrisi’s books published in Rome in 1619 was an abridged version, but the translator never gave credit for the works to Al-Idrisi.

Abu Abdullah Muhammad Ibn Muhammad Ibn Abdullah Ibn Idrisi al-Qurtubi al-Hasani, the greatest geographer and cartographer of his time, died in 1166 or 1180 AD. His exact date of his death is not confirmed.                           

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