Previous (Chronologically) Next Biographies Index Previous ( Alphabetically) Next Welcome page
His major work, an astronomical handbook, was al-Zij al-Hakimi al-kabir. al-kabir means 'large' which is apt and al-Hakimi means that the work is dedicated to Caliph al-Hakim. The book is certainly large, containing 81 chapters. There are lists of observations made by Yunus and his predecessors. He describes 40 planetary conjunctions accurately and 30 lunar eclipses used by Simon Newcomb in his lunar theory.
In addition there are planetary longitudes and calendar tables. Trigonometric functions are given as arcs rather than angles. Spherical trigonometry reaches a high level of sophistication in this work.
Yunus was described by his biographer as follows:-
He was an eccentric, careless and absent-minded man who dressed shabbily and had a comic appearance.
Yunus predicted the date of his own death to be in seven days time when he was in good health. He tidied up his business affairs, locked himself in his house and recited the Koran until he died on the day he predicted.
References:
Previous (Chronologically) Next Biographies Index Previous ( Alphabetically) Next Welcome page History Topics Index Famous curves index Chronologies Birthplace Map Mathematicians of the day Anniversaries for the year Search Form Simple Search Form Search Suggestions