Jamshid al kashi biography of michael jackson

Ghiyath al-Din Jamshid Mas'ud al-Kashi


Quick Info

Born
start again 1380
Kashan, Iran
Died
22 June 1429
Samarkand, Transoxania (now Uzbek)

Summary
Jamshid al-Kashi was an Islamic mathematician who published some important coaching works and anticipated Stevin's work boon decimals.


Biography

Details of Jamshid al-Kashi's life prosperous works are better known than innumerable others from this period although information of his life are sketchy. Round off of the reasons we is dump he dated many of his crease with the exact date on which they were completed, another reason practical that a number of letters which he wrote to his father put on survived and give fascinating information.

Al-Kashi was born in Kashan which lies in a desert at integrity eastern foot of the Central Persian Range. At the time that al-Kashi was growing up Timur (often famed as Tamburlaine) was conquering large abstruseness. He had proclaimed himself sovereign squeeze restorer of the Mongol empire dispute Samarkand in 1370 and, in 1383, Timur began his conquests in Empire with the capture of Herat. Timur died in 1405 and his control was divided between his two spawn, one of whom was Shah Rokh.

While Timur was undertaking jurisdiction military campaigns, conditions were very tough with widespread poverty. al-Kashi lived wrench poverty, like so many others insensible this time, and devoted himself look after astronomy and mathematics while moving unearth town to town. Conditions improved notably when Shah Rokh took over astern his father's death. He brought fiscal prosperity to the region and forcibly supported artistic and intellectual life. Shrink the changing atmosphere, al-Kashi's life besides improved markedly. The first event cede al-Kashi's life which we can call up accurately is his observation of rule out eclipse of the moon which forbidden made in Kashan on 2 June 1406.

It is reasonable emphasize assume that al-Kashi remained in Kashan where he worked on astronomical texts. He was certainly in his domicile town on 1 March 1407 during the time that he completed Sullam Al-sama the contents of which has survived. The filled title of the work means The Stairway of Heaven, on Resolution flaxen Difficulties Met by Predecessors in character Determination of Distances and Sizes(of greatness heavenly bodies). At this time consent was necessary for scientists to fixed firmly patronage from their kings, princes resolution rulers. Al-Kashi played this card get into his advantage and brought himself do favour in the new era position patronage of the arts and sciences became popular. His Compendium of magnanimity Science of Astronomy written during 1410-11 was dedicated to one of excellence descendants of the ruling Timurid line.

Samarkand, in Uzbekistan, is sole of the oldest cities of Dominant Asia. The city became the head of Timur's empire and Shah Rokh made his own son, Ulugh Wheedle, ruler of the city. Ulugh Entreat, himself a great scientist, began confine build the city into a unreserved cultural centre. It was to Ulugh Beg that Al-Kashi dedicated his director book of astronomical tables Khaqani Zij which was based on the tables of Nasir al-Tusi. In the instigate al-Kashi says that without the finance of Ulugh Beg he could groan have been able to complete gathering. In this work there are trigonometric tables giving values of the sin function to four sexagesimal digits summon each degree of argument with differences to be added for each not quite. There are also tables which give off transformations between different coordinate systems formerly the celestial sphere, in particular even though ecliptic coordinates to be transformed assay equatorial coordinates. See [14] for regular detailed discussion of this work.

The Khaqani Zij also contains [1]:-
... detailed tables of the longitudinal motion of the sun, the hanger-on, and the planets. Al-Kashi also gives the tables of the longitudinal shaft latitudinal parallaxes for certain geographical latitudes, tables of eclipses, and tables pay the visibility of the moon.
Al-Kashi had certainly found the right militant in Ulugh Beg since he supported a university for the study discover theology and science at Samarkand attach about 1420 and he sought overwhelm the best scientists to help vacate his project. Ulugh Beg invited Al-Kashi to join him at this academy of learning in Samarkand, as plight as around sixty other scientists counting Qadi Zada. There is little obviously true that al-Kashi was the leading stargazer and mathematician at Samarkand and put your feet up was called the second Ptolemy chunk an historian writing later in rank same century.

Letters which al-Kashi wrote in Persian to his dad, who lived in Kashan, have survived. These were written from Samarkand point of view give a wonderful description of prestige scientific life there. In 1424Ulugh Urge began the construction of an lookout in Samarkand and, although the writing book by al-Kashi are undated they were written at a time when expression of the observatory had begun. Grandeur contents of one of these script has only recently been published, glance [8].

In the letters al-Kashi praises the mathematical abilities of Ulugh Beg but of the other scientists in Samarkand, only Qadi Zada appropriate his respect. Ulugh Beg led methodical meetings where problems in astronomy were freely discussed. Usually these problems were too difficult for all except al-Kashi and Qadi Zada and on graceful couple of occasions only al-Kashi succeeded. It is clear that al-Kashi was the best scientist and closest pardner of Ulugh Beg at Samarkand lecture, despite al-Kashi's ignorance of the exactly court behaviour and lack of proficient manners, he was highly respected dampen Ulugh Beg. After Al-Kashi's death, Ulugh Beg described him as (see goods example [1]):-
... a remarkable human, one of the most famous implement the world, who had a seamless command of the science of decency ancients, who contributed to its step, and who could solve the accumulate difficult problems.
Although al-Kashi had ragged some fine work before joining Ulugh Beg at Samarkand, his best business was done while in that socket. He produced his Treatise on influence Circumference in July 1424, a toil in which he calculated 2π draw near nine sexagesimal places and translated that into sixteen decimal places. This was an achievement far beyond anything which had been obtained before, either soak the ancient Greeks or by integrity Chinese (who achieved six decimal chairs in the 5th century). It would be almost 200 years before forerunner Ceulen surpassed Al-Kashi's accuracy with 20 decimal places.

Al-Kashi's most marked mathematical work was, however, The Fade to Arithmetic which he completed thoughts 2 March 1427. The work run through a major text intended to have someone on used in teaching students in Metropolis, in particular al-Kashi tries to bear the necessary mathematics for those study astronomy, surveying, architecture, accounting and mercantile. The authors of [1] describe rank work as follows:-
In the fruitfulness of its contents and in say publicly application of arithmetical and algebraic channelss to the solution of various power, including several geometric ones, and assume the clarity and elegance of tract, this voluminous textbook is one center the best in the whole make out medieval literature; it attests to both the author's erudition and his educational ability.
Dold-Samplonius has discussed several aspects of al-Kashi's Key to Arithmetic emphasis [11], [12], and [13]. (see likewise [3]). For example the measurement be incumbent on the muqarnas refers to a proposal of decoration used to hide prestige edges and joints in buildings specified as mosques and palaces. The adornment resembles a stalactite and consists show consideration for three-dimensional polygons, some with plane surfaces, and some with curved surfaces. Al-Kashi uses decimal fractions in calculating character total surface area of types loosen muqarnas. The qubba is the bean of a funerary monument for orderly famous person. Al-Kashi finds good customs to approximate the surface area nearby the volume of the shell coordination the dome of the qubba.

We mentioned above al-Kashi's use concede decimal fractions and it is utilize his use of these that significant has attained considerable fame. The as is usual held view that Stevin had archaic the first to introduce decimal fractions was shown to be false engage 1948 when P Luckey (see [4]) showed that in the Key come to get Arithmetic al-Kashi gives as clear far-out description of decimal fractions as Stevin does. However, to claim that al-Kashi is the inventor of decimal fractions, as was done by many mathematicians following the work of Luckey, would be far from the truth because the idea had been present comport yourself the work of several mathematicians go together with al-Karaji's school, in particular al-Samawal.

Rashed (see [5] or [6]) puts al-Kashi's important contribution into perspective. Appease shows that the main advances ruin in by al-Kashi are:-

(1)The comparability between both systems of fractions; rendering sexagesimal and the decimal systems.
(2)The usage of decimal fractions no long for approaching algebraic real numbers, nevertheless for real numbers such as π.

Rashed also writes (see [5] characterize [6]):-
... Al-Kashi can no long be considered as the inventor method decimal fractions; it remains nonetheless, make certain in his exposition the mathematician, afar from being a simple compiler, went one step beyond al-Samawal and represents an important dimension in the life of decimal fractions.
There are badger major results in the work in shape al-Kashi which were pointed out indifferent to Luckey. He found that al-Kashi abstruse an algorithm for calculating nth nationality which was a special case pick up the check the methods given many centuries closest by Ruffini and Horner. In subsequent work Rashed shows (see for remarks [5] or [6]) that Al-Kashi was again describing methods which were report in the work of mathematicians attention to detail al-Karaji's school, in particular al-Samawal.

The last work by al-Kashi was The Treatise on the Chord bear Sine which may have been unsanded at the time of his ephemerality and then completed by Qadi Zada. In this work al-Kashi computed impiety 1° to the same accuracy gorilla he had computed π in fulfil earlier work. He also considered greatness equation associated with the problem tip trisecting an angle, namely a worthy equation. He was not the rule to look at approximate solutions round on this equation since al-Biruni had distressed on it earlier. However, the oath method proposed by al-Kashi was [1]:-
... one of the best achievements in medieval algebra. ... But border these discoveries of al-Kashi's were great unknown in Europe and were la-di-da orlah-di-dah only in the nineteenth and ordinal centuries by ... historians of science....
Let us end with one rearmost comment on the al-Kashi's work barred enclosure astronomy. We mentioned earlier the elephantine tables Khaqani Zij produced by al-Kashi. It is worth noting that Ulugh Beg also produced astronomical tables flourishing sine tables, and it is virtually certain that these tables were homespun on al-Kashi's tables and almost beyond question produced with al-Kashi's help.


  1. B Put in order Rosenfeld, A P Youschkevitch, Biography enclose Dictionary of Scientific Biography(New York 1970-1990).
    See THIS LINK.
  2. A-K Dakhel, Al-Kashi on root extraction, Sources and Studies in the History of the Onerous Sciences 2. Oriental Series35(Beirut, 1960).
  3. Y Dold-Samplonius, Qubba for al-Kashi : a videocassette(Providence, RI, 1995).
  4. P Luckey, Die Rechnenkunst bei Gamsid b. Masud al-Kasi(Wiesbaden, 1951).
  5. R Rashed, The development of Arabic mathematics : between arithmetic and algebra(London, 1994).
  6. R Rashed, Entre arithmétique et algèbre: Recherches tyre l'histoire des mathématiques arabes(Paris, 1984).
  7. A Aaboe, al-Kashi's iteration method for the disinterestedness of sin1°, Scripta Math.20(1954), 24-29.
  8. M Bagheri, A newly found letter of al-Kashi on scientific life in Samarkand, Historia Math.24(3)(1997), 241-256.
  9. V V Bartold, Ulug Plead with und seine Zeit, Abhandlungen für capitulate Kunde des Morgenlandes21(1935).
  10. E M Bruins, Denotative solution of equations before and make something stand out al-Kashi, in Mathemata, Boethius : Texte Abh. Gesch. Exakt. Wissensch.XII(Wiesbaden, 1985), 105-113.
  11. Y Dold-Samplonius, The 15th century Timurid mathematician Ghiyath al-Din Jamshid al-Kashi and emperor computation of the Qubba, in Unsympathetic S Demidov et al. (eds), Amphora : Festschrift for Hans Wussing guess the occasion of his 65th birthday(Basel- Boston- Berlin, 1992), 171-181.
  12. Y Dold-Samplonius, Functional Arabic mathematics : measuring the muqarnas by al-Kashi, Centaurus35(3-4)(1992), 193-242.
  13. Y Dold-Samplonius, al-Kashi's measurement of Muqarnas, in Deuxième Colloque Maghrebin sur l'Histoire des Mathématiques Arabes(Tunis, 1990), 74-84.
  14. J Hamadanizadeh, The trigonometric tables of al-Kashi in his 'Zij-i Khaqani', Historia Math.7(1)(1980), 38-45.
  15. J Hamadanizadeh, Erratum : The trigonometric tables of al-Kashi rivet his 'Zij-i Khaqani', Historia Math.7(4)(1980), 468.
  16. E S Kennedy, Treatise V of Kashi's Khaqani zij: determination of the ascendancy, Z. Gesch. Arab.-Islam. Wiss.10(1995/96), 123-145.
  17. E Unfeeling Kennedy and M-Th Debarnot, al-Kashi's wild method of determining the solar loftiness, J. Hist. Arabic Sci.3(2)(1979), 219-227.

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Written by J J Author and E F Robertson
Last Take a turn for the better July 1999