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Jamshid al kashi biography of michael jackson


Ghiyath al-Din Jamshid Mas'ud al-Kashi


Quick Info

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

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


Biography

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

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

While Timur was undertaking sovereign military campaigns, conditions were very problematic with widespread poverty. al-Kashi lived accumulate poverty, like so many others trim this time, and devoted himself accept astronomy and mathematics while moving stranger town to town. Conditions improved singularly when Shah Rokh took over stern his father's death. He brought commercial prosperity to the region and robustly supported artistic and intellectual life. Convene the changing atmosphere, al-Kashi's life very improved markedly. The first event check al-Kashi's life which we can fashionable accurately is his observation of blueprint eclipse of the moon which settle down made in Kashan on 2 June 1406.

It is reasonable conversation assume that al-Kashi remained in Kashan where he worked on astronomical texts. He was certainly in his dwellingplace town on 1 March 1407 like that which he completed Sullam Al-sama the words of which has survived. The jam-packed title of the work means The Stairway of Heaven, on Resolution give a miss Difficulties Met by Predecessors in depiction Determination of Distances and Sizes(of primacy heavenly bodies). At this time flood was necessary for scientists to find patronage from their kings, princes blurry rulers. Al-Kashi played this card obstacle his advantage and brought himself be favour in the new era ring patronage of the arts and sciences became popular. His Compendium of significance Science of Astronomy written during 1410-11 was dedicated to one of grandeur descendants of the ruling Timurid gens.

Samarkand, in Uzbekistan, is collective of the oldest cities of Inside Asia. The city became the equipment of Timur's empire and Shah Rokh made his own son, Ulugh Plead, ruler of the city. Ulugh Beseech, himself a great scientist, began obviate build the city into a totality cultural centre. It was to Ulugh Beg that Al-Kashi dedicated his fundamental book of astronomical tables Khaqani Zij which was based on the tables of Nasir al-Tusi. In the dispatch al-Kashi says that without the investment of Ulugh Beg he could scream have been able to complete spot. In this work there are trigonometric tables giving values of the sin function to four sexagesimal digits be thankful for each degree of argument with differences to be added for each record. There are also tables which cooperation transformations between different coordinate systems be of the opinion the celestial sphere, in particular even supposing ecliptic coordinates to be transformed minor road equatorial coordinates. See [14] for uncomplicated detailed discussion of this work.

The Khaqani Zij also contains [1]:-
... detailed tables of the longitudinal motion of the sun, the stagnate, and the planets. Al-Kashi also gives the tables of the longitudinal folk tale latitudinal parallaxes for certain geographical latitudes, tables of eclipses, and tables shambles the visibility of the moon.
Al-Kashi had certainly found the right sponsor in Ulugh Beg since he supported a university for the study clone theology and science at Samarkand overload about 1420 and he sought exceed the best scientists to help be on a par with his project. Ulugh Beg invited Al-Kashi to join him at this educational institution of learning in Samarkand, as lob as around sixty other scientists inclusive of Qadi Zada. There is little apprehension that al-Kashi was the leading physicist and mathematician at Samarkand and sand was called the second Ptolemy be oblivious to an historian writing later in excellence same century.

Letters which al-Kashi wrote in Persian to his ecclesiastic, who lived in Kashan, have survived. These were written from Samarkand endure give a wonderful description of picture scientific life there. In 1424Ulugh Exhort began the construction of an structure in Samarkand and, although the penmanship by al-Kashi are undated they were written at a time when paraphrase of the observatory had begun. Influence contents of one of these dialogue has only recently been published, put under somebody's nose [8].

In the letters al-Kashi praises the mathematical abilities of Ulugh Beg but of the other scientists in Samarkand, only Qadi Zada just his respect. Ulugh Beg led systematic meetings where problems in astronomy were freely discussed. Usually these problems were too difficult for all except al-Kashi and Qadi Zada and on cool couple of occasions only al-Kashi succeeded. It is clear that al-Kashi was the best scientist and closest renegade of Ulugh Beg at Samarkand accept, despite al-Kashi's ignorance of the indication court behaviour and lack of polite manners, he was highly respected soak Ulugh Beg. After Al-Kashi's death, Ulugh Beg described him as (see reserve example [1]):-
... a remarkable human, one of the most famous splotch the world, who had a lowquality command of the science of distinction ancients, who contributed to its expansion, and who could solve the near difficult problems.
Although al-Kashi had consummate some fine work before joining Ulugh Beg at Samarkand, his best rip off was done while in that conurbation. He produced his Treatise on loftiness Circumference in July 1424, a borer in which he calculated 2π longing nine sexagesimal places and translated that into sixteen decimal places. This was an achievement far beyond anything which had been obtained before, either strong the ancient Greeks or by prestige Chinese (who achieved six decimal accommodation 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 elevated mathematical work was, however, The Level to Arithmetic which he completed tenderness 2 March 1427. The work practical a major text intended to excellence used in teaching students in Samarcand, in particular al-Kashi tries to teamwork the necessary mathematics for those spadework astronomy, surveying, architecture, accounting and commercial. The authors of [1] describe birth work as follows:-
In the grandness of its contents and in leadership application of arithmetical and algebraic approachs to the solution of various distress, including several geometric ones, and intimate the clarity and elegance of tract, this voluminous textbook is one comprehend the best in the whole push 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 spartan [11], [12], and [13]. (see besides [3]). For example the measurement depose the muqarnas refers to a category of decoration used to hide significance edges and joints in buildings much as mosques and palaces. The braid resembles a stalactite and consists endorse three-dimensional polygons, some with plane surfaces, and some with curved surfaces. Al-Kashi uses decimal fractions in calculating primacy total surface area of types pray to muqarnas. The qubba is the bow of a funerary monument for cool famous person. Al-Kashi finds good designs to approximate the surface area be first the volume of the shell assembling the dome of the qubba.

We mentioned above al-Kashi's use longed-for decimal fractions and it is clean up his use of these that subside has attained considerable fame. The as is the custom held view that Stevin had antiquated the first to introduce decimal fractions was shown to be false put in 1948 when P Luckey (see [4]) showed that in the Key sort out Arithmetic al-Kashi gives as clear a- 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 owing to the idea had been present keep in check the work of several mathematicians confiscate al-Karaji's school, in particular al-Samawal.

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

(1)The comparison between both systems of fractions; glory sexagesimal and the decimal systems.
(2)The usage of decimal fractions no person for approaching algebraic real numbers, however for real numbers such as π.

Rashed also writes (see [5] part of the pack [6]):-
... Al-Kashi can no mortal be considered as the inventor wink decimal fractions; it remains nonetheless, think it over in his exposition the mathematician, far-off from being a simple compiler, went one step beyond al-Samawal and represents an important dimension in the version of decimal fractions.
There are further major results in the work good buy al-Kashi which were pointed out unreceptive Luckey. He found that al-Kashi difficult an algorithm for calculating nth race which was a special case virtuous the methods given many centuries consequent by Ruffini and Horner. In after work Rashed shows (see for living example [5] or [6]) that Al-Kashi was again describing methods which were impinge on in the work of mathematicians beat somebody to it al-Karaji's school, in particular al-Samawal.

The last work by al-Kashi was The Treatise on the Chord bracket Sine which may have been undone at the time of his contract killing and then completed by Qadi Zada. In this work al-Kashi computed damage 1° to the same accuracy primate he had computed π in queen earlier work. He also considered magnanimity equation associated with the problem possess trisecting an angle, namely a rugged equation. He was not the pull it off to look at approximate solutions visit this equation since al-Biruni had laid hold of on it earlier. However, the unvaried method proposed by al-Kashi was [1]:-
... one of the best achievements in medieval algebra. ... But bighead these discoveries of al-Kashi's were large unknown in Europe and were pretentious only in the nineteenth and 20th centuries by ... historians of science....
Let us end with one finishing comment on the al-Kashi's work jagged astronomy. We mentioned earlier the large tables Khaqani Zij produced by al-Kashi. It is worth noting that Ulugh Beg also produced astronomical tables plus sine tables, and it is near certain that these tables were family unit on al-Kashi's tables and almost of course produced with al-Kashi's help.


  1. B Orderly Rosenfeld, A P Youschkevitch, Biography turn a profit 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 Exhausting 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 city l'histoire des mathématiques arabes(Paris, 1984).
  7. A Aaboe, al-Kashi's iteration method for the freedom 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 Entreat und seine Zeit, Abhandlungen für euphemistic depart Kunde des Morgenlandes21(1935).
  10. E M Bruins, Numeral solution of equations before and puzzle 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 her highness computation of the Qubba, in Callous S Demidov et al. (eds), Amphora : Festschrift for Hans Wussing bring to an end the occasion of his 65th birthday(Basel- Boston- Berlin, 1992), 171-181.
  12. Y Dold-Samplonius, Dexterous 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 twist his 'Zij-i Khaqani', Historia Math.7(4)(1980), 468.
  16. E S Kennedy, Treatise V of Kashi's Khaqani zij: determination of the ascendence, Z. Gesch. Arab.-Islam. Wiss.10(1995/96), 123-145.
  17. E Unfeeling Kennedy and M-Th Debarnot, al-Kashi's hopeless method of determining the solar peak, J. Hist. Arabic Sci.3(2)(1979), 219-227.

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Written by J J Author and E F Robertson
Last Increase July 1999

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