Al-Khazini

Infobox_Muslim scholars
notability = Muslim scientist
era = Islamic Golden Age
color = #B0C4DE

image_caption =

title = Al-Khazini
name = Abd al-Rahman al-Khazini
birth = 11th century
death = 12th century
Ethnicity = Byzantine Greek
school tradition = Islamic science, Islamic physics, Islamic astronomy
main_interests = Science, physics, astronomy, biology, alchemy, mathematics, philosophy
influences = Aristotle, Archimedes, Al-Quhi, Alhacen, Biruni, Omar Khayyam
influenced = Gregory Choniades, Byzantine science, Islamic science
notable idea = Experimental scientific method in mechanics; gravitational potential energy; gravity at a distance; distinction between force, mass and weight

Abd al-Rahman al-Khazini ( _ar. عبدالرحمن الخزيني) (flourished 1115–1130) was a Muslim scientist, physicist, astronomer, biologist, alchemist, mathematician and philosopher of Byzantine Greek descent from Merv, then in the Khorasan province of Persia but now in Turkmenistan, who made important contributions to physics and astronomy. [ [http://www.bookrags.com/research/abd-al-rahman-al-khazini-scit-021234 Abd Al-Rahman Al-Khazini] , "Science and Its Times" (2006). Thomson Gale.] He is considered the greatest scholar from Merv.Zaimeche, p. 5.]

Robert E. Hall wrote the following on al-Khazini:

Biography

Al-Khazini was a Byzantine Greek [Kennedy, "Islamic Astronomical Tables," p. 7.] slave of the Seljuq Turks, who was taken to Merv after the Seljuq victory over the Byzantine Emperor Romanus IV. [Klotz, "Multicultural Perspectives in Science Education: One Prescription for Failure".quote|"Al-Khazini (who lived in the 12th century), a slave of the Seljuk Turks, but of Byzantine origin, probably one of the spoils of the victory of the Seljuks over the Christian emperor of Constantinople, Romanus IV Diogenes."] His master, al-Khazin, gave him the best possible education in mathematical and philosophical subjects. Al-Khazini was also a pupil of the famous Persian poet, mathematician, astronomer and philosopher Omar Khayyám (1048-1131), who was living in Merv at the time. [Rosenfeld, p. 686-688.]

Al-Khazini later became a mathematical practitioner under the patronage of the Seljuk court, under Sultan Ahmed Sanjar. Little else is known about his life, but it is known that he refused rewards and handed back 1000 dinars sent to him by the wife of an Emir, and that he usually lived on 3 dinars a year.

Works

"Sinjaric Tables"

Included in his astronomical treatise "az-Zij as-Sanjarī" or "Sinjaric Tables", Al-Khazini gave a description of his construction of a 24 hour water clock designed for astronomical purposes, an early example of an astronomical clock, and the positions of 46 stars computed from the date given in the "Almagest" for the year 500 AH (1115-1116 CE). He also computed tables for the observation of celestial bodies at the latitude of Merv. [Sarton, p. 565.] [Kennedy, "Islamic Astronomical Tables", pp. 7, 37-39]

Al-Khazini's "Zij as-Sanjarī" was later translated into Greek by Gregory Choniades in the 13th century and was studied in the Byzantine Empire. [David Pingree (1964), "Gregory Chioniades and Palaeologan Astronomy", "Dumbarton Oaks Papers" 18, p. 135-160.]

"The Book of the Balance of Wisdom"

Al-Khazini is better known for his contributions to physics in his treatise "The Book of the Balance of Wisdom", completed in 1121, which remained an important part of Islamic physics. The book contains studies of the hydrostatic balance, its construction and uses, and the theories of statics and hydrostatics that lie behind it, as developed by his predecessors, his contemporaries, and himself. [Mariam Rozhanskaya, "On a Mathematical Problem in al-Khazini's "Book of the Balance of Wisdom", in David A. King and George Saliba, ed., "From Deferent to Equant: A Volume of Studies in the History of Science in the Ancient and Medieval Near East in Honor of E. S. Kennedy", Annals of the New York Academy of Science, vol. 500 (1987), p. 427] It also contains descriptions on the instruments of his predecessors, including the araeometer of Pappus and the pycnometer flask of al-Biruni, as well as his own hydrostatic balance and specialized balances and steelyards. [Robert E. Hall (1973). "Al-Khazini", "Dictionary of Scientific Biography", Vol. VII, p. 346.]

Al-Biruni and al-Khazini were the first to apply experimental scientific methods to the fields of statics and dynamics, particularly for determining specific weights, such as those based on the theory of balances and weighing. He and his Muslim predecessors unified statics and dynamics into the science of mechanics, and they combined the fields of hydrostatics with dynamics to give birth to hydrodynamics. They applied the mathematical theories of ratios and infinitesimal techniques, and introduced algebraic and fine calculation techniques into the field of statics. They were also the first to generalize the theory of the centre of gravity and the first to apply it to three-dimensional bodies. They also founded the theory of the lever and created the "science of gravity" which was later further developed in medieval Europe. The contributions of al-Khazini and his Muslim predecessors to mechanics laid the foundations for the later development of classical mechanics in Renaissance Europe. [Rozhanskaya and Levinova (1996), p. 642: quote|"Numerous fine experimental methods were developed for determining the specific weight, which were based, in particular, on the theory of balances and weighing. The classical works of al-Biruni and al-Khazini can by right be considered as the beginning of the application of experimental methods in medieval science."]

The first of the book's eight chapters deals with his predecessors' theories on the centre of gravity, including Al-Razi (Latinized as "Rhazes"), Abū Rayhān al-Bīrūnī, and Omar Khayyám. He also draws attention to the failure of the ancient Greeks to clearly differentiate between force, mass, and weight, and he goes on to show awareness of the weight of the air, and of its decrease in density with altitude.Hill, p. 61. (cf. Zaimeche, p. 5.)] The strict definition for a specific weight is given by Al-Khazini in "The Book of the Balance of Wisdom":

After extensive experimentation, Al-Khazini records the specific gravities of fifty substances, including various stones, metals, liquids, salts, amber, and clay. The accuracy of his measures were impressive and comparable to modern values. In another experiment, Al-Khazini discovered that there was greater density of water when nearer to the Earth's centre, which was later proven by Roger Bacon in the 13th century. [Max Meyerhof (1931), "Science and Medicine", in Sir T. Arnold and A. Guillaume, "Legacy of Islam", p. 342, Oxford University Press. (cf. Zaimeche, p. 7)]

Al-Khazini defines heaviness in traditional Aristotelian terms as an inherent property of heavy bodies:

On the basis that there is denser air when nearer to the centre of the Earth (derived from the Archimedes principle), [Marshall Clagett, "The Science of Mechanics in the Middle Ages", (Madison, Univ. of Wisconsin Pr., 1961), pp. 65-68] and that the weight of heavy bodies increase as they are farther from the centre of the Earth (derived from al-Quhi and Alhacen's theories that weight varies with the distance from the centre of the Earth), al-Khazini postulated that the gravity of a body varies with its distance from the centre of the Earth:Professor Mohammed Abattouy (2002), "The Arabic Science of weights: A Report on an Ongoing Research Project", "The Bulletin of the Royal Institute for Inter-Faith Studies" 4, p. 109-130:quote|"For their parts, al-Quhi and Ibn al-Haytham had the priority in formulating the hypothesis that the heaviness of bodies vary with their distance from a specific point, the center of the earth. [...] In his rescensions of the works of his predecessors, al-Khazini pushed forward this idea and drew from it a spectacular conclusion regarding the variation of gravity with the distance from the centre of the world. All this work represented strong antecedents to the concept of positional weight ("gravitas secundum sitam") formulated by Jordanus in the 13th century."]

quote|"For each heavy body of a known weight positioned at a certain distance from the centre of the universe, its gravity depends on the remoteness from the centre of the universe. For that reason, the gravities of bodies relate as their distances from the centre of the universe. The farther is a body from the centre of the Universe, the heavier it is; the closer to the centre, the lighter it is. For that reason, the gravities of bodies relate as their distances from the centre of the Universe." [Rozhanskaya and Levinova (1996), p. 621-2 (cf. partial quotation at Zaimeche, p. 7).] [Earlier translation, N. Khanikoff, ed. and trans., "Analysis and Extracts of ... Book of the Balance of Wisdom, An Arabic Work on the Water-Balance, Written by 'Al-Khâzinî in the Twelfth Century", chap. 5, sect. 3.1, "Journal of the American Oriental Society", 6. (1858 - 1860): 1-128, at p. 36:

It appears that what al-Khazini meant by "gravity" ("thiql" in Arabic) is both an idea similar to the modern concept of gravitational potential energy, [Rozhanskaya and Levinova (1996), p. 621:] and the moment of a force relative to a point (both meanings were derived from al-Quhi and Alhacen).Rozhanskaya and Levinova (1996), p. 622.] In either case, al-Khazini appears to have been the first to propose that the gravity of a body varies with its distance from the centre of the Earth. [Rozhanskaya and Levinova (1996), p. 622:] In his first sense of the word "gravity", the concept was not considered again until Newton's law of universal gravitation in the 18th century, [Rozhanskaya and Levinova (1996), p. 622:quote|"The phenomenon of variation of the gravity of bodies with variations of their distances from the centre of the Earth was discovered only in the eighteenth century after a certain development in the theory of gravitation.] [Zaimeche, p. 7.] but in his second sense of the word, the concept was considered again by Jordanus de Nemore in the 13th century.

N. Khanikoff, an early translator and commentator of al-Khazini's work, summarized his ideas regarding gravity as follows:

"Treatise on Instruments"

His "Risala fi'l-alat" ("Treatise on Instruments") has seven parts describing different scientific instruments: the triquetrum, dioptra, a triangular instrument he invented, the quadrant and sextant, the astrolabe, and original instruments involving reflection. [Robert E. Hall (1973). "Al-Biruni", "Dictionary of Scientific Biography", Vol. VII, p. 338.]

Alchemy and biology

Al-Khazini wrote the following on evolution in alchemy and biology, comparing the transmutation of elements with the transmutation of species, and how they were perceived by natural philosophers and common laymen in the medieval Islamic world at the time:

ee also

*Islamic science
*Islamic astronomy
*Islamic Golden Age
*Muslim inventions
*Zij

Notes

References

*Donald Routledge Hill (1993). "Islamic Science and Engineering". Edinburgh University Press.
*E. S. Kennedy (1956). "A Survey of Islamic Astronomical Tables", "Transactions of the American Philosophical Society", New Series, 46 (2), Philadelphia.
*Irving M. Klotz (1993). "Multicultural Perspectives in Science Education: One Prescription for Failure", "Phi Delta Kappan" 75.
*Mariam Rozhanskaya and I. S. Levinova (1996), "Statics", in Roshdi Rashed, ed., "Encyclopedia of the History of Arabic Science", Vol. 2, p. 614-642. Routledge, London and New York.
*Boris Rosenfeld (1994), "Abu'l-Fath Abd al-Rahman al-Khazini (XII Century)" by Mariam Mikhailovna Rozhanskaya", "Isis" 85 (4), p. 686-688.
*George Sarton (1927), "Introduction to the History of Science", Vol. I, The Carnegie Institution, Washington.
*Salah Zaimeche PhD (2005). [http://www.muslimheritage.com/uploads/Merv.pdf Merv] , Foundation for Science Technology and Civilization.