IceTea
17-05-02, 10:41 AM
I got this article from Islam Message web page, and thought to share it with you
Fascination with the heavens, coupled with the need to determine the timings of prayers and direction of Qibla in di*verse locales, resulted in the tremendous development of Astrono*my from the very beginning. The progress took place along three interlinked pathways - development of infrastructure; collection of data; and interpretation of data in conjunction with original theoretical models. First path entailed construction of royal and private observatories - at Baghdad, Damascus, Maragha, and Samar*qand etc…[1]...and designing of several new instruments by highly creative innovators of the era, to felicitate observations. In this regard, a very important invention was Astrolab de*signed by Jandab an eighth century scientist.
Al-Battani, Ali Bin Isa and others developed and perfected it to such an extent that it became an instrument of observation and a kind of computing device for calculating complicated trigono*metric functions and for determining astronomical parame*ters/functions. Through it, they could tell the date and hour from the position of certain stars. Movable sights on the instrument were aligned with the star and relevant numbers and signs were read off from windows in the instrument or from its circumference.
Al-Khujandi constructed another very useful device, called Su*dus al-Fakhri. It is now known as Sextant. Farghani, another in*ventor developed and improved the Sun dial known to Greeks and Babylonians. All these devices were revolutionary inventions of their time and with the help of these instruments, astronomers collected data. They carried several observations to determine Obliquity ‘i’[2] and the eccentricity ‘e’[3], compiled tables of all kinds.
Thus by ninth century, a team working under Yahya Mansoor, the director of Al-Mamun Observatory, had made a number of astrono*mical observations and another team which had been given the task of determining the value of one terrestrial degree, managed to measure the radius of the earth from this observation, with only a 2.5% error. By eleventh century, Al-Bairooni using a different method reduced this error to 0.25%. Boozjani: [1011 AD] proved that sun had attraction; this attraction affected moon’s orbit and that it did not exceed 1º 15’.[4] Al-Battani, one of the great mathematicians and astronomers of the world, discovered the cor*rect angle of inclination of earth; proved the ‘Trepidation of Equinoxes’ as being a wrong concept; proved that the orbit of the earth is not circular but elliptical; prepared Astronomical tables known as ‘Zij Al-Battani’ that were of immense value to Astronomers of the 9th and 10th centuries. The list of eminent astronomers of this era and their works is simply too long to narrate here.
After thoroughly studying the Greek theoretical model of the planetary motion and its modification given by Ptolemy, astronomers like Al-Bitruji, Al-Tusi and Qutubuddin Shirazi etc. propounded their own models, while some others like Ibn Al- Shatir suggested further modifica*tions in the Ptolemic model. In fact, Copernicus in his famous book has used what is known today as Al-Tusi’s device for producing linear motion as a resultant of two circular motions. The famous histo*rian W. Hartner has proved even the fact that the geometrical figure of this device as produced by Copernicus, is exactly iden*tical even to the extent of the lettering employed by Al-Tusi in his Arabic astronomical treatise. And it was this device that played a very important role in the development of an alternative non-Ptolemic model of planetary motion[5].
The greatest contribution of these scholars is in mathematics.[6] They founded Algebra; made Trigonometry an independent branch of mathematics; and achieved tremendous advances in other fields like Geometry and spherical geometry etc. In this case too the impetus for the development was provided by the Message[7]. Al-Khwarizmi[8] the founder of Algebra, was the first mathematician to work on the details of ‘Arithmetic and Algebra of inheritance’ besides the systematisation of the theory of quadratic equations. His treatise entitled ‘Hisab Al-jabr wal muqabala’, enjoyed tremendous popularity in the medieval West for centuries. Tabit ibn Qurrah of ninth century, who had translated the works of Eu*clid, Apollonius, Archimedes, and Ptolemy was another fine mathe*matician himself. The only surviving fragment of his original work contains an exceptionally brilliant chapter on the solution and properties of cubic equations.
Umar Khayyam, the famous poet, was another great mathemati*cian[9]. He invented the second and third degree of quadratic equa*tions. The efforts of these mathematicians become all the more re*markable when we realise that they had not yet developed the sym*bolic algebra. Even for third degree equations, Khayyam had to write his problems and procedural steps in words and sentences.”
The algebraic symbols were introduced quite late. Al-Banna and Al-Marrakushi used them in thirteenth and fourteenth century. Later mathematicians like Qunfudh’s and Al-Qalasadi’s works of fourteenth and fifteenth century show quite a developed system of symbols for operations en*tailing extraction of square roots, exponentiation, and for un*known quantities in algebraic equations.
The numerals and the decimal notation used today originally came from India but these scholars gave them a much more explicit, simple and easy to use form, than the highly cumbersome Roman numerals, which it ultimately replaced. The development of Trigonometry, Spherical Trigonometry and Geometry also show the intensely orig*inal creative work done by these scholars. Here too the concepts of Sine and Cosine came from India, but Habsh Al-Hasib and Al-Battani extended them to other Trigonometrical ratios, like tan*gent, secant and their reciprocals. It was Al-Battani, who had derived this formula:
sin a = tan a / ֠(1+tan²a) and Cosa = 1 / ֨1 + tan²a).
Later Al-Nayrizi, Abul Wafa, Al-Khujandi and Abu Nasr Mansur etc. helped develop this branch. It was Abul Wafa who had given this famous formula:
sin (a + ߩ = sin a cos ߠ+ sin ߠcos a.
Abul Wafa had also discussed the quadrature of the parabola and the volume of the paraboloid. Yet trigonometry remained mainly the work of Al-Battani, Al-Bairooni and Al-Tusi etc. For the de*gree of accuracy in mathematical works, Jamshed Al-Kashi tops the list. He gave the value of p up to 16 decimal places and of Sine 1° up to 18 places.
I must also mention two other mathematicians of this era, whose contributions were quite revolutionary in con*tent. Ali Ahmad Nasawi who died in 1030 AD, studied an alterna*tive Indian system of time division based on 60. Indians had divided the day into 60 Ghatika. One Ghatika into 60 pal and one pal into 60 bapal. Thus one pal was equal to 24 seconds and one Ghatika or Ghari was equal to 24 minutes. Nasawi revolutionised this system, by dividing the day into 24 Saat, one Saat into 60 Daqeeqa and each Daqeeqa into 60 Sania. It was this divi*sion of time that was taken by rest of the world as standard. In the language of Message Daqeeqa means a small or minute quantity and Sania means second or the other unit. Thus we can see that the terms ‘minutes and seconds’ are exact translations of the original words used by Nasawi. Moreover, he also worked on the decimal system and made complete conversion charts between both the systems.”
Masalima al-Majriti, an expert mathematician, zoologist and chemist of tenth century, was the World’s first economist. From eighth century till thirteenth century, ‘followers of the Message’ were dominating the world’s economic scene. The entire known world was either trading with them or through them. Majriti studied markets, commercial transactions, different types of bus*inesses and associated traditions. After that he laid down ex*haustive guidelines, rules and laws for the entire commerce. He organised the information, rules, and laws in such a manner that after him commerce became a separate subject by itself. Besides commerce, he also studied zoology and prepared an ex*haustive book on species of animals, theircharacteristics and observation about their habitats. His third interest was chemis*try and on this subject too, he left a standard work. The next important field where this civilisation showed its most sustained effort was medical science. General medicine, pharmacy, ophthalmology, surgery and gynaecology, all received attention from their researchers. One of the brightest star of this era was Mohammed Zakaria Razi [932]. An astronomer, philosopher, botanist, physicist and physician par excellence, Razi contributed immense*ly to the development of medical science. He not only improved the working of several hospitals of Baghdad but also established a new hospital with a streamlined procedure, devising a way to check pollution of the area.
The pollution was checked by placing pieces of meat at all the proposed sites for the new hospital. After three days, the site where the meat showed least deterioration was selected. In this hospital the patients were first screened by a batch of doctors and those with serious and complex diseases were sent to Razi. He studied them, suggested medicines, observed the progress and noted every change and its effect exhaustively. Thus he experimented on hundreds and thousands of herbs and plants; and placed them in suitable categories in a book, which can be called the first medical encyclopaedia[10]. He also wrote ‘A Treatise on the Small Pox and Measles’. This treatise contains the first clear description of the major symptoms of the two dis*eases[11].
continue below :)
Fascination with the heavens, coupled with the need to determine the timings of prayers and direction of Qibla in di*verse locales, resulted in the tremendous development of Astrono*my from the very beginning. The progress took place along three interlinked pathways - development of infrastructure; collection of data; and interpretation of data in conjunction with original theoretical models. First path entailed construction of royal and private observatories - at Baghdad, Damascus, Maragha, and Samar*qand etc…[1]...and designing of several new instruments by highly creative innovators of the era, to felicitate observations. In this regard, a very important invention was Astrolab de*signed by Jandab an eighth century scientist.
Al-Battani, Ali Bin Isa and others developed and perfected it to such an extent that it became an instrument of observation and a kind of computing device for calculating complicated trigono*metric functions and for determining astronomical parame*ters/functions. Through it, they could tell the date and hour from the position of certain stars. Movable sights on the instrument were aligned with the star and relevant numbers and signs were read off from windows in the instrument or from its circumference.
Al-Khujandi constructed another very useful device, called Su*dus al-Fakhri. It is now known as Sextant. Farghani, another in*ventor developed and improved the Sun dial known to Greeks and Babylonians. All these devices were revolutionary inventions of their time and with the help of these instruments, astronomers collected data. They carried several observations to determine Obliquity ‘i’[2] and the eccentricity ‘e’[3], compiled tables of all kinds.
Thus by ninth century, a team working under Yahya Mansoor, the director of Al-Mamun Observatory, had made a number of astrono*mical observations and another team which had been given the task of determining the value of one terrestrial degree, managed to measure the radius of the earth from this observation, with only a 2.5% error. By eleventh century, Al-Bairooni using a different method reduced this error to 0.25%. Boozjani: [1011 AD] proved that sun had attraction; this attraction affected moon’s orbit and that it did not exceed 1º 15’.[4] Al-Battani, one of the great mathematicians and astronomers of the world, discovered the cor*rect angle of inclination of earth; proved the ‘Trepidation of Equinoxes’ as being a wrong concept; proved that the orbit of the earth is not circular but elliptical; prepared Astronomical tables known as ‘Zij Al-Battani’ that were of immense value to Astronomers of the 9th and 10th centuries. The list of eminent astronomers of this era and their works is simply too long to narrate here.
After thoroughly studying the Greek theoretical model of the planetary motion and its modification given by Ptolemy, astronomers like Al-Bitruji, Al-Tusi and Qutubuddin Shirazi etc. propounded their own models, while some others like Ibn Al- Shatir suggested further modifica*tions in the Ptolemic model. In fact, Copernicus in his famous book has used what is known today as Al-Tusi’s device for producing linear motion as a resultant of two circular motions. The famous histo*rian W. Hartner has proved even the fact that the geometrical figure of this device as produced by Copernicus, is exactly iden*tical even to the extent of the lettering employed by Al-Tusi in his Arabic astronomical treatise. And it was this device that played a very important role in the development of an alternative non-Ptolemic model of planetary motion[5].
The greatest contribution of these scholars is in mathematics.[6] They founded Algebra; made Trigonometry an independent branch of mathematics; and achieved tremendous advances in other fields like Geometry and spherical geometry etc. In this case too the impetus for the development was provided by the Message[7]. Al-Khwarizmi[8] the founder of Algebra, was the first mathematician to work on the details of ‘Arithmetic and Algebra of inheritance’ besides the systematisation of the theory of quadratic equations. His treatise entitled ‘Hisab Al-jabr wal muqabala’, enjoyed tremendous popularity in the medieval West for centuries. Tabit ibn Qurrah of ninth century, who had translated the works of Eu*clid, Apollonius, Archimedes, and Ptolemy was another fine mathe*matician himself. The only surviving fragment of his original work contains an exceptionally brilliant chapter on the solution and properties of cubic equations.
Umar Khayyam, the famous poet, was another great mathemati*cian[9]. He invented the second and third degree of quadratic equa*tions. The efforts of these mathematicians become all the more re*markable when we realise that they had not yet developed the sym*bolic algebra. Even for third degree equations, Khayyam had to write his problems and procedural steps in words and sentences.”
The algebraic symbols were introduced quite late. Al-Banna and Al-Marrakushi used them in thirteenth and fourteenth century. Later mathematicians like Qunfudh’s and Al-Qalasadi’s works of fourteenth and fifteenth century show quite a developed system of symbols for operations en*tailing extraction of square roots, exponentiation, and for un*known quantities in algebraic equations.
The numerals and the decimal notation used today originally came from India but these scholars gave them a much more explicit, simple and easy to use form, than the highly cumbersome Roman numerals, which it ultimately replaced. The development of Trigonometry, Spherical Trigonometry and Geometry also show the intensely orig*inal creative work done by these scholars. Here too the concepts of Sine and Cosine came from India, but Habsh Al-Hasib and Al-Battani extended them to other Trigonometrical ratios, like tan*gent, secant and their reciprocals. It was Al-Battani, who had derived this formula:
sin a = tan a / ֠(1+tan²a) and Cosa = 1 / ֨1 + tan²a).
Later Al-Nayrizi, Abul Wafa, Al-Khujandi and Abu Nasr Mansur etc. helped develop this branch. It was Abul Wafa who had given this famous formula:
sin (a + ߩ = sin a cos ߠ+ sin ߠcos a.
Abul Wafa had also discussed the quadrature of the parabola and the volume of the paraboloid. Yet trigonometry remained mainly the work of Al-Battani, Al-Bairooni and Al-Tusi etc. For the de*gree of accuracy in mathematical works, Jamshed Al-Kashi tops the list. He gave the value of p up to 16 decimal places and of Sine 1° up to 18 places.
I must also mention two other mathematicians of this era, whose contributions were quite revolutionary in con*tent. Ali Ahmad Nasawi who died in 1030 AD, studied an alterna*tive Indian system of time division based on 60. Indians had divided the day into 60 Ghatika. One Ghatika into 60 pal and one pal into 60 bapal. Thus one pal was equal to 24 seconds and one Ghatika or Ghari was equal to 24 minutes. Nasawi revolutionised this system, by dividing the day into 24 Saat, one Saat into 60 Daqeeqa and each Daqeeqa into 60 Sania. It was this divi*sion of time that was taken by rest of the world as standard. In the language of Message Daqeeqa means a small or minute quantity and Sania means second or the other unit. Thus we can see that the terms ‘minutes and seconds’ are exact translations of the original words used by Nasawi. Moreover, he also worked on the decimal system and made complete conversion charts between both the systems.”
Masalima al-Majriti, an expert mathematician, zoologist and chemist of tenth century, was the World’s first economist. From eighth century till thirteenth century, ‘followers of the Message’ were dominating the world’s economic scene. The entire known world was either trading with them or through them. Majriti studied markets, commercial transactions, different types of bus*inesses and associated traditions. After that he laid down ex*haustive guidelines, rules and laws for the entire commerce. He organised the information, rules, and laws in such a manner that after him commerce became a separate subject by itself. Besides commerce, he also studied zoology and prepared an ex*haustive book on species of animals, theircharacteristics and observation about their habitats. His third interest was chemis*try and on this subject too, he left a standard work. The next important field where this civilisation showed its most sustained effort was medical science. General medicine, pharmacy, ophthalmology, surgery and gynaecology, all received attention from their researchers. One of the brightest star of this era was Mohammed Zakaria Razi [932]. An astronomer, philosopher, botanist, physicist and physician par excellence, Razi contributed immense*ly to the development of medical science. He not only improved the working of several hospitals of Baghdad but also established a new hospital with a streamlined procedure, devising a way to check pollution of the area.
The pollution was checked by placing pieces of meat at all the proposed sites for the new hospital. After three days, the site where the meat showed least deterioration was selected. In this hospital the patients were first screened by a batch of doctors and those with serious and complex diseases were sent to Razi. He studied them, suggested medicines, observed the progress and noted every change and its effect exhaustively. Thus he experimented on hundreds and thousands of herbs and plants; and placed them in suitable categories in a book, which can be called the first medical encyclopaedia[10]. He also wrote ‘A Treatise on the Small Pox and Measles’. This treatise contains the first clear description of the major symptoms of the two dis*eases[11].
continue below :)