.::THE PYHSICS::.

The study of experimental physics began with Ibn al-Haytham a pioneer of modern optics, who introduced the experimental scientific method and used it to drastically transform the understanding of light and vision in his Book of Optics, which has been ranked alongside Isaac Newton's Philosophiae Naturalis Principia Mathematica as one of the most influential books in the history of physics, for initiating a scientific revolution in optics and visual perception. The experimental scientific method was soon introduced into mechanics by Biruni, and early precursors to Newton's laws of motion were discovered by several Muslim scientists. The law of inertia, known as Newton's first law of motion, and the concept of momentum were discovered by Ibn al-Haytham (Alhacen) and Avicenna. The proportionality between force and acceleration, considered "the fundamental law of classical mechanics" and foreshadowing Newton's second law of motion, was discovered by Hibat Allah Abu'l-Barakat al-Baghdaadi, while the concept of reaction, foreshadowing Newton's third law of motion, was discovered by Ibn Bajjah (Avempace). Theories foreshadowing Newton's law of universal gravitation were developed by Ja'far Muhammad ibn Mūsā ibn Shākir, Ibn al-Haytham, and al-Khazini Galileo Galilei's mathematical treatment of acceleration and his concept of impetus was enriched by the commentaries of Avicenna and Ibn Bajjah to Aristotle's Physics as well as the Neoplatonist tradition of Alexandria, represented by John Philoponus.

.::THE MATHEMATICS::.

Among the achievements of Muslim mathematicians during this period include the development of algebra and algorithms by the Persian and Islamic mathematician Muhammad ibn Musa al-Khawarizmi the invention of spherical trigonometry, the addition of the decimal point notation to the Arabic numerals, the discovery of all the trigonometric functions besides sine, al-Kindi's introduction of cryptanalysis and frequency analysis, al-Karaji's introduction of algebraic calculus and proof by mathematical induction, the development of analytic geometry and the earliest general formula for infinitesimal and integral calculus by Ibn al-Haytham, the beginning of algebraic geometry by Omar Khayyam, the first refutations of Euclidean geometry and the parallel postulate by Nasir al-Din al-Tusi, the first attempt at a non-Euclidean geometry by Sadr al-Din, the development of symbolic algebra by Abu al-Hasan ibn Ali al-Qalasadi and numerous other advances in algebra, arithmetic, calculus, cryptography, geometry, number theory and trigonometry.

.::THE CALIPHATE IN BAGHDAD::.

Abbas took the power from the Ummayads, and then the capital has been transferred to the new city of Baghdad in the 760s. In a sudden, the city became one of the major cultural centres of the entire world, as the Abbasid decorated it with every form of art and encouraged its educational establishments with money and personal participation. Also, the Ummayad institutions of government were developed. In Baghdad, governing powers were exercised by an elaborate, mainly Persian bureaucracy. Vizier, a kind of prime minister was the one who headed for the caliphs and had enormous power. In the administrative division, the emir or governor was the key or crucial person. His responsibility to collect tax was very important to the Baghdad government. The independent-minded emirs were those who always led the rebellions during this reign.

Ulema or high court for the religious issues was the major institutions of the central government. Diwan (financial board) and Kadi (local judge) were those who had jurisdiction in all disputes which incriminate even a Muslim. The sacred law which was based on the Kalamullah, al-Qur’an was operated in a manner by the ulema. It is shari’a. It includes more than religious or doctrinal matters. The decision of ulama’ with the applications of shari’a almost affects the all aspects of public matters and even the private affairs. Al-Qur’anul Karim, the Muslim’s sacred book has been remained as the basis of all law, all administration and government eventhough in a very late date. However, in Modern times and even until today, the Qur’an was still found as the basis of all legal knowledge.

In the Abbasid era, Muslim army was very international in composition. Most of the soldiers were slaves which were taken from all conquered peoples. Most of them were especially from Africans and Egyptians. Their commanders came to have increasing political power as the caliph became weaker. Both the soldiers and commanders were well trained people. The army’s size were incredible large which running up to hundreds of thousands in the field at one period. Still, there is a little doubt that the Abbasid forces were the most impressive of the era and far overshadowed the European’s feudal levies and the Byzantines’ professional soldiery. Abbasid raids into Afghanistan and western India established footholds that were gradually expanded by later Muslim forces.