ST Background info Science in early Islam culture P 22 Astronomy is the study of the stars and planets. Al-Khwarizmi was first to have said to have become interested with the numbers he found in astronomical tables. Ptolemy popularized an erraneous belief by using Posidonius’ incorrect figures regarding the size of the earth, and developed his own theory about the movement of the moon and planets.

ST Background Info Science in early Islam Culture P 24 When a planet reaches it’s highest point in the sky, it’s called it’s zenith. An astronomical table used to calculate positions of stars and planets is called a zij. Al-Farghani’s zij was used for 700 years to come because of how clear and organized it was.

ST Accomplishments Science in early Islam Culture P Al-Battani used an astrolabe over the course of 41 years to measure astronomical constants. Al-Battani was able to measure the angle of the ecliptic correctly, which allowed for him to calculate that a solar year is 365 days, 5 hours, 46 minutes and 24 seconds. Omar Khayyam created a calender that is more reliable than ours today but was never used because people didn’t want to give up the calender they were familiar with.

ST Observational Astronomy Science in Medieval Islam P Preparing new calendars, horoscopes and prayer tables increased the demand for new, more accurate ones which led to the closer scrutinizing of the sky. Most impressive observatories were established in the thirteenth century in Maragha, Persia and in the fifteenth century in Uzbekistan.

ST Ancient Legacies Science in Medieval Islam P 61 Aristarchus believed that the earth rotated on it’s axis and completed a full rotation every day. He also believed that the earth rotated around the sun one time every year, and that the sun and fixed stars did not move. Early Alexandrian astronomer named Apollonius suggested that different distances of a planet from earth can be explained by assuming the planets moved in a circular motion, called an epicycle.

ST Theoretical Astronomy Science in Medieval Islam S 68 The concept of planetary motion involving epicycles was very intriguing to the Islamic astronomers and perplexed them for quite some time. Muslim astronomers eventually objected to the concept of epicyclical motion because it violated the principle of uniformity of motion.

ST Accomplishments Science in Medieval Islam P 60 The Pythagorean’s idea of a great central fire eventually replaced earth as being the middle most part of the universe. Hipparchus used the concept that the planets move in eccentric orbits around earth to explain the apparent motions of the sun in terms of a fixed circular orbit.

ST Accomplishments Science in early Islam Culture S 29 Ptolemy’s model of an earth centered universe started the basis for astronomy. The determination of longitude and latitude structured the most accurate way to pray to Mecca wherever you were. The House of Wisdom was a place where scholars from all over could join and share ideas.

ST Lunar And Luni-Solar Calendars Science in Medieval Islam P 30 1 lunar phase cycle occurs every days The Luni-Solar calendar has mostly 12 months in a year but every thrid or fouth year it has 13.

ST Background The Islamic World S 56 The origin of Islamic astronomy are derived from early Indian, Persian and Greek observations. Al-Battani also made predictions about the eclipses of the sun, and Abd al Rahman al-Sufi produced a fairly accurate chart of constellations.

ST Plotting The Sun’s Path Science in early Islam Culture S 26 The apparent crossings of the sun over the equator occur twice every year in March and September. These are called the Spring and Fall equinoxes. The angle of the ecliptic and the precession of the equinoxes are astronomical constants they only change over time.

ST Accomplishments Science in Medieval Islam S 60 It wouldn’t be until 1800 years after Aristarchus of Samos Nicolaus Copernicus, John Kepler and Galileo Galilei would build off of the idea of a sun centerd solar system Plato and Aristotle refined the mechanics of movement within the Greek cosmos of spheres.

ST Observational Astronomy Science in Medieval Islam P A number of observatories were built at centers such as Rayy, Isfahan and Shiraz in Persia as well as Egypt, usually sponsored by caliphs and other rulers. Al-Battani had his very own private observatory at Rakka, Syria. Al-Biruni in afghanistan,provided observational data forming the basis for astronomical tables.

ST Accomplishments Science in Medieval Islam S Al-Tusi, Persian astronomer, known for his famous concept called the Tusi Couple, a hypothetical model of epicyclic motion that involved a combination of motions, each was uniform with respect to it’s own center. Ibn al-Shatir was an astronomer who served as a muwaqqit at the mosque of Damascus applied this model to the motions of all heavenly bodies in the fourteenth century.

ST Accomplishments Science in Medieval Islam S Al-Mansur assembled a group of Persian, indian and other scientists at Baghdad and by the eight century, the internationalization of Islamic science was well on its way. The son of Hunayn ibn Ishaq produced his own version of Ptolemy’s Al-Majisti.