Post by Islamic Revival on Aug 14, 2004 8:40:06 GMT -5
The Arabs claimed astronomy to be their special subject, and indeed they surpassed by far all their contemporaries in the knowledge of the heavens. Al Biruni quotes in his book a passage from Ibn Khatib saying that the Arabs had no equals in their knowledge of the stars. Even to this day their names are associated with a number of stars, constellations, and astronomical instruments.
They investigated the liberation of the moon, and proved that it is not constant. They determined fully the movements of the planets. Abul Wafa determined accurately the obliquity of the ecliptic in 995 C.E., and calculated the variation in the moon’s motion. He also discovered the third liberation in the moon’s motion which was rediscovered by Tycho Brahe after 600 years. He perfected Ptolemy’s lunar theory, and corrected many errors in the observations of the old astronomers.
The quadrant was invented by Ibn Yunus . Al Batrash (Encyclopedia of Islam) found many errors in Ptolemy’s hypothesis of the solar system and in 1150 C.E. pout forward a new system for the planetary motions.
Ibn Rushd discovered a sunspot.
Ibn Aalam determined the stellar motion by observing that the stars traverse one degree in 70 solar years. He also determined the latitude and longitude of many stars, and measured the greatest declination of the planet Mercury. He discovered the moons (satellites) of Jupiter, discussed the motion of the sun spots, and determined the eccentric orbits of comets. The obliquity of the ecliptic, the points in which the meridian cuts the equator and the ecliptic, the arc of the terrestrial meridian, and the precession of the equinoxes were determined in the reign of the Abbasid Caliphs.
Abu Qasim Abdullah and Abu Hasan Ali Ibn Abu Qasim produced very correct almanacs from 883 C.E. to 933 C.E.
Abu Hasan discovered that the moon’s distance from the Sun is not constant, as assumed by Ptolemy.
Omar Khayyam reformed the calendar in such a way that the solar year proposed by him is more accurate that any calendar proposed either before or after his time.
Mohammad bin Jaber Al Battani , who lived in the 10th century C.E., discovered the wobbling motion of the earth’s orbit. His remarkably accurate calculation of the solar year as 365 days, 5 hours, 46 minutes and 24 seconds is very close to the latest estimates.
Al Farghani determined the diameter of the Earth to be 6,500 miles, and found the diameter of planets.
Al Tusi built an observatory at Meragha in 1262 and directed its activity. It was equipped with the best instruments from Baghdad and other Islamic Centers for learning.
Ulugh Beg computed the length of the year and also prepared tables of planetary motions. He also compiled a catalogue of stars, giving accurate positions of 992 stars.
Reproduced from 2004 calendar by PharmEvo (Pvt.) Ltd.
pharmevo@cyber.net.pk
They investigated the liberation of the moon, and proved that it is not constant. They determined fully the movements of the planets. Abul Wafa determined accurately the obliquity of the ecliptic in 995 C.E., and calculated the variation in the moon’s motion. He also discovered the third liberation in the moon’s motion which was rediscovered by Tycho Brahe after 600 years. He perfected Ptolemy’s lunar theory, and corrected many errors in the observations of the old astronomers.
The quadrant was invented by Ibn Yunus . Al Batrash (Encyclopedia of Islam) found many errors in Ptolemy’s hypothesis of the solar system and in 1150 C.E. pout forward a new system for the planetary motions.
Ibn Rushd discovered a sunspot.
Ibn Aalam determined the stellar motion by observing that the stars traverse one degree in 70 solar years. He also determined the latitude and longitude of many stars, and measured the greatest declination of the planet Mercury. He discovered the moons (satellites) of Jupiter, discussed the motion of the sun spots, and determined the eccentric orbits of comets. The obliquity of the ecliptic, the points in which the meridian cuts the equator and the ecliptic, the arc of the terrestrial meridian, and the precession of the equinoxes were determined in the reign of the Abbasid Caliphs.
Abu Qasim Abdullah and Abu Hasan Ali Ibn Abu Qasim produced very correct almanacs from 883 C.E. to 933 C.E.
Abu Hasan discovered that the moon’s distance from the Sun is not constant, as assumed by Ptolemy.
Omar Khayyam reformed the calendar in such a way that the solar year proposed by him is more accurate that any calendar proposed either before or after his time.
Mohammad bin Jaber Al Battani , who lived in the 10th century C.E., discovered the wobbling motion of the earth’s orbit. His remarkably accurate calculation of the solar year as 365 days, 5 hours, 46 minutes and 24 seconds is very close to the latest estimates.
Al Farghani determined the diameter of the Earth to be 6,500 miles, and found the diameter of planets.
Al Tusi built an observatory at Meragha in 1262 and directed its activity. It was equipped with the best instruments from Baghdad and other Islamic Centers for learning.
Ulugh Beg computed the length of the year and also prepared tables of planetary motions. He also compiled a catalogue of stars, giving accurate positions of 992 stars.
Reproduced from 2004 calendar by PharmEvo (Pvt.) Ltd.
pharmevo@cyber.net.pk