Posted by Scientific Insights on Saturday, February 18, 2017
Muslim Astronomers Improve Astrolabe
Early emergence astrolabe did not come from the Islamic world, but is expected from Ancient Greece. Although there was no residual astrolabe in the Greek left, this astrolabe presence known through the writings Hipparachus astronomers in 150 BC.
Hipparachus revealed discoveries concerning the stereographic projection, a mathematical device that sky three-dimensional drawing into a two-dimensional slab, is the basis of how astrolabe work.
However, in the end, the historians concluded, astrolabe experienced improvements in the Islamic world. According to them, the term astrolabe is derived from an Arabic word which in Greek means star holder.
Astrolabe which still survive today is astrolabe private collection in the National Museum of Kuwait. Astrolabe also has traveled the world through traveling exhibition 'Islamic Art and Patronage, Treasures from Kuwait' since the 1991 Gulf War.
Astrolabe is artificial and signed Nastalus Iraq as well as to the year 927 AD astrolabe structure consists of four main parts. First, mater, which is often called a plate or base plate. Meanwhile, the second part is the rete.
Rete network or on such a plate that shows the stars that have been clearly seen, the ecliptic (the zodiac constellations and part of the sky where the sun outstanding), and some of the stars that can be seen with the naked eye.
The third is that each plate is made for different latitudes. Each plate engraved on the box to mark the peak or the point directly overhead, the horizon, and all elevations in the earth's surface.
The fourth part is alidade or the size of the eye to observe and read the scale. Rete and the plate is designed to fit the mater. In addition, there are certain ways to make observations with an astrolabe.
Someone who will make observations using the astrolabe should hold the ring at the top of the astrolabe. This step aims to astrolabe hanging straight. This instrument can be used for observing the sun, the stars, or the height of a building.
Astrolabe is also useful to determine the time of sunrise or sunset. In addition, many astrolabe has tables engraved on the back. This table displays information that is useful in determining astrological horoscope.
In astrolabe, sometimes also information about the so-called lunar mansions, a feature thought astrology of India which divides the zodiac into 28 parts. Each zodiac refers to the position of the moon for any given day.