Lahoris made world’s best astrolabes in 17th century, says Dutch scholar

[Shahzaz ud din]

Lahoris made world’s best astrolabes in 17th century, says Dutch scholar
Haneen RafiMarch 07, 2018
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DR Jan P. Hogendijk, professor of history of mathematics at University of Utrecht, the Netherlands, speaks at Habib University on Tuesday. —Fahim Siddiqi / White Star


KARACHI: “The best astrolabes in the 17th century were made in the city of Lahore which most people in this country are unaware of,” said Dr Jan P. Hogendijk while speaking at Habib University on Tuesday.

Dr Hogendijk is part of a Dutch team from the department of mathematics, University of Utrecht, the Netherlands, that travels far and wide to educate people about the historical significance of the astrolabe, its uses and the general history of astronomy in mediaeval Islamic civilisation.

There are many uses of an astrolabe, said Dr Hogendijk. It was used at a time when there were no watches, so one of its uses was to determine time. You can also use it to find the direction of the poles, during the day and even at night. During the day you need the sun for it while at night you will need the starts. It is also used in astronomy.

“They started making astrolabes in Lahore in 1560 and continued till 1700s. A family in Lahore became very good in making astrolabes which were more sophisticated than what was being made in the rest of the world,” said Dr Hogendijk.

‘Around 2,000 Islamic astrolabes still exist’

They looked like complex pieces of art but were an accurate representation of the constellations in the sky, he added. All the pieces made were made following precise mathematical measurements and thus were considered to be the best in the world.

The thickness of those plates was only one millimetre and eventually it was decided to investigate what made the astrolabes from Lahore so distinct from any other. Thus a synchrotron was used to examine them. “It was found that the astrolabe made in Lahore had a different metal composition and contained much more zinc than it was assumed to be possible,” he said. “This is part of Pakistan’s heritage and thus more people must know about it.”

Dr Hogendijk, also a professor of history of mathematics, was at the hub of the lecture and he debunked myths regarding astrolabes; for one he insisted that astrolabes were never used for navigation as is widely believed. He criticised the rampant misinformation present on the internet which has misled people into believing this.

Dr Hogendijk said: “There are around 2,000 Islamic astrolabes that still exist. In the golden era of Islam, astrolabes were widely used in society, and their mention is also present in Rumi’s poetry.” He quoted examples from Rumi’s poetry where astrolabes are referenced.

“When we try to access information on astrolabes, we find mostly European sources, even though there is a rich Islamic tradition with regards to astrolabes. This is why we conduct these workshops.”

About the interest Dutch people have in mediaeval Islamic science, Dr Hogendijk said that it is also because “we have in our country one of the best collections of Islamic manuscripts in the world. Since 1630 CE the University Library in Leiden preserves one of the largest collections of mediaeval Arabic manuscripts in the world.”

Dr Hogendijk’s team included Willem Frederik de Graaf and Tom Jon Ester Reijngoudt, who will help him conduct a workshop on the standard astrolabe.

“Each participant in the workshop will receive a model of an astrolabe which is based on the astrolabe by al-Khujandi, which is now in Doha, Qatar. All participants will then solve exercises by themselves.”

Published in Dawn, March 7th, 2018

 

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Astrolabe

Not to be confused with cosmolabe.
For other pages with a similar name, see Astrolabe (disambiguation).
For a list of ships, see French ship Astrolabe.

A modern astrolabe made in Tabriz, Iran in 2013.



An astrolabe made of gilded brass from about 1540–70.

The Canterbury Astrolabe Quadrant, England, 1388.

A 16th-century astrolabe showing a tulip rete and rule.
An astrolabe (Greek: ἀστρολάβος astrolabos; Arabic: ٱلأَسْطُرلاب‎ al-Asturlāb) is an elaborate inclinometer, historically used by astronomers and navigators to measure the inclined position in the sky of a celestial body, day or night. The word astrolabe means "the one that catches the heavenly bodies."[1] It can thus be used to identify stars or planets, to determine local latitude given local time (and vice versa), to survey, or to triangulate. It was used in classical antiquity, the Islamic Golden Age,[2] the European Middle Ages, and the Renaissance for all these purposes.

The astrolabe's importance not only comes from the early development of astronomy,[1] but is also effective for determining latitude on land or calm seas. Although it is less reliable on the heaving deck of a ship in rough seas, the mariner's astrolabe was developed to solve that problem.




EtymologyEdit
OED gives the translation "star-taker" for the English word "astrolabe" and traces it through medieval Latin to the Greek word astrolabos,[3][4] from astron "star" and lambanein "to take".[5] In the medieval Islamic world the Arabic word "al-Asturlāb" (i.e. astrolabe) was given various etymologies. In Arabic texts, the word is translated as "ākhdhu al-Nujuum" (Arabic: آخِذُ ٱلنُّجُومْ‎, lit. "star-taker"), a direct translation of the Greek word.[6]

Al-Biruni quotes and criticizes medieval scientist Hamzah al-Isfahani who stated:[6] "asturlab is an arabization of this Persian phrase" (sitara yab, meaning "taker of the stars").[7] In medieval Islamic sources, there is also a folk etymology of the word as "lines of lab", where "Lab" refers to a certain son of Idris (Enoch). This etymology is mentioned by a 10th-century scientist named al-Qummi but rejected by al-Khwarizmi.[8]


HistoryEdit
Ancient worldEdit
An early astrolabe was invented in the Hellenistic civilization by Apollonius of Perga between 220 and 150 BC, often attributed to Hipparchus. The astrolabe was a marriage of the planisphere and dioptra, effectively an analog calculator capable of working out several different kinds of problems in spherical astronomy. Theon of Alexandria (c. 335 – c. 405) wrote a detailed treatise on the astrolabe, and Lewis[9] argues that Ptolemy used an astrolabe to make the astronomical observations recorded in the Tetrabiblos. Some historians attribute the astrolabe's invention to Hypatia, the daughter of Theon of Alexandria,[10] noting that her student Synesius credits her for the invention in his letters.[11]

Astrolabes continued in use in the Greek-speaking world throughout the Byzantine period. About 550 AD, Christian philosopher John Philoponus wrote a treatise on the astrolabe in Greek, which is the earliest extant treatise on the instrument.[a]Mesopotamian bishop Severus Sebokht also wrote a treatise on the astrolabe in the Syriac language in the mid-7th century.https://en.m.wikipedia.org/wiki/Astrolabe#cite_note-13 Sebokht refers to the astrolabe as being made of brass in the introduction of his treatise, indicating that metal astrolabes were known in the Christian East well before they were developed in the Islamic world or in the Latin West.[12]

Medieval eraEdit

A treatise explaining the importance of the astrolabe by Nasir al-Din al-Tusi, Persian scientist

Astrolabe of Jean Fusoris (fr), made in Paris, 1400

An 18th-century Persian astrolabe

Disassembled 18th-century astrolabe

Exploded view of an astrolabe

Animation showing how celestial and geographic coordinates are mapped on an astrolabe's tympan through a stereographic projection. Hypothetical tympan (40 degrees North Latitude) of a 16th-century European planispheric astrolabe.
Astrolabes were further developed in the medieval Islamic world, where Muslim astronomers introduced angular scales to the design,[13] adding circles indicating azimuths on the horizon.[14] It was widely used throughout the Muslim world, chiefly as an aid to navigation and as a way of finding the Qibla, the direction of Mecca. Eighth-century mathematicianMuhammad al-Fazari is the first person credited with building the astrolabe in the Islamic world.[15]

The mathematical background was established by Muslim astronomer Albatenius in his treatise Kitab az-Zij (c. 920 AD), which was translated into Latin by Plato Tiburtinus (De Motu Stellarum). The earliest surviving astrolabe is dated AH 315 (927–28 AD).[16]In the Islamic world, astrolabes were used to find the times of sunrise and the rising of fixed stars, to help schedule morning prayers (salat). In the 10th century, al-Sufi first described over 1,000 different uses of an astrolabe, in areas as diverse as astronomy, astrology, navigation, surveying, timekeeping, prayer, Salat, Qibla, etc.[17][18]


Astrolabium Masha'Allah Public Library Bruges (nl) Ms. 522
The spherical astrolabe was a variation of both the astrolabe and the armillary sphere, invented during the Middle Ages by astronomers and inventors in the Islamic world.[c] The earliest description of the spherical astrolabe dates back to Al-Nayrizi (fl. 892–902). In the 12th century, Sharaf al-Dīn al-Tūsīinvented the linear astrolabe, sometimes called the "staff of al-Tusi", which was "a simple wooden rod with graduated markings but without sights. It was furnished with a plumb line and a double chord for making angular measurements and bore a perforated pointer".[19] The geared mechanical astrolabe was invented by Abi Bakr of Isfahan in 1235.[20]

Herman Contractus, the abbot of Reichman Abbey, examined the use of the astrolabe in Mensura Astrolaiduring the 11th century.[21] Peter of Maricourt wrote a treatise on the construction and use of a universal astrolabe in the last half of the 13th century entitled Nova compositio astrolabii particularis. Universal astrolabes can be found at the History of Science Museum in Oxford.

English author Geoffrey Chaucer (c. 1343–1400) compiled A Treatise on the Astrolabe for his son, mainly based on Messahalla. The same source was translated by French astronomer and astrologer Pélerin de Prusse and others. The first printed book on the astrolabe was Composition and Use of Astrolabe by Christian of Prachatice, also using Messahalla, but relatively original.

In 1370, the first Indian treatise on the astrolabe was written by the Jain astronomer Mahendra Suri.[22]

A simplified astrolabe, known as a balesilha, was used by sailors to get an accurate reading of latitude while out to sea. The use of the balesilha was promoted by Prince Henry (1394-1460) while out navigating for Portugal.[23]

The first known metal astrolabe in Western Europe is the Destombes astrolabe made from brass in tenth-century Spain.[24][25] Metal astrolabes avoided the warping that large wooden ones were prone to, allowing the construction of larger and therefore more accurate instruments. Metal astrolabes were heavier than wooden instruments of the same size, making it difficult to use them in navigation.[26]

The astrolabe was almost certainly first brought north of the Pyrenees by Gerbert of Aurillac (future Pope Sylvester II), where it was integrated into the quadrivium at the school in Reims, France sometime before the turn of the 11th century.[27] In the 15th century, French instrument maker Jean Fusoris (c. 1365–1436) also started remaking and selling astrolabes in his shop in Paris, along with portable sundials and other popular scientific devices of the day. Thirteen of his astrolabes survive to this day.[28]One more special example of craftsmanship in early 15th-century Europe is the astrolabe designed by Antonius de Pacento and made by Dominicus de Lanzano, dated 1420.[29]

In the 16th century, Johannes Stöffler published Elucidatio fabricae ususque astrolabii, a manual of the construction and use of the astrolabe. Four identical 16th-century astrolabes made by Georg Hartmannprovide some of the earliest evidence for batch production by division of labor.

Astrolabes and clocksEdit
Mechanical astronomical clocks were initially influenced by the astrolabe; they could be seen in many ways as clockwork astrolabes designed to produce a continual display of the current position of the sun, stars, and planets. For example, Richard of Wallingford's clock (c. 1330) consisted essentially of a star map rotating behind a fixed rete, similar to that of an astrolabe.[30]

Many astronomical clocks use an astrolabe-style display, such as the famous clock at Prague, adopting a stereographic projection (see below) of the ecliptic plane. In recent times, astrolabe watches have become popular. For example, Swiss watchmaker Dr. Ludwig Oechslin designed and built an astrolabe wristwatch in conjunction with Ulysse Nardin in 1985. Dutch watchmaker Christaan van der Klauuw also manufactures astrolabe watches today.