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A rare Arabic
manuscript from AD 902, a translation of a Greek manuscript on the code of
research of burning mirrors, has been located in the Tareq Rajab Museum,
a researcher said on Tuesday.
Professor Roshdi
Rashid revealed that he recently discovered the manuscript during a
lecture titled "Burning Mirrors: An example of the Application of
Greek and Arabic Geometry" in a fifth cultural season organised by
the Dar AI Athar AI Islamiyyah.
Director of
Research at the University of Paris, Rashid is also the recipient of a
KFAS award for Islamic Sciences.
The
manuscript outlined an important application of geometry that developed by
the 10th century to a new concept of anaclastics or dioptrics, Rashid
said.
"There
is none so old," said Rashid, although an identical copy to the
manuscript in Kuwait, that was made in Cairo in the 14th century, exists
in India.
The manuscript is
of a reference in Greek to burning mirrors, one of many in a library built
up by Kings
and Caliphs during the 9th century, who had discovered how to set light to objects 30 cubits
away and wanted to meet a challenge to set light to objects 100 cubits
away.
Rashid discovered
the manuscript while on a quest to delve "as deeply as possible into
history, in order to find the
earliest applications of geometry and to understand their
significance."
"Burning
mirrors became an important subject of research in Alexandria during
the third and the second
centuries B.C. (Conon of Alexandria, Archimedes, Dosithcus, Apollonitis),"
Rashed said.
The manuscript is
an Arabic translation of Greek works, since lost, that established the
fruit of two projects he researched; the theory of conic sections and
catoptrics (on which Archimedes wrote a book between 125 and 180).
Archimedes
established two great traditions of optics, Rashid said. Firstly he
researched burning, a branch of mathematics at that time, and secondly he
studied parabola and hyperbola connected to optics.
"With the
linkage of the two domains, it was possible to answer the question of
burning at a certain distance by reflection of sun rays," Rashed
said.
Apollonius
continued to write on conic sections after the death of Archimedes in 212,
Rashid said.
Having
established this invention confirmed a legend that burning mirrors were
used to set fire to a Roman fleet who seiged Syracuse in the 6th century.
At the beginning
of the ninth century, scientists who were not content with their Greek and
Byzantine predecessors looked anew at the problem of convergence of
reflected rays to a single point and the distance of this point.
Rashed said the
philosopher and mathematician, Abu Ishaq Yusuf AI Kindi, is one of the
most important figures in this field.
"The work of
AI Kindi was pursued by many others, and now, thanks to the new materials
accumulated, a surprisingly rich intellectual and scientific context is
beginning to take shape," Rashed said.
One century later
scientists extended their focus on burning mirrors to burning instruments
as a whole: "geometric investigations of the focal points associated
with near and far sources, not only of elliptic and parabolic
mirrors."
Rashed
said in 985 this led to a totally new and unsuspected development of
planoconvexe and equiconvexe lenses. A new chapter devoted to anaclastics
or diopties was then born, he said.
"This
chapter, with the linkage of two domains optics and especially
theory of refraction, and theory of conics was developed by al 'Ala' ibn
Sahl and his successors: Ibn AlHaytham in particular, Rashid said.
The Greek legacy
on Burning Mirrors was twice transformed during the 9th to 10th centuries,
from the works of AI Kinch on elliptic and parabolic mirrors to the
concepts by Ibn Sahl on anaclastics or dioptrics.
Ibn Sahl advanced
the study of lenses thanks to the
use of conics, Rashid said.
Given a beam of
light rays from a given source ibn Sahl experimented to determine by which
combination of refractive surfaces he could
transform it into a
pencil of rays under certain conditions, for example if the rays be
parallel or converge toward a point.
The lectures have
been organised by the Ministry of Information Islamic Art Museum. They are held at the Abdullah
Al
Salem School Theatre, the AI Maidan Centre, behind Shaab Leisure Park in
Maidan Hawalli every Monday evening.
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