Hundred Great Muslims

168 Hundred Great Muslims
views were to some extent shared by Al-Biruni and Avicenna. His book on optics
'Kitab Al Manazir' was translated into Latin by F. Risner and published in Basle
in 1572 A.C. His other work on twilight was translated into Latin and published
in the same year. His optics has immensely influenced the Western scientists,
including the celebrated Roger Bacon and Vitelo.
AI Hazen has written several treatises on physical optics, including one on
light. He thinks that light is a sort of fire which is reflected at the spheric limit
of the atmosphere. In another treatise entitled, 'On Twilight Phenomena', he has
calculated this atmosphere to be about 10 miles in height. Some of his treatises
on physical optics deal with the halo, the rainbow, and with spherical and
parabolic mirrors. He has fully explained the factors which cause a rainbow. He
has also written treatises dealing with shadow and eclipses. All of these invaluable
treatises are of a highly mathematical character. "Most of his works were
products of the last ten years of his life", writes Max Meyerhof, "as was his
fundamental study on the burning glass, in which he created a dioptric far
superior to that of the Greeks. The work exhibits a profound and accurate
conception of the nature of focussing, magnifying, and inversion of the image,
and of the formation of rings and colours by experiments." The Muslimscientists
were always particular in supporting their hypothesis with experiments. So was
the case with Alhazen. During lunar eclipses, Alhazen observed the semi-lunar
image of the Sun on a wall which was opposite to a small hole made in the
window shutters. This was the first record of the 'camera obscura' . Alhazen has
also written commentaries on the optical works of Ptolemy and Euclid and on
the physics and problemata of Aristotle.
His 'Mizanul Hikma' deals with the density of the atmosphere in which he
has established a connection between the height of the atmosphere and its
increasing density. He demonstrated that the weight of body increases in
proportion to the increasing density of the atmosphere. He explains the force
with which bodies will rise out of heavier media, in which these are immersed
and also 'discussed the submergence of floating bodies as ships upon the sea'.
He has discussed the problem regarding the centre of gravity and has
successfully applied it to the investigation of balances and steelyards, explaining
the relations between the centre of gravity and the centre of suspension. He
recognised gravity as a force, a theory which was later on developed by Newton.
He knows correctly the relation between the velocities, spaces and time of falling
bodies, and has very distinct idea of capillary action. "The determination of the
densities of bodies", observes a Western writer, "as given by \ "iazen, approach
very closely to our own; in the case of mercury they are ..a more exact than
some of those of the last century."
His treatise on 'Configuration of the Universe was translated into Latin. A
Hebrew translation of it was made by the Jew Jacob bin Mahir, which was again
translated into Latin by Abraham de Balmes in the latter half of the 15th
century. This book was again translated in Spanish by Abraham de Toledo in
the latter half of the 13th century A.C.