NMSAT :: Networked Music & SoundArt Timeline

1011 __ al-Bayt al-Muthlim''' (Dark room) — camera obscura
Abu Ali Al-Hasan Ibn al-Haitham (965-1039)
Comment : The first camera obscura was later built by Persian or Arab scientist Abu Ali Al-Hasan Ibn al-Haitham, born in Basra (965-1039 AD), known in the West as Alhacen or Alhazen, who carried out practical experiments on optics in his Book of Optics (The Book of Optics (Arabic: Kitab al-Manazir‎; Latin: De Aspectibus or Opticae Thesaurus: Alhazeni Arabis) was a seven-volume treatise on optics, physics, mathematics, anatomy and psychology written by the Iraqi Muslim scientist Ibn al-Haytham (in Europe Latinized as Alhacen or Alhazen) in 1011–21, when he was under house arrest in Cairo, Egypt.) In his various experiments, Ibn al-Haytham used the term “al-Bayt al-Muthlim” (Arabic: ), translated in English as "dark room", to describe the camera obscura. While earlier philosophers such as Mozi, Aristotle, Theon of Alexandria and Al-Kindi (Alkindus) described the effects of a single light passing through a pinhole camera, none of them suggested that what is being projected onto the screen is an image of everything on the other side of the aperture. Ibn al-Haytham was the first to demonstrate this with his lamp experiment where several different light sources are arranged across a large area, and he was thus the first scientist to successfully project an image from outdoors onto a screen indoors with a camera obscura. Most of his professional career took place in Cairo, where he was summoned for his first engineering task of regulating the flow of the Nile river. In his experiments, Ibn Al-Haitham used the term “Al-Bayt al-Muthlim, translated in English as dark room. In the experiment he undertook, in order to establish that light travels in time and with speed, he says: "If the hole was covered with a curtain and the curtain was taken off, the light travelling from the hole to the opposite wall will consume time." He reiterated the same experience when he established that light travels in straight lines. A revealing experiment introduced the camera obscura in studies of the half-moon shape of the sun's image during eclipses which he observed on the wall opposite a small hole made in the window shutters. In his famous essay "On the form of the Eclipse" (Maqalah-fi-Surat-al-Kosuf) he commented on his observation "The image of the sun at the time of the eclipse, unless it is total, demonstrates that when its light passes through a narrow, round hole and is cast on a plane opposite to the hole it takes on the form of a moon-sickle. The image of the sun shows this peculiarity only when the hole is very small. When the hole is enlarged, the picture changes”. (Compiled from various sources.)
Urls : http://www.precinemahistory.net/900.htm (last visited )

No comment for this page

Leave a comment