Ok, in a diversion from usual light related matters, here's some neat reading about the "History of Light." Of course, history in this sense is relative as light was around long before we measly humans were! This is a really long article, starting at 4.5 Billion BC, think the Big Bang, and moving up to the development of the sulfur lamp in 1994. I actually didn't even know they made a sulfur lamp that's heated by microwaves and can emit a huge amount of light. The major problem with this light is that the microwave unit is rated to last 15,000-20,000 hours and the lap is rated to last upwards of 60,000 hours.
Random Sample Entry:
ALHAZEN (IBN AL HAITAM) - (965 - 1039)
Abu Ali Mohamed ibn al-Hasan Ign al-Haytham (also: ibn al-Haitam) was an Arabian scientist and scholar, also known as 'Alhazan'. He was one of the earliest, to write and describe optical theory. He studied light, the nature of vision, the eye, and solar and lunar eclipses. His early experiments led to a forerunner of the [CAMERA OBSCURA] which he used to prove that light travels in straight lines. He also studied reflection and refraction, and published a book on optics in 1038. Alhazan's work became an historical reference work in the evolution of optics. His treatise on optics was translated into Latin by Witelo (1270) and afterwards published by F. Rismer in 1572 with the title "Opticae Thesauris Alhazeni Libri VII cum ejusdem libro de crepusculis et nubium ascensionibus" Other manuscripts are preserved in the Bodleian Library at Oxford and in the Library of Leiden.
CAMERA OBSCURA - (c 1000)
The development of the modern day camera is based on the early discovery of the camera obscura. Although it is difficult to prove the original inventor, certainly one of the first to describe and use the principles of the camera obscura, was [ALHAZEN], in 1038. Others including Roger [BACON], and Giovanni [PORTA], also are credited with the invention or development of the camera obscura. The principals of the camera obscura were frequently used by early painters and artists, in their studies of architecture, much like a photograph is used today.
The camera obscura at first was simply a small room, completely darkened and light-tight. A small pinhole was made in an outside wall and the brightly illuminated exterior scene would be projected on the opposite wall. No lens was required. The image was inverted, or projected up-side-down. The principal of the camera obscura evolved into a small box, with drawing paper being used to trace the image and by about the year 500, artists began using the device as a drawing aid. Some versions were made with an internal mirror to reverse the image and turn it right side up again. Over the years, the camera obscura became smaller in size and eventually evolved into the modern day camera.
Lots more interesting tidbits can be found at his website.
Link: Bill Williams http://www.mts.net/~william5/history/hol.htm
