Land, Edwin

Figure 2.20 The transformation performed by the color opponency mechanism may be a simple rotation of the coordinate system. In this case, the mechanism for color constancy may operate on the rotated coordinates. (Reprinted from Vision Res., Vol. 26, No. 1, Edwin H. Land, Recent advances in retinex theory, pp. 7-21, Copyright 1986, with permission from Elsevier.)...

Polaroid , the material of which most polarizers are currently made, is composed of a clear sheet of polyvinyl alcohol. It is stretched in one direction to align the molecules and dyed with iodine molecules that align themselves along the polymer molecules. This polaroid film will transmit light only in a direction perpendicular to that in which the film was stretched. Polaroid was first made in 1928 by Edwin Herbert Land from quinine sulfate periodide. " The initial idea for this came from the observation of William Bird Herapath that when iodine is dropped in the urine of a dog that has been fed on quinine, shiny green crystals (now referred to as herapathite) with strongly polarizing properties are formed. 

However, Edwin A. Abbott s fanciful two-dimensional world described in Flat-land is no more the world of molecules and chemical reactions than it was the world around us. While molecular topology is adequate to explain many aspects of chemical behavior, the evolution of quantitative models for structure-activity relations is unavoidably moving into the realm of three-dimensional (3D) structure. Modern computing enables rapid manipulation of 3D chemical structures, and it is leading the way for a proliferation of models for the quantification of electronic structure. For complex behavior of chemicals including physicochemical properties, reactivity, and biological activity, 3D structures are essential. 

Rowland Institute at Harvard, 100 Edwin H. Land Blvd., Cambridge, MA 02142, USA... 

FLATLAND takes its name from the book FT.ATLAND A Romance of Many Dimensions written by Edwin A. Abbott in 1884. In his book, Abbott depicts his world through the eyes of 19th century Victorian satire, imagining a land of two dimensions. Likewise, the depiction of our three-dimensional world of chemistry in the two dimensions of the printed page is the aim of the FLATLAID system, developed by the author for use on a VAX computer operating under the VliS environment. 

Instant photography (Edwin Herbert Land) Land develops the simple process to make sheets of polarizing material. He perfects the Polaroid camera in 1972. 

The first programmable computer, the Zl, is developed by Konrad Zuse Sunglasses become polarized by Ray Ban using a Polaroid filter developed by Edwin H. Land Polyst5frene is developed... 

Seventy-five years later, in 1938, Edwin Land invented the sheet polarizer, called H-film, that has been industrialized as the Polaroid filter. Attached to the windows of ships and trains these filters can act as blinds, and they also have been widely used in polarized sunglasses. There was a time when Polaroid filters were considered as antiglare systems for large-scale windshield and headlights of cars [1]. 

Research on innovative alternatives to the polarizer using iodine that has been industrialized by Edwin Land can be seen [14], but has not reached the range of practical use yet Presentation of academic research results delving further into Land s inventiOTi do not exist. Fortunately, the ciystal structure of herapathite has been elucidated by Bart Kahr et al. in 2009 [15] and the anisotropic hght absorption of the iodine complex can now be explained theoretically, 157 years after the artificial ciystal had been discovered by William Herapath. 

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