Light refers to visible electromagnetic radiation. The human eye can typically detect radiation (light) in the wavelength range of about 400 to 750 nanometers. Nearby shorter and longer wavelength ranges, although not visible, are commonly called ultraviolet and infrared light. It commonly describes a source of illumination, spiritual or mental illumination; enlightenment, useful information, and a notable person within a specific field or discipline, which gives the term a broader and more practical sense than a single short definition would suggest. Depending on context, it can also point to the manner in which the light strikes a picture; that part of a picture which represents those objects upon which the light is supposed to fall; the more illuminated part of a landscape or other scene; opposed to shade, a point of view, or aspect from which a concept, person or thing is regarded, and a flame or something used to create fire, so the category can cover literal uses, related ideas, and more figurative extensions of the same core meaning. Taken together, these meanings present Light as a flexible theme rather than a narrowly technical label, covering the central idea people usually mean when they use the word while still leaving room for closely related senses that appear in real language.
