Parts of a Day - Night, Firefly, Nocturnality, Terminator, Twilight, Sunrise, Sunset, Daytime, Night Photography, Noon, Midnight, Daylight, Dawn (Paperback)

Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Pages: 28. Chapters: Night, Firefly, Nocturnality, Terminator, Twilight, Sunrise, Sunset, Daytime, Night photography, Noon, Midnight, Daylight, Dawn, Happy hour, Golden hour, Blue hour, Night market, Night bus service, Crepuscular, Witching hour, Evening, Dusk, Anpao, Afternoon, Magnetic midnight. Excerpt: Twilight is the time between dawn and sunrise or between sunset and dusk, during which sunlight scattering in the upper atmosphere illuminates the lower atmosphere, and the surface of the earth is neither completely lit nor completely dark. The sun itself is not directly visible because it is below the horizon. Owing to the distinctive quality of the ambient light at this time, twilight has long been popular with photographers and painters, who refer to it as the "blue hour," after the French expression l'heure bleue. Twilight is technically defined as the period before sunrise and after sunset during which there is natural light provided by the upper atmosphere, which receives direct sunlight and scatters part of it towards the earth's surface. The collateral adjective for twilight is crepuscular; it is most frequently encountered when applied to certain insects and mammals that are most active during that time. Description of twilight Twilight after sunset in ParbhaniTwilight is defined according to the solar elevation angle, which is the position of the geometric center of the sun relative to the horizon. There are three established and widely accepted subcategories of twilight: civil twilight (brightest), nautical twilight, and astronomical twilight (darkest). (For these definitions, an ideal horizon 90 from the zenith is used.) Under civil twilight circumstances, the horizon is clearly visible, and terrestrial objects are easily perceptible without artificial light.Morning civil twilight (civil dawn) begins when the geometric c...