A shadow is an area where direct light from a light source cannot reach due to obstruction by an object. It occupies all of the space behind an opaque object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or reverse projection of the object blocking the light. The sun causes many objects to have shadows and at certain times of the day, when the sun is at certain heights, the lengths of shadows change.
An astronomical object casts human-visible shadows when its apparent magnitude is equal or lower than −4. Currently the only astronomical objects able to produce visible shadows on Earth are the sun, the moon and, in the right conditions, the planet Venus.
Read more about Shadow: Variation With Time, Non-point Source, Shadow Propagation Speed, Color of Shadow On Earth, In Photography, Fog Shadows, Other Notes, Mythological Connotations, Heraldry
Other articles related to "shadow, shadows":
... The offices of shadow U.S ... Representative and shadow U.S ... The office originated with the election of the first Shadow Senators in 1796, and the position of Shadow US Representative first appeared in 1956 in the Territory of Alaska ...
... The Turkish shadow theatre, also known as Karagöz ("Black-Eyed") after one of its main characters, is descended from the Oriental Shadow theatre ...
... vehicles, the standard wheelbase Silver Shadow measured 224 inches (5,700 mm), 4,700 lb (2,100 kg) and had a book price of £6,557 in the first year of production ... The Silver Shadow was produced from 1965 to 1976, and the Silver Shadow II from 1977 to 1980 ...
... he unsuccessfully contested the election for the Shadow Cabinet, coming in 36th out of the 49 candidates and winning 55 votes ... He was subsequently appointed to the Labour front bench as a shadow minister in the Foreign Affairs team ... October 2011 he was appointed to the post of Shadow Secretary of State for Education, following the Shadow Cabinet reshuffle ...
... In heraldry, when a charge is supposedly shown in shadow (the appearance is of the charge merely being outlined in a neutral tint rather than being of one or more tinctures different from the field on which it is ... Shadows can be colored by a colored transparent source of the shadow ...
Famous quotes containing the word shadow:
“A perfect beauty of a sunflower! a perfect excellent lovely
sunflower existence! a sweet natural eye to the new hip moon, woke up alive and excited grasping in the sunset shadow sunrise golden monthly breeze!”
—Allen Ginsberg (b. 1926)
“O love, my love! if I no more should see
Thyself, nor on the earth the shadow of thee,
Nor image of thine eyes in any spring,—
How then should sound upon Life’s darkening slope
The ground-whirl of the perished leaves of Hope,
The wind of Death’s imperishable wing?”
—Dante Gabriel Rossetti (1828–1882)
“He [Pompey] stands, the shadow of a great name.”
—Marcus Annaeus Lucan (39–65)