Search results
Results From The WOW.Com Content Network
An alternative definition is that the penumbra is the region where some or all of the light source is obscured (i.e., the umbra is a subset of the penumbra). For example, NASA 's Navigation and Ancillary Information Facility defines that a body in the umbra is also within the penumbra.
Earth's shadow (or Earth shadow) is the shadow that Earth itself casts through its atmosphere and into outer space, toward the antisolar point. During the twilight period (both early dusk and late dawn ), the shadow's visible fringe – sometimes called the dark segment or twilight wedge [ 1 ] – appears as a dark and diffuse band just above ...
A shadow is a dark area on a surface where light from a light source is blocked by an object. In contrast, shade occupies the three-dimensional volume behind an object with light in front of it. The cross section of a shadow is a two-dimensional silhouette, or a reverse projection of the object blocking the light.
A seismic shadow zone is an area of the Earth's surface where seismographs cannot detect direct P waves and/or S waves from an earthquake. This is due to liquid layers or structures within the Earth's surface.
The definition of the term was originally derived from its primary scientific meaning, which is "a space of partial illumination (as in an eclipse) between the perfect shadow on all sides and the full light". [10] By analogy, rights that exist in the constitution's penumbra can be found in the "shadows" of other portions of the constitution. [13]
Earth's terminator as seen from space. A terminator or twilight zone is a moving line that divides the daylit side and the dark night side of a planetary body.The terminator is defined as the locus of points on a planet or moon where the line through the center of its parent star is tangent.
Scene with shadow mapping Scene with no shadows. Shadow mapping or shadowing projection is a process by which shadows are added to 3D computer graphics.This concept was introduced by Lance Williams in 1978, in a paper entitled "Casting curved shadows on curved surfaces."
In physics, mirror matter, also called shadow matter or Alice matter, is a hypothetical counterpart to ordinary matter. [1] Overview