A shadow is a region of darkness where light is blocked by an object. Light, or visible light, is Electromagnetic radiation of a Wavelength that is visible to the Human eye (about 400–700 It occupies all of the space behind an opaque object with light in front of it. Space is the extent within which Matter is physically extended and objects and Events have positions relative to one another Opacity is the measure of impenetrability to electromagnetic or other kinds of radiation especially visible Light. The cross section of a shadow is a two-dimensional silhouette, or reverse projection of the object blocking the light. In Geometry, a cross section is the intersection of a body in 2-dimensional space with a line or of a body in 3-dimensional space with a plane etc In mathematics the dimension of a Space is roughly defined as the minimum number of Coordinates needed to specify every point within it A silhouette is a view of some object or scene consisting of the outline and a featureless interior with the silhouette usually being black

Contents 1 Features 2 Non-point 3 Colored shadows 4 Shadow propagation speed 5 Other notes 6 Psychology 7 Mythological connotations 8 Heraldry 9 See also

Features

The closer to 90 degrees the angle between an elongated object and the direction of the light it blocks, the bigger its shadow. A chandelier is a branched decorative ceiling-mounted light fixture with two or more arms bearing lights The Fernsehturm ( German for "television tower" is a Television Tower in the city centre of Berlin, Germany. The smaller the angle between the direction of the light and the surface on which the shadow occurs, the longer the shadow is. If the object is close to the light source, the shadow is large. If the surface is curved there are further distortions.

Non-point

For a non-point source of light, the shadow is divided into the umbra and penumbra. A point source is a single identifiable localized source of something For other uses of the word "umbra" see Umbra (disambiguation. For other uses of the word "umbra" see Umbra (disambiguation. The wider the light source, the more blurred the shadow.

If there are multiple light sources there are multiple shadows, with overlapping parts darker, or a combination of colors. For a person or object touching the surface, like a person standing on the ground, or a pole in the ground, these converge at the point of touch.

Colored shadows

If white light is produced by separate colored light sources, the shadows are coloured.

Illuminate a room with a red light, and the shadows are exclusively gray, or dark. Illuminate the shadows with a white light, and the shadows are green. Where both lights are blocked, or in other words where the shadows intersect, the shadows are gray. Away from the intersection, where the red light is blocked the shadows are green, and where the white light is blocked the shadows are red. In other words, light colors shadow or brighten them, according to the complementary color of the light blocked to cast the shadow. In the case of white and red lights, the complement of white is red; with white and green lights, the complement of white is green.

In the absence of multiple light sources, colored lights illuminate spaces where other lights are not blocked. In the above example, the red shadow cast by blocking white light is not a shadow with the white light off, but it is illuminated in red.

In the absence of white light, colored lights blocked by an opaque surface cast shadows in the colors complementary to the lights blocked. For green light, red shadows, and vice-versa; blue, orange; yellow, purple; intermediate light, intermediate shadows.

Shadow propagation speed

The further the distance from the object blocking the light to the surface of projection, the larger the silhouette (they are considered proportional). Also, if the object is moving, the shadow cast by the object will project an image with dimensions (length) expanding proportionally faster than the object's own length of movement. The increase of size and movement is also true if the distance between the object of interference and the light source are closer. This, however, does not mean the shadow may move faster than light, even when projected at vast distances, such as light years. A light-year or light year (symbol ly) is a unit of Length, equal to just under ten trillion Kilometres As defined by The loss of light, which projects the shadow, will move towards the surface of projection at light speed.

The projected shadow may appear to have moved faster than the speed of light, but there is no actual physical manifestation moving upon the surface. The misconception is that the edge of a shadow "moves" along a wall, when in actuality the increase of a shadow's length is part of a new projection, which will propagate at the speed of light from the object of interference. Since there is no actual communication between points in a shadow (except for reflection or interference of light, at the speed of light), a shadow that projects over a surface of large distances (light years) cannot give information between those distances with the shadow's edge. [1]

Other notes

A shadow cast by the Earth on the Moon is a lunar eclipse. EARTH was a short-lived Japanese vocal trio which released 6 singles and 1 album between 2000 and 2001 An eclipse is an astronomical event that occurs when one Celestial object moves into the shadow of another Conversely, a shadow cast by the Moon on the Earth is a solar eclipse. A solar eclipse occurs when the Moon passes between the Sun and the Earth so that the Sun is wholly or partially obscured

On satellite imagery and aerial photographs, taken vertically, tall buildings can be recognized as such by their long shadows (if the photographs are not taken in the tropics around noon), while these also show more of the shape of these buildings. Satellite imagery consists of photographs of Earth or other planets made by means of Artificial satellites. Aerial photography is the taking of Photographs of the ground from an elevated position

A shadow shows, apart from distortion, the same image as the silhouette when looking at the object from the sun-side, hence the mirror image of the silhouette seen from the other side (see picture). "Mirror Image" is an episode of the Television series The Twilight Zone.

Shadow as a term is often used for any occlusion, not just those with respect to light. For example, a rain shadow is a dry area, which, with respect to the prevailing wind direction, is beyond a mountain range; the range is "blocking" water from crossing the area. For the Australian television series see Rain Shadow (TV series. Wind is the flow of Air or other Gases that compose an Atmosphere (including but not limited to the Earth's) A mountain range is a chain of Mountains bordered by highlands or separated from other mountains by passes or valleys An acoustic shadow can be created by terrain as well that will leave spots that can't easily hear sounds from a distance. An acoustic shadow is an area through which sound waves fail to propagate due to topographical obstructions or disruption of the waves via phenomena such as wind currents

Psychology

The Shadow side in Jungian psychology (Carl Jung), is a part of the unconscious mind consisting of repressed weaknesses, shortcomings, and instincts. In Jungian psychology, the shadow or " shadow aspect " is a part of the Unconscious mind consisting of repressed weaknesses shortcomings Analytical psychology (or Jungian psychology) refers to the school of Psychology originating from the ideas of Swiss psychiatrist Carl Jung, and then advanced Many observers throughout history have argued that there are influences on Consciousness from other parts of the Mind. Psychological repression, or simply repression, is the psychological act of excluding desires and Impulses (wishes Fantasies or feelings

Mythological connotations

An unattended shadow or shade was thought by some cultures to be similar to that of a ghost, a flicker of a life unable to end for some reason. in article whose view you add If its your "private" view it has no place here

It is also believed as an alternative construct that shadows are in fact a representation of God's presence around an object; like a halo. A halo (ἅλως also known as a nimbus, Aureole, glory, or gloriole) is a ring of light that surrounds a person in art Early eastern beliefs also play to this theory. For example, Vishnu (a prominent Hindu god) would appear to help followers by assisting with tasks by lending some of his extra arms to assist the burden of the person. For other meanings see Vishnu (disambiguation. Vishnu ( IAST viṣṇu Devanagari विष्णु (honorific A Hindu ( Devanagari: हिन्दू is an adherent of the philosophies and scriptures of Hinduism, a set of religious, Philosophical

Heraldry

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 placed), it is called umbrated. Heraldry in its most general sense encompasses all matters relating to the duties and responsibilities of officers of arms. In Heraldry, tinctures are the colours used to Emblazon a Coat of arms. Supposedly only a limited number of specific charges can be so depicted.

See also

• Shade
• Shadow play
• Shadow people
• gnomon

Shade is the blocking of Sunlight (in particular direct sunshine by any object and also the Shadow created by that object Shadow play (Chinese 皮影戏 pi ying xi or shadow puppetry is an ancient form of Storytelling and Entertainment using opaque often articulated figures Shadow people (also known as shadow men, shadow folk, or shadow beings) are Supernatural shadow-like creatures of both modern Folklore The gnomon is the part of a Sundial that casts the Shadow. Gnomon (γνώμων is an Ancient Greek word meaning "indicator" "one who

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