"If it can be written, or thought, it can be filmed..." STANLEY KUBRIC

Shadow

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Shadows on a pavement
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Shadows on a pavement
  • A shadow is the area on a 3-D object that receives no illumination from the primary light source. The shadow is always lower in brightness than the true tone of the object. A properly placed shadow will reveal shape and form on an object.

Contents

Features

Shadows from a chandeliershowing umbra and penumbra
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Shadows from a chandelier
showing umbra and penumbra
Shadow in Berlin...
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Shadow in Berlin...

The closer to 90 degrees the angle between an elongated object and the direction of the light it blocks, the bigger its shadow. 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.

For non-point sources of light, the shadow is divided into the umbra and penumbra. 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 colored.

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 shadows or brightens 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 of text inverted
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Shadow of text inverted

Faster than light

It is speculated that a shadow moves faster than the object which casts it. A cross-section of a shadow (a silhouette) is displaced by the motion of an object in front of a point source of light. The further the distance from the object blocking the light, the larger the silhouette and the greater the displacement by motion. An object moving at lightspeed (such as a laser) might cast a silhouette which is displaced at faster than the speed of light. This phenomenon may be related to holography. However, it is thought that this phenomenon obeys general relativity.

Other notes

A shadow cast by the Earth on the Moon is a lunar eclipse. Conversely, a shadow cast by the Moon on the Earth is a solar eclipse.

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.

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).

The term shadow is also used with regard to other things than light, for example rain: a rain shadow is a dry area, which, with respect to the prevailing wind direction, is beyond a mountain range; it is dry because air masses lose part of their water when they move over these mountains.

Furthermore, it is possible to see shadows by moonlight on clear evenings.

Fiction

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  • In Peter Pan the main character loses his shadow: it snaps off when he leaps out of the window, which is slammed closed behind him. It is put in a drawer and later sewed back on by Wendy.
  • In many fantasy games, shadow is widely referred to as the source of dark arts and black magic. Shadows, mainly in this genre, are said to be the departed souls of people that have had their lives tragically cut short or did not receive acceptance in heaven or hell.
  • In the Chronicles of Amber series of novels (also by Zelazny), Shadow is a metaphysical substance in which all possible universes can exist, if a person who meets certain criteria desires to go to them.
  • In ninja fiction, ninjas are supposedly able to become "one with the shadows" or, "a living shadow." In the manga Naruto, a special shuriken is named "The Windmill of Shadows." In the series Naruto, Nara Shikamaru possesses the technique to control a person's body movements once his shadow touches theirs. He can also manipulate his shadow into several shapes. This is known as Kagemane no Jutsu (The Art of Me-and-My-Shadow). Also, in the game Samurai Warriors, Hanzo Hattori Can reach a level named the shadow.
  • In Slayers and an episode of Inuyasha, throwing a knife onto the ground in a person's shadow would paralyze them, aptly named "Shadow Bind".
  • In Kingdom Hearts the basic and most common heartless enemy are called Shadows.
  • In Dungeons & Dragons, there is a class named "Shadowdancer" that supposedly draws on shadow powers to induce abnormal effects in combat.
  • In many cartoons that are very loosely based in reality (such as Loony Tunes) or comedy movies with roughly equal disregard for reality (such as Dracula: Dead and Loving It), it is possible for shadows to act completely independently of the person who is supposed to be casting them. This often ranges from a person's shadow fighting with them or going the wrong way to shadow puppets running amok (usually a shadow puppet in the shape of a monster). It is also possible for people to make photorealistic shadow puppets (such as the Eiffel Tower or a horse galloping through a desert or jumping over recognizable obstacles) in these mediums.
  • In The Seventh Tower book series, creatures from a spirit-world are bound to people and become free-willed shadows.

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. Supposedly only a limited number of specific charges can be so depicted.

See also

Template:Commons

es:Sombra fr:Ombre (lumière) id:Bayang-bayang he:צל nl:Schaduw ja:影 nn:Skugge pl:Cień fizyczny pt:Sombra ru:Тень simple:Shadow

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