Shadow


 * shadow is the area between object and light source. In history, many of its forms are viewed as supernatural beings, unattended shadows, in some cultural even be viewed as ghost or shade. As a result, we discuss various type of shadows here.
 * Sciophobia, or sciaphobia, is the disease afraid of shadows.


 * In history, shadows have status as follow:
 * soul:shadow used to be viewed as a person's soul; as a result, vampire doesn't have shadow or mirror image for its lack of soul, and we know the story that someone sell his soul to gain wealth and lose his shadow.
 * In china, shadow are divided into two parts, so-called "shadow(影子)" and "罔兩," similar to the Umbra(本影) and Penumbra(半影) in the division of science: physics. In an ancient Taoist(道家) book Zhuangzi(莊子) of Zhuangzi, there is a Fable in which 罔兩 talks to the shadow(影子).

Spetial form of shadows

 * shadow with length:
 * shadow with dimension:The term fog shadow depict a kind of shadow with dimension,it is a natural scene;however, it is odd to human because we are not used to see shadows in 3 dimension.

derivatives of shadows

 * Silhouette:It is a form of art that express something or a scene like a shadow.