Shadow is a region where light cannot reach because of obstruction by an object. Thus, a shadow basically refers to obscurity of light. The cross-sectional representation of a shadow consists of a two- dimensional silhouette or a reverse projection of the object, thereby leading to obstruction of light. Shadow is also used to indicate ghosts, spirits or phantoms, several times. Shadow is a faint or unclear representation or view. Shadow often provides shade. Shadow is used to indicate a trivial, small degree of something. Astronomical objects such as earth, sun and moon cast human visible shadows. Ezra Cornell had once remarked, “As for the Pope, I am too old to be frightened by his shadow, and am quite sure his shadow or Substance will do less harm to the liberties of my country than will a party, who seek to acquire political power by exciting religious bigotry in the minds of their duped followers.”
