Occult detective fiction Occult detective fiction Occult detective fiction combines the tropes of detective fiction with those of supernatural horror fiction. Unlike the traditional detective, the occult detective is employed in cases involving ghosts, curses, and other supernatural elements. Some occult detectives are portrayed as being themselves psychic or in possession of other paranormal powers. Edgar Allan Poe wrote three stories featuring a detective involved with the occult named C. Auguste Dupin, starting with "The Murders in the Rue Morgue" which was first published in 1841. Fitz James O’Brien’s character Harry Escott is another contender for first occult detective in fiction. A specialist
Dupin indicatrix Dupin indicatrix In differential geometry, the Dupin indicatrix is a method for characterising the local shape of a surface. Draw a plane parallel to the tangent plane and a small distance away from it. Consider the intersection of the surface with this plane. The shape of the intersection is related to the Gaussian curvature. The Dupin indicatrix is the result of the limiting process as the plane approaches the tangent plane. The indicatrix was invented by Charles Dupin. For elliptical points where the Gaussian curvature is positive the intersection will either be empty or form a closed curve. In the