apparition

Supernatural appearance in the image of a living or dead person or animal, or an inanimate object. A ghost is specifically the apparition of a deceased human or animal.

In its widest sense, the phenomenon incorporates visions, clairvoyance, hallucinations, and other such supernormal experiences.

The belief in apparitions is ancient and is to be found in some form or other in every society. Explanations and interpretations are numerous and cover a wide range of theories, including illusion, astral projection, and psychometry.

Research organizations There has been much recent investigation of the phenomenon, especially by the Society of Psychical Research, which was founded 1882 (US branch founded 1885, Boston). Other establishments include the Parapsychology Foundation of New York, which was established 1951, and has done much pioneer work in the realm of extrasensory perception (ESP); the Institute of Psychophysical Research, Oxford, founded 1961; and the Foundation for Research on the Nature of Man, founded 1964 (Duke University, North Carolina), which has produced very radical theories on the poltergeist phenomenon. Since World War II, Russia has conducted extensive studies on parapsychology, which includes supernatural phenomena such as apparitions.