Scrying

Scrying (also called seeing or peeping) is the practice of looking into a translucent ball or other material with the belief that things can be seen, such as spiritual visions, and less often for purposes of divination or fortune-telling. The most common media used are reflective, translucent, or luminescent substances such as crystals, stones, glass, mirrors, water, fire, or smoke. Scrying has been used in many cultures in the belief that it can divine the past, present, or future. The visions that come when one stares into the media are believed by some to come from one's subconscious and imagination, though others believe they come from gods, spirits, devils, or the psychic mind, depending on the culture and practice.

Although scrying is most commonly done with a crystal ball, it may also be performed using any smooth surface, such as a bowl of liquid, a pond, or a crystal.

Like other aspects of divination and parapsychology, scrying is not supported by science as a method of predicting the future. However, a 2010 paper in the journal Perception identified one specific method of reliably reproducing a scrying illusion in a mirror and hypothesized that it "might be caused by low level fluctuations in the stability of edges, shading and outlines affecting the perceived definition of the face, which gets over-interpreted as ‘someone else’ by the face recognition system." The Ganzfeld experiment involves sensory deprivation which might also be seen as comparable with scrying.