Doppelgänger

In fiction and folklore, a doppelgänger or doppelganger is a paranormal double of a living person.

It also describes the sensation of having glimpsed oneself in one's own peripheral vision with no chance of the supposed phenomenon having been a reflection.

A doppelgänger is often perceived as a sinister form of bilocation and is regarded by some to be a harbinger of bad luck. In some traditions, a doppelgänger seen by a person's relative or friend portends illness or danger while seeing one's own doppelgänger is said to be an omen of death.

Recent scientific experimentation has duplicated several doppelgänger effects when electrical stimulation was applied to the left temporoparietal junction of a patient's brain.

In contemporary vernacular, the word doppelgänger is often used in a more general sense to identify any person that physically ‒ or perhaps even behaviorally ‒ resembles another person without regard to the word's original paranormal meaning, thus shifting it back to the original German meaning of look-alikes.