While many people claim ghosts are real, there is no hard evidence for their existence. There is, however, a large body of anecdotal evidence that describes encounters with ghosts and spirits.
Some scientists speculate that phenomena such as magnetic fields and temperature changes, in particular damp and cold areas, may lead people to believe they have encountered a ghost.
Many people believe that Albert Einstein's theories actually support the existence of ghosts in that they state that energy is never actually created or destroyed; rather, it transforms. The energy of a dead body, however, is transformed and released in a variety of explainable physical ways.
Despite the lack of hard proof, people from all over the world and virtually all cultures do believe that ghosts exist and some claim to have seen or interacted with them.