Guitarmasterx7 said:
ghosts and all proof thereof are created out of a figment of imagination. People like your friend will probably "witness" a ghost at least once in their life and use that to justify their belief. There was a test done where they took two groups of people, and put them in an abandoned movie theatre for three hours. They told group A they where thinking of things they could do to redesign it and make it worth going to again, and they told group B that there was some supposed curse on the theater or some shit and that it was said to be haunted and it caused the owner to shut the theater down. Group B reported hearing ghostly noises and all these unexplainable "supernatural" phenomenons. Group A reported absolutely nothing.
That's hardly definitive. That is, in fact,
expected. I don't think anyone in the world was surprised by those results. A far better test would be to take multiple (at least 3 in my opinion) groups to a theater that actually
is haunted (reputedly), and tell them
all that they were simply being asked for renovation advice, or some other innocuous explanation.
If the people are preconditioned to believe that the place is perfectly normal, but
still hear noises or other "supernatural" phenomenon, then that would be much better proof ghosts existing. If they don't, then they don't exist. Though it would be ideal to repeat the experiment at multiple sites, because even if ghosts
do exist, many, many sites (I'm going to randomly say 90%) are false, people just leading each other on.