Ghosthunter and author John Kachuba talked about some of his investigations, and theories regarding hauntings and spirits. There are a number of possible explanations for ghostly phenomena, and one of them ties in with the theory of parallel universes or alternate worlds, currently considered in quantum physics. It's very possible that what we call ghosts could be the result of these worlds bumping up against each other, creating a momentary crossover that allows us to see into another dimension, he noted. Other manifestations may be related to natural earth energies like ley lines or magnetism.

There are also "residual hauntings" where the impression or memory of some traumatic event lingers. "The emotional content of that...event is left in the form of energy in the environment that under the right conditions...replays itself again and again, until finally at some point it dissipates," he said. Kachuba talked about "corner ghosts," entities that are seen in a flash from the side view, but disappear when looked at head on. One theory posits that ghosts or spirits are visible in the infrared spectrum, and because there's a thin band around the cornea that allows a small amount of view in that range, that may be why people sometimes see these things in their peripheral vision, he suggested.

One interesting case he investigated was that of "Shadow Man" sightings in a basement Art Complex in Ohio (a former Catholic school), in which numerous witnesses described a dark, moving figure. After his visit, the Complex director called Kachuba to tell him of subsequent visitors, a group of nuns who had taught at the school over 20 years ago. One of them said, "By the way, is the shadow still in the basement?" They identified the figure as one of the sisters, who had hung herself in the basement. Kachuba was intrigued that the artists and the nuns who did not know each other, both described the same phenomena, over two decades.

UFOs on History Channel

First hour guest, writer and paranormal expert Lee Speigel commented on a new 2-hour History Channel special, Secret Access: UFOs On The Record, which will air on Thursday night. The show was based on Leslie Kean's book, which explores the 5% of investigated UFO cases that remain unexplained, such as a 1986 sighting by a Japan Airlines pilot. More here.

News segment guests: Cal Orey, Greg Hunter