Sirs, The context of this question may seems strange but there is a physical phenomenon at work in my home that I’d like to see if it can be explained. Please, if you don’t believe the story that has given rise to the question, do not disregard the question itself. Several years ago I was playing around with an audio tape recorded in a cemetery. I was trying to record the voices of any spirits that might be there. I met with some success. But the one major problem was that these ghost followed me home an have taken up residence in my home. Over the years I have been able to glean some information about who they are and where they are. From what I’ve been told or have gathered these ghost exist in a place that consists of only them. No other naturally occurring materials. Now there seems to be a inability to make physical contact with anything including one another. Something I noticed. It seems that the plane ( just a word I choose) they exist in can intersect with our world. Even though they seem to have a prefect view of us. When this intersection takes place they can, to a limited extent and in a very small way physically interact with thing in our environment. That sparked a question in my mind. Could their inability to be physical be more a condition of where they are than what they are made of? Put another way; Could a environment dictate whether or not a thing has a tangible physical presence? So, a quick example, a ghost exists in it’s plane and is unable to touch or effect anything in that plane as it exists in a non-solid state as a result of the physical laws that govern that plane but once that ghost manages to cross over to another plane (say, ours) the physical laws change and impact the ghost differently. This spirit then is able to take on a more physically solid state. I guess if I where to put the question in a less paranormal way.... Why would it be that when Item A is in “Place Z” it exists but in a non-solid state but when it moves from “Place Z” to “Place Y” it becomes far more dense?