Interesting that you picked that up. There are two kinds of minds, the scientific and the believer who runs on faith. I'm a mix of both since I'm a God fearing man plus most if not all significant religions believe in ghosts / spirits.
In my latest book "The Fabric of the Soul" On Kindle, the scientific explanations of ghosts are explained. The gravitational field is such that there is an image of us in radiated dot-waves. In addition that is a higher image of us in ultra high light speed photonic energy. This is spiritual energy. When we die this image of us is a ghost or spiritual entity. It will see us but it will see the light of God at the center of the Earth. Normally our soul or ghost will move toward the light to become part of God's energy. Some of us will not see the light and will be cast into the outer darkness. Thus they will leave the Earth's gravitational field and be lost in space. Then they will quickly perish. Some of us who are destined to become part of the local Kingdom of Heaven may resist moving toward God and remain as ghosts or spiritual entities for awhile. In any event everything has a spiritual dimension and can remain free of God or the outer darkness for awhile.You need God's radiation to survive long term. Some ghosts can maintain themselves within a volcano for awhile. The concept of hell fire is wrong since fire produces extra spiritual energy which is needed to survive. Ghosts do not feel the heat but only the warmth of the spiritual radiation.