The Science Behind Why People See Ghosts: [skeptic.com]

Imaginary fiends.

A few weeks after my wife passed there was the distinct odor of weed in the mud room. She always smoked, but very little the past few years. It happened two other times, once when I was cleaning out the backpack she always used. The odors lasted only a few seconds. Finally one night when I came home late and walked through the front door it was as if I walked into a cloud of it. I might add that there was none in the house. I finally "got it" I took this as her message that she was all right and not to worry about her. I told her I got it. It never happened again. It was comforting.

Einstein taught us that all matter is a form of energy, so since energy can neither be created nor destroyed, we have always existed and will always exist in some energy form, and quantum physics already tells us different dimensions exist.

I dunno about "ghosts" as most people describe them, but in research done on children ages 2-6 who remember past lives, the accuracy of whose memories were verified by researchers, many of the children reported being ghosts between reincarnations.

The incidents they described happening while in this state were verified as well, so I suppose they do exist.
I've always been visited by loved ones at their moment of death, or simply experienced their deaths with them. I'd start crying and tell my husband what happened, asking him to verify the time. I was always right.
I always hoped I was only imagining, but I never was.

When I visited my ex's home and we camped in the yard for a family reunion, during the night I was visited by his late dad in a vivid dream. We chatted awhile and he told me how he met his wife, what she was wearing and how she looked, and told me he approved of me for a wife for his son.

When I related the story to my ex the next morning, I used the words his "dad" used, and they were the old-fashioned words of his time. My ex verified that's just how it happened and those were the expressions he used.

Ghosts fall into the "made up" category for me. I've never seen any sign of ghosts or ever seen a compelling video about them. I think people give credit to ghosts for things they can't explain. Its also kind of a belief thing i have family that completely believe in them, say they seen things move and go flying. I think their loony

A chemical imbalance or ingested substance in the brain causing hallucinations. The other explanation is certain substances like clay, for instance, can trap light from a moment in time. Then, when the light from a different source refracts the image burned in the material, is run like a projector.

Imagination, or something with a source that can be determined. See Joe Nickell. He has written books about ghost investigations.

There is only one kind of "ghost."

"Because," said Scrooge, "a little thing affects them. A slight disorder of the stomach makes them cheats. You may be an undigested bit of beef, a blot of mustard, a crumb of cheese, a fragment of an underdone potato. There's more of gravy than of grave about you, whatever you are!"

I have never seen a ghost or anything that I thought could be one, even where and when others claimed to see one. I have however observed that certain places cause others to think they see them. One of these is what I would call absurd spaces; place where the architecture of a building makes no sense to the observer. One of these was a duplex that had been converted to a group home for children; upstairs was fine the rebuild had completely remade it into a large home but downstairs was a different story. There were blind corners and hallways that went nowhere. Most of the staff claimed there were ghosts, the nonsensical space made their imaginations go wild.
The other thing I have observed is tha low level infrasound seems to cause some people to see and hear things. The rumble of traffic, earthquakes, distant thunder as well as some animals can generate this type of sound. It does play on peoples brains and it is has been exploited by the military of some nations.
One more thing I have observed can generate ghosts and that is the telling of really good ghost stories. The power of suggestion I guess.

I can't really vote, because I think there is probably a whole host of different explanations, depending on the circumstances of each "sighting". I'd rule out dead folk, though. Probably most cases could be explained in a conventional way if we had enough information about them.

I don’t believe in ghosts per se but the only scenario I could imagine that would explain their potential existence is some sort of dimensional bleed through or maybe time being non linear and maybe there’s some way for timelines to cross over. BUT as a scientist I really need some support or otherwise from theoretical physicists to even begin to believe this. So call out to anyone with the right training or background - is it even within the realms of possibility for dimensions or multiverses to interact? Let’s forget about whether it does happen for a moment - mathematically, is it even possible?