Semiotic Phantom (n)

related noun: semiotic haunting.

The Semiotic Phantom was invented by William Gibson.  According to William Gibson, semiotic phantoms  are “bits of deep cultural imagery that have split off and taken a life of their own, like the Jules Verne airships that those old Kansas farmers were always seeing…Semiotic ghosts Fragments of the Mass Dream.” From “The Gernsback Continuum.”  The invisible presence of a past imagination of the future, or an erased past that, nonetheless, survives as pentimenti.  There’s no such thing as a past, because the past is always present.  A strange variation on the Ghost of Christmas Yet – the haunting of futures that weren’t.
For example: this is a recent semiotic phantom–the recent discovery of Newgrange Henge, which revealed itself as if drafted by some giant architect with invisible ink directly onto the landscape—a reminder that the past never passes.

A hallucinatory experience (or perhaps entirely real?) resulting from studying microhistory too much.  The ruins of previously imagined potential futures, ruins of desire, ghosts of never-realized entelechies.  Often the result of hallucination, drug use, or studying too much history, one finds oneself suddenly swept up in a world that could have been but never was.  The pentimento of intention/desire.

According to Gibson you can be cured of these semiotic hauntings by really bad media: think porn, binging Netflix, Tom Swift novels.

“Hell of a world we live in, huh?” The proprietor [asked as I sat] anxious to….submerge myself in hard evidence of the human near-dystopia we live in. “But it could be worse, huh?”

“That’s right, I said, “or even worse, it could be perfect.”

He watched me as I headed down the street with my little bundle of condensed catastrophe.

Related: entelechy, pentimenti, if-only, future shock, mellagia.