Updated: Dec 30, 2021
The Trace Hypothesis, perhaps by far the most well-known of the pseudoscientific explanations for apparitional experiences, owes much of its popularity among modern amateur ghost hunters and indeed its common nomenclature among those groups to The Stone Tape. This 1972 BBC Christmas ghost story by Quatermass creator Nigel Kneale discarded a long history of highly speculative thought and created a curious hypothesis uniquely its own.
The so-called Stone Tape Theory is often erroneously attributed to archaeologist turned parapsychologist T.C. Lethbridge, who developed an interest in ghosts after an inexplicably top-hatted encounter at Trinity College, Cambridge. His actual contention, that apparitions are impressions or memories recorded in natural energy fields and re-experienced by those with low pyche-fields of their own, owes much to the ideas of H.H. Price.
Welsh philosopher H.H. Price specialised in the philosophy of perception and speculated that the afterlife was a realm of mental images situated in the psychic ether between the mental and material planes. Such mental imagery could, according to Price, become detached from its originating mind and attached instead to a place or object where sensitive minds would later be able to experience it as hallucination.
This place-memory hypothesis originates with early psychical research pioneers such as Eleanor Sidgwick, who suggested that apparitional hallucinations were the result of something in the actual building itself; Edmund Gurney, who elaborated that these images could, by unknown means, be impressed on the environment for later replay by those with sensitive minds; and other predecessor of Price at the Society of Psychical Research.
Another antecedent can be found in the fascinating natural theology of mathematician and father of computing Charles Babbage, which included the curious claim that, due to the transfer of motion between particles, the sound waves produced by human speech leave a permanent, albeit inaudible, impression on the atmosphere. This impression, he concluded, turned the air itself into a vast library of all that has ever been said.
The now dominant form of this long history of speculation, that emotional energy can be imprinted upon stone, preferably quartz or limestone, and re-experienced by sensitive minds, is, however, almost entirely the invention of the Sci-Fi writer Nigel Kneale. And, as entertaining as it may be, there is no known mechanism that would allow the process to take place, and in this bastardized form no tradition of philosophical thought in support of it.