Tuesday, August 7, 2012

How To See a Ghost

By Stephen J. Gertz

To see the spectres, it is only necessary to look steadily at the dot, or asterisk, which is to be found on each of the plates, for about a quarter of a minute...Then turning the eyes to the ceiling...of a darkened room...the spectre will soon begin to make its appearance - From the Introduction.
There are ghosts that live within us, the phantoms of friends and loved ones no longer in our lives, of relationships and actions that haunt us forever afterward. The past is a ghost that never goes away; it is immortal. It never dies. Time wears a white sheet and often jumps out from within a dark corner, suddenly, says, Boo!, and leaves you shaken with a bad case of the willies.


Then there are the ghosts that haunt us from without, the phantasms that go bump in the night, apparitions that invade the material world. If you're lucky, it's only Caspar the Friendly Ghost. If your luck has run out, you may see a banshee washing the blood-stained clothes of one who is about to die - the person who stares back at you from the mirror.


That class of wraith, author J.H. Brown proves, is an illusion, a trick of the eye.


Spectropia, written in 1864 by Brown in alarm over the popular interest in spiritualism - he called it a "mental epidemic" - was produced for children but Brown aimed to slay the dragon in adults, his goal "the extinction of the superstitious belief that apparitions are actual spirits by showing some of the ways our senses may be deceived...the eye pre-eminently so."


Brown blamed mediums, whom he considered to be charlatans preying on a gullible public and, as an early-day Amazing Randi, set out to debunk spiritualist claims.


To do so he provided ghostly plates that, when attention is concentrated upon each and then focused upon a blank wall a spectral image of the plate will be seen. He demonstrated the (then standard) optical principle of persistence of vision wherein an after-image remains on our retinas for 1/25th of a second, lingering in the visual cortex of the occipital lobe of our brains before it decays and disappears


Spectropia went though a five editions and many issues 1864-1866. An American edition appeared almost immediately after the first U.K. publication. It was translated into Dutch in 1870.  Spectropia was a very popular book.


Persistence of vision was refuted in 1912 by Gestalt psychologist Max Wertheimer, who conclusively demonstrated that what was actually occurring was an optical illusion called the phi phenomenon in which the brain fills in information from a series of individual images that when seen at a certain speed create the sense of constant, uninterrupted flow of motion, i.e. cinema.

The Unjolly Green Giant Ghost.
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Later edition.

BROWN, J.H. Spectropia, or, Surprising spectral illusions: showing ghosts everywhere, and of any colour. London: Griffith and Farran, 1864. First edition. Octavo. 12 text pp., sixteen color plates on 16 leaves.
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