Interesting-sounding programme on haunted houses tonight

[dlorde]

So where did they get their ghosts and apparitions from before The Age Of Electricity ?

 

[Baby Nemesis]

So where did they get their ghosts and apparitions from before The Age Of Electricity ?

They say some of the magnetic fields are "natural".

 

[EHocking]

So where did they get their ghosts and apparitions from before The Age Of Electricity ?

Magic Lanterns.

See Phantasmagoria.^wiki

 

[Baby Nemesis]

I've found another explanation for some ghost sightings: Infrasound

Several years earlier, Tandy was working late in the "haunted" Warwick laboratory when he saw a gray thing coming for him. "I felt the hairs rise on the back of my neck," he said. "It seemed to be between me and the door, so the only thing I could do was turn and face it." [Does that sound a bit like communicating with one or two of the posters on here? ... No? ... OK then, maybe it doesn't. Much.] But the thing disappeared. However, it reappeared in a different form the next day when Tandy was doing some work on his fencing foil. "The handle was clamped in a vice on a workbench, yet the blade started vibrating like mad," he said. He wondered why the blade vibrated in one part of the room but* not in another. The explanation, he discovered, was that infrasound was coming from an extractor fan. "When we finally switched it off, it was as if a huge weight was lifted," he said. "It makes me think that one of the applications of this ongoing research could be a link between infrasound and sick-building syndrome." When he measured the infrasound in the laboratory, the showing was 18.98 hertz--the exact frequency at which a human eyeball starts resonating. The sound waves made his eyeballs resonate and produced an optical illusion: He saw a figure that didn't exist.

Interesting stuff.

Apparently infrasound can come from quite a few natural sources as well, not just electrical ones. See the Wikipedia entry on it.