Tandy’s first guess was that an anesthetic bottle was leaking, and the fumes were causing the cleaner to hallucinate. Everything checked out fine, so he put it down to, as they say at Warwick Castle, a nervous disposition. The next night, though, working late again, Tandy began to feel strange himself. “I felt my hackles go up.”[39] Again, Tandy suspected fumes. He wondered whether someone had left the stopper off the tricoethylene, which his lab mates used for degreasing machine parts. “That wasn’t it, so I thought, Right. I’ll go have a coffee. I came back in. Same thing.” Again with the hackles. “Then I see this gray object around to the side of me. I would say I was projecting a form onto it, trying to make sense of it, but… it had arms and legs at one point. I turned to look at it and it disappeared. The following day I was going in for a fencing competition—”
“Really?”
“Yeah. So anyway, I’d brought my foil in to fix it. I’d put it in the vise and gone over to my desk, and when I turned back, it was moving on its own. Aaaaaa!” I don’t know how to spell the sound Tandy just made. Imagine an opera singer being garroted at the crescendo of an aria. What he means is, it scared the bejeebers out of him. But only for a moment. “I thought, No, no, come on, there has to be a reason for this.”
Ever the engineer, Tandy set out to find the answer. Had the cleaner come in at this juncture, she would not have been reassured about the safety and normalcy of her place of employment. She would have found Vic Tandy on his hands and knees, sliding a fencing weapon slowly across the linoleum. Every few seconds, he’d stop to jot notes on a pad. By watching for where the blade started to vibrate, he could measure the peaks and troughs of the sound wave he suspected might be his ghost and pinpoint the frequency. (When sound pressure waves hit an object, they cause it to vibrate; if the object is an eardrum, the brain reads these vibrations—a certain range of them, anyway—as sound.)
Tandy’s suspicion was that his ghost was the product of inaudible, low-frequency sound waves—infrasound. Indeed, when he set up his measuring equipment in the lab, he found a sharp peak at nineteen hertz. (Infrasound runs from zero to twenty hertz.) If the source is powerful enough, infrasound can, in addition to setting fencing foils aquiver, engender all manner of mysterious-seeming phenomena. Unbeknownst to audience members, infrasound pulses were sent out at certain points during a piano concert at Liverpool’s Metropolitan Cathedral in September 2002. It was at these points that concertgoers reported—via a questionnaire distributed before the concert began—a variety of physical effects, such as tingling on the back of the neck and “strange feelings in the stomach,” as well as an intensification of their emotions.
Infrasound has also been reported to cause vision irregularities: sometimes blurring, sometimes a vibrating visual field. The eyeball, Tandy explains to me, has a resonant frequency of nineteen hertz. Meaning that in the presence of a standing nineteen-hertz infrasound wave, your eye would start to vibrate along with the waves. This is similar to the effect of a powerful operatic voice on a wineglass: When the voice—created by pressure waves from vibrating vocal cords—hits on the resonant frequency of glass, the glass in turn begins to vibrate and may, if the note is held, even shatter.
Tandy explains that peripheral vision is extremely sensitive to movement, a helpful adaptation for dealing with predators that sneak up on you from the side. “If your eyeball is dithering, the sides—the peripheral vision—are where it’s going to register.” The blurry gray ghost in the edge of the cleaner’s vision could have resulted from just such a dither.
Next Tandy went off in pursuit of the source. He found it in the basement. “The maintenance people had replaced an exhaust fan,” he says. “I think they made it themselves. Huge, huge amount of unneeded energy. I mean, it was quite surprising the fan wasn’t standing still and the building going ’round it.”
All of this got Vic Tandy thinking. What if he were to visit some of England’s purportedly haunted spots and take some sound readings? What if the feelings people report when they think they’ve been in the presence of spirits are in fact the effects of infrasound? The more he thought about it, the more sense it made. Old buildings have thicker, more solid walls, which resonate better. And old abandoned castles and cellars often have no furniture or curtains to absorb sound waves. Infrasound would also help explain why reports of ghosts are often localized—why people sense a presence in just one part of a room. Infrasound tends to “pool”—it registers strongly in the spots where the peaks and troughs of sound waves overlap, and disappears where peak and trough cancel each other out. Tandy even has an infrasound-based explanation for why people sometimes feel cold in the presence of what they take to be a ghost. Infrasound can activate the fight-or-flight response, and part of that response is a curtailing of blood to the extremities. Hence the chills (and the racing heart and thus, it stands to reason, the unease).
Tandy knew from local hearsay that the Coventry Tourist Information Centre was a promising place to start. Though they spent their days pushing “Warwick Ghosts—Alive!” the staff was convinced that something ghostly was going on directly below them. Excavations for the foundation of the tourism office had uncovered a fourteenth-century cellar that the tourism staff now uses for storage. In a Journal of the Society for Psychical Research article on the project, Tandy quotes a Coventry tour guide who had accompanied a Canadian journalist to the cellar: “The gentleman was frozen to the spot and the colour drained from his face.”
Tandy went in to take some measurements. I asked him if he felt anything. He said only once—a brief, sudden sense of something “washing over him.” His wife Lynne, who has accompanied him on several visits, volunteers that she felt nothing. “Though I do sometimes feel a strange oppressiveness in the Sainsbury’s dairy area.” I volunteer that, owing to her accent or my fourth-grade maturity level, this came through as: “the Sainsbury’s derriere.” Lynne’s look suggests that the humor isn’t registering. It suggests she might think I’m something of a dairy area myself.
Tandy did not find infrasonic frequencies in the cellar, but he did find them just outside it. The eighteen-hertz entity lives in the hallway that opens into the cellar (though its source remains unknown). Tandy figures people were blaming the cellar because of how it looked. As he puts it, “You don’t get ghosts in well-lit white-walled concrete corridors. You get ghosts in vaulted fourteenth-century cellars.”
According to a Dortmund University nonlethal weapons expert named Jürgen Altmann, infrasound can, in a small percentage of the population, set off vibrations in the liquid inside the cochlea. These vibrations—which happen because of an uncommon anatomical weakness in the bone structure of the ear—could create a sudden, inexplicable feeling of motion, which could lead to the unease that some of the cellar visitors reported.
The majority of visitors, however, feel nothing. Tandy gave a talk earlier in the week and took the entire crowd over to the cellar afterward. Despite their having been primed to feel something, only one out of the group of fifty did. The same meager odds appear to apply for industrial infrasound. NASA astronauts on liftoffs are exposed to massive infrasound vibrations, to no apparent deleterious effect. (It was, in fact, in a NASA contractor’s report that Tandy read about the vibrating eyeball effect. NASA had experimentally exposed volunteers to infrasound back in the sixties, to be sure, as Tandy puts it, “that they didn’t deliver jam to the moon.”) It is thought that only a small portion of the population is sensitive to infrasound. Tandy believes that when the odd office worker starts talking about Sick Building Syndrome, infrasound may in fact be the culprit. There are said to be people so debilitatingly sensitive to infrasound that even the very low levels of it that come off the ocean can make them nauseous. At any rate, it’s not the sort of situation where you can set up a speaker and inflict mental and physical discomfort on demand.
39
Tandy is speaking metaphorically. Humans don’t have erectile hair or feathers on the backs of their necks. Looking into this, I learned that hackle feathers are popular for fly-tying. It took a while to figure this out, because the Google entries would say things like, “This is a Metz Grizzly Hen Neck hackle. It could be used for a Matuka-style streamer wing, however, and it’s a top choice for streamer collars, as it’s soft and pulses when the barbules are ‘unzipped.’”