c. 1967 Kevan and Geraldine drove down a narrow, curved driveway, each side lined with large oak trees. They circled around to the rear of the property and saw a large barn surrounded by grassy fields. It wasn''t visible from the road, but as Kevan drove toward the back of the house, a large circular above-ground swimming pool popped into view. With no air conditioning and the hot, humid days of late summer approaching, the pool would become a refreshing treat. As Kevan and Geraldine stepped out of the car, they were greeted by a warm August breeze and the sound of chirping birds. A slim, mid-thirties woman with shoulder-length dark hair and a sharp-pointed nose emerged from the house. In a thick Scottish accent, she introduced herself as Pat Hannah, their new neighbour.

Pat lived on the other side of the duplex with her husband, Bill. Even though my parents were married in April, they had been living apart for several months while Kevan finished high school and Geraldine, having dropped out of school, worked as an assistant at a veterinary hospital. Both were eager to get out on their own and start a life together. They entered the house through a side door directly into a small kitchen. The light from the window above the sink was large enough to illuminate the entire room, painting the kitchen with the warm summer sun. Pat led them into the living room; a narrow, dark-wood staircase led up to the second floor, where their bedroom and bathroom were located. Kevan instantly loved the house because of its high ceilings, describing it as "gothic and spooky." The air was stale and itchy with dust, likely due to the house sitting empty for a while.

Off one side of the living room was a door leading into Pat''s half of the house. There were locks on both sides, but eventually, no one bothered to use them. Although my mother would describe the first months on Airport Road as an idyllic start to married life, her contentment was short-lived. "Things began to happen," she said. "Our stereo system would jump from station to station without adjustment." The jumps occurred randomly, and it didn''t matter which radio station was playing at the time. Even the television was affected, channels skipping or turning off and on at random. "We even called people," she added.

"They said we were on the flight path of airplanes, and that anything might happen with the electronics in the house." While that theory might have given my mother some relief, she described a litany of other unusual occurrences that couldn''t be explained away by the interference of the planes passing overhead. She remembered relaxing in an armchair and being startled by the sudden sensation of someone peering over her shoulder. When she spun around to look, only the curtains waved back. Other times, she would move from one room to the next and feel a sudden drop in temperature, as if she were descending into a cold cellar. Lights went on and off. On some mornings, as she made her way to the kitchen to make coffee, she found the cabinet doors wide open, exposing the pearl-white dishes within. Mum had just turned eighteen and had never experienced unexplainable phenomena before.

She had few places to turn for help, unlike today, when one can search the internet for the "top signs your house is haunted." Reports of temperature drops, appliance shenanigans and shadowy movements are ubiquitous. I have never witnessed any of these phenomena and, like several other science-minded skeptics, have even sought out known haunted homes, restaurants and buildings in the hopes of a first-hand scare. Some have camped out in haunted houses equipped with machines to measure magnetic fields, monitor temperature and pressure fluctuations, capture video and audio, and detect changes in ions. None have produced meaningful results, though it may be a limitation of the technology available today. The house on Airport Road was demolished years ago, and there was never a scientific investigation into the cause of the disturbances my mother described. An investigator''s first step would be to rule out any natural causes for the sounds and sightings she experienced. Random noises could be explained by rodents scratching in the walls.

Appliances mysteriously powering on or off could portend electrical faults. Temperature changes might be linked to structural defects causing drafts and damp areas. Even the creepy sensation of being watched has a scientific explanation. In the late 1990s, Victor Tandy heard rumours that his Coventry, England, lab was haunted. He had been working as a researcher in a medical equipment design company when he encountered a visibly distressed cleaning woman. While she was cleaning, she''d sensed something moving nearby, even though she was alone in the lab. Tandy assumed the movements she saw were from changes in room pressure or a lighting effect. However, in subsequent days, he and his colleagues also experienced the "spooky" feeling of cold spots, and the sensation of someone lurking nearby, although no one was visible.

One night while working alone at his desk, Tandy felt he was being watched, and a figure slowly emerged to his left, at the periphery of his vision. The apparition was grey and made no sound, and it moved as a person would. Tandy remembers a chill in the room and the hairs on the back of his neck bristling in response. When he turned to face the apparition, it immediately disappeared. "It would not be unreasonable to suggest I was terrified," Tandy said. Tandy was a fencing enthusiast, and his first clue in solving the mystery came unexpectedly one night when he was adjusting the blade of his fencing sword, or foil, something he typically did ahead of upcoming competitions. He secured one end of the blade into a vice, and after a few minutes, he noticed the free end of the blade was swaying up and down, like a vibrating tuning fork. Tandy immediately understood the sword must be receiving energy from an unknown source.

He tested the effect of moving the blade to different parts of the room. In one area, it stopped moving completely, but when Tandy moved it close to his desk in the middle of the room, the blade began vibrating again. Tandy determined the blade was responding to a low-frequency standing sound wave, and he was able to calculate the sound wave frequency at 18.98 hertz, or cycles per second. Low-frequency sound waves below twenty hertz are well below the threshold of human hearing and termed "infrasound." Although he couldn''t hear or feel a source of the infrasound wave, Tandy ended up proving an overhead fan was the culprit. When the fan was off, the vibrations ceased. Curious as to how infrasound might affect human subjects such as himself and the cleaning lady, Tandy investigated the literature and found a technical report on low-frequency sound waves from the National Aeronautics and Space Administration.

NASA documented that sound frequencies of eighteen hertz, a level almost identical to the standing wave measured in Tandy''s lab, can affect the eyes. He concluded that the vibration likely caused a "smearing" of his vision, explaining the appearance of the appa-ition. Tandy also discovered that low-level sound frequencies could mess with a person''s sense of well-being, causing "increased muscle tension and hyperventilation"--similar to his fearful response. Interestingly, not everyone responded to infrasound the same way, potentially explaining why some lab personnel felt uneasy and others didn''t. His conclusion, though it may seem hard to believe, was that barely audible sound waves could cause fear and anxiety in some people, com-parable to tickling an elephant with a feather. More plausible was that vibrations within the sensitive membranes of the eyes might create temporary visual aberrations, explaining the ghostly apparition at the edge of Tandy''s vision. The most conclusive evidence against a supernatural source was that once they fixed the fan, the lab remained "ghost" free. In North America, approximately 45 percent of Americans and 47 percent of Canadians believe in ghosts, according to several independent polls conducted between 2006 and 2012.

Across the Atlantic, a similar percentage of Brits also believe ghosts exist. With these figures in mind, it''s easy to understand why ghosts and spirits are prevalent in popular culture. The paranormal is like catnip for the populace. It''s not surprising that an army of people, from amateur ghost hunters to legitimate scientists, have attempted to prove or disprove the existence of spirits. In the same way that Tandy believed infrasound caused paranormal-like sensations, other scientists suspect that electromagnetic fields (EMFs) can cause hallucinations in some people. Significant levels of EMFs have been recorded at locations with a history of paranormal activity, such as Dragsholm Castle in Denmark or Engsö Castle in Sweden. Perhaps the old farmhouse rented by my par-ents was close to a power line and experienced EMF fluctuations. The Canadian neuroscientist Michael Persinger designed a helmet, known as the "God Helmet," to study the effect of weak EMFs on brain function.

The helmet directed EMFs to specific regions of the brain that in some individuals create sensations that mimic paranormal activity. Persinger''s test subjects exhibited a wide range of responses. Many felt nothing, but one man ripped the helmet from his head, too creeped out to continue. Others experienced more moderate reactions, such as sensing a presence in the room even though they were locked in the chamber alone. Ironically, EMF effects exhibit the same inconsistent and unpredictable responses as reported haunt.