A "spirit" photo supposedly showing a ghost.

The Science of Ghosts and Hauntings

They are called phantasms, specters or spirits. The ancient Greeks referred to them as shades while in Scotland they are known as wraiths. The Germans use the word spook, unless they cause a racket in which case they get the label poltergeist. Most people just call them ghosts and are either fascinated by them, or are terrified of them, or sometimes both.

The belief that human spirits could continue to haunt the living after death goes back to ancient times. We know that many primitive societies' burial customs included rituals to banish the spirits of the departed from the earth. As far back as biblical times, King Saul had the Witch of Endor summon the spirit of dead prophet Samuel for advice. More recently, in the late 19th and early 20th century, the belief that the living could contact the dead through spiritualism and séances tickled the public's fancy. Currently TV shows where "ghost hunters" trek to supposedly haunted locations to find spooks are popular on the cable channels.

What does science have to say about ghosts and their hauntings? Are they real? Or are they just the product of our overactive imaginations?

Souls Not at Rest

Most ghost stories are connected with the idea that spirits are the souls of people who died under difficult circumstances - for example, murder or suicide - and continue to inhabit the earth. Troubled by their death, they haunt the places where they lived and died, unable to move on to the afterlife. One early account of this involves the Greek philosopher Athenodoros Cananites. Athenodoros became interested in a haunted house in Athens and started watching it at night. Late one evening an old man, bound at the feet and hands with rattling chains, appeared to him and beckoned the scholar to follow him. The ghost disappeared suddenly and Athenodoros had the spot where he vanished dug up. A man's shackled bones were found at the location and after a proper re-burial, the haunting ended.

Tales like those of Athenodoros are typical but don't really prove that ghosts exist. For science to confirm anything a phenomenon must be repeatable. Unfortunately ghosts, if they exist, do not seem to keep a regular schedule and their sporadic appearances make scientific observation nearly impossible. In addition, there is no scientific theory involving physics to explain how ghosts would work.

The Problems of Proving Ghosts

This, however, does not prove that ghosts do not exist. For many years scientists refused to believe in meteorites because their falling out of the sky was sporadic and not predictable or repeatable. Scientists also viewed the universe as perfect and had no theory to explain how there could be little pieces of extra rock floating around in space.

Of course, meteorites do exist and they now have been observed on many occasions. They also fit in with our current scientific theories. Might we one day be able to prove ghosts exist? Even if we can't do that today, perhaps science can do the next best thing and prove that a location is "haunted."

Part of the "haunted" Edinburgh Vaults. (Licensed from Kjetil Bjørnsrud/Wikipedia Commons)

This is exactly the type of research that Professor Richard Wiseman of the University of Hertfordshire in the United Kingdom has done. Wiseman is known for his investigations on the quirky side of science, delving into such areas as humor, luck and the paranormal.

The Haunted Edinburgh Vaults

In 2001 Wiseman decided to investigate the underground "haunted" vaults under Edinburgh, Scotland's, South Bridge. The bridge was constructed in the late eighteenth century and consists of nineteen large stone arches supporting a road lined with several three-story buildings. A number of rooms and corridors were built under the arches to house workshops, storage areas and accommodations for the poor. This place soon became a disease-ridden slum that was abandoned by the late nineteenth century. The area was rediscovered and opened for public tours in 1997 and soon tourists and guides were experiencing many unusual phenomena, including a strong sense of presence, the appearance of several apparitions and the sounds of 'ghostly' footsteps. Soon the Vaults acquired a reputation for being one of the most haunted spots in Edinburgh.

Since some of the rooms in the Vaults had the reputation of being haunted, while others did not, Wiseman designed his experiment to see if people who were not familiar with the reputations of each of the rooms would sense anything unusual with them.

Over the course of four days volunteers entered the vaults and recorded any unusual experiences that they felt and whether they thought it might have been caused by a ghost. Lighting levels, air movement, temperature, and magnetic field levels were also recorded. When the data was examined, it became apparent that the volunteers consistently rated certain rooms as being more "haunted" than others. Their observations also correlated with past records of haunting reports kept by the tour company that ran the vault tours.

Wiseman suspects that people feel a location is haunted not because of actual ghosts at the location, but because of environmental factors. In the experiment volunteers were more likely to have reported haunted experiences in vaults with high ceilings and high levels of exterior lighting directly outside the vault. Wiseman suggests this may be because people feel especially vulnerable in a room with a high ceiling and may also be made nervous by passing from a well-lighted corridor into a relatively dark room.

Hampton Court Palace was the location of one of Wiseman's experiments. (Licensed Richard James Lander/Wikipedia Commons)

Wiseman also conducted a similar experiment at Hampton Court Palace in England. Two sections of the palace, the Haunted Gallery and the Georgian Rooms, had reputations for ghostly encounters. These areas were divided into grids and volunteers recorded the locations where they experienced strange sensations. Their observations were consistent with each other and the reputation of those sections of the rooms. Wiseman also identified a correlation with those "haunted" areas having weak magnetic fields. This might suggest that for some reason people may be disturbed by a magnetic field in such a way that it makes them feel the location is "haunted."

Ghosts and Infrasound

Wiseman isn't the only one that thinks environmental factors may cause people to think a location is haunted by ghosts. Vic Tandy, of the School of International Studies and at Law Coventry University, was working in a medical lab in 1998 when people started to report ghostly encounters and experiences at the location. A cleaning woman even resigned after seeing an apparition. Tandy himself also had the feeling that he was being watched by a figure in the corner of his eye that disappeared when he turned to face it.

One day Tandy brought a fencing foil (a long, thin sword) into the lab in order to repair it. He put one end of sword in a clamp and was surprised when the other end suddenly started vibrating wildly. Some experimentation showed the sword did this while in the center of the room, but stopped near the walls. Tandy finally discovered that the room contained a low frequency sound wave.

Low frequency sound, sometimes referred to as infrasound, usually can't be heard by humans. Even though these frequencies, usually 1 to 20 vibrations a second, are too low for human ears there is some indication people can still sense the presence of infrasound. In some sensitive people it can even cause nausea, anxiety and chills. The sound wave discovered by Tandy had a frequency of 18.98 hertz and was caused by a newly-installed fan. The sound wave was bouncing off the walls of the building and colliding with itself to create a powerful "standing wave" in the center of the room which was strong enough to shake the sword.

One theory explaining why this sound wave affects humans is that 18.98 hertz is the frequency at which a human eyeball starts resonating. The sound waves make the eyeballs vibrate and might produce an optical illusion such as the vision of a figure that doesn't really exist. Another theory is that infrasound of sufficient intensity can also affect the balance system in the human ear, making people feel sick.

When the new fan was shut off the standing wave went away along with all the reports of a ghostly presence in the lab. Tandy wrote a paper about the experience for the Journal of the Society for Psychical Research.

The "Ghost" in the Cellar

Video Bonus: Professor Wiseman looks at some ghost photographs.

Because of his success in chasing down the ghost in the lab, Tandy was called to investigate reports of a ghost in the 14th century cellar of the Coventry Tourist Information Centre where a number of visitors had reported feeling a ghostly presence.

This cellar might seem to be the perfect place for a ghost to hide. Built centuries ago, it was probably first used to store goods for the booming woolen business in Coventry. The cellar served several different structures over the years as the various buildings above where constructed and demolished. Finally during World War II when it was forgotten after a bomb destoryed the building on top of it. When the tourist center was built it was rediscovered and opened to the public.

Guides for the Information Centre reported a number of visitors had reported the feeling of a presence or a cold chill in the basement. A few people had actually turned pale and many, without explanation, would "leave rather hastily." At least one man also reported seeing the apparition of a woman that seemed to be peering over his right shoulder.

Tandy and his team investigated the cellar and found a 19Mz standing wave very similar to the one they found in the medical laboratory. However, they could not track down the source of the sound to any particular cause. Tandy suspects that the natural resonance of the chamber and the connecting corridor interacted to create the standing wave.

The Winchester Mansion in San Jose, California, has the reputation as a haunted house.

So are all hauntings just the result of infrasound? Richard Wiseman decided to test this by conducting an experiment. Working with Dr. Richard Lord, an acoustic scientist at the National Physical Laboratory in England, Wisemen staged a concert for 750 people. Four pieces of music were performed during the concert and without informing the audience, during two of the pieces the scientists used a 7-meter pipe to produce infrasound. Audience members were then asked to describe their response to the music and although unaware of the use of the pipe, 22% of the listeners reported feeling chills, revulsion and fear when the low frequency sound was added to the music.

Though environmental causes might not explain all ghosts, experiments like these may go a long way towards explaining why we feel certain locations may be haunted.

Copyright 2009 Lee Krystek. All Rights Reserved.