In the 1984 and 2016 film versions of “Ghostbusters”, a group of scientists are shunned by academia for insisting that ghosts not only exist, but can be captured using advanced technology. While these aren’t the first fictional stories to depict the paranormal as legitimate science, they are arguably the most iconic.
The archetype of the gadget-wielding scientist tracking down ghosts and ghosts has since become prevalent, especially in popular TV shows like “Ghost Hunters.”
Today, ghosts are considered the realm of pseudoscience because there is no physical “theory” as to how or why they might exist. For this reason, it is difficult to prove – or disprove – their existence. Yet throughout history, that hasn’t stopped enterprising scientists and technologists from trying to find ways to “detect” them.
Most of these attempts are based on folk accounts of what ghosts are, in an effort to guess what kinds of traces they might leave. When it comes to developing ghost-hunting technology, the fashionable thinking seems to be this: figure out what kinds of physical clues a ghost might provide that it was present, then build machines capable of to identify them. This approach is undoubtedly necessitated by the paradox of trying to use science to detect what is inherently ethereal.
If ghosts or spirits exist in our world, that would by definition mean that there was an interaction between the realm of matter and the realm of metaphysics. Since metaphysics is, by definition, impossible to quantify (hypotheses like panpsychism exist to explain the existence of an immaterial substance: consciousness), any scientific approach should study in one way or another the residue or other points of contact left by undead souls in the physical world.
To put it more simply: if you try to prove that an invisible man is walking around a room, you won’t see his feet, but you might hear his footsteps and discover his footprints.
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The difference between an invisible man and a ghost, of course, is that a human being is still made of flesh and blood, and would therefore leave tangible marks on the world around them even if they were invisible. We don’t know what a ghost would actually be made of, which means ghost hunters have to guess the impact of a poltergeist on its immediate surroundings. So even when ghost hunters use legitimate scientific equipment, they do so based on speculation rather than a clear idea of what to look for.
Take electromagnetic field (EMF) detectors. These are some of the devices most frequently used by ghost hunters, who search for anomalies assuming they signify paranormal activity. Some ghost hunters, like those from the science-focused paranormal investigative group Para Science, look for two types of radiant electromagnetic emissions: ionizing and non-ionizing radiation. They argue that the presence of this radiance in certain contexts may indicate a visitation from an otherworldly presence. Yet there are often mundane explanations for what these detectors also detect. EMFs can be found virtually anywhere, and an unusual detection of EMFs is much more likely to reflect incomplete scientific knowledge.
“They are surprised to get results in an old house, when in fact there are all sorts of non-ghost sources such as faulty wiring, nearby microwave towers, sunspot activity , etc,” Joe Nickell, a senior fellow at an independent research organization called the Center for Inquiry, told NPR about EMFs and ghost hunting. “Even electronic equipment – walkie-talkies and television cameras and all the other electronic gadgets they carry around – have electromagnetic fields.”
That’s not how ghost hunters see it. As a British businessman who sells supposedly scientific paranormal kits told Live Science, “In a haunted place, strong and erratic fluctuating EMFs are commonly found. It seems that these energy fields have a definite link with the presence of ghosts.” While he acknowledged that no one knows why this alleged connection exists, he added “abnormal fields are easy to find. Anytime you locate one, a ghost may be present…any erratic EMF fluctuation you can detect may indicate ghostly activity.”
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Yet just because people say a place is haunted and there are EMFs doesn’t mean the haunting is the real explanation. Some studies suggest that exposure to certain types of EMF can lead to physical and psychological side effects such as paranoia, nausea, and the belief that one is having profound experiences. In the 1980s, a Canadian psychologist named Dr. Michael Persinger created a famous “God helmet” that placed electromagnetic transmitter coils around a subject’s head. Once the helmet was activated, the wearer’s temporal lobes were pounded with electromagnetic fields. More than four out of five people to whom this happened said they felt some presence in the room with them, including on some occasions visions of God.
A similar effect can occur with infrasound, which paranormal investigators have also claimed is a sign of ghostly actions. Low-frequency infrasound, like EMF, is all around us, and it can have a seemingly enigmatic effect on our minds and bodies because the audio frequency is below the range of normal human hearing. Everything from the movements of tectonic plates beneath our feet to the rumble of thunderclouds across the sky can produce low-frequency infrasound. Depending on the origin and nature of the sound, those exposed may experience headaches, dizziness and nausea, as well as psychological effects such as anxiety and a sense of dread. Research suggests that infrasound helps inspire, or at least reinforce, perceptions of paranormal encounters.
There are many other popular anti-ghosting technologies. Ghost hunters can use sensitive infrared cameras and microphones, special thermometers to measure ambient temperatures, and night vision goggles to be able to see in the dark. Unlike Ouija boards, dowsing rods and ghost boxes, they are real scientific instruments that can be used for valid research. However, all of them have the same problem as EMF detectors and infrasound monitoring equipment. Because they are used based on guesswork about what a hypothetical ghost might do, rather than empirical and repeatedly demonstrated facts, their effectiveness is questionable at best.
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The implications of using pseudoscience to detect ghosts are far greater than just understanding what is going on in the afterlife. As noted scientist Carl Sagan wrote in his 1995 book The Demon-Haunted World: Science as a Candle in the Dark, humanity suffers globally when people collectively lose their appreciation for genuinely scientific approaches to solving of problems.
“I have a presentiment of an America in the days of my children or my grandchildren,” Sagan wrote, “when the United States was a service and information economy; when almost all manufacturing industries have eclipsed to other countries; when impressive technological powers are in place. in the hands of a very few, and no one representing the public interest can even grasp the issues; when people have lost the ability to set their own agendas or knowingly question those in authority; when, clutching our crystals and nervously consulting our horoscopes, our failing critical faculties, unable to distinguish between what feels good and what is true, we fall back, almost without realizing it, into superstition and darkness. “
This observation lends a sad irony to the way science now provides tools to people who, knowingly or unknowingly, use them in unscientific ways.