Five Scientific Explanations for Spooky Sensations
by Andrea Michelson/Smithsonian.com
Tis the season to celebrate the supernatural, whether that means visiting a haunted house or donning a spooky costume. But while some might scare themselves silly in the name of Halloween fun, 42 percent of Americans believe ghosts are for real, according to a 2013 Harris Poll. The belief in ghosts dates back to at least ancient Mesopotamian times, and it seems to have lodged itself in the collective psyche. But in many cases, science can explain what might seem like a message from beyond. Here are five scientific explanations for encounters with the supernatural.
The “Fear Frequency”
Just below the range of human hearing, infrasound can cause some strange sensations. Humans can’t hear sound below 20 hertz, but some people subconsciously respond to lower frequencies with feelings of fear or dread, reports Jennifer Ouellette for Gizmodo. In one account from 1998, engineer Vic Tandy of Coventry University spent a night in a lab believed to be haunted. He and his colleagues experienced anxiety and distress, felt cold shivers down their spines, and Tandy even reported seeing a dark blob out of the corner of his eye. It turned out that there was a silent fan creating sound waves at around 19 hertz, the exact frequency that can cause the human eyeball to vibrate and “see” optical illusions. “When we finally switched it off, it was as if a huge weight was lifted,” Tandy told Chris Arnot for the Guardian.