According to a HuffPost/YouGov poll conducted in 2013, 45 percent of Americans believe in ghosts. That's not so surprising when you consider the abundance of unexplained paranormal phenomena that people claim to experience every day.
However, more often than not, there's a proven scientific explanation behind 'ghostly activity' that a rational society such as ours should probably take note of more often.
So here are 5 pieces of scientific proof that will explain away your ghostly nightmares!
1. 'Feeling' a ghost's presence
Ghost hunters often claim that cold spots in a haunted location is a sign of an undead presence. This is because ghosts supposedly absorb heat from their environment to replenish energy.
Scientists, on the other hand, call this phenomena the cold. Even if a room is completely sealed off, there is a perfectly simple explanation for a sudden drop in heat. Objects all possess their own temperature, with some being warmer than others. These objects will either try to store or release heat in an attempt to equalize the room's overall temperature, causing the process of convection to take place. This is why cooler air may gather in one part of a room, creating the allusion of a supernatural presence.
If you think your house might be haunted, try turning up your thermostat.
2. Hallucinogenic gasses will make you go crazy
William Wilmer, an ophthalmologist, published a paper in 1921 describing a series of rather strange events that occurred to a family simply named the 'H' family.
The H family were repeatedly tormented by slamming doors, unattributed footsteps and creepy moving furniture that seemed to have a life of its own. One child claimed to be attacked by an unknown stranger, while the mother awoke to find a woman and a man looking at her from the end of her bed, before they suddenly vanished. What else could possibly describe these phenomena other than ghosts?!
Well, carbon monoxide poisoning for one. After seeing all the plants in the house die, the family discovered their faulty furnace was leaking the invisible odorless gas, causing nausea, confusion and hallucinations. Modern day houses are now built with carbon monoxide sensors, so make sure yours are working - for the good of your sanity!
3. Shadow people are all in your head
Have you ever caught a glimpse of something spooky in the corner of your eye, only when you turn your head to look at it, it's suddenly vanished?! I've experienced this unsettling feeling so many times, I've started to question my own sanity.
Some people think these momentary apparitions may be demons or astral bodies, though that's actually a little less frightening than the truth. Swiss scientists decided to put their fears of ghosts to rest by electrically stimulating an epileptic patient’s brain, and the results were rather horrifying.
The patient claimed to see a 'shadow being' behind her, replicating her every movement. When the doctors asked her to read something from a card, the shadow tried to grab it from her. The scientists had stimulated a part of her brain that perceives its sense of self: the left temporoparietal junction, to be precise. By messing with this crucial function, the brain became confused with its own body, creating a a replica 'shadow person'. Researchers believe the discovery of this bodily malfunction is key to uncovering why we sometimes see spooky shadows we can't otherwise explain.
4. Humans move Ouija boards, not ghosts
Ouija boards have become popular with mediums, used as a tool to communicate with those beyond the land of the living. Usually, a group of people will place their hand on a piece of wood called a planchette, before asking the summoned ghost a question. The spirit will then respond by moving the planchette to spell put an answer - but do they actually work?!
Well, physicist Michael Faraday discovered that the board only appeared to work because of something called the ideomotor effect. This is when the power of suggestion causes muscles to move unconsciously. If a group of people are told something will happen, they will often subconsciously make it so.
To prove this, in 1853 four doctors conducted an experiment, asking volunteers to place their hands on a table. At first, they secretly told half of the people it would move to the right and half it would move to the left. Of course, the ideomotor effect ensured the forces moved against each other equally and the table didn't budge. When they told everyone it would go in the same direction, it did. Mystery solved.
5. Scarily bad photography
Orb photography, as seen above, is offered by some ghost hunters as proof of a supernatural presence. These strange white balls are naked to the eye, but suddenly reveal themselves in creepy images like this, but are they really ghosts?
Well, no. These apparitions are actually dusk specks too close to the lens, which become exposed and blurred by the camera's flash. Other causes of strange out of focus elements include dirty lenses, stray hairs and shaky arms. This should inspire you to use your camera more carefully, or you might get a fright!
If you're still not convinced about the presence - or lack thereof - of ghosts, check out Listverse's full rundown HERE.