There's always time to rethink.

The paranormal idea of ghosts had been passed on for ages -- thanks to depictions of media and popular culture, they're more socially accepted. But fear has more to say: we are never alone in this world. With whom are we else sharing it (among animals and plants, of course) -- is the question.

Nearly half of all Americans believe in ghosts, according to a 2013 poll by Huffington Post. That's 45% to be exact, while 64% believed in life after death. Interestingly, the outlet cited "Real Ghosts, Restless Spirits and Haunted Places" author Brad Steiger, who spent a whopping 60 years (more than, actually) of paranormal research.

Steiger's statement was easy, "I spend little time these days theorizing about what ghosts might be. I completely accept the existence of such phenomena."

Are ghosts real, then?

Read on, because we provided five scientific rationales behind the existence of such paranormal beings. While the notion of ghosts can both be viewed subjectively and objectively, the latter is more generally accepted by everybody.

1. The Ideomotor Effect

The Ouija board is one of the most popular channels of paranormal communication. Listverse noted that such method sprang from the spiritualist movement in the 1840s, when talking with the dead became rampant.

However, known physicist Michael Faraday contended through experimentation that people expected the table to move, and so it did. Apparently, it's all muscle work -- the body responds unconsciously to what the mind believes so. There are no spirits, only muscles.

2. The Infrasound

In 1998, a series of unexplainable events took Vic Tandy's medical lab in horror. The Week cited that his coworkers felt chilled, weird figures roamed at night and even the Coventry University lecturer himself spotted a dark apparition.

Curious, Vic laid out to discover the root of all terror -- and found a new, innocent ventilation fan.

Situated at the other end of the lab, the fan emitted a very low frequency standing wave (19Hz) which reflected itself at the center of the room. It cannot be heard by humans. He wrote, "In effect, the wave was folded back on itself reinforcing the peak energy in the center of the room."

3. The Angular Gyrus

This is a part of brain that when electrically stimulated, triggers a sensation of someone behind you -- following and copying your very movement. According to HowStuffWorks, stimulation to other parts of the brain also cause people to experience hallucinations and near-death encounters.

4. Maybe You're Just Sensitive

Dr. Richard Wiseman of the University of Hertfordshire was reported by BBC to explain that people are responding unconsciously to environmental cues such as temperature, light intensity and room space.

The outlet added that mediums are more sensitive to such cues that result to haunted feelings, and not to ghosts themselves. That's a major difference!

5. Forces That We Don't Just Understand (Oh no...)

Discovery News reported about Boston University professor Robert Schoch, who claimed that people seeing their relative's spirit at the exact moment of the latter's death, are under Extra Sensory Perception (ESP) -- only that it can't be measured.

Citing the influence of the Earth, he stated, "It turns out that the incidents of crisis apparitions correlate with geomagnetic flux." Still, he implied that nature has something to do with it!

And that's it -- ghosts can be both real and unreal, depending on how you "see" them.

Perhaps the mind could be more frightening than ghosts themselves.

See our list of Halloween must-watch here.