What is a Poltergeist?

       Unexplained banging comes from within the walls, belongings disappear for days before returning to their rightful places, and drawers open and slam shut on their own. These happenings are what people consider the work of a poltergeist.
       Poltergeist is a German word that translates to "noisy ghost". What separates poltergeists from regular ghosts is how they can be responsible for physical disturbances; they've been described as troublesome spirits or ghosts in folklore, although no conclusive scientific evidence has been able to explain what people consider the happenings of a poltergeist. The earliest known cases of poltergeist activity date back to the first century, and cases of the mischievous ghosts are still being reported today.
       This supernatural occurrence is usually focused upon a particular person, and often it is an adolescent. This is one fact that supports the theory that telekinetic abilities manifested by a living person in turmoil is what is mistaken as poltergeist activity, because a teenager going through puberty may be in such distress that they are able to develop telekinetic abilities. Another theory that goes along with this is that someone who has been physically abused may be able to develop such abilities to protect themselves or to take revenge.
       Another theory claims that a poltergeist is a person who died but did not have their spirit move on. If they had unfinished business or were in anger when they died, they may have some impact on the physical world even though they are no longer part of it. This can explain why a child or adolescence is targeted, because they are the most vulnerable and easily influenced family member.
      There have been many attempts to explain the phenomenon of poltergeists scientifically, and theories that have been thought up include ball lightning, static electricity, ionized air, electromagnetic fields, ultrasound, and infrasound. Scientists also claim that carbon monoxide poisoning can cause people to suffer from hallucinations.
       So, what is a poltergeist? You tell me.