Poltergeists

When you hear the word "poltergeist", you probably think of that one movie that has ghosts in it and a girl touching a TV because "They're here."  It's just another one of those movies that parents make their kids watch so that the little critters go to bed early, right?

Wrong.

Poltergeist literally means "noisy ghost" in German.  A poltergeist is catagorized as a type of haunting, where the actual entity has a tendency to move things and slam cabinets shut or leave them wide open.  You may think it's your cat trying to get you back for leaving it without a pet sitter while you went to summer camp, but it actually is and never was a living thing.

Don't bury that mother fucker in the Pet Sementary

According to the first law of thermodynamics, energy cannot be created nor destroyed, simply just converted to different energy.  Most poltergeists are reported in houses with family problems or recent events that have really caused them to hurt. Our brain is a powerful organ, and we still have yet to understand it. 

Gentlemen's Brain.

So, in all reality, a poltergeist is nothing but the energy left behind by another living thing.  Perhaps the energy could be positive if the organism was happy with itself, or perhaps the energy could be negative where the organism was filled with anger (dark side).  Science can't explain everything, yet.  The future has much to unfold on poltergeists, let me get your guy's output on what you think they could be/if ghosts really exist.