Quite difficult question and definitely not one with a straight answer.
Ghosts are part of the traditions and folklore of all cultures and countries in the world. Most towns (old ones more frequently) own at least one haunted house or ghostly area.
Many scientists who are trained in paranormal phenomena have tried to prove or at least explain in part the reason for the presence of what affected people call "poltergeist" (noisy spirits) and ghosts.
Skeptics basically use the principle of Occam's razor, which states that the simplest adequate explanation for any event is the most likely explanation. For instance:
-The typical haunted house is an old place with many years out of maintenance, this create creaking sounds, howling noises created by the wind thru open / broken windows, hollow spaces generate eco sounds, deformed shapes or ragged curtains create spectral shadows or shapes, rats can make scary noises.
-A person or group of persons under a stressful situation (i.e. visiting a place where a murder has been commited) can become easily panicked (and panic can be very contagious). When you are in a creepy place, in the darkness and you are stressed your senses (mainly vision and hearing) can be very deceptive.
-If you are in a forest on a Camp, and somebody tells stories about something creepy that happened in that forest, chances are if you stay awake (and if you are alone is worst) you will transform every tree branch on arms and legs, and the wind will be much more like a howl or haunting scream.
Finally, again this question has no answer, BUT I can say that ghost or no ghosts being real, our imagination can be very tricky and can play games with us. If you don't believe this try staying alone at home one night and rent 2 or 3 good horror/suspense movies (i.e. The Sixth Sense, The Changeling and Stir of Echoes), and let me know if you don't start feeling that someone is looking behind you, or something moves in the shadows in the corner of your eye, or something like that. Most of the people I have challenge to do this, do not even finish the first movie and end up knocking my door to stay overnight.
And this doesn't mean that they have ghosts at their homes :)
Comments
Scientists are born skeptics and skeptics are non-believers, even in Jehovah, GOD!
by Dreasan on December 28th, 2005
This is a good well balanced answer- the bad rating is unfair.
by Anonymous on February 16th, 2006
This answer rocks! Love it!
by Adz3r0 on December 26th, 2008