Recently we received a request for a good resource for some very common scientific explanations for hauntings that people easily mistake. This would seem to be fairly straightforward, but not quite...
Sadly, there really isn't a "perfect tome" about all possibilities to explain why people experience certain things... and regardless, one has to look at things from a "Case-to-Case" basis. That wouldn't be a single book... that would be an encyclopaedia that would make Britannica look tiny. Dripping taps, HVAC vents, sunlight, decay (in various forms,) health issues like sleep paralysis, electrical issues with wiring/grounding/shielding, etc, etc... are all reasonable possibilities in some cases.
Much like if anyone was to find substantiated evidence of the existence of ghosts, it's unlikely any book or thought will answer every question or if there will even be a "single" answer...
As pointed out, the same way that mistaken things can range in terms of people feeling they've "run into" a ghost (and it IS a case of mistaken identity, so to speak)...
- Dust in photographs
- Simple disorientation/Physical health issues
- Temperature/Humidity environmental elements
- Sounds or light
- ...and this list does go on and on...
...if one showed that these experiences were indeed paranormal, you have to look at the hypothetical causation there.
Working on the "paranormal possibilities", you need to consider hypothesis...
Right now, the vast majority feel that ghosts are either "caused" by the DPH (or "dead person" hypothesis) or psi (pronounced "sigh" - which is something tangible put into the environment that comes from the witness(es) from an unknown psychical ability). Scientifically, if we accept these things happen, there is far and away more legitimately studied evidence to support psi as a cause rather than the "DPH". (For the best info and idea of psi, look into The Philip Experiments which were done in Toronto and considered by most people worldwide to be a benchmark in these studies and also look up any of the work on the subject by Dean Radin or Rupert Sheldrake.)
Another consideration is that in ufology, cases which are termed "high strangeness" (usually involving people claiming to be abducted and the like,) often feature the witness seeing apparitions prior to the "big" experiences... and we could add to this miscellaneous hypothesis things like looking into mass sightings of angels or saints, deathbed visions (which are not limited to the person dying, if you read through the work of Dr. Carla Wills-Brandon,) and a lot of other concepts and ideas.
To be properly scientific in an investigation, the investigator must do one essential thing... throw out everything they are certain must be true and be absolutely neutral and employ critical thinking skills in their collection of data and go only where the data takes them. To paraphrase Epictitus, it is impossible to learn about that which someone is certain they already know everything about.
So, as opposed to saying, "I'm going to prove Grandma is haunting this house!", a good investigator simply says, "This person/These people experience these things at this house. I want to know why." and look into all probabilities without favouring one over the other.
To do good work means being unbiased, neutral, and remembering that all claims, be they extraordinary or not, require evidence... and yes, that does include the claim that everything is bunk.
Science does not say "Ghosts don't exist"... mostly because science is a method, not a person or even a group... proper and honest scientists say, at best/worst, "There is not enough empirical evidence to show ghosts exist BUT there is no evidence to show that all witness reports and events are explainable outside the hypothesis of some form of ghost."
In other words, a good scientist makes proclamations based on empirical evidence... not on belief and faith... or non-belief and non-faith. Being sceptical is being scientific... but only in as much as someone is being an honest sceptic... saying they need more evidence to comfortably have a belief themselves. When someone says to me, and I hear it A LOT, "I'm a sceptic, I don't believe in that crap!", I respond with the fact that the statement is incorrect... they are a non-believer that does not believe... a sceptic has not made a decision towards belief or disbelief... and I am a sceptic.
Ergo: Scientific does not mean absolute negative debunking. Scientific means creating a model that is repeatable and can be both predicted and measured to show solid evidence of a hypothesis.
...and make sure people know that...
Hypothesis is a "best guess".
If a hypothesis is tested and shows legs in terms of being correct AND is replicated and tested by a few neutral parties, THEN it becomes a theory. (Einstein's theory of relativity is still only a theory as we don't have 100% absolutes on all parts of it... but it's basis is what allows us to understand how to split the atom and that works, but working and "absolutely empirically proven" are different animals.) If a theory becomes completely measurable and predictable and can be re-created in a controlled environment by many people, it becomes empirical fact.
So, if someone looks into a haunting and says it's not happening because the person is nutty, then they would need to be a clinical psychiatrist or psychologist to validate that claim, then they'd need to prove that the experiences happened only when the person was experiencing a psychotic episode of some sort, and then replicate that instance with hard data a few times (and let a neutral peer group do the same,) before their hypothesis might become theory... and when it comes to something so "liquid" as the physical human condition, it's almost impossible to take this hypothesis to absolute empirical fact.
Basically, what a good investigator needs to do is...
#1: Be safe, legal, and ethical.
#2: Stay neutral in their beliefs.
#3: When hearing of experiences or events, separate the inserted hypothesis and faith from the experience and look at the hard facts.
#4: Examine the hard facts and look for possible "natural" causation before moving to a "supernatural" hypothesis.
#5: Back up any or all findings and claims with proof or evidence.
#6: Don't be afraid to say, "I don't know". Better to let people know you're unsure then make a pronouncement that's incorrect.
For further reading and information you may also want to look at some blog posts which are current from us:
Ghost Hunting Courses:
http://psican.org/links/ghosthuntingsnotparapsychology/
Five Steps Towards Proof:
http://psican.org/links/fivesteps/
Ghost Hunting Gadgets:
http://psican.org/links/gadgetry/
Learning to be a Ghost Hunter:
http://psican.org/links/learning/
Buying Equipment:
http://psican.org/links/buyingthings/
About Quantum Physics:
http://psican.org/links/physics/
