Friday, October 1, 2010

The Pseudoscience of Ghost Hunting part 2: EMF

We've seen them on every ghost hunting show. They're marketed as ghost meters by many providers. EMF meters are widely believed to detect the presence of spirits, but where did this idea come from? Could ghosts actually produce an electromagnetic field? Or is the appeal stemmed from the famous PKE meter from the Ghostbusters movies?

I have exhausted all of my own resources trying to find the original thought behind ghosts and EMF. No one i can find seems to know why emf meters are used. I can only presume that most amateur groups are only emulating what they see on tv. My guess is, in the effort to sound scientific, ghost hunters will use any piece of fancy technology they can afford (being that the now less popular Geiger counters are so expensive) and attach scientific sounding techno- babble. Who's going to question it? Ask any ghost hunter about what electromagnetic fields are and how they're produced. I doubt you'll get a concise answer. It all sounds impressive, so people buy into it.
So, what is an electromagnetic field? Shortly, it's the combination of an electric field and a magnetic field . The electric field is produced by stationary charges and the magnetic field by moving charges (currents), these two are often described as the sources of the field.

Plugging a wire into an outlet creates electric fields in the air surrounding the appliance. The higher the voltage the stronger the field produced. Since the voltage can exist even when no current is flowing, the appliance does not have to be turned on for an electric field to exist in the room surrounding it.

Magnetic fields are created when the electric current flows. Magnetic fields and electric fields then exist together in the room environment. The greater the current the stronger the magnetic field. High voltages are used for the transmission and distribution of electricity whereas relatively low voltages are used in the home. Electric fields around the wire to an appliance only cease to exist when the appliance is unplugged or switched off at the wall. They will still exist around the cable behind the wall.

Of course, there are larger sources of EMF including the Earth itself. This is how compass' point north, but the types of EMF detected with "ghost meters" measure low frequency fields. Like that of a refrigerator, cell phone or a tv camera.

Another thing I’ve noticed is how many investigators hold and rotate the detector while taking measurements. This may or may not be an issue depending on the EMF detector. If it’s a single pole detector then it becomes a major issue, which the majority of EMF detectors being employed are of this type. The reason it’s such an issue is that single pole detectors are polarized, therefore changing orientation of the meter can change it’s ability to accurately measure the strength of an EM field.This can lead to the false conclusion that a field has died off when in reality the field hasn’t changed strength at all

Surprisingly, most ghost hunters know most of this, but they still continue to use them. Why would they do so? I wager that the only reason they use EMF detectors at all is because they so easily find "anomalies." Rather than think about the fact that they seem to find such anomalies everywhere they go, they declare each and everyone paranormal.

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