Paranormal vigil baselines
The graph above shows magnetic variation over 40 minutes at a quiet suburban location. You may be surprised to see just how much it varies (ranging over a couple of hundred nT). Note how it is neither entirely random nor is there any obvious pattern. This is quite typical of short-term variations of such environmental quantities. It is not random, it is chaotic.
Chaotic variations are often based on quite simple underlying variables. The interplay of just a few non-random variables can produce overall changes that appear random. Magnetic fields in houses, for instance, may reflect appliances being switched on and off, fields from nearby houses and geomagnetic variations. Put together it can produce chaotic results like those in the graph.
Randomness (where one reading is independent of the preceding values), on the other hand, is surprisingly rare in nature. One of the few examples is radioactive decay where it is impossible to predict when the next atom in a lump of radioactive material will decay.
So don't assume that 'background' readings will vary in a random, or a predictable way. It could well be chaotic.
Keep instruments still!
Many instruments used in paranormal investigations are designed to be portable. It is tempting to walk around with them and 'point' them at anything apparently paranormal. Don't do this!
To capture any anomalous reading, you need a continuous record from a single location. If something paranormal is reported, you need to see if the readings on nearby instruments changed. For many instruments, readings will naturally vary from place to place and over time. If you move the instrument around it could be the result of natural variation OR a ghost or a bit of both. But you won't know which.
Baselines; what are they?
At some vigils, baseline measurements are made before the official start of proceedings. These are readings, using instruments such as EMF meters and thermometers, showing initial conditions. On the face of it, this seems like a good idea. We need to know what typical readings for a location are before the vigil starts so we can readily distinguish anomalous readings during the vigil.
However, there are problems with this approach. Firstly, how do we know the baseline readings are typical? They might, by pure chance, happen to be the highest or the lowest readings, for the day. Secondly, if we get significantly different readings during the vigil, how do we know these aren't just part of a natural daily, hourly or irregular, but normal, variation unrelated to ghosts or paranormal phenomena?
Effectively, by taking baselines before a vigil, we are saying that the time before the vigil is 'normal' and the vigil time is 'special'. There seems no obvious logical reason for this assumption.
Most environmental parameters (eg. temperature, magnetic fields, radiation) vary all the time. Some variations are predictable (such as temperature changes during the course of a day) while others are less so (such as magnetic field - see left).
To obtain valid baselines, you really need to visit the same vigil site repeatedly and do long-term monitoring to find out the natural variations over a day. Only when you know how parameters vary naturally when there are no ghosts (or other paranormal phenomena) being witnessed can you look for anomalies.
If you can only do one vigil at a particular location (which is never ideal because of the new house effect) you should strongly consider positional baselines.
With a positional baseline, you put paired instruments at two static locations. Paired instruments must measure the same parameter (eg. magnetism) and have a similar specification (ideally they'd be the same model!). You put one of the pair at a 'hot spot', where paranormal phenomena have been repeatedly reported. The other location is one very close nearby (maybe an adjacent room) that is as similar as possible (temperature, lighting, etc.) but which has never produced paranormal reports. This is called the control zone.
You would expect readings to be similar over the course of the vigil. Any major differences, particularly when something is reported, could be significant. They may indicate a variable related to the reported paranormal event.
Positional baselines are useful in detecting differences, both permanent and temporary, between hot spots and control areas. Any environmental differences could be related to the source of the paranormal reports. They may, for instance, point to normal causes that no one has yet noticed.
What is an anomalous reading for temperature or magnetic field? Few people are familiar with the ways magnetic fields, or even temperature, vary naturally. And yet, some researchers still claim that a particular reading is anomalous, often because it is sudden and / or short-lived.
Even when investigators are relatively familiar with a technology, and what it is measuring, spurious anomalies are frequently reported.
Consider cameras, for instance. Most people are familiar with these instruments, if only in a mobile phone, and the photographs that they produce. However, if you look at the anomalous photo pages on this web site, you will see how some natural phenomena can look anomalous at times.
Indeed, the orb saga is highly instructive when it comes to considering what an anomalous reading is. Though it is possible to reproduce artificially any kind of orb reported with nothing more than an ordinary camera, some people still claim they are paranormal. If this can happen with cameras, with which most people are familiar, what about EMF meters? They are much less familiar to most people as are the fields they measure. And yet, some people still confidently claim to find paranormal effects with them.
It is said by some, for instance, that sudden increases in the magnetic field in a room can indicate the presence of ghosts. So can switching on an electrical appliance! So what makes such a reading 'anomalous'? Certainly, if it is accompanied by a simultaneous paranormal event reported nearby, it could be considered related.
However, many 'anomalous' readings are reported during vigils in the absence of any simultaneous paranormal reports. Only someone with a thorough understanding of the instruments, how they operate and what they measure should make such a claim. Less experienced researchers should be more cautious in their claims.
If an apparently anomalous reading occurs during a vigil, do try to investigate it (without causing major disruption). There may be an intermittent natural cause present that would otherwise have been missed. For instance, magnetic field fluctuations could be associated with automated electrical equipment.