In our everyday lives we are as much immersed in magnetic fields as we are in air. Unlike the air, however, we don’t notice the magnetism, even during magnetic storms.
This image shows magnetic field lines. They are a bit like contours on a map. Just like contours, the distance between the field lines indicates the strength of the field in that area (the magnetic flux density). Just as closely spaced contours imply a steep slope, so close field lines show a high magnetic field strength. Note the arrows indicating the direction of the field. This determines which way a force from this field acts.
What the picture shows specifically is a geomagnetic field being distorted by a permanent magnet (the rectangle on the right side). Without the magnet, the lines would be parallel, heading diagonally downwards towards the ground (as they down in the bottom left of the picture). This is the way the geomagnetic field looks in the UK. The bar magnet is distorting the natural geomagnetic field locally.
Geomagnetism and the paranormal
It is currently fashionable in paranormal research circles to link geomagnetism with the occurrence of paranormal and anomalous phenomena. Some paranormal group web sites carry geomagnetic ‘weather’ displays.
Various studies have shown apparent (but not highly significant) connections between the timing of paranormal reports (such as ghosts, UFOs, cryptids) and variations in the geomagnetic field. Such studies are not straightforward, though. For instance, what exactly qualifies as a ‘paranormal report’ (see is my house haunted)? Also, many such reports will undoubtedly turn out to have mundane explanations.
Variations in the geomagnetic field (or geomagnetic ‘weather’) are caused by changes in the sun (such as solar flares). Given their origin, you won’t be surprised to learn that such variations affect the whole world magnetic field. However, these changes are not instantaneous everywhere and nor does the field change to the same degree all around the world. This is important because many studies use a planetary index of geomagnetic variation. As the name implies, this measures the average changes across globally spaced sites. It cannot give the exact variations at any given place.
Studies of geomagnetic variation and paranormal reports rely on using large numbers of samples to even out these variabless. However, although the geomagnetic field is everywhere, it is frequently distorted (see left) by local magnetic sources (particularly in urban areas), such as objects made of steel and electrical equipment. These localised distortions can easily exceed those caused by natural geomagnetic weather (see right and this study by ASSAP).
Thus, it would help hugely if magnetic field measurements were made at the site where the paranormal reports occurred and, ideally, while something was being witnessed. Unfortunately, few paranormal researchers have suitable magnetometers to use on site, so the the subject remains shrouded in uncertainty.
Geomagnetic variations (or geomagnetic ‘weather’) are not as dramatic as many people imagine. Though they do cause auroras and can even bring down electrical regional power supplies, local overall field changes are far from dramatic.
A large geomagnetic storm produces a reduction of around 0.5% in the overall field. What is more, this change is spread over many hours. Most storms are far less intense than that. Thus, local field variations are not hugely dramatic at all. It seems doubtful, on the face of it, that such minor field variations could lead to significant changes in the number of paranormal reports though more research is needed.
It has been suggested that more rapid geomagnetic variations could cause hallucinations. These would be in the frequency range used by Michael Persinger to induce hallucinations magnetically in lab experiments. Field-testing these ideas is the subject of the MADS project.
There are some geomagnetic variations that are in the right frequency range to induce hallucinations. They are called Pc1 pulsations (caused by variations in the Earth’s magnetosphere) and they have a frequency range of 0.2 to 5 Hz. However, they are far too weak (typically 0.1nT) to produce hallucinations.
There are also things called ‘Schumann Resonances’ which are caused by lightning resonating around the world. Though they also have suitable frequencies (7.8, 14, 20, 26Hz) they are far too weak at 0.05 nT. For comparison, the geomagnetic field is around 50,000 nT overall in the UK. For more details, see this study by ASSAP.