It’s increasingly clear that unlocking the mystery of the Hum will require a team of experts from some diverse disciplines. There are very few people who are fortunate enough to have a college-level working knowledge of radio physics, human anatomy (the auditory system in particular), geomagnetism, geology, psychology, and biochemistry. I am working on putting a team together.
I present below what I suspect is one piece of the puzzle: the behaviour of VLF EM energy as it interacts with the Earth’s magnetic field. This is not a scientific article, but rather it is designed to help people understand the mechanism I am proposing.
We know that if you sprinkle iron filings over a piece of paper that has a magnet underneath, you can see what is meant by a “magnetic line of force”, or “magnetic field line”; each point on the magnet is “connected” by a curved path to another part of the magnet. The same is true for Earth’s magnet: if you live in the Northern hemisphere, then you are magnetically related to a specific place/area in the Southern hemisphere, roughly at the same southern latitude. These pairs of points are called “magnetic conjugates”. Key here is that an EM disturbance in one location on the planet very rapidly creates a mirror disturbance in the opposite hemisphere at the conjugate location.
This was predicted many decades ago and has been observed many times since. As one example, Knob Lake, Canada, has a conjugate point in the vicinity of Byrd Station, Antarctica. Locating your conjugate point on the globe requires using some arcane search engines: here’s one:http://omniweb.gsfc.nasa.gov/vitmo/cgm_vitmo.html). NOTE: the location of magnetic conjugates can quite (sometimes quickly) drift tens (and in some cases hundreds) of kilometres away from their expected locations. Events in the ionosphere, including increased or decreased solar activity, levels of lightning activity , and local magnetic anomalies and mountain ranges, can all effect the location and characteristics of conjugate points. To add to the complexity, magnetic field lines can “slip” or even “break” and then re-form.
When a powerful VLF transmitter operates, not only does it propagate by the three ways I explained previously, it also creates a disturbance that travels up the magnetic field into space and then lands back at the conjugate point, creating a strong VLF signal in the opposite hemisphere.