Edmund Halley was the first scientist to notice the motion of the Earth's magnetic field. In those days scientists only knew of the magnetism produced by solid objects. This led Halley to think that there was more than one physical object moving around inside the Earth. He refined his idea until he developed his theory of Concentric spheres.

It has been known for hundreds of years that the Earth's magnetic field is produced by something at the Earth's core. But what exactly is this? Scientists have since then deduced that the deep Earth is molten and that convection currents in this material might be generating a magnetic field.

Certain types of seismic waves do not pass through the Earth and this led scientists to deduce that this part of the Earth must be molten. Of course it could also be a giant cavity too, but no one has thought in those terms because of the Cavendish experiment which tells us that the Earth's mass is approximately 6 trillion tons.

Everyone accepts the Dynamo theory that convection currents cause the magnetic field. It is regarded these days as fact. However, this theory has various problems with it. It does not work for Mercury because Mercury is so small it should have cooled down by now, and it can't have convection currents inside it. Each planet seems to operate by different rules. Venus has no discernable magnetic field and yet it is so similar to the Earth that it should have a sizeable one. Also the planetary magnetic fields are variously inclined. If the magnetic fields were generated only by planetary rotation then the magnetic poles would match up with the geographic poles - but they do not - ever.

Scientists have also discovered strange things, for example, in one case it was found that here on Earth there are four gigantic stationary magnetic lobes which have not moved for three centuries (that's how far our data goes back). This does not conform to what the Dynamo theory predicts.

Geomagnetic reversals have often taken place in the past. The fast rate at which they take place makes one doubt whether a convection current driven Dynamo can be driving this whole process. Surely slugglish lava inside the Earth can not operate like this? But a nuclear reaction inside the Earth might behave in such a way.

The Dynamo seems to be unattached to the Earth. I say this because of the Great Magnetic jerk which took place in the 1960's which occurred without any warning whatsoever, and without any detectable physical effects. Nobody has ever advanced a theory as to why or how this could occur.

Could it be that the Earth's magnetic field is actually created by a free-floating nuclear fission star at the centre of a Hollow Planet?