The Earths Magnetic Field

Most of us hardly ever consider the Earths magnetic field. We navigate by it, are protected from many harmful solar particals that constantly colide with our atmosphere and it is not an exageration that without it the environment would be very different and may not support life (as we know it) at all.

Einstein considered that the mechanism of the earths production of a magnitic field to be "one of the great unsolved mysteries of Physics".The only other planet in our solar system to have a significant magnetic field is Mercury.

Most often the magnetic field of the earth is atributed to the 'dynamo effect'. Briefly, the molten outer core, which is located beneath the Earths mantle rotates a little faster than the outer surface of the Earth. The inner core which is thought be solid rotates in the opposite direction. This complex motion, along with the eddys and movements within the molten inner core are thought to produce a dynamo effect.

Most of this is of course congecture, but it is so far the best explination that we have. Part of the permanent record that we do have however is that certain rock specimens in similar locations have different directions in thier permant polarity. A phenominon that was recorded in the sea bed of the Atlantic. The polarity having effected the molten rocks at that time. The implication is that the earths magnetic field has reversed its polarity on many occasions. About 170 times in the past 70 Million years, The average time period between flips seems to be about 300,000 year, however the last time it happened was nearly 800,000 years and one at least one occasion there seems to have been only 11,000 years separating them. What governs the time periods between them is at the moment inexplicable. Why it happens as of yet has no explination. It is thought that when the transition begins it takes somewhere in the region of 1-2 thousand years.

'The Chip Shop' takes place in a time when this flip has its earliest beginings some 2 centuries previously (mid 19th Century) but is still just begining to happen, taking the already weakening magnetic field and the wandering natthure of our magnetic poles as markers and sujest that the 'flip' will accelerate over time.

In Glatzmaier and Roberts virtual model of the earths interior one sugestion is that during the reversal magnetic fields become tangled and it is possable that new pooles may be created in various unexpected places and multiple poles may exsist. 'The chip Shop' clearly is takeing literary licence and does not claim that this situation represents Glatzmaier and Roberts excelent work. The premise that 'The Chip Shop' uses though is not without some basis.