Comment Re:Polarity switch (Score 1) 333
No, the poles already reversed once in theory http://en.wikipedia.org/wiki/Earth's_magnetic_field, and are likely to keep reversing, though none of us will be around to find out.
This is not really a theory at this point. It has been demonstrated clearly in the geologic record that the earth's polarity has completely reversed at least hundreds of times (as wikipedia notes, "at an average interval of approximately 250,000 years").
