At every level, I am interested in how the Earth works. The partially molten nickel-iron core of the Earth is probably the source of its magnetic field.
All magnets have polarity.
Depending on the density and the purity of the material involved, changes in a magnet's polarity can take place. Some evidence indicates that changes in the Earth's magnetic field have occurred in the past, and so could happen again. I wonder what such a phenomenon might mean for life as we know it. I had occasion several years ago to ask my dear and respected friend Buckminster Fuller about the possibility of change in the Earth's polarity. I specifically asked him what might affect changes in the Earth's polarity.