The fiery demise of ancient huts in southern Africa 1,000 years ago left clues to understanding a bizarre weak spot in the Earth's magnetic field -- and the role it plays in the magnetic poles' periodic reversals.
The fiery demise of ancient huts in southern Africa 1,000 years ago left clues to understanding a bizarre weak spot in the Earth's magnetic field -- and the role it plays in the magnetic poles' periodic reversals.