Ive always thought it was weird how little press or acknowledgement the fact that the earths magnetic field regularly reverses gets.
Afaik there has been evidence of this since the late 40's when the 1st magnetic surveys of the ocean floor were carried out. They noticed the sea floor was made of bands of rocks with different magnetic configurations. Note: This was also crucial evidence in favour of the theory of continental drift, they realised that the Atlantic floor was like two conveyor belts issue from the centre.