Once every 450,000 years or so, the Earth undergoes a radical transformation.

The planet's magnetic field will literally flip.

The North Pole becomes the South Pole and vice versa.

Despite the fact that we know this has happened many times in the Earth's history,

we really don't know what would happen if the poles were to reverse today.

Learn more about when the Earth's magnetic poles reverse on this episode of Everything Everywhere Daily. Before I get into the details of how and why the Earth's magnetic poles will reverse,

it's important to understand how geologists know that the Earth's magnetic poles have reversed in the past.

Many rocks are made up of magnetic minerals, usually magnetite or the more weakly magnetic

chemotite, both of which are based on iron.

When a rock first forms from liquid magma, the individual magnetic molecules will align themselves with the Earth's

magnetic field.

As the rock solidifies and cools, the individual mineral molecules are then locked into

place with this particular magnetic orientation.

In the late 19th and early 20th centuries, geologists began to notice that some rocks were magnetized

opposite to the Earth's magnetic field.

The first person to notice this was a French

geologist by the name of Bernard Broon. In the 1920s the Japanese geologist

Montanori Maruyama suggested that the cause of the oppositely orientated rocks was due to the Earth's magnetic poles having been reversed.

While Madhayama and Broons suspected that the Earth's poles had switched,

they didn't know when it happened or how many times it had happened. The best guess was that it happened millions of years ago.

In the 50s and 60s, however, there were two developments that helped solve this puzzle.

The first of which was the development of

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