Does the Earth wobble as it spins?
Indeed it does. Astronomers have been monitoring its wobble over the last
century and have found that the axis of the Earth dithers in a roughly circular
path called the Chandler Wobble. At the North Pole of the Earth, if you were
standing there and plotting where the axis emerges on the surface of the Earth,
its track would execute a circular loop about 20 feet in diameter. This is
reflected in a 0.1 arcsecond circular wiggle in the paths of stars during the
course of a year. This wobble is not the same year after year and can vary from
10 feet to 50 feet over the course of several decades. The largest amplitude was
recorded, I believe, in 1910. The cause of this has many sources including
rearrangements of mass deep in the Earth's interior
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