What is the Chandler wobble and who discovered it?

No, it’s not a dance move.

The Chandler wobble is a slight wobbling of Earth on its axis. It got its name from the guy who discovered it was happening in 1891—S. C. Chandler.

Still want to know how it’s done? If you’ve ever worked on a pottery wheel, you’re familiar with the concept.

Earth is spinning, but it’s ever-so-slightly off center in its rotation. If there were big pens sticking out of the North and South Poles that were scribbling on giant pieces of paper, we’d end up with irregular circles.

In reality, these circles measure anywhere between 10 and 50 feet in diameter—not much of a wobble, really, but sometimes enough to throw you off by about one-fifth of a mile if you’re navigating by the stars.