If the arctic circle is moving North somewhere, does that mean it's moving South somewhere else? Or is it shrinking?,(reply>), Alex Willcox   Tom Scott, please show us how this works! Alex has explained it so carefully, but I still can’t quite get it.,(reply>), @OriginalPiMan The north pole isn't shifting in relation to the surface of the Earth. The Arctic and Antarctic Circles, just like the Tropics of Capricorn and Cancer, are defined by the tilt of the Earth in relation to the sun. The Polar circles are defined as the furthest north (or south) you can go and see the center of the sun on winter solstice. Go further north (or south) and the sun drops below the horizon. As the Earth's tilt reduces, those latitude more toward the poles: if the tilt reduced to 0 degrees, there'd be no Arctic Circle at all.,(reply>), @OriginalPiMan It's the axial tilt reducing.   Think of the earth like a spinning top toy slowly leaning over and rising back up again.,(reply>), @Witch Sorrowful Eh, no. The Arctic circle is going north, and the antarctic circle is going south.<br><br>Yes, there is wobbling but it's not the arctic circle wobbling, it's the earth wobbling, like a spinning top toy slowly leaning over and rising back up again.,(reply>), It'd be shrinking, moving north everywhere. The Antarctic circle would also be shrinking but south, staying exactly the same size in diameter as the Arctic circle and parallel to it