A brief remark at a talk in October led me to a clever bit of science that offered a way through the paleomagnetic mirror problem. By that I mean the ambiguity that results when a moving continent heads toward the equator. The paleomagnetic record shows it reaching the equator, then moving closer to the magnetic polebut in which hemisphere? Just from magnetic evidence, there's no way to decide whether the continent plowed straight onward into the opposite hemisphere or backed off and stayed on its original side of the line. The solution had to do with the Coriolis force, the only way we have to tell the left-handed hemisphere from the right-handed hemisphere. So far this method has been useful only once, but I was pleased that a method existed at all. Details in this new article, "Disambiguating the Paleomagnetic Record."