After the introduction of a new kind of atomic clock, the world's most expert timekeepers are considering making an update to how we measure a simple second. It would be more accurate, sure. But it would also force us rethink theoretical physics as we know it.
Jérôme Lodewyck and his colleagues report that the two new optical lattice clocks they've been testing at the Paris Observatory are about as accurate as accurate gets, and the improved precision might justify a change in the global time standard. Developed at the National Institute of Standards and Technology, these optical lattice clocks are about 100 times more accurate than the atomic clocks currently used to sync the world's watches. Even still, it would take you a few million years before you'd notice the difference.