I knew that there were different methods for maintaining the standards of time, but until I read this Guardian Unlimited article, I didn’t realize just how many divergent systems there were and by how much they differed. I also hadn’t realized that the Moon is slightly, steadily slowing the Earth’s rotation, necessitating the addition of “leap seconds” at irregular intervals. Between this phenomenon and the differing time scales, “the scales can be as much as 30 seconds apart and the gap between them is growing steadily.” This could eventually lead to not only confusion among different systems but also to misreported GPS positions causing an accident, for example. The ITU is working on settling on a universal standard, but they have a lot of different considerations to take into account; the article goes into in a little more detail on some of these.
