January 18, 2012 | 4
An open letter to the knuckleheads at the International Telecommunication Union:
I’m hearing that you guys are considering dropping the Leap Second – the second added every year or so to Coordinated Universal Time to make sure CUT, kept by incredibly accurate and complex atomic clocks, squares as closely as possible with astronomical time, kept by the incredibly accurate and complex universe. According to this story by the AP, there’s a movement afoot to do away with the leap second for the seemingly sensible reason that the leap second is inconvenient for programmers.
Don’t be a bunch of knuckleheads. Please leave our system of time connected to our universe, you dopes.
Okay, that’s a little glib. Here’s the deal. As you know, places like the Royal Observatory in Greenwich, England and the U.S. Naval Observatory in the United States (the broadcasts of their timekeepers were coordinated in 1960, by the way, according to the non-Wiki Encyclopedia Britannica) keep extremely accurate clocks and broadcast signals from those clocks. Those signals are essential for GPS systems, cell phone systems, all kinds of communications and measuring systems. Pretty much everything is connected to those time broadcasts now, based on those radiation cycles. That’s how your computer knows what time it is; your cell phone too. You can even buy inexpensive clocks and watches that pick up the broadcasts, in case you fear your computer, phone, or radio station might be off by a tenth of a second or so.
Accuracy, of course, is good. Everybody knows the story of the Harrison’s chronometer, but increasing accuracy in timekeeping has been a hallmark of advancing science since forever. Nowadays we use atomic clocks, which keep time by counting … well, let the U.S. Naval observatory explain it: “cycles of radiation corresponding to the transition between two hyperfine levels of the ground state of cesium 133.” As you well know, 9,192,631,770 of those equal one second, and there you are. A nice approximation of the old-school second, which has existed since the Babylonians took to making base-60 calculations and divided hours into minutes and seconds, 60 of each, making the second equal 1/86,400 of a mean solar day. The Babylonians something more thatn 2000 years ago began using base 60 because it simplified calculation, being divisible by 2, 3, 4, 5, 6, and 10 (according to this non-Wiki site). The Egyptians, by the way, had divided the day into 24 hours as early as 1300 B.C.E., just because it sort of felt best to them that way.
But the real news in all that time calculation, of course, is the “mean solar day,” which is just what it sounds like. If you go to any good time site you will learn about sidereal time and rotational time and barycentric coordinate time and on and on, but the point is that if you think about the passage of time, on this planet you’re going to be thinking about day and night and seasons and years, because on a rotating planet with a tilting axis orbiting a star, those cycles form the foundation of any meaningful discussion of time. However nice it is that we can measure cesium 133 radiation cycles and use them for extreme accuracy, removing the connection between those radiation cycles and the cycles of the planets and satellites and tides and seasons is profoundly dangerous.
Yes, the leap second comes up every couple years and is a pain for people managing the GPS and computer systems that manage our entire world. But if you decide to leave the leap seconds out, the atomic clocks and the universe itself begin sailing on different paths. In a year or two your atomic wall clock and your radio station will disagree, and in a few thousand years they’ll be completely catywampus. It sounds like nothing, but in a world where we’re constantly encouraged to interact through screens and speakers, where we exist in climate controlled environments whose very existece is systematically dismantling the actual climate, anything that reminds us there’s a real world out there is a positive. Have you ever flipped on your computer to check a weather forecast rather then sticking your head out the door to check the sky? You’re already in danger, my friend.
So it’s refreshing that at the exact same moment the knuckleheads are considering severing the connection between accurate
timekeeping and the planet for which it keeps time, I ran across this ecological calendar, the perfect antidote to that kind of thinking. This calendar comes in four banners, one per season. It notes solar and lunar cycles and a million other things. It’s entire job is to remind you that you live somewhere – on a particular planet. That it’s today, not yesterday – that the moon is in a particular phase, that there’s an eclipse coming up, that it’s spring or fall or whatever. And hopefully to encourage you to think about why. The fact that the creators call this calendar that urges you to look around yourself and experience your surroundings the way a Neanderthal might have “a new way to experience time” shows you how far gone we already are.
Divorcing superaccurate timekeeping from the universe it’s meant to describe solves no problem and exacerbates a profound one. Don’t do it.
I mean really: they call it “Coordinated Universal Time” for a reason. Do you really want people to start saying, “Which universe?”