I had one of those fantastic experiences today, serendipitous, where I closed a 35 year-old circle, quite unexpectedly.
I travelled north of Fort Collins this morning with my colleagues from the Fort Collins Museum and Discovery Science Center to visit radio station WWVB, which broadcasts the atomic time all over the country and the world (their shortwave signal, broadcast as WWV, has been picked up as far away as South Africa and the South Pole). Do you have a “radio controlled” watch or clock? It gets its signal from WWVB in Fort Collins.
We were visiting as part of our larger project of talking with the science and cultural groups in the area, which is in turn part of our exhibit master planning process for the new museum. Basically, we’re going on cool field trips to find out what’s going on in our community. Besides visiting WWVB, we’ve talked to New Belgium brewery, and are scheduled to meet with the Seed Repository at CSU, the folks at WaterPik, CSU’s Atmospheric Science research center, and the Vestas wind turbine people.
We spent several fascinating hours at the facility, which is part of the National Institute of Standards and Technology, which is ultimately part of the US Department of Commerce. The “official” atomic clock is at NIST in Boulder; but we learned today that the signal broadcast from the antennae in Fort Collins (there are two) comes from a duplicate “clock” on site here, which is synchronized several times a day to the one in Boulder. So, although the “official” time is kept in Boulder, the signal you get is generated by the clock in Fort Collins.
We learned just a bazillion fascinating things today, and probably that many more went over our heads. The guys out there were fantastic and showed us all around: time stamp generators, transmitters, the cesium clock itself, the antennae, and the immense gridwork of towers and cables that support the antennae. We honest to god saw the, I’m not kidding, switch that they throw — manually — to send the “bit” that goes out in the signal when it’s Daylight Savings Time. Some of — much of — the technology looks like mid-1960’s Star Trek. There are Dymo tape labels on the electronics cabinets and dot matrix printers. But this stuff was built to last — and when it gets replaced, often the “new” technology doesn’t last as long (as they found out a few years ago when a new support cable for one of the towers fatigued unexpectedly and snapped). We also learned about leap seconds; they keep track of the discrepancy between the atomic clock and the actual rotational speed of the Earth (which is tending to slow down), and when that discrepancy reaches a nice round number, in this case, a second, the “Leap Second” switch gets thrown and we get an extra second. We just had one not too long ago. Currently, the discrepancy is at .409 milliseconds, so it will be awhile before we need another leap second adjustment.
I could go on and on, even worse than I’m doing now. (It was just so dang cool!). But back to my “circle.” We also visited the shortwave signal generator, known as WWV. Besides the time signal, the shortwave also broadcasts an audio component — listen to a recording (not live) here. I’m such a geek, but it was so freakin’ cool to listen to the signal, right there in the room where it was being generated! And watching my atomic wristwatch tick along in perfect synch — it was like my watch had returned to the Mothership! But the best part was suddenly remembering, when I heard that sound, how I would take Dad’s shortwave radio out to my observatory, when I was a teenager, and listen to the signal while I made my astronomical observations. I reasoned, if I saw anything noteworthy, I would need an exact time stamp for my report! I haven’t listened to that signal for 35 years.