Fate of the leap second hangs in the balance
Scientists decide today to keep it or scrap it
Clocks around the world are ticking portentously toward a scientific showdown today in Geneva, where delegates at a gathering of the International Telecommunication Union — the UN agency that regulates global measurement of time — will decide whether to abolish the “leap second.”
Canada and Britain are among the nations poised to resist scrapping the practice of adding one second to the world’s clocks every few years to account for slight wobbles in the Earth’s movement through space, the result of earthquakes, variations in tides and other “error”inducing natural phenomena.
But the U. S., France, Japan and a host of other pro- reform nations seem likely to prevail in getting rid of the leap second, widely deemed a troublesome relic of bygone days in an era with satellites requiring continuous, pinpoint accuracy in timekeeping, all geared to hyper- precise “atomic clocks” that are maintained by scientific institutes around the world — including the National Research Council of Canada.
While Canada’s atomic clock would remain part of a global network of devices required to maintain the new, “Co- ordinated Universal Time” — or UTC — the occasional onesecond adjustments necessary to keep those atomic clocks in sync with our imperfectly orbiting Earth would be eliminated, ending the 40- year reign of socalled “celestial” universal time, or UT1.
In November, an Industry Canada official said this country opposes the proposed abolition of the leap second.
The current system “works very well for Canada,” the department said at the time. “There are no agreed reports that would suggest any serious problems caused by leap seconds. Therefore, it would be more costly for Canada to adopt a new system, considering that we have heavily invested in the software and hardware to cope with leap seconds.”
Similar arguments have been advanced in Britain, where the proposed change to atomic time is being cast as the death- knell for Greenwich Mean Time, the historic, U. K.- based precursor of UT1.
Some critics have argued that ignoring the Earth’s wobbles eventually will — in 550 years, to be precise — result in a onehour difference between UTC, which is essentially oblivious to the sunrise- and- sunset rhythms of the Earth, and planetaryrotation- based UT1.
Proponents say such a drift would require corrections only very rarely, allowing the world to run for generations or even centuries without resorting to the adjustments that now happen every few years — at unpredictable times — under the leap- second system.
The decision will come nearly 130 years after Canadian engineer Sir Sandford Fleming introduced his groundbreaking plan to standardize international time. Since then, countries have re- negotiated the framework for coordinating clocks around the globe, but the latest debate over reforms has proven particularly thorny.
Proponents of UTC insist that killing the leap second and basing a new time regime on atomic exactitude will eliminate potentially disastrous complications in systems requiring perfect synchronization, such as satellite navigation, Internet network protocols, global financial data transfers and various fields of telecommunication.
The last time a leap second was added to global time — at midnight on Dec. 31, 2008 — hightech systems around the world were forced to make adjustments to avoid experiencing malfunctions of the sort widely envisioned during the “Y2K” scare before the turn of the millennium on Jan. 1, 2000.