11.15.2005Biological or atomic?
From Scientific American: Wait a Second
Leap seconds are needed because the earth's spin is slowing down, gradually and unevenly. The rotational changes arise because of tidal forces exerted by the moon and inertial effects related to the liquid outer core sloshing around and to the cycle of evaporation, in which water at the equator gets deposited at the poles as ice that melts seasonally.
The present system is a compromise between taking advantage of the most accurate timepieces--that is, atomic clocks--and respecting traditional timekeeping via the sun's position. To people who want to end leap seconds, Levine explains, "the really fundamental quantity is not time but frequency--and frequency comes from quantum mechanics; it is a property of atoms. And what these folks really want is for time to represent frequency in a smooth, continuous way." Levine does not speak officially for NIST, but he is the person who, on December 1, will formally alert authorities to add the leap second at the end of the month.
The existing compromise system, Levine notes, also sows confusion. For one, the leap second occurs in the middle of the day in Asia and Australia, causing a time hiccup during stock trading. For another, the more timescales there are, the easier it is for a programmer to make an error in calculations.
I like the idea of time 'hiccups' on the trading floor of a stock exchange with people rabidly screaming and waving their arms, and then everything coming to a sudden halt for a second or two, and then everything picking back up again. I find the general prospect of attempting to fit geocentric (and hence, biological) time to our more accurate and technologically advanced atomic time pieces, and that the imprecision of the fit allows for gaps and fits and jerks, like a computer slowly booting up.
I suppose the pragmatic efficiencies of switching to unified and universal time makes it the defacto forerunner in this debate, but there is something crude and exacting and mechanical in severing the concept of time from the biorhythmic process that yielded its discovery.
edit: For anyone who cares, you can read all the live blog updates on the WSIS proceedings here. I'll try to keep abreast of the details.