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Then came trains and factories, and with them the need to coordinate the schedules of hundreds and even thousands of people. It was the railroad companies that invented time zones, in 1883. Because of the earth's rotation, the sun was highest at different times in New York City and, say, Washington, which lay a bit farther west. The 11-min. difference in local noon could lead to disaster at intersections.
Factories, meanwhile, required workers to begin their days together: it's no coincidence that inexpensive alarm clocks and wristwatches began appearing at the end of the 1800s. "In the 19th century," says historian Michael O'Malley, author of Keeping Watch: A History of American Time, "we were urged to merge our sense of time with mechanical devices. It allowed for new forms of social organization."
It also led to a vicious cycle. Once factory owners realized that time was money--a notion that led to the first so-called efficiency experts in the 1920s--the idea of making every second count began to spread through society. Result: efficiency became an American virtue. Today every conceivable business is open around the clock; we multitask frantically, applying makeup or talking on the phone while driving; we cram our kids' lives with team sports and lessons. Children don't play anymore: they schedule play dates. "We are," says author Gleick, "driven by time."
Technology continues to make things worse. Before digital clocks and watches became common, people rounded to the nearest five minutes when telling each other the time: now we give the exact minute. Before cell phones and faxes and answering machines, we accepted being out of touch. Before the Internet, we didn't feel entitled (much less obliged) to shop or do research or work around the clock.
Technology also demands that time be measured ever more precisely. An accurate mechanical clock proved to be so valuable to the British maritime industry in the eighteenth century that the government awarded a hefty prize to its inventor, Joseph Harrison (a story elegantly told in Dava Sobel's 1995 best seller Longitude).
But such a timepiece would be virtually useless today: computers, communications satellites, global-positioning receivers and telephone-switching systems need a precision beyond anything conceivable even 50 years ago. Time technology long since abandoned mechanical devices and even the hum of quartz crystals. For true precision--accuracy to a billionth of a second--you need to travel, virtually at least, to a place like the perfectly circular, well-guarded park that sits in northwest Washington. There, on the grounds of the U.S. Naval Observatory, a nondescript concrete building houses the nerve center of the U.S. Directorate of Time.
Behind its barred windows sit 28 atomic clocks, four of them holding atoms of hydrogen and the rest cesium. When excited by lasers or irradiated with microwaves, the atoms begin to dance with an utterly regular vibration that's monitored by computer. Once each second, the results are fed into America's Master Clock; the measurements from this and similar clocks around the world are sent to the International Bureau of Weights and Measures outside Paris--the ultimate timekeeping authority. It is there, next Friday, that the pulsing of billions of atoms will officially signal that civilization's odometer has turned over from 1999 to 2000.