By Peter Weiss
Just days before the new year began, the United States followed through on a resolution to keep better track of time in the years ahead. On Dec. 29, the National Institute of Standards and Technology (NIST) in Boulder, Colo., switched to a new type of timekeeping technology—the atomic fountain clock—as the nation’s primary time standard (SN: 8/7/99, p. 92).
Stunning developments in atom cooling and trapping since the 1980s led to the new clock type (SN: 10/25/97, p. 263). The NIST F-1 fountain clock that went into service last month uses lasers to congeal cesium atoms into a cold ball.