How do the professional timekeepers of the world determine, to the precise nanosecond, when a new year begins? They simply consult an atomic clock. And last week, just in time to ring in the new, the Hewlett-Packard Co., of Palo Alto, Calif., unveiled the latest in these meticulous timepieces. Twice as accurate as earlier models, the $54,000 device -- the size of a desktop computer -- will remain reliable to the second for the next 1.6 million years, a period far longer than modern humans have existed.
Who could possibly need such precision? Practically everyone, indirectly at least. Telephone and computer...