replica in the NIST in Your Community exhibit shows
how NIST's fountain clock (NIST-F1) uses atoms to determine
the duration of one second. One of the two most accurate
clocks in the world, NIST-F1 subdivides the second into
more than 9 billion equal parts. It will neither gain
nor lose a second in nearly 20 million years.
needs a clock this good? NIST's ultra-accurate time
services help navigate spacecraft through the solar
system, synchronize telecommunications and computer
operations, and measure fundamental processes like the
speed of chemical reactions.