Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

PML General Interest


NBS/NIST Radio Stations: The Story of an Old Timer

A series of webpages leading you on a journey on the history of the NBS/NIST radio stations.

A Walk Through Time

A descriptive look at the history of timekeeping from ancient to modern methods, with a brief introduction to NIST Time and Frequency Services.

From Sundials to Atomic Clocks: Understanding Time and Frequency (25.7 MB PDF)

Originally published in 1977, this full-length book provides a comprehensive, easy-to-understand introduction to the field of time and frequency. Readers of nearly all ages and educational backgrounds should find it enjoyable. 306 pages.

NIST Web Clock

Compare your computer's clock with NIST's atomic clock set to Coordinated Universal Time (UTC).

FAQ (frequently asked questions) and Glossary of Frequency and Timing.

General Interest Time and Frequency Publications

Exhibits from the Physical Measurement Laboratory

in the NIST Virtual Museum

SI Redefinition Portal

A series of special reports on the worldwide consensus plan to redefine the SI.

Marie Curie and the NBS Radium Standards

A history of the NBS radium standards and Marie Curie's involvement.

The Fall of Parity

Experiments in late 1956 demonstrating that our world is distinguishable from its mirror image.

The Scanning Tunneling Microscope

Invention of a precursor instrument, the topografiner, between 1965 and 1971.

Online Museum of Quantum Voltage Standards

Celebrating the 100th Anniversary of the Discovery of Superconductivity

Nobel Prizes*

NIST's David Wineland shared the 2012 Nobel Prize in Physics. NIST/JILA Fellow Jan Hall shared 2005 Nobel Prize in Physics.

NIST's Dr. Eric Cornell shared the 2001 Nobel Prize in Physics with two other researchers.

NIST's Dr. William D. Phillips shared the 1997 Nobel Prize in Physics with two other researchers. * Links include numerous articles, official statements, congratulations, and photographs.


Created June 29, 2009, Updated February 22, 2023