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A NIST Physical Measurement Laboratory Presentation

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The Evolution of Time Measurement through the Ages

stonehenge thumbnail
Ancient Calendars
water clock thumbnail
modern timepieces thumbnail
A Revolution
in Timekeeping
cesium clock thumbnail
The "Atomic" Age
world time thumbnail
World Time Scales and
Time Zones
International Space Station satellite thumbnail
NIST Time Services
Bibliography (stack of books thumbnail)

Version History

National Institute of Standards and Technology (NIST)
Physical Measurement Laboratory (PML)
Time and Frequency Division (for additional information on time services and standards)

Go to Time Exhibits

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May 1995