Topic
Timekeeping
3 questions tagged Timekeeping — spanning every one of the seven Ws.
where
Where is the world's most precise atomic clock kept?
Some of the world’s most precise atomic clocks are kept at national metrology labs such as NIST in Boulder, Colorado. These clocks are so accurate they can lose or gain less than a second over billions of years.
PhysicsTimekeeping
how
How do atomic clocks keep time so accurately?
Atomic clocks measure the exact frequency of transitions in atoms, usually cesium or rubidium. The cesium standard defines the second as 9,192,631,770 vibrations of a specific radiation.
TechnologyTimekeeping
what
What was the Roman calendar reform under Julius Caesar?
Julius Caesar reformed the Roman calendar in 45 BCE by creating the Julian calendar, a solar calendar with a leap day every four years. It replaced a lunar-based system that had become badly out of sync.
Ancient RomeTimekeeping