This New Atomic Clock Is So Precise Our Ability to Measure Gravity Constrains Its Accuracy
NIST's new atomic clocks will help create the world's most precise map of how Earth's gravity warps spacetime.
Physicists Used Atomic Clocks to Test Einstein’s Theory of Relativity in a 14-Year Experiment
A foundational thought experiment in Einstein’s theory of general relativity just got its most precise confirmation ever by turning the entire Earth into a laboratory.
Why Nuclear Clocks Will Be the Most Accurate Clocks on Earth
Atomic clocks are the golden standard of timekeeping today, but a new technique to use the nucleus of an atom to keep track of time could be even more precise.
Why the Whole World Is Fighting Over the Leap Second
Enjoy today’s leap second, it could be one of our last.
The Plan to Lose Leap Seconds Would Throw Our Clocks Out of Sync With the Earth
Our clocks are more accurate than the Earth's rotation, and we need to decide whether to keep them in step.
The US Has a New, Super-Accurate Atomic Clock
Three times as accurate as its predecessor, it'll only lose a second over 300 million years.