Time doesn't come from your phone. It doesn't come from your watch either. It comes from atoms oscillating in a vacuum — billions of times a second — inside a system that never stops checking itself.

This site displays a prototype of a “Web 2.0” version of the daily Federal Register. It is not an official legal edition of the Federal Register, and does not replace the official print version or the ...

The length of a second was initially determined astronomically, using Earth's rotation. One second was defined as 1/86,400th of a solar day. As technology advanced, we realized Earth's rotation isn't ...

Breakthroughs, discoveries, and DIY tips sent every weekday. Terms of Service and Privacy Policy. Atomic clocks have served as the world’s most precise means of ...

A powerful laser shines into a jet of gas, creating bright plasma and generating ultraviolet light. The light leaves a visible white line as it interacts with leftover gas in the vacuum chamber. This ...

The nucleus of an atom is now the modern version of sand flowing through an hourglass. Researchers have spent 15 years trying to increase accuracy in timekeeping. The U.S. standard currently relies on ...

Scientists have developed the most precise and accurate atomic clock to date – if you ran it for twice the current age of the universe, it would only be off by one second. This could not only improve ...

Abstract: In this study, a quantum measurement method of radio-frequency (RF) attenuation based on atomic resonance is realized for the first time utilizing the interaction among atoms and RF waves.