I was just getting acquainted with caesium standard clocks, now they’re changing to strontium.
At the heart of this new clock is the element strontium. Inside a small chamber, the strontium atoms are suspended in a lattice of crisscrossing laser beams. Researchers then give them a little ping, like ringing a bell. The strontium vibrates at an incredibly fast frequency. It’s a natural atomic metronome ticking out teeny, teeny fractions of a second.
This new clock can keep perfect time for 5 billion years.