New Clock May End Time as we Know it
NPR:
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.
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But this new clock has run into a big problem: This thing we call time doesn't tick at the same rate everywhere in the universe. Or even on our planet.
Right now, on the top of Mount Everest, time is passing just a little bit faster than it is in Death Valley. That's because speed at which time passes depends on the strength of gravity.
Well my mind is blown.