NIST's New Atomic Clock Is So Precise Our Ability To Measure Gravity Constrains Its Accuracy (vice.com)

dmoberhaus writes: Researchers at the National Institute for Standards and Technology (NIST) have developed an atomic clock that is so precise that our models of Earth's gravity aren't accurate enough to keep up with it. As detailed in a paper published this week in Nature, the atomic clock could pave the way for creating an unprecedented map of the way the Earth's gravity distorts spacetime and even shed light on the development of the early universe. "The level of clock performance being reported is such that we don't actually know how to account for it well enough to support the level of performance the clock achieves," Andrew Ludlow, a physicist at NIST and the project lead on the organization's new atomic clock, told me on the phone. "Right now the state of the art techniques aren't quite good enough so we're limited by how well we understand gravity on different parts of the Earth."

Comments

New, extremely accurate altimeter?

[Anonymous Coward]

Since you can measure gravity extremely accurately, and gravity varies with height, does that mean they've just invented an extremely accurate altimeter?

Re:New, extremely accurate altimeter?

[charliemerritt03]

Yes, but it must be locally calibrated. I was talking to a guy that used to work at WWV, he said that moving an older clock up one story would make a very noticeable change in it's tick time - this one might be sensitive to inches.