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NIST physicists Steve Jefferts (foreground) and Tom Heavner with the NIST-F2 cesium fountain atomic clock, a civilian time standard for the United States. NIST-F2 is a caesium fountain atomic clock that, along with NIST-F1, serves as the United States' primary time and frequency standard. [1] NIST-F2 was brought online on 3 April 2014. [1] [2]
The first set of units defined using the caesium standard were those relating to time, with the second being defined in 1967 as "the duration of 9 192 631 770 periods of the radiation corresponding to the transition between the two hyperfine levels of the ground state of the caesium 133 atom" meaning that: 1 second, s, = 9,192,631,770 Δt Cs
NIST-F1, source of the official time of the United States. NIST-F1 is a cesium fountain clock, a type of atomic clock, in the National Institute of Standards and Technology (NIST) in Boulder, Colorado, and serves as the United States' primary time and frequency standard. The clock took fewer than four years to test and build, and was developed ...
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The Federal Aviation Administration said Friday that it is setting up a new process for air tour operators in Hawaii to be approved to fly at lower altitudes after numerous fatal crashes in recent ...
Travelers hoping to visit Hawaii in coming weeks are being asked to avoid West Maui, which has been ravaged by wildfires.
1925 John Rodgers leads a non-stop flight attempt from California to Hawaii in a Naval Aircraft Factory PN. 1927 January - Lewis Hawaiian Tours starts flights between islands in a five-seat Ryan modified from a swept-wing standard. [4] 1927 The Dole Air Derby challenged aviators to fly from Oakland, California to Honolulu. Only two aircraft ...
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