just a second..
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.
Aug 7, 2009
8:46pm
Jul 25, 2009
11:52am
Jul 21, 2009
7:40pm
Music from a Tree
Diego Stocco
Jul 21, 2009
7:28pm
Jul 21, 2009
7:26pm
Jul 21, 2009
7:25pm
Jul 21, 2009
7:24pm
Jul 21, 2009
7:24pm
Jul 21, 2009
7:11pm
Jun 3, 2009
11:57pm
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