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Old 11-11-2010, 05:44 PM
Spatial Rift 47 Spatial Rift 47 is offline
Join Date: Dec 2000
Location: Boston, MA
Posts: 3,222
Chronos - yeah, probably.

I should note a correction: the cesium-133 transition used to define the second is taken from a hyperfine correction to the ground state, with no external magnetic field present. The extremely small separation between the energy levels is produced by internal magnetic fields, i.e. those of the subatomic particles. So you would just get a bunch of cesium-133, make it as cold as possible, and wait. Once you record the radiation, you correct for the remaining temperature and for various other effects like time dilation (Earth's gravity will change the measurement depending on altitude).