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A comment on In Vienna and Beijing, the First (Thorium) Nuclear Clocks Begin to Tick. Parent comment

Re:In Vienna and Beijing, the First (Thorium) Nuclear Clocks... by froh on Thursday October 08, 2026 @05:34AM (#50003713)
TIL an atomic clock is not a nuclear clock.

the former brings (cesium) atoms, including their electrons, into resonance.

the latter brings (thorium) _nuclei_ into resonance.

both then "just like any clock" measure that oscillation. "simples" ;-)

and I learned "environment" creating drift is temperature, magnetism, anything that influences electrons.

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Re:In Vienna and Beijing, the First (Thorium) Nuclear Clocks... by soltanov on Thursday October 08, 2026 @05:53AM (#50003839)
Spot on. Shielding electron transitions from stray thermal and magnetic shifts takes brutal trapping setups. The nucleus provides that isolation for free.
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Re:In Vienna and Beijing, the First (Thorium) Nuclear Clocks... by rdtsc on Thursday October 08, 2026 @02:35PM (#50010009)
"atomic" and "nuclear" have been used interchangeably at various times. In the past almost everything was "atomic". But more recently and more formally atomic deals with nucleus and it's electron shells, and nuclear deals just with the nucleus.
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