Second

From Sciencemadness Wiki
Revision as of 20:19, 23 October 2022 by Mabus (Talk | contribs) (Created page with "{{Stub}} The '''second''' (symbol: '''s''') is the unit of time in the International System of Units (SI), historically defined as {{frac|1|86400}} of a day – this factor d...")

(diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)
Jump to: navigation, search

The second (symbol: s) is the unit of time in the International System of Units (SI), historically defined as 186400 of a day – this factor derived from the division of the day first into 24 hours, then to 60 minutes and finally to 60 seconds each (24 × 60 × 60 = 86400).

Currently, the second is defined 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. To allow for the relativistic affects of gravitational time dilation at different altitudes, the second measured for any atomic clock is also corrected to mean sea level.

References

Relevant Sciencemadness threads