|attosecond||10−18 s||shortest time uncertainty|
in present measurements
|femtosecond||10−15 s||pulse time of ultrafast lasers|
(100 as = 0.1 fs)
|nanosecond||10−9 s||time for molecules to fluoresce|
|second||1 s||base unit|
|week||7 days||Also called sennight|
|fortnight||14 days||2 weeks|
|lunar month||27.2–29.5 days||Various definitions exist.|
|common year||365 days||52 weeks + 1 day|
|leap year||366 days||52 weeks + 2 days|
|tropical year||365.24219 days||average|
|Gregorian year||365.2425 days||average|
|Olympiad||4 year cycle|
|lustrum||5 years||Also called pentad|
|Indiction||15 year cycle|
|jubilee (Biblical)||50 years|
|exasecond||1018 s||roughly 32 billion years, more than twice|
the age of the universe on current estimates
|cosmological decade||varies||10 times the length of the previous|
cosmological decade, with CÐ 1 beginning
either 10 seconds or 10 years after the
Big Bang, depending on the definition.
- math conquer
Wednesday, 10 October 2012
Sunday, 7 October 2012
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