'1/60 of a minute, until 1960 it was defined as 1/86,400th of a mean solar day'
Second
SIMPLE SCIENCE: 1/60 of a minute, until 1960 it was defined as 1/86,400th of a mean solar day
1/60 of a minute, until 1960 it was defined as 1/86,400th of a mean solar day
1/60 of a minute, until 1960 it was defined as 1/86,400th of a mean solar day
SIMPLE SCIENCE
Second
SIMPLE SCIENCE