A unit of measurement is one unit of a quantity: for example, one second. Standard units of measurement are the units most typically used to measure a quantity. Time has various units of ...

This week, Sam Kean takes a look at some ridiculously precise standards — the meter, the second, and other international standard units ... And metrologists (measurement scientists) didn ...

the official standard for demarcating the universe into manageable, studyable chunks. Metric measurements — also known as the International System of Units, or SI — are managed by a formal ...