Measurement is one of the hallmarks of civilization. How far is it? How much does it weigh? What time is it? These are all questions that we hear every day. Indeed, asking the time is probably the number one question that we ask, especially when we are...

Si stands for Système International (d’Unités)—the system of units used in measurement. The measures of main interest to biological psychologists are: length, measured in metres (m) and area, measured in square metres (m2);...

Dimension Unit Symbol Length Meter m Mass Kilogram kg Temperature Kelvin K Time Second s Electric current Ampere A Luminous intensity Candela cd Amount of substance Mole mol Derived units Force Newton N Energy Joule J Power Watt W Pressure Pascal...

Fundamental quantities of this system are length (meter), time (second), mass (kilogram), electric current (ampere) temperature (Kelvin), luminous intensity (candela) and amount of substance...

The International System of Units (abbreviated SI from the French Le Système international d'unités) is the modern form of the metric system. It is the world's most widely used system of units, both in everyday commerce and in science. The older...