Mankind has a fascination with measurement. Down the centuries we have produced a plethora of incompatible and duplicatory systems for measuring everything from the width of an Egyptian pyramid to the concentration of radioactivity near a nuclear reactor and the value of the fine structure constant. With the introduction first of the metric system and of its successor the Systeme International d'Unites (SI), the scientific community has established a standard method of measurement based on only seven core units.

The Encyclopaedia of Scientific Units, Weights and...

Mankind has a fascination with measurement. Down the centuries we have produced a plethora of incompatible and duplicatory systems for measuring everything from the width of an Egyptian pyramid to the concentration of radioactivity near a nuclear reactor and the value of the fine structure constant. With the introduction first of the metric system and of its successor the Systeme International d'Unites (SI), the scientific community has established a standard method of measurement based on only seven core units.

The Encyclopaedia of Scientific Units, Weights and...