What is measuring?
On the Cultural History of Measuring
Measuring accompanies us every day. We no longer even notice when we measure and what we measure. For example, our day begins with the alarm clock, which is based on time measurement. We weigh our bodies with bathroom scales, and when we cook, we weigh the ingredients with kitchen scales or measuring cups. We buy food by weight. The water consumption is indicated by the water meter. We choose our clothes according to measurements from the weather stations, and when we drive a car, we are bombarded with information about speed, oil temperature, fuel level or distance travelled. Measuring is trivial and yet exciting.
“Man is the measure of all things.”
– (Attrubuted to) Protagoras
Ancient Measures
Measuring units developed in parallel with writing. With its 4,500 years, the Mesopotamian Nippur cubit is the oldest surviving measure of length, but by no means the oldest. Until modern times, human anatomy was usually the measure of all things, such as foot, cubit, Tagwerk (a day’s work), acre, bushel or pound.
“We must not forget that measures are made for humans, and not humans for measures.”
– Isaac Asimov
To Every Sovereign His Own Mass
The sovereignty over measurements was an instrument of domination as measures and weights were the privilege of the sovereign. Thus, there was no will and, above all, no central authority to harmonise the measurements. The Styrian measures of capacity and length remained in place until about 1853.
“Measure what is measurable, and make measurable what is not so.”
– (Attributed to) Galileo Galilei
On the Way to Equal Measurements
The initial spark for a universal system of measurement was the French Revolution, whose National Assembly introduced the metre in 1791. There are objective criteria behind the new measure of length: it is the ten-millionth part of the length of an Earth meridian between the North Pole and the equator.
“Exact measuring means excluding avoidable uncertainty factors and correctly assessing the amount of avoidable uncertainties.”
– Andrew Robinson
A Standardised System of Measurement for (almost) the Whole World
In 1960, the 11th General Conference on Weights and Measures adopted the “International System of Units”, abbreviated SI, consisting of seven base units. These base units are largely based on derived natural constants.
| Base Units and name of dimension | Unit | Unit symbols |
|---|---|---|
| Time | second | s |
| Length | metre | m |
| Mass | kilogramme | kg |
| Electric current | ampere | A |
| Thermodynamic temperature | kelvin | K |
| Amount of substance | mol | mol |
| Luminous intensity | candela | cd |
“Precision is considered a sign of diligence, skill and impersonality.”
– Theodore Porter
Anglo-Saxon Foot–pound–second System
The British and the Americans use their traditional, non-metric systems. Speed is measured in miles per hour (mph); in rugby and American football, yards are fixed units. Internationally, the FPS system is used in maritime transport and aviation, although it differs from the SI system.