Reader Question – Felipe Ferreira da Costa, Rio de Janeiro, RJ
Because the Americans did not accept the world unification of measures, carried out under the influence of France. The process began in the French Revolution, in the 18th century, and was consolidated in the 20th century. Before that, there were no standards. Commercial transactions were made between neighboring peoples, who negotiated the equivalence of length, weight and volume.
Standardization began to become a necessity in the 15th century, thanks to the great navigations and the more frequent contact between distant peoples. The meter, the base measure of the International System of Units (SI), was suggested by the French priest Gabriel Mouton, in 1670. It came from a fraction of the planet (the distance from the Equator to the North Pole divided by 10 million). It was an objective measure (which also gave rise to kilos and liters, as you can see below) and valid for anyone. When the SI was established in 1960, the US already had its own system, inherited from England. In addition to the States, only two countries do not adopt the metric system: Myanmar, in Asia, and Liberia, in Africa.
EVEN ON THE THERMOMETER
The preferred temperature scale in the US is Fahrenheit. It was used in industry worldwide until the measurement system was unified in 1960. From then on, degrees Celsius became a worldwide standard.
Note: contrary to what was shown in the image, 1 cubic meter is equivalent to a thousand liters 😉