The often chaotic history of the metric system, whose origins date back to the French Revolution, illustrates the challenge represented by its global adoption. Indeed, until the end of 18e A century, France alone had nearly 250,000 different units of measurement, while elsewhere in the world, each nation, and sometimes even each region, used its own systems to quantify the world around it. This situation represented a real nightmare for the scientists of the Enlightenment, who dreamed of creating a universal system based on a fixed and invariable constant.
Responsible for defining a new system, the Academy of Sciences decided that the new basic measurement would correspond to the length of a ten-millionth of the distance between the North Pole and the Ecuador, measured from Paris. This measure, baptized the “meter” and rigorously established by a group of eminent scientists, became the cornerstone of all the metric units of mass and measure which followed. Even the volume measurements were derived: thus, 1 milliliter is equivalent for example to 1 cubic centimeter of water.
If the French state quickly adopted the new system, the general public put much more time to get used to it. The implementation took delay, even though the metric system aroused the enthusiasm of scientists from around the world, who now used it to define concepts such as electricity or magnetism. Little by little, the idea began to spread, and in 1866, the United States adopted a law authorizing the use of metric units in trade.
The metric system was slowly diffused across the country, first thanks to the distribution of states to states in order to help them normalize their weights and measures, then thanks to the meter agreement, an agreement signed in 1875 by many powers such as the United States, Germany, Russia and France. This treaty gave birth to an international body responsible for the regulation of weights and measures, thus opening the way to a broader adoption of the metric system by the United States.
However, while scientists were continuing their work of improvement and expanded its use to new areas, the adoption of the metric system continued to drag in the country. In 1960, the metric system was extended and modernized in order to cover a greater number of fundamental units of our planet, from voltage to speed, passing through the thermal capacity to radiation. That year, the metric system took the name of an international system of units (SI), and was officially defined and adopted on a global scale.
The majority of countries followed the movement, setting up concrete reforms: road panels, packaging, school programs, everything was gradually converted to the metric system. Even the United Kingdom, for a long time, ends up aligning itself with its European neighbors. (Note, however, that, from Brexit, some opponents demand a return to imperial units, a controversial proposal still not adopted to date.)
In the United States, despite a federal policy encouraging the use of the metric system, the transition remained laborious. This resistance to change was partially fueled by industrialists fearing complexity and the cost of conversion, by suspicious legislators vis-à-vis an influence deemed “foreign”, and by persistent debates on the potential impact of a federal adoption on the individual rights of the States.
Result: generalized confusion relating to metric units. In 1975, the Metric Conversion Act Officially designated the IS as a privileged measurement system of the country: however, even federal agencies were slow to adopt it in fields such as industry, education, trade and daily life. The example of road signs is particularly speaking: after the adoption of the law, the federal authorities tried to make a new motorway in Arizona a showcase of the metric system, by installing terminals in kilometers rather than in miles. However, this experiment remained isolated, and the rest of the network kept the panels in imperial units.
Even today, the two systems coexist largely in the United States. “We are playing in a hybrid measurement environment, which is not without risk,” she notes. It is not uncommon to see double signaling, and metric measures are sometimes relegated to the background on graduated rules, panels or tools, which can cause expensive errors and disorient the public.
“The major organizations, which had the necessary resources and technical staff, quickly seized the strategic interest of the metric system,” explains Benham. “They adopted best practices and went forward. On the other hand, small businesses and individuals still need support, as well as teachers who form future generations who, they will still have known only the metric system.
Benham remains convinced that a voluntary transition to the metric system is possible in the United States, and encourages individuals to pay attention to the metric measures already present in their daily lives. “I compare it to an iceberg,” she says: if the imperial units dominate on the surface, many sectors actually use the metric measures behind the scenes-whether on food labels, speed meters or thermometers.
In the end, according to the expert, a real tilting can only be done when individuals choose themselves to adopt the metric system in their everyday life. This is why Benham relies on education in her work and applies these principles herself on a daily basis: she, for example, configured her phone to measure the distances in kilometers rather than Miles, and uses degrees Celsius instead of the fahrenheit.
“The technology is there. Change will come. It is simply slower than if it was imposed. »»
For American readers curious to carry out the transition, Benham recommends take a look at the virtual tools of the American National Institute of Standards and Technology (NIST), which offer advice on the integration of metric measures in all areas, from cooking to gardening, including health. “Once you have overcome the obstacle to learn a greater number of different units, it’s easy,” she explains.