May 14, 2017

Why Doesn’t America Use the Metric System Like the Rest of the World?

America — why can’t it just be like the rest of the world and use the metric system? (Full disclosure: this complaint comes from a frustrated American who finds herself constantly converting metric units into ‘American’ units and vice versa.) This latest video from Veritasium discusses the weird history of metric standards in the United States.

The most annoying bit for fans of the metric system? The U.S. technically uses metric standards. It signed the Metre Convention in 1875. The U.S. should’ve upheld the treaty since then, especially during the introduction of SI units in 1960. However, the nation still uses conventional standards at an overwhelming rate. Units like feet and pound find their scientific basis in the metric system. But, because the U.S. loves to overcomplicate things, they throw in a conversion factor while still claiming it’s “metric.” So then we (the metric expats) have to convert back.

There’s even an “American kilogram” which serves as the basis for the conversions. Technically, there are two standards — K4 and K20. Original standards were made in the 1880s and given to signatories of the treaty. The U.S. received both K4 and K20 as a result. The platinum-iridium cylinders were to set the standard for the entire country to go metric. Both K4 and K20 are housed in the National Institute of Standards and Technology in Washington D.C. K20 is most commonly used to make all mass standards for the U.S., despite the annoying conversion factors involved.

So why didn’t the United States follow through? Why don’t they join the rest of the world and use metric standards? Bits and pieces of metric standards creep into American society. For example, no one signs up to run a 3.1-mile race; they run a 5K. Construction companies and engineering firms label reports in kilometers per hour and liters rather than gallons. However, hesitancy in a full-scale conversion comes from a number of different factors. While metric applications would be great for global transactions (especially amongst the scientific community), opponents feel like it would fail to catch on with the general public. Labor unions even opposed the switch because that would mean global cooperation. Easier global transactions, they feared, would mean easier ways to ship jobs overseas.

Via Veritasium