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Did you know?

The kilometer, a unit of length in the metric system, is standard for measuring distances in most of the world, but did you know that it was officially defined in terms of the Earth’s geometry? Originally, a kilometer was devised as one ten-millionth of the distance from the Equator to the North Pole, a fraction of the Earth’s meridian. This fascinating origin reflects humanity’s quest to make sense of the vastness of our planet.

Moreover, the metric system’s global reign didn’t happen overnight. The U.S. is one of the few countries primarily using miles, yet if you’re ever curious, consider that a marathon—26.2 miles—is approximately 42.195 kilometers! Imagine, the very races where athletes push the limits of human endurance are framed by this historical unit, rooting the challenge in a nearly ten-thousand-year-old tradition.