150 years ago, the Metre Convention determined how we measure the world — a radical initiative for the time

Unified systems of measurement are important for scientific progress. (Shutterstock)

On May 20, 1875, delegates from a group of 17 countries gathered in Paris to sign what may be the most overlooked yet globally influential treaty in history: the Metre Convention.

At a time when different countries (and even different cities defined weights and lengths based on local artifacts, royal body parts or grains of wheat, this rare agreement among nations offered something simple yet undeniably impactful: consistency.