150 Years of the Metre: From French Revolution to Laser Light
2025-05-23
The 1875 Metre Convention standardized measurement, ending inconsistent units across countries. Initially defined as one ten-millionth of the distance from the North Pole to the equator through Paris, the metre's definition has evolved with scientific advancements. Early definitions relied on platinum-iridium bars, then krypton-86 light wavelengths. Today, it's defined by the speed of light, enabling precise measurements like the Moon's gradual recession from Earth. Despite global adoption, remnants of imperial units persist in various contexts, highlighting the ongoing challenges of standardization.