Jean Picard (geographer)

Jean Picard was a French astronomer and geographer in the 17th century, known for making precise measurements of Earth's size. He was the first to accurately calculate Earth's circumference using advanced observation techniques, such as measuring the difference in star positions at different locations. His work helped improve maps and our understanding of Earth's shape, contributing significantly to the development of geodesy—the science of Earth's shape and size. Picard’s methods laid the groundwork for future geographic and astronomical studies, enhancing navigation and scientific knowledge during his time.