Eratosthenes circumference earth. He calculated the total circumference of the .

Eratosthenes circumference earth. May 27, 2024 · Learn how Eratosthenes, a Greek scholar, calculated the Earth's circumference around 240 B. Sep 8, 2025 · Eratosthenes measured Earth’s circumference mathematically using two surface points to make the calculation. He is best known for his remarkable calculation of the Earth's circumference, which he estimated to be approximately 25,000 miles. using a well in Egypt and a stick in Alexandria. 276 BC - c. He noted that the Sun’s rays fell vertically at noon in Syene (now Aswān), Egypt, at the summer solstice. Oct 19, 2023 · Table of Contents (click to expand) Eratosthene calculated the circumference of Earth by measuring the length of a stick’s shadow in Alexandria and the distance between Alexandria and Syrene on foot. Today, most scientists set the earth's circumference at 40,096 kilometers (24,901 miles). Discover the significance, accuracy, and legacy of his innovative method and observation. c. 5°). Eratosthenes' errors Syene is not on the Tropic of Cancer, where the sun's rays are directly overhead during the summer solstice. Recognizing the curvature of the Earth and knowing the distance between the two cities enabled Eratosthenes to calculate the planet’s circumference. May 6, 2025 · Explore Eratosthenes’ groundbreaking map, his method for measuring Earth’s size, and his role in the birth of scientific geography. Eratosthenes, a Greek scholar and the head librarian of the Library of Alexandria, made significant contributions to our understanding of the Earth's size in 240 B. Discover his life, achievements, legacy, and the importance of his method for science and geography. At around 200 BC, Eratosthenes (c. This gives Eratosthenes' estimate less than a one percent error—an excellent approximation of the earth's circumference. Jul 1, 2023 · Amazingly, Eratosthenes didn’t have much more than a stick and his brain when he made the amazing discovery. He calculated the total circumference of the . 197 BC) determined the circumference of Earth with remarkable accuracy. How Eratosthenes discovered the circumference of the Earth Born in Cyrene, an ancient Greek colony in modern-day Libya in 276 BC, Eratosthenes was a polymath, meaning that he had vast knowledge of many different subjects, including mathematics, astronomy, music theory, and poetry. As related accomplishments, he also demon-strated that Earth is essentially spherical and measured the tilt of its axis (23. He then took the inverse tangent of the ratio between the shadow’s length and the stick’s length to find the angle of inclination of the Sun. Eratosthenes erected a pole in Alexandria, and on the summer solstice he observed that it cast a shadow, proving that the Sun was not directly overhead but slightly south. Learn how Eratosthenes, a Greek scholar and librarian, used geometry and shadows to estimate the Earth's circumference in 240 b. Find out how his calculation contributed to geodesy, exploration, and the study of the Earth. Eratosthenes method was very simple; he measured the length of a shadow from a vertical stick of a known height in two cities on the same day. He is best known for being the first person known to calculate the Earth's circumference, which he did by using the extensive survey results he could access in his role at the Library. The length of one stadia is not exactly known, but it is thought to be between 515 and 686 feet. C. Contrary to the myth that people universally believed in a flat Earth before Columbus, educated Jan 9, 2015 · Eratosthenes was able to calculate the circumference of the Earth to be 250,000 stadia. The Earth’s circumference was first accurately measured more than 2,200 years ago by a Greek astronomer named Eratosthenes. This corresponds to a circumference of between 24,384 and 32,481 miles, but it is likely that he calculated a value of about 25,000 miles. Jun 17, 2024 · Learn how Eratosthenes, an ancient Greek astronomer and geographer, calculated the Earth’s circumference using geometry and trigonometry. ndrs n3sx1 0fzhu tkkw4on z3 d35o upnq mbto gwin thyy