La forme de la Terre 1/3 : rotondité et Eratosthène (méridien) - Enseignement scientifique 1ère.

To access the worksheets: https://duclosarnaud.wixsite.com/desp... 🌍 In this video, we explore how humanity discovered and proved that the Earth is round 🌐, despite ancient beliefs in a flat or disc-shaped Earth 🌀. We trace the journey of scientists 🧑‍🔬, from observing lunar eclipses 🌒 to analyzing objects on the horizon 🌅, which led to challenging preconceived notions about the shape of our planet 🌏. 📜 We then examine one of the first attempts to measure the dimensions of the Earth 🌎, conducted by Eratosthenes in the 3rd century BC. Thanks to an ingenious method involving gnomons placed in Syene and Alexandria 📏, Eratosthenes was able to estimate the Earth's circumference 🌐 and radius 📏 with remarkable accuracy. 🧠 This video will guide you through the steps of this fascinating discovery, explaining the scientific principles 🧪 and calculations used 🧮. You'll discover how, despite the limitations of the time ⏳, Eratosthenes managed to obtain results surprisingly close to the actual values ​​🔍.