Eratosthenes

Definition

Eratosthenes was a Greek mathematician, geographer, and astronomer known for being the first person to calculate the circumference of the Earth using a method based on geometry and the angle of shadows. His work laid the groundwork for understanding the Earth's size and shape, which became essential during the conquests of Alexander the Great, as these explorations necessitated accurate geographic knowledge for navigation and mapping newly acquired territories.

5 Must Know Facts For Your Next Test

1. Eratosthenes lived during the 3rd century BCE and was the chief librarian at the Library of Alexandria, a major center of learning in the ancient world.
2. He used measurements of shadows cast by objects in different locations to estimate the angle between them, leading to his calculations about the Earth's circumference being remarkably close to modern estimates.
3. Eratosthenes' work in geography also included creating one of the earliest maps of the known world, demonstrating how geographic knowledge was essential for trade and exploration.
4. His calculations highlighted the significance of mathematical principles in understanding natural phenomena, laying a foundation for future scientific inquiry.
5. Eratosthenes' ideas about Earth’s size influenced later explorers, including those during and after Alexander's conquests, who relied on accurate maps for navigation and military strategy.

Review Questions

• How did Eratosthenes contribute to our understanding of Earth’s dimensions, and why was this important for navigation during Alexander's conquests?
  • Eratosthenes calculated the Earth's circumference using geometric methods that involved measuring shadows in different locations. This accurate estimation of Earth's size was crucial for navigation during Alexander's conquests because it allowed explorers and military leaders to understand distances between regions, facilitating more effective planning and movement across vast territories.
• In what ways did Eratosthenes’ geographical knowledge influence subsequent exploration and mapping during the era of Alexander the Great?
  • Eratosthenes’ advancements in geography provided crucial insights that improved map-making and navigation. His calculations inspired later scholars and explorers to adopt more systematic approaches to measuring distances and mapping new territories conquered by Alexander. This geographical foundation enabled more efficient communication and military strategies within Alexander's vast empire.
• Evaluate how Eratosthenes’ work on geography not only enhanced navigation during Alexander’s time but also laid groundwork for future scientific exploration.
  • Eratosthenes’ work established a scientific approach to measuring Earth's dimensions and mapping geographical features. His methods demonstrated how mathematics could be applied to real-world problems like navigation. This not only supported military endeavors during Alexander's conquests but also influenced future scientists and explorers to pursue rigorous methodologies in their studies, setting a precedent for the systematic exploration that characterized later periods of discovery.

Related terms

Circumference: The distance around a circle, which Eratosthenes calculated for the Earth, contributing to the understanding of its size.

Geography: The study of the Earth's landscapes, environments, and how human culture interacts with these elements, heavily influenced by Eratosthenes' contributions.

Alexander the Great: A king of Macedonia who created one of the largest empires in history and whose conquests emphasized the importance of geography in understanding his empire's expanse.