Eratosthenes and the Circumference of the Earth

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Eratosthenes and the circumference of the earth Determining the distance between Alexandria and Syene wasn’t an easy task for Eratosthenes because at that time he didn’t have any measurement tools like the hodometer which was used by the Romans that can measure how much the wagon had traveled. It was also merely impossible for him to count how many steps it would take him to walk from Alexandria to Syene (Nicastro, 2008). Trigonometry could have made the whole process easier; however, that was impossible because “it wasn’t invented until well after his death” (Nicastro, 2008, p.115). Even after all these struggle, Eratosthenes did find a way to measure the distance between Alexandria and Syene. Kline (1972) concludes that Eratosthenes guesstimated the distance between Alexandria and Syene using the knowledge: how long it took the camel trains to reach to Syene and his final answer was 5000 stadia. Eratosthene’s inaccuracy in his assumptions about Egypt’s geography resulted in wrong calculation of where the poles are (Nicastro, 2008).To describe what was the source of error Nicastro (20080 said, “Syene wasn’t located due south of Alexandria, but about three degrees’ latitude east of the line between the cities” (p.118). Another source of error was that Syene wasn’t located under the tropic of cancer on the summer solstice like Eratosthenes assumed. This means that the sun couldn’t have shown directly on the well at Syene, but was three degree off the well (Nicastro, 2008) References Kilne, M. (1972). Mathematical thought from ancient to modern times. New York, NY: Oxford University Press. Nicastro, N. (2008). Circumference: Eratosthenes and the ancient quest to measure the globe. New York, NY: St. Matrin’s
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