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How did Eratosthenes discover the approximate circumference of the earth?
Wiki User
∙ 8y ago
He used only simple geometry and observation of the sun
Eratosthenes assumed that the sun was so far from the earth that its rays were practically parallel when they reached it, and that the earth was spherical. Then, he calculated the the degree of elevation of the sun at Alexandria and Syene at specific times, and estimated the distance between the two. By so doing, he was able to calculate what he thought was the number of stadia per degree of elevation of the sun. Then, he multiplied this quantity by 360 degrees (the maximum elevation of the sun assuming that the earth was spherical) to calculate the circumference of the earth.
Wiki User
∙ 8y ago
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The Greek geographer mathematician astronomer and poet who calculated the circumference of Earth was?
Eratosthenes
What Greek astronomer used observations of the Sun's position at noon on the summer solstice at Alexandria and Syene to determine the circumference of the Earth?
n the 200s BC, Eratosthenes figured out a very clever method for measuring the size of the Earth. He heard about a well in Syene (in modern Egypt) where the sunshine reached the bottom only at noon in the summer solstice. So he knew exactly when the sun was directly overhead. Further north in Alexandria he put a stick straight up in the ground and measured the angle of its shadow at that precise moment as 7.2°. It meant that the distance from Syene to Alexandria was 7.2/360 of the Earth's circumference. Since he knew this distance, he could compute the circumference as 39250km, a diameter of about 12500km.n the 200s BC, Eratosthenes figured out a very clever method for measuring the size of the Earth. He heard about a well in Syene (in modern Egypt) where the sunshine reached the bottom only at noon in the summer solstice. So he knew exactly when the sun was directly overhead. Further north in Alexandria he put a stick straight up in the ground and measured the angle of its shadow at that precise moment as 7.2°. It meant that the distance from Syene to Alexandria was 7.2/360 of the Earth's circumference. Since he knew this distance, he could compute the circumference as 39250km, a diameter of about 12500km.
Describe how eratosthenes measure the size of Earth?
Eratosthenes measured the size of Earth by using the Sun's angles, as well as a bit of geometry.
How did eratosthenes determine the size of the earth?
The used an orange
What beliefs about earth and the heavens were proved by the discoveries of Aristarchus and Eratosthenes?
that the earth was not flat nor square but it was round
What describes how Eratosthenes discovered the approximate circumference of the earth?
Which of the following describes how Eratosthenes discovered the approximate circumference of the earth
When did Eratosthenes discover that the earth is not flat?
He did not do so. Earth was well-known to be a globe for at least two hundred years before Eratosthenes' time. What Eratosthenes did was to measure the earth's circumference for the first time. He did that at some time between 236 BC and 195 BC.
Who found circumference of earth?
Eratosthenes
Who is calculate the circumference of earth?
Eratosthenes
What did Eratosthenes determine?
He postulated the circumference of the earth.
What place does Eratosthenes based the circumference of the earth?
rome
Greek scholar that estimated the earth's circumference?
Eratosthenes
Who was the greek mathematician who measured the circumference of the earth?
Eratosthenes
Who was the first person to calculate the earth circumference?
Eratosthenes
Who was the first to discover the earth's diameter?
Eratosthenes
What did eratosthenes want to find?
he wanted to find the circumference of the earth.
What do Aristarchus and Eratosthenes have in common?
Both postulated on the earth's circumference.
