Is Eratosthenes method of determining the circumference of the Earth logical and reasonable?

Eratosthenes also calculated the distance from the Earth to the Moon and to the Sun, but with less accuracy. Yet his most lasting achievement was his remarkably accurate calculation of the Earth’s circumference (the distance around a circle or sphere).

How did Eratosthenes determine the circumference of the Earth?

Eratosthenes then measured the angle of a shadow cast by a stick at noon on the summer solstice in Alexandria, and found it made an angle of about 7.2 degrees, or about 1/50 of a complete circle. Eratosthenes then used this to calculate the circumference of the Earth to be about 250,000 stadia.

What is the significance of Eratosthenes experiment?

Eratosthenes analyzed the observations with the assumption that the earth is a sphere and the sun is very far away. The geometry of the situation is sketched at the right. He concluded that the circumference of the earth was about 50 times greater than the distance from Alexandria to Aswan.

What is the meaning of Eratosthenes?

Eratosthenes Add to list Share. Definitions of Eratosthenes. Greek mathematician and astronomer who estimated the circumference of the earth and the distances to the Moon and sun (276-194 BC) example of: astronomer, stargazer, uranologist. a physicist who studies astronomy.

How did Eratosthenes know the time?

Eratosthenes actually measured the length of the shadow of a tall building in Alexandria when the Sun reached its highest point in the sky on the Summer Solstice. This corresponds to noon in both Alexandria and Syene, where the Sun cast no shadow at the bottom of a deep well (hence the Sun was directly overhead).

How did Eratosthenes estimate the size of the earth quizlet?

How did Eratosthenes measure the circumference of the Earth? He used geometry and ratios to determine the size of the Earth, by basing his calculations on observations of the sun. The earth is round and the sun’s rays are parallel.

What is sieve of Eratosthenes method?

In mathematics, the sieve of Eratosthenes is an ancient algorithm for finding all prime numbers up to any given limit. It does so by iteratively marking as composite (i.e., not prime) the multiples of each prime, starting with the first prime number, 2. It may be used to find primes in arithmetic progressions.

What is pronunciation of Eratosthenes?

[ er-uh-tos-thuh-neez ] SHOW IPA.

How do we know the circumference of the earth?

Eratosthenes sent a man to Syene from Alexandria on foot to measure the distance between Alexandria and Syene. Thus, Eratosthenes measured the distance between the two cities is 800 km. He multiplied by 800 km to 50 and calculated that the Earth’s circumference is 40,000 km.

How did Eratosthenes calculate the Earth’s circumference?

Eratosthenes will always be remembered for the calculation of the Earth’s circumference circa 240 BC, using trigonometry and knowledge of the angle of elevation of the Sun at noon in Alexandria and Syene (now Aswan, Egypt).

What is Eratosthenes’ method?

Eratosthenes’ method requires that one know or determine the vertical angle of the sun above the horizon or from the zenith (a point directly overhead) at solar noon at two locations along the same line of longitude. The distance between the two locations must also be known.

Why is Eratosthenes called the father of Modern Geography?

Eratosthenes’s theories and calculations were published in his Geography, a title that reflects the first-known use of the term, which means “writing about the Earth.” Although his calculations were disputed in his own time, they allowed the development of maps and globes that remained among the most accurate produced for over a thousand years.

Why is Eratosthenes called beta?

So diverse were his abilities that his contemporaries apparently referred to him as “Beta”—the second letter of the Greek alphabet—implying that he was well versed in too many scholarly disciplines to be the best at any one of them. Eratosthenes is best known for his astonishingly accurate and ingenious calculation of the Earth’s circumference.