How did Eratosthenes measure distance?

He made this estimation from the time it took walkers, who were trained to measure distances by taking regular strides, to trek between the cities. By solving the equation, he calculated a circumference of 250,000 stadia, or 25,000 miles (40,000 kilometers).

Why did Eratosthenes move to Alexandria?

Ptolemy III invited Eratosthenes to Alexandria, Egypt for two reasons; to tutor his son and to be the librarian for the great Alexandrian University. Eratosthenes jumped at the chance. At the University, he was able to at most interested him and associate with other scholars.

How did Eratosthenes measure 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. You just studied 5 terms!

Who first measured the earth?

The first person to determine the size of Earth was Eratosthenes of Cyrene, who produced a surprisingly good measurement using a simple scheme that combined geometrical calculations with physical observations. Eratosthenes was born around 276 B.C., which is now Shahhat, Libya. He studied in Athens at the Lyceum.

Who first discovered the size of the Earth?

Earth’s circumference was first accurately measured more than 2,000 years ago by the Greek astronomer Eratosthenes, who at the time lived in the Egyptian city of Alexandria.

What is the main ideas of Eratosthenes?

Eratosthenes saw that the heavens seemed to rotate once a day around Earth. The axis of rotation formed an imaginary line from the North Pole to the South Pole through Earth’s center. Eratosthenes calculated the tilt of Earth’s axis relative to the plane of its equator with good accuracy.

What were the first Greek dramas called?

However, throughout the 5th century BC playwrights continued to innovate. The playwright Aeschylus added a second speaking role, called the antagonist, and reduced the chorus from 50 to 12. His play ‘ The Persians ‘, first performed in 472 BC, is the oldest surviving of all Greek plays.

Who is the father of geography?

b. Eratosthenes – He was a Greek mathematician who had a profound interest in geography. He was the founder of Geography and holds the credit to calculate the circumference of the Earth. He also calculated the tilt axis of the Earth.

How did Eratosthenes measure the size of the Earth?

Eratosthenes hired a man to pace the distance between the two cities and learned they were 5,000 stadia apart, which is about 800 kilometers. He could then use simple proportions to find the Earth’s circumference — 7.2 degrees is 1/50 of 360 degrees, so 800 times 50 equals 40,000 kilometers.

How do we describe a position on the Earth’s surface by stating its?

We describe a position on the earths surface by stating its A latitude and | Course Hero.

What is the baseline we use to calculate the distance of stars to the Earth?

To measure the distance of a star, astronomers use a baseline of 1 astronomical unit (AU), which is the average distance between Earth and the sun, about 93 million miles (150 million kilometers). They also measure small angles in arcseconds, which are tiny fractions of a degree on the night sky.

What is the exact shape of the earth?

The oblate spheroid, or oblate ellipsoid, is an ellipsoid of revolution obtained by rotating an ellipse about its shorter axis. It is the regular geometric shape that most nearly approximates the shape of the Earth.

When did Eratosthenes discover the Earth was round?

June 19, 240 B.C.: The Earth Is Round, and It’s This Big. A modern illustration shows how Eratosthenes actually calculated the circumference of the Earth. Courtesy NOAA Ocean Service Education 240 B.C.: Greek astronomer, geographer, mathematician and librarian Eratosthenes calculates the Earth’s circumference.

Who first measured the distance to the sun?

Historically, the first person to measure the distance to the sun was the Greek astronomer Aristarchus around the year 250 B.C. He used the phases of the moon to measure the sizes and distances of the sun and moon. During a half moon, the three celestial bodies should form a right angle.