How did ancient people calculate 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.

How did the Greeks find out the circumference of the Earth?

In the third century BCE , Eratosthenes, a Greek librarian in Alexandria , Egypt , determined the earth’s circumference to be 40,250 to 45,900 kilometers (25,000 to 28,500 miles) by comparing the Sun’s relative position at two different locations on the earth’s surface.

How did Eratosthenes measure the circumference of the Earth using parallel lines?

Eratosthenes calculated the distance between Alexandria and Syene using records involving camel caravans. The distance he used was 5000 stadia. Thus, the circumference of the Earth is 250,000 stadia, which translates to somewhat less than 25,000 miles (depending on how ancient units convert to modern units).

How do we measure the size of the Earth?

On the day the Sun shone on the bottom of the wells in Syene, Eratosthenes measured the Sun’s position in the sky over Alexandria. It was seven degrees away from the zenith, meaning Syene must be seven degrees away from Alexandria as measured on the circle that is Earth’s circumference.

How do they measure the earth?

It was generally agreed upon that measuring the size of Earth could be done by measuring the altitude of a star from two cities situated on the same meridian. Then, a difference expressed in degrees would be found.

How would you determine the circumference of 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.

What is the circumference of Nearth hint apply the technique used by Eratosthenes to measure Earth’s circumference?

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 was length measured in ancient times?

In ancient times, the body ruled when it came to measuring. The length of a foot, the width of a finger, and the distance of a step were all accepted measurements. Inch: At first an inch was the width of a man’s thumb. Span: A span was the length of the hand stretched out, about 9 inches.