The Discovery that the Earth is Round

By: Courtney Dussinger, Kathryn McLaughlin,

 Maggie Lamb & Maddy Sova

  Thoughts before the discovery

The most popular theory before the idea that the earth could be round:The Flat Earth Theory

Idea that the earth was a flat object rather than spherical

Picture an island floating in spaceThis theory was commonly believed around

the world in many different cultures.These include Ancient Egypt, Babylonia,

China, and Greece

Reasoning behind the Flat Earth Theory

Religious reasoning Many people took the Bible literally:

the world is said to have “four corner”; therefore it would be a square

Logic behind theory Flat earth seemed to be true from what humans   

 could see around them until it was questioned in 4th century B.C.

The DiscoveryIn 192 BC Eratosthenes claimed that the earth

was round.

He discovered this based on his observations of shadows. He recorded the shadows cast at cities

hundreds of miles from each other and noticed the different angles cast by the shadows.

The Earth’s CircumferenceEratosthenes used his surroundings to come up with

the the circumference of the Earth. He used the shadows from the obelisk in the center of

town and a well, located in the center of a city called Syene, which was to the South.

He knew the sun shone directly over this town of Syene on the summer solstice at 12 pm.

Then he measured and discovered that the sun's angle of elevation was 1/50th of the earth's circumference.

He didn't use the measurement system that we use today, but instead used stades. One stade was equivalent to the length of a stadium.

The discovery of the circumference led to the discovery that the earth was not flat.

Diagram of His Theory

This theory was not verified until 1700 years later when Christopher Columbus sailed West proved this theory true.

Eratosthenes’ measurements are within 2% to what we believe as true today.

Impact on Society When the Earth was discovered to be round, it had a huge impact

on society. Many people were skeptical in the beginning, but now it is a known fact that the Earth is indeed round.

With the discovery of a round Earth, there have been many more findings because of it: The ability to make spherical maps has greatly increased

allowing us to plot and keep track of the multitude of places discovered and those still left to find.

It also helped to increase trade and travel. Once this discovery was made, it was possible to determine

many other calculations. The size of the Earth and the distance from the Earth to the moon were able to be calculated.

These calculations had the most impact on society and science after the breakthrough of the discovery that the Earth is round.

Bibliography Cessna, A. (2009, December 28). Flat earth theory . Retrieved from

http://www.universetoday.com/48753/flat-earth-theory/ 

Hewitt Paul, G. (2009). Conceptual physics. (10 ed., pp. 3-4). San Francisco: Pearson Addison-Wesley.

Map projection - mercator. (2003, February 11). Retrieved from http://nationalatlas.gov/articles/mapping/a_projections.htm

 Paul, W. (2011, December 10). How can one prove that the world is round?. Retrieved from http://www.physlink.com/education/askexperts/ae535.cfm 

Siegel, E. (2011, September 21). Who discovered the earth is round?. Retrieved from http://scienceblogs.com/startswithabang/2011/09/who_discovered _the_earth_ is_ro.php

 Simanek, D. E. (2006, March). The flat earth. Retrieved from http://www.lhup.edu/~dsimanek/flat/flateart.htm