So much can be written about the earth, and most articles on Earth Day talk about the environment. I thought to go in a different direction. We’re going to learn about the earth and how we know it is round.
There is an increasing amount of people who have rejected the long held belief that the world is round. They believe that the earth is actually flat.
An online poll showed that the younger the demographic, the fewer the people who believe that the earth is round, with 94% of those 55 and up believing but only 66% of those 18-24. This same poll didn’t show correlation between religious beliefs and their belief in the shape of the world. It did show that the younger demographics were more likely to believe science in relation to topics like climate change. However, many climate change calculations depend on NASA satellites along with other scientific observations.
That led me to wonder, how did we discover the earth is round?
The idea that the earth is round goes back to Aristotle. He pointed to observable phenomena such as the round shadow the earth leaves on the moon during a lunar eclipse as a defense to this idea.
Aristotle also reported an estimate of the earth’s circumference made by mathematicians that was 400,000 stades, which converts to about 45,000 miles and is 1.8 times the actual circumference.
The idea that throughout the Middle Ages it was the prevailing belief that the earth is flat is actually a myth.
In the past people have credited Christopher Columbus for discovering the world to be round but this wasn’t the case. In fact, in his paper “Flat Earth or round sphere: misconceptions of the shape and the Earth and the fifteenth-century transformation of the world”, Lesley Cormack writes that “they challenged Columbus on his…ability to do what he proposed. They did not, however, deny that the Earth was spherical, but rather used it sphericity in their arguments” (p. 370).
An experiment carried out in 240 B.C.E. by Eratosthenes allowed him to calculate the radius and circumference of the earth. In fact, his results are within 10% of what we know now to be the circumference of the earth.
His experiment was based on an observation he made while in the North African city of Aswan. On the Summer Solstice at noon he observed that the sun shined down to the bottom of a well in the city, and the well did not cast a shadow, indicating the sun was right overhead. He set this up in Alexandria by putting a stick in the ground and noting that the stick cast a shadow at the same time and day as the well in Aswan.
He used the angle of the shadow to calculate the radius of the earth. Millersville University conducted this same experiment, and you can read their explanation here. On March 20th of this year, over 5,000 schools took part in replicating Eratosthenes’ experiment.
The theory that the earth is round has been around for over 2,000 years, so it is interesting to see people reject that theory. Many who do claim that it is a coverup by NASA and/or other government organizations. To them, I would want an answer to what the government has to gain from that level of coverup.
You can view my sources here.
The Mill Review 