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How did Eratosthenes know the Earth was round?
Greek philosopher Eratosthenes is said to have calculated the Earth's circumference in 240 BC. How did he do it? Was the Earth being round common knowledge at that time?
Michael Scalise
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.
Junior Point du Jour
Jeniferlynn Johnson
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.
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How did Eratosthenes measure the circumference of the earth?
HERE ARE SOME SITES YOU MIGHT WANT TO TAKE A LOOK AT... WITH A SHORT DESCRIPTION OF WHAT INFORMATION IT HAS ON THE WEBPAGE. * http://en.wikipedia.org/wiki/Eratosthenes- This is the Wikipedia page for Eratosthenes. It has a lot of information about him as well as how he measured the circumference of the Earth. It also lists reasons why Eratosthenes's calculation of the Earth's circumference has limited accuracy. * http://www.juliantrubin.com/bigten/eratosthenes.html - This site has all the information about how Eratosthenes measured the circumference of the Earth. It has a diagram to illustrate and explain further. This site also lists other sites and books relating to the math topic. * http://outreach.as.utexas.edu/marykay/assignments/eratos1.html - This is a webpage with information on how to do an activity related to Eratosthenes and his calculation of the Earth's circumference. It has some diagrams, some that show how Eratosthenes measured it, and some show real-world examples of how you can calculate the Earth's circumference just like Eratosthenes. Along with the drawing, this webpage has instructions on how you can measure the circumference of the Earth in real-life situations. * http://www.astro.cornell.edu/academics/courses/astro201/eratosthenes.htm - This webpage shows how the Earth's circumference was measured by Eratosthenes using geometry. It has a nice, easy-to-understand diagram to further explain Eratosthenes's calculation. The information on the webpage is probably very reliable since it's from a university. * http://mathforum.org/library/drmath/view/58988.html - This webpage is from Dr. Math's website. It has a very detailed explanation of how Eratosthenes measured the circumference of the Earth. There are no diagrams though. * http://eduwww.mikkeli.fi/opetus/myk/kv/comenius/erathostenes.htm - This webpage has a short summary of Eratosthenes's life. It has information on how the sieve of Eratosthenes, another thing Eratosthenes worked out in during his lifetime, worked. This page also has a lot of information about Eratosthenes and his calculation of the Earth's circumference, with a couple of drawings to make it easier to understand. * http://maps.unomaha.edu/Peterson/carta/Notes/eratosthenes.html - This website has a short biography of Eratosthenes and also how he measured the circumference of the Earth. The explanation is very detailed and easy to understand even without the support of diagrams. This site has a .edu in the address, so I think it will be very reliable. * http://www.pbs.org/wnet/hawking/cosmostar/html/cstars_eratho.html - This PBS webpage has a short summary of Eratosthenes's life. This webpage has a little bit of information of Eratosthenes measure of the circumference of the Earth. It also tells how other great mathematicians, like Posidonius and Ptolemy, tried to measure the circumference of the Earth.
Who said that the earth is a sphere?
Columbus said the earth was sphere when he traveled to America
Who was first mathematician to have measured the circumference of the earth?
Eratosthenes of Cyrene using shadows at two different places in Egypt. An amazing achievement for those times (about 200-250BC)
When did euratosthenes calculate the circumference of the earth?
It is not known when, or even if, Euratosthenes did calculate the circumference of the earth. However, it is known that a very accurate estimate was obtained by Eratosthenes in the early years of the third century BC.
What are you filtering with sieve of eratosthenes?
The Sieve of Eratosthenes filters numbers, letting the composites fall through while the primes remain.
Who explored that earth is round?
Eratosthenes figured it out. I don't really know what you mean by this question, though.
Which greek scientist said te earth is round?
Eratosthenes did.
What beliefs about earth and heavens were proved by the discoveries. Of Aristarchus and Eratosthenes?
that the earth was not flat nor square but it was round
What beliefs about earth and the heavens were proved by the discoveries of Aristarchus and Eratosthenes?
that the earth was not flat nor square but it was round
What beliefs about earth and the heaven were proved by the discoveries of aristarchus eratosthenes?
that the earth was not flat nor square but it was round
Contribution of eratosthenes?
Eratosthenes had many contributions : he was the first person to calculate the circumference of the earth he invented latitude and longitude he was the first person to prove earth was round he was the first to calculate the tilt of Earth's axis
What ancient writer used mathematics to show the Earth was round?
Eratosthenes 5th Century BCE.
Did Magellan discover the earth was round?
Although Ferdinand Magellan's expedition was the first circumnavigation of the Earth, many ancient scholars were already aware that the Earth was round. The Greek scientist Eratosthenes was the first to calculate the Earth's circumference, thus proving the Earth's roundness.
Did Eratosthenes discover that the world is round?
yes
What describes how Eratosthenes discovered the approximate circumference of the earth?
Which of the following describes how Eratosthenes discovered the approximate circumference of the earth
Why did aristole conclude that earth was round?
Actually Aristole didn't conclude this theory. Gallileo proved the Earth was round. Eratosthenes of Cyren put the idea out in the open, but Nicholas Copernicus and Galileo Galilei showed the theory to the public.
Who founded the earth is round?
The idea of a round Earth appears to have originated in Greek Philosophy. Aristotle provided the first evidence of a round Earth, noting that explorers traveling south saw southern constellations rise higher above the horizon and that Earth cast a round shadow on the moon. Eratosthenes used the angle of sunlight at different latitudes to estimate Earth's circumference with surprising accuracy.
