How Eratosthenes Estimated the Circumference of the Earth Over 2,000 Years Ago
Posted on August 25, 2016 Comments (4)
In this video Carl Sagan explains how Greek astronomer Eratosthenes, in 200 BC, was able to deduce and calculate the earth was a sphere about 40,000 km in circumference.
It is wonderful to see how a bit of thought and curiosity have lead mankind to learn so much.
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Posted by curiouscat
Categories: Science
Tags: history, Science, science explained, science facts, science webcasts, scientific inquiry
Categories: Science
Tags: history, Science, science explained, science facts, science webcasts, scientific inquiry
4 Responses to “How Eratosthenes Estimated the Circumference of the Earth Over 2,000 Years Ago”
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August 27th, 2016 @ 4:42 pm
The YouTube video is saying an error occurred. However, it does seem like an interesting topic. I will check back later to see if it is working.
August 27th, 2016 @ 10:01 pm
Ah, YouTube died when using the direct url with the start time. They seem to tell you to use a # instead of & that is found in the url when embedding on https://support.google.com/youtube/answer/171780?hl=en
Doing that does allow the video to play. Though it doesn’t actually start it at the tie you give. YouTube, and Google more generally, are still providing absolutely horrible help files more than a decade after saying they aim to organize the world’s information. They still can’t even organize their own help system. That is pitiful.
September 28th, 2016 @ 11:30 am
I’m glad I was able to come back and watch the video. It is ever so interesting that someone thought to figure out the circumference based on the shadows of sticks. I really thought there was going to be more to the way it was determined. Thanks for sharing.
October 16th, 2016 @ 3:46 pm
This was really interesting. Thanks for sharing.