mooeypoo Posted June 22, 2008 Posted June 22, 2008 If I sail a ship to the far far seas, continue on, and on, and on and– well, you got the point. Where will I find myself? Well, if I travel in a more-or-less straight line (ignoring weather or geography, or time constraints, or my pending homework) I will end up right where I started. Why? Because the Earth is round. Duh. Today we have a lot of sophisticated (and simple) methods of calculating the curvature and size of the earth. But how did humanity figure this out in the first place? I mean.. it’s so easy, without the help of satellites, airplanes and Jules Verne, to look at the flat horizon and mistake the earth for a flat table top. How could anyone figure out not only that the world is not flat, but also calculate the size of its radius? Well, when in doubt, try it out. Hey.. I think I like that motto. It’s rhyming, and rhymes are usually true. Just ask Dr Seuss. Plus.. it works! (Read more and watch the video...) Do you have anything to say? Wish to discuss the experiment? Ask questions or criticize the method? Post and debate here! Please don't forget you need to register to be able to post.
Country Boy Posted July 1, 2008 Posted July 1, 2008 Looking at the other topics here, I'm not clear how serious one is supposed to be! Eratosthenes, a Greek living in Egypt about 200 BC accurately calculated the radius of the earth (and so the curvature:1 divided by the radius). He had heard that, in a certain town on the Nile River, south of where he lived, on a certain day of the year, the noon sun shone straight down a well without touching the walls of the well (i.e. the town was on the Tropic of Cancer and the day was midsummer). Eratosthenes hired a man to walk from his village to that southern town, counting his steps and thus finding the distance between the two towns. He also measured the angle the sun made on that day in his own town. Assuming the sun was far enough away that the two light paths could be taken to be parallel, the ratio of that angle to 360 degrees must be the same as the ratio of the distance between the two towns divided by the circumference of the earth. Notice, by the way, that this was a good 1700 years before Columbus! The usual idea that every one except Columbus believed the earth was flat is simply not true. All educated people of the time new about Eratosthenes and knew the earth was a globe. Columbus was one of a small group who believed that Eratosthens calculation was wrong and that the earth was much smaller than he had calculated. Apparently their argument was a purely "stylistic" one- they did not believe that the earth could have all of it land (the "known" land of the day, Europe, Africa, and Asia) on one side of it and only empty ocean on the other. Apparently it didn't occur to them that there might be unknown land on the other side of the earth!
John Cuthber Posted July 1, 2008 Posted July 1, 2008 "Apparently it didn't occur to them that there might be unknown land on the other side of the earth!" At the time that made perfect sense. Why would God have put land where there were no people? Incidentally, anyone who watched a ship sail over the horizon and back knew the earth wasn't flat.
mooeypoo Posted July 4, 2008 Author Posted July 4, 2008 Yeah, I'm planning a "Corrections/Additions" video, and those would definitely be in it. I actually had a few mails about this subject.
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