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Timeline for The origin of $\pi$

Current License: CC BY-SA 3.0

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Apr 13, 2017 at 12:20 history edited CommunityBot
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Aug 15, 2013 at 6:34 comment added jimjim @RahulNarain : did you see the link for $\pi=42$?
Aug 15, 2013 at 5:38 comment added user856 That's not right. As MJD says, $\pi$ is a particular number, $3.14159\ldots$, which is the circumference-to-diameter ratio of a circle on a Euclidean plane. Said ratio for a circle on a sphere may not be equal to $\pi$, but that does mean that the value of $\pi$ itself is changing; it just means that circles on spheres do not follow $\pi$.
Aug 14, 2013 at 21:30 history edited jimjim CC BY-SA 3.0
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Aug 14, 2013 at 21:27 comment added jimjim @MJD: One of many definitions of $\pi$ is the ratio of circumference of the circle to it's radius. On a sphere a circle could be considered to having 2 redies, to see that draw a circle on the equator and draw another one parallel to the equator to the north or south of the first one. now ask yourself what is the radius of each circle on the sphere? the one on equator has two equal radius starting on either poles, but the other one has 2 unequal radius on the sphere. Now if every circle has 2 different radius on a sphere, it has 2 different ratios for it's ratio of radius to its circumference.
Aug 14, 2013 at 19:31 comment added MJD This is very confusingly stated. I am not sure just what you are getting at, but $\pi$ is a particular number, and does not change its value "on a sphere" any more than the number 17 does.
Aug 14, 2013 at 6:58 history answered jimjim CC BY-SA 3.0