What is the main reason of the discrepancy I found here?
6
175Ṁ178resolved Apr 26
100%36%
Wrong identification of the hills
12%
Misalignment between hilltops and horizon in the pictures
15%
Wrong distance or altitude of the hills or reference point
13%
Atmospheric refraction
1.9%
The Earth is not spherical
7%
Local geographical features
15%Other
Trying to measure the radius of the Earth with simple observations following Al Biruni’s method: https://mariopasquato.substack.com/p/its-easy-to-say-abu-rayhan-muhammad
It doesn’t work that much. Order of magnitude is right, but the number is off.
Resolves to my own assessment a month from now.
This question is managed and resolved by Manifold.
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@KnMatt I am assuming that the nearby hills are much closer to me than the horizon, so locally the Earth is flat. This should be right if the radius of the Earth is indeed ~1-10 thousand kilometers: the hills are a few km away and the horizon should be about 80km away. A bit of circular reasoning, could be avoided by doing the exact calculation.