Timeline for Could an underground civilisation deduce the size and shape of their planet?
Current License: CC BY-SA 4.0
5 events
| when toggle format | what | by | license | comment | |
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| Oct 10, 2021 at 13:50 | comment | added | John Doty | @RotemShalev In the question as posed, the inhabitants have knowledge of the "Density of surrounding rock and material". Common rocks have densities of 2.5-3, so even without precise knowledge, this method will yield a decent estimate. | |
| Oct 10, 2021 at 13:31 | comment | added | Rotem Shalev | This assumes that surface rock and deep rock have the same density. Is this true? | |
| Oct 8, 2021 at 20:42 | comment | added | John Doty | @RossPresser Others have covered surveying to determine the size and shape, spherical or not, of the habitable level, so I didn't mention it. If the distance to the surface varies, this method, applied at multiple sites, can determine that. | |
| Oct 8, 2021 at 20:36 | comment | added | Ross Presser | This tells you the distance to the surface at the test location. It tells you nothing about whether your planet is a sphere, or has 4000km mountains every two degrees, or anything else about the shape. | |
| Oct 8, 2021 at 19:54 | history | answered | John Doty | CC BY-SA 4.0 |