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Old 08-29-2020, 02:42 PM   #7
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Join Date: Jan 2004
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Re: The Coriolis Effect

Originally Posted by ecriture d'adulte View Post
{Bad links Can Mod delete previous version pls.}

This has been debated for 300+ years. Newton held the view that rotation was absolute and not simply relative to some inertial frame. The Einstein/modern view is that the universe supplies a chosen reference frame in which distant galaxies are not rotating and that defines 0 rotation. But that brings up the obvious question. We know that centrifugal forces cause rotating planets to bulge at the sides, so are we really going to say that if the entire universe was just one planet in empty space centrifugal forces would cease to exist and it wouldn’t be meaningful to talk about whether it was rotating or not? I think most people have some issues with that but experiment obviously doesn’t allow us to test it either way
Would it not be more fair to say that the distant galaxies simply reveal the non-rotating frame, and do not actually supply it? (or is supply to be meant in exactly this sense - perhaps a problem of language or translation)? Mach's statements are stronger, but in the end Mach had to be abandoned by Einstein.

The gravitational field due to a rotating body was first attempted by Thirring who used Einstein field equations in the linear approximation and showed that a rotating thin spherical shell produces near its centre forces analogous to the Coriolis and centrifugal forces of classical machines.
This paper goes further and shows the same effects with exact solutions of Einstein's equations.

A universe consisting of just one rotating planet would presumably have some gravitational and electromagnetic fields. And if the planet had varying density or surface imperfections (mountains, etc) it would produce gravitational waves as it rotated, and would not produce these when it did not rotate. So it would seem that empty space is something that can be "rotated relative to" (and we know that empty space is far from empty, quantum mechanically speaking).

Last edited by TimM; 08-29-2020 at 03:05 PM.
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