Part of the answer to this question is:
As discussed in Vol. X, JRRT considered, then rejected a heliocentric creation for Middle Earth.
There is a large collection of writing which never became part of any major text dealing with the problems this caused.
And the related problems of Elvish aging. Certain characters have to be born in certain places and married in certain places, and if the Elvish aging rate is inappropriate for that then things fall apart.
There's a lot of ink spent answering this problem.