https://www.mathpages.com/home/kmath077/kmath077.htm https://www.mathpages.com/home/kmath077/kmath077.htm is a good overview of why trying to make the expansion

https://www.mathpages.com/home/kmath077/kmath077.htm https://www.mathpages.com/home/kmath077/kmath077.htm is a good overview of why trying to make the expansion explanation even work with Newtonian gravity ultimately leads you to general relativity.