James Owen Weatherall, professor of logic and philosophy of science at the University of California, Irvine, [writes]: It turns out that orbital rotation in general relativity is much more subtle than Newton, or anyone else before the 20th century, imagined. In fact, David Malament, a philosopher of physics at the University of California, Irvine, has shown that there is no notion of rotation in general relativity that lives up to the basic picture sketched above.

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