I think this thread started with a question about whether or not an object
dropped through a hole bored from the north to the south pole would
experience simple harmonic motion.
That seemed reasonable to me, given the assumptions - no friction,
temperature near core wouldn't melt the object, the earth is homogeneous . .
.
Someone, however, (perhaps Leigh?) posted that it would not, but didn't give
an explanation. Please help with the explanation.