The current discussion of rotation made me realize that I have a startling
gap in my historical/philosophical/cultural knowledge.
We all know at least a reasonable facsimile of the history of ideas
regarding Earth's revolution around the Sun, but it occurs to me that we
don't often talk about--and I, for one, am essentially ignorant about--the
history of ideas with regard to Earth's rotation about its own axis. I
wonder if others, like myself, have tended to conflate the two ideas and
to assume that Earth began revolving AND rotating with Copernicus.
Perhaps it did, but I don't know.
Indeed, once Earth is put into orbit around the Sun, it must also rotate
on its axis in order to explain the diurnal appearance of the Sun. But
one doesn't have to completely abandon the Ptolemaic model to let the
stars remain fixed. A rotating but nonrevolving Earth clearly allows the
rest of the universe to behave in a *significantly* more sedate manner
without completely offending those whose religious beliefs required Earth
to be the center of things. I'm particularly curious about what Brahe
thought about all of this since his model sits right on the cusp of the
transition to the sun-centered view. Did his Earth rotate?
I'm particularly interested because I have always pointed out to students
that the transition to a revolving Earth required natural philosophers to
ponder the nature of gravity since it could no longer be easily attributed
to the tendency of material objects to seek their natural place. A
rotating Earth would be less, but only a *little* less troubling to
those with Aristotelian notions of dynamics.
What does anyone out there know about this stuff? Are there any good
references?