> (i.e. imposing the arbitrary constraint of a stationary Earth).
It's not really arbitrary--given the understanding at the time, there was no ability to measure the motion of the earth. In particular, stellar parallax which was understood as a contra-indication and too small to measure just yet. So a non-stationary Earth went against what they knew at the time rather strongly.
That said, relativity comes back and makes choosing a frame of reference arbitrary in the end, though some are easier to do physics in than others.
It's not really arbitrary--given the understanding at the time, there was no ability to measure the motion of the earth. In particular, stellar parallax which was understood as a contra-indication and too small to measure just yet. So a non-stationary Earth went against what they knew at the time rather strongly.
That said, relativity comes back and makes choosing a frame of reference arbitrary in the end, though some are easier to do physics in than others.