" Rapunzel knew exactly when her adopted birthday was coming because of her careful tracking and observation of the heavens. What had started out as a child's interest in the longer days of summer and shorter days of winter had progressed into a study that would have been the praise of any university professor. She knew all the constellations, of course; which ones came and went with the seasons (Orion), which ones stayed wandering the heavens forever (the Big Bear). She could predict when Jupiter would rise. She could predict some lunar eclipses. She had astrolabes and pendulums and squares and straightedges and compasses for measuring the precise height of an astral object above her window ledge. "

― Liz Braswell , What Once Was Mine