How held back might science be in an alternate history with one change: a permanently cloudy sky. Ptolemy, Copernicus, Kepler, Galileo, Newton, Einstein, would all have had so much less purchase on the shape of the universe to build their theories on. So much science depends on the fundamental insights from those models.
We would be a more inward focused civilization, and lesser for it.
We would be a more inward focused civilization, and lesser for it.