The starting point for any worldview that encompasses heaven and Earth is terrestrial experience. Early worldviews are the models of earth supplemented with ideas about the observed movements of the stars. The advance toward the infinite space of the cosmos, which commences in early modern times, is driven by the continual invention of new instruments - from Galileo's telescope to contemporary radiotelescopes and gravitational wave detectors. The planetary system suddenly appears rather small compared to the fixed stars of the Milky Way. Einstein's Theory of Relativity replaces Euclidian geometry with a curved spacetime. The differences cannot be mesured locally. However, Einstein's presumption of a curved spacetime is confirmed again and again for cosmological dimensions.