征税
发表于 2025-3-28 14:57:02
The Expanding Universe,e 19th century until 1924, the thenunknown size of the Galaxy was at the heart of a controversy. The controversy concerned the existence of galaxies other than our own: were the so-called spiral and elliptical nebulae. in fact other galaxies—“island universes,” as the German philosopher Immanuel Kan
ensemble
发表于 2025-3-28 22:41:09
Homogeneous, Isotropic Universes,d of Universe has such features, and what are its other properties? Observation alone cannot provide the desired answers; theoretical investigation is required as well. The theoretical developments that yielded answers to these and some of the questions raised in earlier chapters began in 1915 when