Released: 25 January 2018 Duration: 21 minutes, 51 seconds   A hundred years ago cosmologists were struggling to understand the nature and structure of the universe, and at the heart of this struggle was the island universe hypothesis. Today we find ourselves confronted with a similar question posed at a far greater scale. As we confront these great questions of cosmology, whether a hundred years ago or today, we find ourselves faced with as many philosophical questions as scientific questions when we challenge the boundaries of our understanding. In Part II we focus on cosmological scales of time and what this means for human observation of a very old universe. Links: The Realm of the Nebula, Edwin Hubble   Universal Natural History and Theory of the Heavens, Immanuel Kant   The Great Debate   The Scale of the Universe, Shapley and Curtis   The 1920 Shapley-Curtis Discussion: Background,Issues, and Aftermath, V. Trimble   NGC 6822, a remote stellar system, Edwin Hubble   F. H. Bradley   deep time   Stellar Movements and the Structure of the Universe, Arthur Eddington   The Retrodiction Wall   Addendum on the Retrodiction Wall   Eternity in six hours: Intergalactic spreading of intelligent life and sharpening the Fermi paradox, Stuart Armstrong and Anders Sandberg   The End of Cosmology? Lawrence M. Krauss and Robert J. Scherrer   Credits: Writer and Host: Nick Nielsen Voiceover and Producer: Paul Carr Music: Jason Robinson