Renowned cosmologist David Spergel joins Brian Greene to discuss the triumphs and tensions of precision cosmology, exploring remarkable successes as well as persistent discrepancies bedeviling current understanding. This program is part of the Big Ideas series, supported by the John Templeton Foundation. Participant: David Spergel Moderator: Brian Greene #davidspergel #worldsciencefestival #briangreene #cosmology #astrophysics #cosmicmicrowavebackground #planck