Cosmologists debate: Was the Big Bang the beginning?

Was the big bang the beginning of time or was there a before the big bang? Here two of the world's leading cosmologists debate whether the universe had a beginning or not. Featuring Thomas Herzog who was one of Stephen Hawking's main collaborators on his No Boundary or Hartle/Hawking model and Robert Brandenberger one of the authors (along with leading string theorist Cumrun Vafa) of Sting Gas Cosmology. Thomas's book One the Origins of Time, can be found here: https://www.amazon.co.uk/Origin-Time-... and my upcoming book, The Battle of the Big Bang can be pre ordered here: https://press.uchicago.edu/ucp/books/... Our film on the No Boundary Proposal which starred Stephen Hawking, Jim Hartle and Thomas Herzog can be found here:    • Before the Big Bang 5: The No Boundary Pro...   A timeline is below 00:00 Introduction 1:10 on being Stephen Hawking's PHD student 2:17 Robert's story 4:02 Does the CMB prove a beginning? 7:52 Penrose Hawking Singularity 17:15 Inflation and the BGV theory 24:38 The Hartle Hakwing No Boundary Proposal 36:14 Emergent universe 46:14 Holography 58:00 Entropy 65:00 Can we even know if the universe begun?