Before the Big Bang 9: A Multiverse from "Nothing"

Did the universe have a beginning or has it always existed? Is there just one universe or many? In this series we explore competing models for what happened at or before the big bang. In this episode we interview Alex Vilenkin who proposed the universe had a spontaneous origin from “nothing" and with no cause! He also showed how our big bang would not be alone, that there would be an infinite number of big bangs generating a multiverse. The idea of a universe from nothing has of course been discussed elsewhere. But here we clear up many misunderstandings of the concept with the scientist who invented it. In particular, the proposal that the universe came from nothing is not to be confused with the proposal that the universe originated from a vacuum fluctuation. Below is lit of topics we discuss. Please note we did not release the film until Alex Vilenkin saw a draft and approved it. 00intro and Alex Vilenkin talk about his early life. 2:28 The uncertainty principle 3:16 Tryon’s proposal 5:32 Inflation 7:00 Quantum Tunneling 8:21 Tunnelling From Nothing 12:38 Difference between Tryon’s and Vilenkin’s proposal 13:45 Semi Classical Gravity 15:04 What caused the universe 16:05 Interpretation of QM and implications for cosmology 19:00 Why don’t tigers appear in our living room if things can come from nothing? 21:07 how do we get a multiverse? 23:25 was inflation before or after the big bang? 25:12 Alan Guth’s reaction to Vielnkin’s multiverse proposal. 26:10 Experimental tests of the multiverse 28:17 Indirect test of the multiverse and fine tuning. 33:08 has a recent undermined the multiverse? 36:46 experimental probe of tunnelling form nothing 37:42 geometry of the universe and tunnelling form nothing. 38:50 are the physical laws just description or are they are more than that? 39:24 way are the laws of physics the way they are? 40:31 Boltzman Brain 42:15 The Hartle Hawking Proposal 43:21 Responding to Neil Turok and colleagues new critique 44:50 BGV theorem 47:15 low entropy 47:41 Does anyone back the one big bang one era universe? 48:13 Does infinity exist in the real world? 50:51 Where next for the proposal and early universe cosmology?