How William Lane Craig misrepresents science
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I'm joined by Dr. Daniel Linford and Phil Halper to explain what Craig gets wrong about science's bearing on the beginning of the universe. Specifically, we respond to a recent video by @ReasonableFaithOrg .Like the show? Help it grow! Consider becoming a patron (thanks!): https://www.patreon.com/majestyofreasonIf you wanna make a one-time donation or tip (thanks!): https://www.paypal.com/paypalme/josephcschmidOUTLINE0:00 Intro2:22 Craig’s video9:22 Material causality18:14 Beginning to exist20:05 Big Bang and cosmological models33:18 No particular model is probable?36:26 Past finitude doesn’t imply beginning51:57 Quantum gravity55:51 Window shade analogy1:00:10 BGV Theorem1:17:13 Vilenkin’s paper1:26:00 Sean Carroll and Guth1:38:12 The fixed Kalam1:41:20 Abstract object counterexamples?1:51:45 Second law of thermodynamics1:55:10 The universe as a counterexample?1:57:56 Document! Don’t just assert!2:06:45 ConclusionNOTEAt 1:15:05, I wanted to summarize the problems with Craig’s use of the BGV theorem. I didn’t provide the most helpful summary in the video, so here’s a summary:(1) At best, the BGV theorem shows that a spacetime region which has been expanding on average throughout its history could not have been expanding forever. Such an expanding region must have begun its expansion at some finitely distant point in the past. This does *not* imply that all of spacetime *itself* has a beginning because all of spacetime may not have been expanding on average throughout its history. In such a case, the BGV Theorem would be inapplicable to the whole of spacetime itself. In fact, as pointed out in the video, both Guth and Vilenkin explicitly say that the BGV theorem only shows that the *inflation* of the universe has a beginning, it doesn’t show that the *universe as a whole* or *spacetime as a whole* has a beginning.(2) Recent literature purports to give grounds to doubt the BGV theorem. Whether or not this recent literature is correct, it reveals that this is not a settled issue. Instead, it is an active area of research and debate. Relevant papers here include Lesnefsky et al (2023) https://journals.aps.org/prd/abstract/10.1103/PhysRevD.107.044024, Geshnizjani et al (2023) https://link.springer.com/article/10.1007/JHEP10(2023)182, Nomura (2012) https://arxiv.org/abs/1205.5550, and Aguirre (2007) https://arxiv.org/abs/0712.0571.(3) The BGV theorem is only a theorem about classical spacetimes. But we probably don’t live in a classical spacetime. We have good reasons internal to the standard model and general relativity for thinking that these theories will be surpassed by a new theory able to incorporate both. So our current understanding of spacetime will be replaced by something else. So the BGV theorem does not apply to the spacetime we live in.(4) Even if we do live in a classical spacetime, the Malamant-Manchak theorems show that, in all likelihood, we couldn’t ever know enough about the global structure of spacetime to know that *all* of spacetime had a beginning.(5) Even if the BGV theorem shows that the past is finite — and, as explained above, it does not — we cannot infer that the universe (i.e., the totality of all physical reality) began to exist, for the reasons given in the section of the video entitled “Past finitude does not entail beginning to exist”.