In this unedited, on-site conversation with cosmologist Dr. Brian Keating, we examine what counts as evidence in modern physics by pressing on one of cosmology’s most trusted observations: the cosmic microwave background. The discussion centers on a core tension between measurement and interpretation: specifically whether a near-perfect black body spectrum can reasonably be attributed to an early-universe plasma. As assumptions about the Big Bang, black body radiation, and material physics are questioned, the exchange becomes increasingly uncomfortable, revealing how deeply theoretical commitments shape scientific judgment. What emerges is not a verdict, but a rare, unfiltered look at how evidence, authority, and first principles collide in contemporary physics. PATREON https://www.patreon.com/c/demystifysci PARADOX LOST PRE-SALE: https://buy.stripe.com/7sY7sKdoN5d29eUdYddEs0b HOMEBREW MUSIC - Check out our new album! Hard Copies (Vinyl): FREE SHIPPING https://demystifysci-shop.fourthwall.com/products/vinyl-lp-secretary-of-nature-everything-is-so-good-here Streaming: https://secretaryofnature.bandcamp.com/album/everything-is-so-good-here 00:00 Go! An emotionally charged take on physics 00:06:00 Reexamining the Story We Tell About the Universe 00:11:00 The Three Pillars of the Big Bang 00:13:00 How the CMB Is Actually Measured 00:16:00 The Surface of Last Scattering Explained 00:18:00 Why the CMB Is Considered a Relic of a Hot Universe 00:20:22 Measuring Expansion Without Direct Distance 00:21:27 Atomic Simplicity and Early-Universe Conditions 00:23:04 Is Science a Narrative or an Empirical Model? 00:25:19 Historical Cosmology and Paradigm Shifts 00:28:22 Why the CMB Is the Most Perfect Black Body Ever Measured 00:33:30 What Produces Black Body Radiation in the Laboratory 00:35:09 Can Gaseous Plasma Produce a Perfect Thermal Spectrum? 00:36:58 When the Universe Became Transparent 00:38:51 Expansion Assumptions and Acoustic Evidence 00:39:34 Material Structure and Black Body Precision 00:43:02 Measurement vs Interpretation in Cosmology 00:44:11 Does the CMB Really Prove the Big Bang? 00:47:00 Would Emissivity Errors Change Cosmology? 00:50:02 Lab Black Bodies vs Cosmic Sources 00:53:09 Are We Applying Earth Physics Correctly? 00:56:26 Measuring Temperature vs Explaining Origins 00:58:12 Emotional Attachment to Cosmological Models 01:01:01 Gases Can't Radiate Planckian Spectra 01:04:19 What Actually Makes a Black Body? 01:05:56 How Cosmologists Use the CMB as a Thermometer 01:08:32 Authority, Gatekeeping, and Scientific Credibility 01:10:38 Would Alternative Models Change the Numbers? 01:12:55 Could the CMB Be Local Rather Than Cosmic? 01:16:11 Do Lattices Matter for Black Body Radiation? 01:18:45 Precision, Agreement, and Cross-Checks 01:20:22 A Philosophical Divide Over Evidence 01:22:16 Peer Review, Outsiders, and First Principles 01:24:07 Filtering Ideas and the Cost of Evaluation 01:26:13 Expertise, Frustration, and Misalignment 01:28:36 Who Bears the Burden of Proof? 01:30:02 Expertise vs Novel Ideas in Physics 01:31:25 Can Gases Ever Behave Like Black Bodies? 01:33:42 The Sun is on Trial Too? #physics, #cosmology, #astrophysics, #quantummechanics , #bigbang, #cosmicmicrowavebackground, #philosophyofscience, #physicsfun , #theoreticalphysics, #spacetime , #fundamentalphysics , #longformpodcast, #physicspodcast, #philosophypodcast MERCH: Rock some DemystifySci gear : https://demystifysci-shop.fourthwall.com/ AMAZON: Do your shopping through this link: https://amzn.to/3YyoT98 DONATE: https://bit.ly/3wkPqaD SUBSTACK: https://substack.com/@UCqV4_7i9h1_V7hY48eZZSLw@demystifysci RSS: https://anchor.fm/s/2be66934/podcast/rss MAILING LIST: https://bit.ly/3v3kz2S SOCIAL: - Discord: https://discord.gg/MJzKT8CQub - Facebook: https://www.facebook.com/groups/DemystifySci - Instagram: https://www.instagram.com/DemystifySci/ - Twitter: https://twitter.com/DemystifySci MUSIC: -Shilo Delay: https://g.co/kgs/oty671