Respectable Anti-Realism: Quantum Mechanics Turns Epistemic
Hans Busstra and Dr. Lídia del Rio talk to Dr. Matthew Leifer, Assistant Professor of Physics at Chapman University, about the epistemic interpretation of quantum mechanics.
Classically, when physicists call themselves ‘realists’ they mean that we should assume that a physical, observer-independent universe is fundamental. But if this counts as realism, anti-realism is perhaps the more respectable position.
Leifer points, for instance, to ‘Bell-Wigner mashups’: thought-experiments that entangle different observers to arrive at disturbing consequences; for instance, that there is no ‘absoluteness of facts’ for all observers, in a classical sense.
Our previous video on the Frauchiger-Renner thought-experiment with Lídia del Rio:
https://youtu.be/v7kxWT_zI60
Selected publications by Matthew Leifer:
Leifer, Matthew S. “Uncertainty from the Aharonov–Vaidman identity.” Quantum Studies: Mathematics and Foundations, vol. 10, pp. 373–397, 2023. PDF/Abstract (arXiv) mattleifer.info+12mattleifer.info+12arxiv.org+12
Catani, Lorenzo; Leifer, Matthew S. “A mathematical framework for operational fine tunings.” Quantum, vol. 7, article 948, 16 Mar 2023. PDF/DOI/ArXiv mattleifer.info+1quantum-journal.org+1
Catani, Lorenzo; Leifer, Matthew S.; Scala, Giovanni; Schmid, David; Spekkens, Robert W. “What is nonclassical about uncertainty relations?” Physical Review Letters, vol. 129, iss. 24, 2022. Abstract (via arXiv) chapman.edu+8arxiv.org+8mattleifer.info+8
Leifer, Matthew S.; Duarte, Cristhiano. “Noncontextuality inequalities from antidistinguishability.” Physical Review A, vol. 101, iss. 6, p. 062113, 2020. PDF/Abstract (arXiv) fetzer-franklin-fund.org+2mattleifer.info+2arxiv.org+2
Timestamps:
0:00 Introduction
3:06 What is classicality?
5:56 Classical information vs quantum information
11:42 Experimental metaphysics
14:18 Metaphysical implications of Bell’s work
18:42 What is realism?
21:51 Realism vs anti-realism
25:58 The internal realism of theories
29:51 How the public understands quantum mechanics
32:14 Interpreting quantum mechanics is like tightrope walking
34:51 On naive realism
38:41 How would you define physicalism?
44:33 On mind and consciousness
48:19 Panpsychists have physics-envy
49:25 It’s unclear what the Copenhagen interpretation is…
56:54 On the quantum-classical cut
1:09:29 Craziness derived from sensible premises
1:14:50 Why ‘for all practical purposes’ is not a solution
1:21:44 On Bell-Wigner mashups
1:30:37 What constitutes an observer?
1:33:53 Matt on the meaning of quantum mechanics and the limits of physics.
All music licensed under Storyblocks and Soundstripe
All stock footage licensed under Storyblocks.
Used under fair-use: fragment from “Memento”, Christopher Nolan, 2000
Interview content copyright by Essentia Foundation, 2025
www.essentiafoundation.org
@ijf03208rek
August 5, 2025 at 7:04 pm
this is the best channel on youtube. it's just a fact. everybody in the world should watch these videos so they can realize how wrong it is to assume this world is strictly materialistic and nothing else.
@ThatTenzing
August 5, 2025 at 7:04 pm
Always holding his head on the thumbnail 😅
@siddharthytshorts3667
August 5, 2025 at 7:04 pm
So finally science is on the right direction…
@sedadmin8275
August 5, 2025 at 7:04 pm
Gave it up 7 minutes in. Doesn’t make a bit of sense.
@sustainablealternative2912
August 5, 2025 at 7:04 pm
predatory semanticism is now the next AI and warship monopoly propagenda ,…
@kymbriel
August 5, 2025 at 7:04 pm
Thanks for publishing this conversation. I hope lots of people appreciate it. I, for one, interpret this deeply human behaviour as our shared quest to understand mysterious phenomena. Maybe, if we keep being humble, honest and curious, we can expand the boundaries of what we can prove. Sensing is central to this effort. Some human beings are more sensitive than others. We struggle to arrive at agreements for why this is true. I wonder how this expands to include the perception of machines and the development of sensors.
@bobaldo2339
August 5, 2025 at 7:04 pm
"Information" does not in any sense "sit out there". Information is processed sensory inpit (sensation). Only when it is processed by our brains does sensory input become information.
This in no way is a comment on whether or not the commonly agreed upon external "reality" actually "exists".
@barrypickford1443
August 5, 2025 at 7:04 pm
All the key channels are starting to speak the same story.
The change is coming folks
Anonymous
August 5, 2025 at 7:04 pm
Please interview Jacob Barandes!!!
@KathrynMclaughlin-gv1cz
August 5, 2025 at 7:04 pm
Please have a scientist in NDE research come on the show. Consciousness does go beyond the physical body.
@TimelineTheSchizoid
August 5, 2025 at 7:04 pm
"and as physicists, we are very unprepared" is such a massive understatement. The crisis in causality has brought out the worst in us, as some become dogmatic about the old models. Meanwhile people are taking the news and trying to run away with their personal takes on the matter.
@The_Turiya
August 5, 2025 at 7:04 pm
I’m so confused, don’t particles reduce to fields, particles being field excitations? What part of that is “physical” ?
@wmstuckey
August 5, 2025 at 7:04 pm
As we explain in Chapter 9 "What's Really Going On?" of our book "Einstein's Entanglement: Bell Inequalities, Relativity, and the Qubit" (Oxford UP, 2024), the properties of quanta are defined contextually, they are not "intrinsic." For example, a rubidium atom in an atomic trap has a worldline (simultaneous position and momentum) as needed to render it a bodily object of classical mechanics by exchanging 100,000 photons per second with its environment. In contrast, a silver atom in the Stern-Gerlach experiment does not interact with the classical environment and produces a quantum bit of information (qubit). So, is an atom quantum or is it classical? Depends on the spatiotemporal context of bodily objects established via the exchange of quanta.
@builderofcastles
August 5, 2025 at 7:04 pm
The first, and largest mistake science has ever made is separating physics and metaphysics.
Our world is continuum from spiritual to physical.
@Heatlthiswealthinexile
August 5, 2025 at 7:04 pm
Magnificent……😉🤝
@ubergeraldine
August 5, 2025 at 7:04 pm
Many worlds? I think the people like anything which allows them free rein and excuses them from self responsibility.
@TheSpiritualCollective444
August 5, 2025 at 7:04 pm
One point to note: classical music is a symphonic harmony of selfeggio frequencies that also align with Langland's Theory of mathematical classification organizational groups and both are aligned, in turn, with Gregorian Chanting frequency: Ergo, "Classical" music is quite literally the definition of "Quantum Pysics." The notion of "classical"'is simply awaiting the integration of another creation which equals the "quantum" solution as a comprehensive, accurate polyhedron-esque envisioned innovative reality in a parallel/dimension whereby you can "straddle" both simultaneously. That's my personal experience, at any rate, and firm belief in its repeated accuracy as measured through data indicating successful evidence as validity re: theory & practice. ❤ Morgan
@TheSpiritualCollective444
August 5, 2025 at 7:04 pm
Neuro-diverse brain processors see anomalies, for example, as the majority of their perspectives/observers whereas the polar opposite is normally standard for neuro-typical brains (ergo both observers would have an extremely high probability that each would "measure" completely differntent outcomes as the main priority of their focussed reality.
@TheSpiritualCollective444
August 5, 2025 at 7:04 pm
The Big Bang never MADE a "bang" because there was no one to "hear" or "observe" it right?
@SQ_SherryQ
August 5, 2025 at 7:04 pm
I've needed this channel for my entire life …. WOW
Comments are closed.