Mindscape 253 | David Deutsch on Science, Complexity, and Explanation

David Deutsch is one of the most creative scientific thinkers working today, who has as a goal to understand and explain the natural world as best we can. He was a pioneer in quantum computing, and has long been an advocate of the Everett interpretation of quantum theory. He is also the inventor of constructor theory, a new way of conceptualizing physics and science more broadly. But he also has a strong interest in philosophy and epistemology, championing a Popperian explanation-based approach over a rival Bayesian epistemology. We talk about all of these things and more, including his recent work on the Popper-Miller theorem, which specifies limitations on inductive approaches to knowledge and probability.

David Deutsch received his Ph.D. in theoretical physics from the University of Oxford. He is currently a visiting professor in the Department of Atomic and Laser Physics at Oxford. He is a pioneer in quantum computation as well as initiating constructor theory. His books include The Fabric of Reality and The Beginning of Infinity. Among his awards including the Dirac Prize, the Dirac Medal, the Edge of Computation Science Prize, the Isaac Newton Medal, the Breakthrough Physics Prize, and a Royal Society Fellowship.

#podcast #ideas #science #philosophy #culture

[davidsimpson]

“Knowledge is different from eucalyptus leaves.” Best quote ever

[abitbohr]

Deutsch is the greatest thinker of our times.

[trucid]

AI generated timestamps

0:00 - Intro
0:29 - David Deutsch met Hugh Everett
1:10 - Deutsch pioneered quantum computing
1:58 - Explanatory knowledge is transforming the universe
2:41 - Monotony: long periods of stasis followed by rapid change
4:50 - Patreon shoutout
5:26 - Starting the interview with David Deutsch
5:45 - Deutsch recalls meeting Hugh Everett
8:33 - Everett understood the nuances of his own theory
12:06 - Wheeler invited Everett to give a seminar at UT Austin
14:16 - Deutsch was already sympathetic to Everettian QM before meeting Everett
18:27 - Newton may have understood more about energy/dynamics than he revealed
21:24 - Explanatory knowledge emerged relatively recently in the universe
23:03 - Knowledge allows "people" to transform the universe
25:15 - No beings with greater explanatory powers than humans
26:11 - Human brains are Turing complete
30:13 - Turing completeness is a hardware property
31:13 - Humans also have explanatory universality
33:50 - Mathematics and explanation are not fully formalizable
35:08 - Optimism: everything is possible with enough knowledge
36:17 - A simple program could lead to AGI, but we lack the right philosophy
39:05 - AGI may arise suddenly like Darwinian evolution
40:31 - Constructor Theory formalizes what transformations are possible
43:27 - Constructor Theory related to explanation and knowledge
48:12 - Still unclear on advantages of Constructor Theory perspective
49:25 - Constructor Theory provides overarching principles like conservation laws
51:47 - Newton may have understood energy concepts
53:43 - Constructor Theory connected to Popper's philosophy
55:05 - Deutsch rejects Bayesian epistemology
56:26 - Bayesian epistemology embeds credences that obey probability calculus
58:06 - Popper/Miller theorem: evidence only increases credence of propositions that closely match evidence
1:00:30 - Good explanations are key, not Bayesian credences
1:03:10 - Non-transitivity of support for explanations
1:07:36 - Using Bayesian reasoning in limited practical cases
1:08:54 - Looking for best explanations, not high probability theories
1:13:39 - Can't assign credences to unknown theories like simulation hypothesis
1:15:47 - False precision of credences, seek good explanations
1:18:21 - Galileo sought simplest explanation, not most probable
1:22:25 - Good explanations can't be formalized but can be judged philosophically
1:24:08 - Reject explanations that can explain anything
1:25:08 - Deutsch believes quantum theory is false
1:26:49 - Conflict between quantum theory and general relativity
1:28:22 - Theories are approximations, useful in different domains
1:29:03 - Problems with axioms of quantum field theory
1:31:09 - Considering alternative QFTs without problematic axioms
1:33:48 - Testing new QFT ideas like non-commuting particles
1:34:49 - New QFT compatible with Everettian view
1:35:57 - Preferring Heisenberg picture over Schrodinger
1:36:58 - Multiple worlds in quantum computation before decoherence
1:38:25 - Worlds split when computations branch and recombine
1:39:11 - Deutsch working on textbook and sci-fi book
1:40:06 - New approach to teaching QM focused on information
1:41:13 - Goal to change how quantum mechanics is taught

[ethiesm]

Thanks Sean!!!! Great questions and beautiful runway you gave David without interruption

[HenryJasonVarga]

He is one of my favourite contemporary thinkers.

[HarryNicNicholas]

fascinating way of thinking, thank goodness. stuff i've never encountered before.

[davegrundgeiger]

As I sit down to play this, I'm beyond excited. These are far and away my two most admired scientists. I, like others, have been looking forward to this exchange for a long time. Now, nobody bother me for the next 1 hour, 42 minutes, and 6 seconds. 🙂

[grawl]

Deutsch! At last. This will be a treat. :)

[aidanhall]

Deutsch is a Nobel mind, hopefully his year will come 🙏🏻

[davidsimpson]

I’m so excited to listen to this one!! Carroll and Deutsch are heroes of mine.

[snarkyboojum]

I literally involuntarily murmured "Woooahh" when I saw that this episode exists. Wow - what a treat. Thank you so much, Sean (and David)!

[Philosophie]

thank you very much, the very great conversation

[aaron]

Not pretending to understand any of this but... I see why Deutsch wants to look at physics from a different angle: to create the kind of understanding breakthrough Darwin made. My problem is the examples of Constructor Theory I've heard just seem to state the obvious. The question of 'what is possible' already occurs in the course of current scientific thinking. Not sure what this theory is adding besides formalization of something rudimentary. What am I missing?

[shonufftheshogun]

I’m curious if Sean has read either of a David’s books The Beginning of Infinity or The Fabric of Reality. David has specific vocabulary that can take some getting used to.

[zombieinjeans]

Finally! What a great episode! I'm really looking forward to his new books and the paper on why Bayesian epistemology is false.

[lefttraces]

Yaaayy we’re in the best branch of the universe where this exists🥳

[YanusDV]

HOLY MOLYYY its David Deutsch!!!! with Sean Carroll!!! * insert Jonah Hill screaming meme *

[johnrod]

Dr. Carroll - you're a very patient interviewer. This 7 second part summarizes everything succinctly: 1:10:45 until 1:10:52. Thank you for all the interviews so far. I follow your work and books. Looking forward to reading the upcoming one.

[FABRIZIOZPH]

I actually have to say I'm slightly disappointed, it sounded to me as if Sean waa actually holding back and biting his tongue due to several potential flaws in his argumentation

[johncarter]

Always learn a lot and have alot of new thoughts and ideas when listening to conversations with David Deutsche. Thanks!