

ToKCast
Brett Hall
This is a podcast largely about the work of David Deutsch and his books ”The Beginning of Infinity” and ”The Fabric of Reality”.
Episodes
Mentioned books

Sep 21, 2021 • 1h 15min
Ep: 89 ”Quantum Information” Chiara Marletto‘s ”The Science of Can & Can‘t” Ch 4 readings and discussion
As the title suggests: this is about Quantum Information. It is “Quantum Information Theory” to be more precise. Now physics is sometimes regarded as strange by people who know little about it. And even for people who know a little more about it - well they might regard quantum physics as strange. And even those who know a little about quantum physics - they can regard quantum information theory as rather esoteric. This episode, following Chapter 4 of Chiara Marletto’s excellent book, begins from the ground up to explore how quantum systems can do more with information than classical systems (which is what all present day computers use). There is an excellent talk by David Wallace about the Mach Zehnder interferometer that I mention. It’s here: https://www.youtube.com/watch?v=GRJT9... Coupled with my own remarks about it here: https://www.youtube.com/watch?v=Cu4HH... Anyone should come away with a good understanding of what is actually going on.

6 snips
Sep 11, 2021 • 1h 25min
Ep: 88 Critically Creative (Critical and Creative Thinking 2.0).
There is an article associated with this podcast episode here: https://www.bretthall.org/critically-creative-1.html
I mention this article from the University of Sydney, Australia: https://www.sydney.edu.au/students/critical-thinking.html
While recording this podcast, I had in mind teachers: they are my primary “target audience” so to speak. But this will, I hope be useful for anyone with a “stake” in the education system: so of course students, their parents, university lecturers, administrators - people in a position to make decisions about schools and curriculum. The topic is essentially “Critical Thinking” and what I think it is, in the Popperian tradition. As I will mention, unlike even just 15 years ago, “Critical Thinking” is now a fashionable term thrown around in schools, universities and among those charged with deciding what students are taught and how. Often “Creative Thinking” is thrown into the mix as well. All sorts of activities are devised for students to improve these “skills”: sometimes entire new subjects are created for students to take that are supposed to be about improving “critical thinking”. It’s all - from the education system’s point of view - very new. And because it’s new *there* they are, largely speaking, inventing things on the fly or designating certain techniques or rules or activities “critical and creative thinking”. It really is all the buzz in many places.
The time stamps below will give you some better idea of the full content.
Time Stamps
00:00:00 Introduction - and what should be in a school curriculum.
00:04:00 Educational buzz words and “lock in”.
00:07:55 Some initial thoughts about +the practical* uses of epistemology
00:10:30 Teaching vs Learning Strategies and “Student Engagement”
14:30 Criticisms - what are they?
15:30 What it takes to pass exams.
16:40 To be creative should you obey no rules?
18:30 A second pass on the practical applications of critical thinking
22:25 The Grass Eating cure for the 100th time ;)
25:20 “The Explanation Criteria”
28:30 Peer review (& double blind placebo controlled trials in medicine) and *when* it is we can say we know what we know.
32:45 Critical Thinking everywhere
33:00 Explanationless science, mathematics 35:30 What is “criticism” exactly?
36:00 As applied to history & music.
36:50 How to come up with good criticisms and some discussion of the possibility of heuristics for better critical thinking.
39:10 Constructive vs Destructive criticism. (& the distinction between ideas and people).
44:00 Popper - an introduction for those involved in education
45:30 The anti-rational hangup ballast.
48:35 A very general two-step process for framing any analysis that requires the use of “critical thinking”.
50:13 Some more specific explicit unpacking of some critical thinking “techniques” or heuristics.
52:09 A “fundamental” theorem of criticism or the chief principle of critical thinking. :)
56:27 Creative thinking: the little we know.
59:00 Remarks about economics and free vs regulated markets
01:01:27 How can we improve creative thinking?
01:01:03 Creativity and criticism in evolution by natural selection
01:04:07 How does human creativity work? Remarks on AGI.
01:09:09 How a child teaches us
01:14:38 Final “critically creative” thoughts.
01:18:00 Typical “critical thinking” as it is taught at university: https://www.sydney.edu.au/students/critical-thinking.html
01:20:00 The purpose of critical and creative thinking as taught at schools/universities.

6 snips
Sep 7, 2021 • 1h 15min
Ep 87: David Deutsch‘s ”The Fabric of Reality” Chapter 3 “Problem Solving” Part 1
This is the first part of a discussion about chapter 3 of "The Fabric of Reality". It is about...problem solving with a significant focus on science and how scientific theories are generated. It contains criticism of the prevailing "justificationist" and "inductivist" notions. I see it as a good companion to (perhaps an introduction to) my episode "The Aim of Science" which I would consider a little more "heavy". This was wide ranging and a lot of fun to produce!

Aug 28, 2021 • 1h 13min
Ep 86: The Aim of Science
This is an "irregular" ToKCast which is all about a short essay by Popper titled "The Aim of Science". I read parts of the essay and comment on it and compare it to some more recent developments in the philosophy of science. Readings for this - like the paper itself - can be found here: http://www.bretthall.org/the-aim-of-s... The thing about the essay that is amazing is how certain paragraphs are as clear as anything one might say on this topic today: and yet he is breaking the ground in many ways with what he is saying. People struggled until Popper to even make a coherent case for what science was all about let alone how it managed to do it. There are only a few images in this "video" so you can easily get away with listening to the audio only version of this.

Aug 27, 2021 • 1h 6min
Ep 85: ToKCast Do Explain Part 2
The original link for this (without the introduction I provide here) can be found at: https://www.youtube.com/watch?v=zEcHS... “Do Explain” is a podcast interview series created by Christofer Lövgren (Chris as I call him because I can’t pronounce his surname). Find “Do Explain” anywhere podcasts can be found - for example Apple here: https://www.google.com/url?sa=t&rct=j... or “Tune In” here https://www.google.com/url?sa=t&rct=j... The main website and host for Do Explain for now is here: https://doexplain.buzzsprout.com In this episode I cover all my "big hits" - consciousness, free will, Bayesianism and as the original title says "The nature of knowledge".

Aug 27, 2021 • 12min
Ep 84: David Deutsch answers a question about the nature of the laws of physics (a question for David: 7).
This is essentially a sequel to episode 1 of this series about the "reality of abstractions". This question considers the special case of the laws of physics. In what sense do the laws of physics exist? Can we deny their existence as some philosophers do?

Aug 13, 2021 • 41min
Ep 83: "The Science of Information" (Chiara Marletto's "The Science of Can & Can't" (Pt 2: Readings & more)
In this episode I actually do some readings from the chapter (unlike in last episode). Here we really delve into the new science of the constructor theory of information. We learn about what the physical requirements are for information to exist in our universe and therefore why it is that information is a physical property. The very possibility that matter can allow for negation (or flip) operations and copy operations is a property of matter in our universe. It did not have to be this way. A physical account, therefore, of these operations and further the so-called “interoperability” of information (the substrate independence of information or the capacity of information to be transferred or copied from disparate media to other media) all lead to a discussion of the universality of information. All of these are counterfactual rather than factual properties of physical systems in our universe.
This is fascinating but subtle stuff that few physicists have yet grasped the significance of and for that reason alone is well worth understanding for anyone who would like to be at the cutting edge of problem solving at the foundations of physics.

Aug 7, 2021 • 12min
Ep 82: David Deutsch answers a question about Gödel and undecidability. (A question for David number 6).
This is me asking David about interesting and inherently uninteresting things. What effect might "undecidable" propositions have in the physical world? David gives an answer I have been looking for.

Aug 6, 2021 • 40min
Ep 81: "The Science of Information" (Chiara Marletto's "The Science of Can & Can't" (A prelude to Ch 3)
In this the fourth episode about Chiara Marletto's excellent work "The Science of Can and Can't" I discuss the science of information. Chapter 3 of the book is called "Information" but in this episode I do not actually read from the book. This is a broader overview of issues in epistemology, folk philosophy, physics and mathematics that have some connection to the topic of "information". I thought these might be useful contextual remarks before leaping into reading the book. That will happen next episode. Quite a few images and I move through a mathematical problem at one point on the screen which may be difficult given audio only. The video version is here: https://www.youtube.com/watch?v=s8uTVbdjMy8

Jul 19, 2021 • 46min
Ep 80: David Deutsch's "The Fabric of Reality" Chapter 2 “Shadows”
This episode dives into the intricacies of quantum theory, offering a clear explanation of the multiverse. It explores the relationship between consciousness and fundamental physics, delves into the concept of shadows and parallel universes, and discusses quantization and the behavior of light. The episode also touches on the intriguing behavior of tangible and shadow photons, raising questions about the existence of shadow matter and the multiverse.


