ToKCast

Ep 222: David Deutsch’s ”The Fabric of Reality” Chapter 12 ”TimeTravel” Part 1

Is time travel into the past and the future possible? What is time dilation? Subjective and objective senses of "time travel". David Deutsch's own documentary on Time Travel from the BBB (192) https://youtu.be/C6_gxoLwrWw?si=8vw8cwbP49XkY6e8

Ep 221: Do Not Destroy The Means of Error Correction

Here I present a "positive vision" of the kind I complained was absent in the episode right before this ("Criticism is never enough"). Here I am riffing off a line which contains a deep truth out of the Beginning of Infinity where Socrates is speaking with the god Hermes. In that passage David links a moral injunction "Do not" to an epistemological concept (error). From this stepping stone I explore some of the institutions which emerge from such a commitment, but which themselves can also be regarded as fundamental features of a dynamic society.

Ep 220: Criticism is never enough

Another response episode. This time to Douglas Murray and Jordan Peterson. Douglas and Jordan are seeking a way to construct a positive vision for society, but they seem at a loss for what in fundamental terms, this might include. Part 1 of 2.

Ep 219: Response to Peter Boghossian Part 3, Appendix

Parts 1 and 2 were, admittedly, long. So if you could not persevere through those, this gets the major points out serving both as an appendix to tie up some loose ends and as a summary of parts 1 and 2.

Ep 218: Peter Boghossian Response PART 2

Here I get to the part of the discussion Peter has about my own "airchat" explanation of "anyone can understand anything". I go through arguments based on the Church-Turing Principle, computational universality and how denials of explanatory universality are appeals to the supernatural and other topics.

Ep: 217 Peter Boghossian Response Part 1

The great epistemologist, Peter Boghossian, created a video on Youtube that responded to me, in part. It's to be found in full here: https://youtu.be/5Vf-T8K0_zE?si=T2XkG8h8iNj1ZXGR
This first part is largely a response to Richard Dawkins on his notion of "Middle World" and Michael Shermer's notion we are not evolutionarily capable of understanding anything.

Ep 216: Astrobiology and Cancer

Part 2 in a series about the work of researcher Charley Lineweaver. In this episode, a targeted focus on the one thing we did not discuss out of all of Charley's scientific interests in my interview with him in Ep 215: his recent work with Paul Davies on "The Atavistic Model" of Cancer. For the peer reviewed paper on The Atavistic Model by Lineweaver and Davies see: https://www.mso.anu.edu.au/~charley/papers/LineweaverDaviesVincent2014.pdf
For more recent work on the theory see: https://ui.adsabs.harvard.edu/abs/2014APS..MARF14002L/abstract
and https://ui.adsabs.harvard.edu/abs/2017PNAS..114.6160B/abstract
 

Ep 215: Charley Lineweaver

A conversation with physicist, cosmologist, astrobiologist, polyglot and polymath - Charley Lineweaver.
00:00 - My introduction
08:57 - Charley’s fascinating early years
12:14 - From an English/History degree to physics
13:53 - Charley’s historic work on the Cosmic Microwave Background
17:34 - Methods of probing deep space
19:51 - Our accelerating universe
22:15 - Dark Matter Candidates
23:20 - The Fermi Problem and the “Planet of the Apes” Hypothesis
28:37 - Natural experiments in the evolution of intelligence
33:38: What can the early appearance of life on Earth tell us about aliens?
37:31: Non-intelligent alien life.
38:06: Deep homology and misconceptions about convergent biological evolution
44:31 The Shadow Biosphere
48:53 The significance of extremophiles
50:23 Does life arise from non-life easily or not? What do we know?
53:32 What is life?
55:56 A “debate” about people?
1:10:20 - The Potato Radius
1:15:00 - What Charley is working on now

Ep 214: Resources, Wealth, Technology, Error Correction and Knowledge Creation

The title is long enough so you look for more here? ;) This one is largely, in truth about energy and what it can do for us. Across the almost 90 minutes I cover how the concepts in the title logically cohere and depend one upon the other and we take a look at "the universal constructor" and compare the possibilities for an optimistic distant future with the reality of our situation now. Fair warning: many Australian examples are employed here. A tiny bit of Trump, a dashing of Deutsch, a yard of Yaron, morsels of Musk, some of Australia's mining magnates for better or worse and plenty of physics, philosophy and even politics. Those on my livestream may have heard a less polished (more profanity stricken) version of some of this material. This is me back to being polite even if there are reasons for frustration...
 
(See Youtube version for graphs, data and so on: https://youtu.be/ovs18b10d4Q )

Ep 213: ToKCast in Auckland - live

This is a recording (with a brief introduction first) of a keynote address I gave to open the 2024 "Naturalistic Decision Making Association" conference. People from business, government and academia came together for 3 days to talk about how to make better decisions under pressure. It was an opportunity for me to share the work of David Deutsch and Karl Popper with everyone from people working in international militaries and government defence organisations, through to leaders in business and university academics and students. Regular listeners will notice this is an adaptation of another recent episode - but I think this live version is better as I say in my introduction.

Ep 212: Livestream 3, June 28 2024

More questions, more lengthy and more verbose than ever. Enjoy, or drift of to sleep with me ;)

Ep 211: Livestream 2, June 26 2024

Fear not! ToKCast is not becoming a pure Q&A "show". This is literally a kind of "break" for me that I find easy and I note the listeners find fun. Today's a little shorter and - here's some of the topics covered!
 
00:00: David Deutsch mentioned on Lex Fridman
04:15: Dennis Noble debates Richard Dawkins on the selfish gene
16:47: The goal driven life and AI
27:51 Self similarity - minds and universes
34:39: The hard problem of consciousness and Popperian epistemology
41:30: Wave particle duality
53:53 The fun criterion - and some reflections on responsibility and “toil”.
1:05:44 - Communication and the difficulty thereof between people
1:07:13 - Roger Penrose and the universality of (quantum) computation (or Taking Theories Seriously…)
1:13:35 Book recommendations.

Ep 210: Livestream - Question, Answer and repeat for 2+ hours

I put out a call on Twitter/@X for questions and got a deluge. Between those and more from YouTube itself - this is the result ranging over predicting the future, through to theories of learning, AGI and AI, optimism and epistemology - many of the major hits and more.

Ep 209: Rational Decision Making

Riffing on Karl Popper and David Deutsch (especially). A broad overview, covering lots of the basics of "social" or "rational" choice theory, Bayesianism (again!), misconceptions, good ideas and bad. Errors my own as always.

Ep 208: David Deutsch’s ”The Fabric of Reality” Chapter 11 ”Time: The First Quantum Concept” Part 3

Here we explore the distinction between classical notions of time (including spacetime physics) as approximations to how time is understood in the multiverse. How perfectly deterministic laws lead to subjective unpredictability. Consequences for free will, questions about what happened before time began (or after it ends), new discoveries since the publication of The Fabric of Reality was published in 1997 and David's subtle alterations to phrasing between The Fabric of Reality and The Beginning of Infinity (in particular with reference to identical vs fungible and how tossing "fair" coins in our universe isn't 50/50 heads and tails. If you would like to discuss any of the content in this video with me at length, sign up to Airchat at https://www.air.chat where I am active daily answering people's questions and engaging with those interested in the work of David Deutsch and associated thinkers and ideas explored in his work, wider physics, philosophy and everything.

Ep 207: Variations on a Conjecture

If you are distracted by, or simply prefer a version without, the background music - you can find that here: https://youtu.be/xSbqTTs1nl0
 
My preferred version is here: https://youtu.be/2IneL4VpShE as there are some helpful (though not essential) visuals.
This is about knowledge creation and the the commonalities between the two forms known (evolution (by natural selection) and explanatory) and the differences between them. It teases out and synthesises some of the work of Darwin, Popper and Deutsch on these matters of what creativity means. I also consider the place of prediction and prophecy and the "urge" to know what the future will hold. This is sometimes the dividing line between optimism and pessimism.
You can support this ongoing exercise in optimism, exposition and encouraging rapid progress by following the links here: https://www.bretthall.org/ Thankyou for any and all support. Know it is much appreciated.

Ep 206: Sam Kuypers (Time: The First Quantum Concept Part 3 - and more).

Sam Kuypers is a theoretical physicist who specialises in the physics of time. If you have the time, Sam can take up as much of it as you like telling you about how our ideas of time have changed…over time. As Sam will reveals: times, they are not a-changing. But there is change! Newtonian physics has a notion of time (or at least Newton himself did), Relativity as discovered by Einstein in the early 1900s radically transformed our notion of what time is and now, in the 21st Century, Sam Kuypers and others are beginning to develop a quantum theory of time. And this is why Sam joins me for this episode as we unpack time as a quantum concept: the very topic of Chapter 11 of “The Fabric of Reality” and go deep on Sam’s more recent contributions to our understanding of the reality of time. Appropriately, time stamps are below.
 
You may have to take your time with some of this.
 
 
00:00 - Introduction to this episode
05:04 - Introduction to Sam Kuypers
06:30 - The day-to-day of a theoretical physicist
10:30 - What led Sam to Oxford University
12:10 - What was Sam’s doctoral thesis about?
15:20 - The importance of Everett
16:30 - “Classical” Time and “universal time”.
27:00 - Julian Barbour and time as a series of instants
30:35 - Spacetime and the timeless view of physical reality.
33:35 - The clash of General Relativity and Quantum Theory I
37:20 - The clash of General Relativity and Quantum Theory II
40:40 - c-numbers and q-numbers
42:30 - The significance of (non) commutability (i.e the Heisenberg Uncertainty Principle).
46:05 - The Page-Wooters Construction (Quantum Time I).
53:15 - Can there be change if nothing is ever changing? (Quantum Time II)
55:31 - The Heisenberg vs Schrödinger “Pictures” of Quantum Theory.
57:35 - What is “locality” in physics?
58:40 - Entanglement and: "Does Quantum Theory allows for faster than light communication?” 
1:00:48 - Unitary Quantum Theory (vs: Everettian Quantum Theory)
1:05:33 - Philosophical Realism, Physics
1:06:40 - Does Time Exist?
1:07:58 - Is Time Travel Possible?
1:11:30 - How did Sam find his way into physics?
1:14:30 - The Dutch Enlightenment vs The British Enlightenment
1:20:50 - The Netherlands, international trade, tolerance and specialisation
1:23:08 - The Invention of Free Trade and misconceptions with long lifetimes.
1:16:30 - The peculiar rivalry between European Allies
1:28:40 - Prosperity and Pessimism: Are both on the ascendency?
1:32:19: Why are people special?
1:37:14: Liberalism, Authoritarianism and Climate Change
1:40:25: Science, Morality and (eg: Dutch) Innovation
1:43:30 - Concluding Remarks 
 
 
 
 

Ep 205: David Deutsch’s ”The Fabric of Reality” Chapter 11 ”Time: The First Quantum Concept” *Part 2*

Part 2: Time is in the instant. The instant is not in time. More on the quantum theory of time and how the "spacetime" view of time, and the flow of time are false. How time relates to the "block universe" model and how the multiverse fixes the paradoxes at the heart of our common sense (and classical physics) ideas about time - more readings from "The Fabric of Reality" chapter 11 and in addition:
A couple of acrostics about David Deutsch in terms of "Popper".
David's changing view of free will.
Readings on "free will" from "A Science of Can and Can't" by Chiara Marletto.
A summary of a paper by Marletto and Vedral on the "Page and Wooters" construction.
Brief remarks on Marietto's "Constructor Theory of Thermodynamics"
Kuyper's thesis "Developments in Unitary Quantum Theory"
The paradoxes involved in trying to picture time using diagrams.
Machian Dynamics (Ernst Mach's idea about absolute space and time being false and instead how the universe has dynamics of its own).
The Schrödinger vs Heisenberg Pictures
The Kuypers and Deutsch paper on "Everettian Relative States in the Heisenberg picture"
"And other topics" as Sam Harris says. Reference: Mentions of Sam Kuypers paper on "q number time" throughout: https://royalsocietypublishing.org/doi/full/10.1098/rspa.2021.0970

Ep 204: David Deutsch’s ”The Fabric of Reality” Chapter 11 ”Time: The First Quantum Concept” Part 1

This is really "episode 0" but not quite because we do indeed get to some readings and unpackings of the chapter. But in the overall scheme, that forms a minor part of a longer introduction to the "common sense" understanding of time and then to some relativity (of simultaneity) and reflections on the work of other physicists and popularisers.
 
Note clips from "The Lord of the Rings" and "Spaceballs" movies are owned by their respective copyright holders.

Ep 203: David Deutsch’s ”The Fabric of Reality” Chapter 10 ”The Nature of Mathematics” Part 4

Some more long introductory remarks and commentary throughout readings of the closing pages of the chapter culminating in the explanation of the "punchline" conclusion of the chapter which is: "Necessary truth is the subject matter of mathematics. It is not the reward we get for doing mathematics". This is a good exploration of fallibility, the relationship of physics to mathematics and how science is, in a sense, logically prior to mathematics (and logic for that matter!)...all because proof is a physical process.