I have created a podcast about the news from September 22, 2022 about David Deutsch winning The Breakthrough Prize for his work in laying the foundations of quantum computation. The Youtube version is here: https://youtu.be/MdTb6nsHxGY and the podcast version can be found anywhere podcasts are available. It is episode 154 of ToKCast (eg, here: https://brettroberthall.podbean.com/e/ep-154-breakthrough-in-quantum-computation-prize/ ).
As indicated in the podcast, below is a list of all the articles printed so far about 2023’s Breakthrough Prize.The official website: https://breakthroughprize.org/
Their Youtube announcement: https://www.youtube.com/watch?v=DF-UG0N8hOs
Oxford University’s announcement: https://www.ox.ac.uk/news/2022-09-22-professor-david-deutsch-awarded-breakthrough-prize-fundamental-physics-0
The Guardian: https://www.theguardian.com/science/2022/sep/22/quantum-computing-research-physics-breakthrough
Scientific American: https://www.scientificamerican.com/article/quantum-physics-titans-win-breakthrough-prize/
The Quantum Insider: https://thequantuminsider.com/2022/09/22/four-quantum-pioneers-share-the-breakthrough-prize-in-fundamental-physics/
Forbes: https://www.forbes.com/sites/alexknapp/2022/09/22/2023-breakthrough-prizes-announced-deepminds-protein-folders-awarded-3-million/?sh=3e6b14064fcb
Phys.org: https://phys.org/news/2022-09-winners-breakthrough-prizes-unveiled.html
PR News: https://www.prnewswire.com/news-releases/winners-of-the-2023-breakthrough-prizes-in-life-sciences-mathematics-and-fundamental-physics-announced-301631100.html
Below is a partial transcript of the podcast.
Quantum computing breakthrough (prize!).
Well, stop the presses as we say. Or we interrupt normal programming to bring you…some news! And we don’t do news here at ToKCast: we do the timeless, not timely. But here is one of those rare exceptions.
David Deutsch has shared in the winning of the Breakthrough Prize.
What is the Breakthrough prize? Ok, it’s not the Nobel prize but if scientists and others are asked to rank let’s say the top prizes in science on one hand then after the Nobel comes The Breakthrough Prize. It’s very top tier. I mean just google “most prestitgious awards in science”. Here’s one such list: https://ieconferences.cikd.ca/most-prestigious-science-awards-in-world-1/
David will perhaps cringe, and so might others in my circles, or even fans of ToKCast, but truth be told on ToKCast I really do focus almost exclusively on the ideas. David Deutsch regularly gets acknowledged as the originator of the ideas and original expositor of them, of course. But I don’t tend to focus on the singular intellectual mind that is David Deutsch. But today, with the recent award of that prize, I will take, as they say in Australian Parliament a moment on indulgence - when the matters are outside the usual stream of business. I think this occasion warrants it.
At the website of the Breakthrough Prize they say “Knowledge is humanity’s greatest asset. It defines our nature, and it will shape our future. The body of knowledge is assembled over centuries.Yet a single mind can extend it immensely. Einstein reimagined space and time. Darwin distilled the chaos of life to a single idea. Turing figured out what it means to think. Great scientists enrich us all. They enable technologies that ease our lives, but they also show us what’s beyond our horizons.”
That is a glorious introduction to the process of science and knowledge creation. It at once dispels the myth…of the myth of the lone scientist working largely in isolation and being the giant for others to stand on the shoulders of. There is a pervasive idea denigrating the whole notion of the heroic lone mind literally creating explanatory knowledge. Today the dogma being forced upon us is that it is always almost entirely a collaboration. This may be true of the industrial, modern academia centric style of incremental science that is done. The “publish or perish” doctrine of careerism in the sciences. It is a shame and not the fault of those scientists (in the main). They are victims of a system.
But some manage to buck the trend through what must be said choice and force of individual well alone. The iconoclastic individual coming up with insights often precisely because they insist they work best alone. I would say: uncontaminated, perhaps, by “group think” or the need to fall in line politically, ideologically, spiritually, philosophically and…scientifically. Newton was one. Einstein was one. Turing was one. David Deutsch is one such and in being so was able to bring the discussions around computation - it’s potential and its limits (then regarded as a part of pure mathematics) into physics and in doing so invented the theory of quantum computation. This is the reason David won the Breakthrough Prize: for his contributions to the foundations of that field. But what’s the big deal about quantum computation? From his book, “The Beginning of Infinity” a few choice quotes come to mind: “Quantum computation, which is currently believed to be the fully universal form of computation, happens to have exactly the same set of computable functions as Turing’s classical computation. But quantum computation drives a coach and horses through the classical notion of a ‘simple’ or ‘elementary’ operation. It makes some intuitively very complex things simple.” And later on how quantum computers actually work “history. In one type of quantum computation, enormous numbers of different computations, taking place simultaneously, can affect each other and hence contribute to the output of a computation. This is known as quantum parallelism. In a typical quantum computation, individual bits of information are represented in physical objects known as ‘qubits’ – quantum bits – of which there is a large variety of physical implementations but always with two essential features. First, each qubit has a variable that can take one of two discrete values, and, second, special measures are taken to protect the qubits from entanglement – such as cooling them to temperatures close to absolute zero. A typical algorithm using quantum parallelism begins by causing the information-carrying variables in some of the qubits to acquire both their values simultaneously. Consequently, regarding those qubits as a register representing (say) a number, the number of separate instances of the register as a whole is exponentially large: two to the power of the number of qubits. Then, for a period, classical computations are performed, during which waves of differentiation spread to some of the other qubits – but no further, because of the special measures that prevent this. Hence, information is processed separately in each of that vast number of autonomous histories. Finally, an interference process involving all the affected qubits combines the information in those histories into a single history.” And thus, I would say: the output of the computer. And then he goes on later to say “In such computations, a quantum computer with only a few hundred qubits could perform far more computations in parallel than there are atoms in the visible universe. At the time of writing, quantum computers with about ten qubits have been constructed. ‘Scaling’ the technology to larger numbers is a tremendous challenge for quantum technology, but it is gradually being met.”
My own very modest attempt to explain quantum computation can be found where I discuss "The Beginning of Infinity" Chapter 11 "The Multiverse" - Part 3 of that series or ToKCast Episode 26 https://www.youtube.com/watch?v=RwJdhiMqIrU&list=PLsE51P_yPQCQqJDb65AIVLads8PKxYuPm&index=3
As I have said in episodes of ToKCast before this work on quantum computation is why David Deutsch is most famous among his peers and physicists and possibly the second reason I found the ideas of David Deutsch to be worth promoting (the first was the existence of his first book: The Fabric of Reality).
Whenever the question of “what do you do?” comes up these days, or whenever I am speaking to some group of younger people about the history of ideas and the present state of our knowledge - my “in” is typically computers. We see what they know about their origins. It allows me to explain the last name on that list above where the people at the Breakthrough Prize name check the luminaries: Einstein, Darwin and…Turing. There is indeed debate about whether it was Babbage, Lovelace, Church or Turing who was most central to the ultimate invention of the theory (as well as the implementation) of computers…or rather “computation” as a field of mathematics, computer science and engineering, software and hardware development and ultimately science. Many, if their hand is forced, nominate Turing as the real key. His approach was mathematical but assumed a physical device. He laid the most important groundwork for modern classical electronic digital computers that we know today as laptops, desktops, smartphones and watches, tablets and Teslas (well the onboard computers anyways…). Turing was an accomplished and unique thinker and he gifted us the ideas that led to an understanding of the universal classical computer often simply called the Universal Turing machine. And he is the Turing of the Church-Turing Conjecture: the hypothesis that any physical process can be computed. The first name on that list Einstein is the pre-eminent example of someone who redefined physics largely from the ground up. Gravity was not a force once Einstein was done with explaining it: it was the curvature of space time. Time was no longer a constant for everyone in the universe. How fast one moved through time depended on how fast one was moving through space. Lengths are not always the same, masses (or momenta) are not always constant for a given body. They too are relative to a velocity. But the speed of light is always and everywhere constant for observers. Light was no longer a wave but something more complex and more like a particle. Entanglement is a thing. So Einstein rightly deserves the reverence he has in the pantheon of names. And likewise Darwin - our third name there - undid the magic of creationism and explained how life can adapt and thus change over time through a process of natural selection.
Imagine if we could speak to Turing now? Someone who ushered in an entire multi-billion dollar industry of technology? Imagine if Einstein were still alive and we could further question him about disrupting the foundations of physics? Imagine if we could interrogate Darwin with what we know now about evolution? And let’s throw in Karl Popper who, like Darwin, utterly overturned the entire field he was working in by explaining knowledge was no about parochial “beliefs” people had in minds we “read from the book of nature” but rather was something truly objective and which could be out there in physical reality transforming objects?
This, I then go on to say, is why I am fascinated by the work of David Deutsch and in speaking to the man himself and trying to provide his ideas with more and more reach.
Like Turing, Deutsch has actually transformed a billion dollar industry: he laid the foundations of the field of quantum computation and this is why he won the Breakthrough Prize.
Like Einstein, Deutsch is beginning to transform the very foundations of physics - helping create an entire new mode of explanation: constructor theory.
And if anyone today is the intellectual successor to Karl Popper in philosophy, it is David Deutsch who has updated a number of Popper’s insights, refining and taking them further with, notably, his notion of good explanations and his exhalation of people as universal knowledge creators. And in doing this he has explained the unification of Darwin’s work in evolution with Popper’s as both being examples of knowledge: information that once instantiated somewhere, tends to cause itself to remain so - something both genes and good ideas have in common.
So it is wonderful to see David Deutsch winning The Breakthrough Prize. For me it brings some additional well deserved prominence to his ideas and hopefully to all his other ideas which can be world changing. The optimism of David’s perspective on Popperian epistemology as an unending steam of explanation creation that underpins potentially infinite progress needs to be far more widely known. It is the counter to a pervasive pessimism. His nascent Constructor Theory developed with Chiara Marletto and other collaborators needs to be explored more deeply - it could revolutionise physics and allow for more progress. He’s done it before. He’s done it with quantum computation. His books The Beginning of Infinity and The Fabric of Reality should still be at the top of best seller lists for their ideas are making an impact but not enough of an impact. David Deutsch is not a guru, nor is he omniscient - but he is modest and he knows his own fallibility because that is a trait shared by all humans. So he will say of Constructor Theory that it may fail. But it may not. It is worth trying. As he has wryly quipped before “String Theory was worth trying” - and it’s been given a few decades. We should at least have a generation of physicists, mathematicians, biologists, philosophers and other scientists and intellectuals to investigate where constructor theory might go. David Deutsch is such a modest fallibilist that he does not actively try to persuade anyone that he is right. He is not dogmatic, he will not force himself into conferences or into public speaking engagements. It is for those reasons, among others, his ideas do need something of a “promotions department” - which is what I am beginning to do here. After all, David is too busy coming up with the actual ideas which will transform the world so someone has to take on the task of outreach.
And David Deutsch is generous - but I will not say “generous to a fault” - because it’s not a fault. But his ideas are all out there in the public domain for free (all those papers on quantum computation) or next to free (his books) and they have already had a disproportionate impact given what a person can accomplish in a given lifetime. It is the age of speaking about “equality” and so forth: well if the world was “equal” Deutsch would be a billionaire, no?
It is so early on in explaining these ideas. Will they go on to have the impact the physics of Einstein in the 20th century did? Or classical computation of Turing did? Or 20th century philosophy did? Well he already has them all covered now in the 21st century with Constructor Theory, Quantum Computation and his improvements on Popper have. And have a mentioned his substantive reimagining of Everettian Quantum theory which, taken seriously, can foundational change our understanding of physical reality at the deepest levels - including that of personal identify and the notion of fungibility.
Most of us missed living at a time when we could have heard Einstein speaking - much less spoken to him ourselves. All of us missed the opportunity to hear Darwin. We can only wish to have spoken to or heard more from Turing. And while we can still hear Popper in his own words in recordings today, we cannot hear anymore from him.
But we have David Deutsch. This is something I have said to people for many years and I have the sense they have sometimes gone away with a shrug not really taking my implication seriously. Perhaps this award will help do some of that work for me from now on. It only acknowledges the advances in quantum computation and though that is a big part of his work - it is not all of it. The whole of it is extremely diverse. Almost as diverse as it can possibly be. For it covers the very “fabric” of reality. It is itself a beginning of infinity. If you’re fascinated with one part of it: explore the rest. There is literally no end to it once you begin. And if you’ve taken seriously the implications of what I’ve said here, then why aren’t you following David on Twitter @DavidDeutschOxf and why are you keeping up with what’s happening at the website “www.constructortheory.org" and why don’t you have copies of his books bought for family and friends? One day you might be able to say with a knowing smile and intellectual pride when the guy at the local phone store is trying to upsell you to the Apple Quantum qPhone Pro Max and begins to explain how it works using the multiverse as explained by that guy on the new £50 British banknote, “Yeah” you say “I knew of David Deutsch way before we all had quantum computers and universal constructors everywhere. I’ve even read his book.”
“Don’t you mean books?” says the salesperson.
Congratulations David Deutsch.
As indicated in the podcast, below is a list of all the articles printed so far about 2023’s Breakthrough Prize.The official website: https://breakthroughprize.org/
Their Youtube announcement: https://www.youtube.com/watch?v=DF-UG0N8hOs
Oxford University’s announcement: https://www.ox.ac.uk/news/2022-09-22-professor-david-deutsch-awarded-breakthrough-prize-fundamental-physics-0
The Guardian: https://www.theguardian.com/science/2022/sep/22/quantum-computing-research-physics-breakthrough
Scientific American: https://www.scientificamerican.com/article/quantum-physics-titans-win-breakthrough-prize/
The Quantum Insider: https://thequantuminsider.com/2022/09/22/four-quantum-pioneers-share-the-breakthrough-prize-in-fundamental-physics/
Forbes: https://www.forbes.com/sites/alexknapp/2022/09/22/2023-breakthrough-prizes-announced-deepminds-protein-folders-awarded-3-million/?sh=3e6b14064fcb
Phys.org: https://phys.org/news/2022-09-winners-breakthrough-prizes-unveiled.html
PR News: https://www.prnewswire.com/news-releases/winners-of-the-2023-breakthrough-prizes-in-life-sciences-mathematics-and-fundamental-physics-announced-301631100.html
Below is a partial transcript of the podcast.
Quantum computing breakthrough (prize!).
Well, stop the presses as we say. Or we interrupt normal programming to bring you…some news! And we don’t do news here at ToKCast: we do the timeless, not timely. But here is one of those rare exceptions.
David Deutsch has shared in the winning of the Breakthrough Prize.
What is the Breakthrough prize? Ok, it’s not the Nobel prize but if scientists and others are asked to rank let’s say the top prizes in science on one hand then after the Nobel comes The Breakthrough Prize. It’s very top tier. I mean just google “most prestitgious awards in science”. Here’s one such list: https://ieconferences.cikd.ca/most-prestigious-science-awards-in-world-1/
David will perhaps cringe, and so might others in my circles, or even fans of ToKCast, but truth be told on ToKCast I really do focus almost exclusively on the ideas. David Deutsch regularly gets acknowledged as the originator of the ideas and original expositor of them, of course. But I don’t tend to focus on the singular intellectual mind that is David Deutsch. But today, with the recent award of that prize, I will take, as they say in Australian Parliament a moment on indulgence - when the matters are outside the usual stream of business. I think this occasion warrants it.
At the website of the Breakthrough Prize they say “Knowledge is humanity’s greatest asset. It defines our nature, and it will shape our future. The body of knowledge is assembled over centuries.Yet a single mind can extend it immensely. Einstein reimagined space and time. Darwin distilled the chaos of life to a single idea. Turing figured out what it means to think. Great scientists enrich us all. They enable technologies that ease our lives, but they also show us what’s beyond our horizons.”
That is a glorious introduction to the process of science and knowledge creation. It at once dispels the myth…of the myth of the lone scientist working largely in isolation and being the giant for others to stand on the shoulders of. There is a pervasive idea denigrating the whole notion of the heroic lone mind literally creating explanatory knowledge. Today the dogma being forced upon us is that it is always almost entirely a collaboration. This may be true of the industrial, modern academia centric style of incremental science that is done. The “publish or perish” doctrine of careerism in the sciences. It is a shame and not the fault of those scientists (in the main). They are victims of a system.
But some manage to buck the trend through what must be said choice and force of individual well alone. The iconoclastic individual coming up with insights often precisely because they insist they work best alone. I would say: uncontaminated, perhaps, by “group think” or the need to fall in line politically, ideologically, spiritually, philosophically and…scientifically. Newton was one. Einstein was one. Turing was one. David Deutsch is one such and in being so was able to bring the discussions around computation - it’s potential and its limits (then regarded as a part of pure mathematics) into physics and in doing so invented the theory of quantum computation. This is the reason David won the Breakthrough Prize: for his contributions to the foundations of that field. But what’s the big deal about quantum computation? From his book, “The Beginning of Infinity” a few choice quotes come to mind: “Quantum computation, which is currently believed to be the fully universal form of computation, happens to have exactly the same set of computable functions as Turing’s classical computation. But quantum computation drives a coach and horses through the classical notion of a ‘simple’ or ‘elementary’ operation. It makes some intuitively very complex things simple.” And later on how quantum computers actually work “history. In one type of quantum computation, enormous numbers of different computations, taking place simultaneously, can affect each other and hence contribute to the output of a computation. This is known as quantum parallelism. In a typical quantum computation, individual bits of information are represented in physical objects known as ‘qubits’ – quantum bits – of which there is a large variety of physical implementations but always with two essential features. First, each qubit has a variable that can take one of two discrete values, and, second, special measures are taken to protect the qubits from entanglement – such as cooling them to temperatures close to absolute zero. A typical algorithm using quantum parallelism begins by causing the information-carrying variables in some of the qubits to acquire both their values simultaneously. Consequently, regarding those qubits as a register representing (say) a number, the number of separate instances of the register as a whole is exponentially large: two to the power of the number of qubits. Then, for a period, classical computations are performed, during which waves of differentiation spread to some of the other qubits – but no further, because of the special measures that prevent this. Hence, information is processed separately in each of that vast number of autonomous histories. Finally, an interference process involving all the affected qubits combines the information in those histories into a single history.” And thus, I would say: the output of the computer. And then he goes on later to say “In such computations, a quantum computer with only a few hundred qubits could perform far more computations in parallel than there are atoms in the visible universe. At the time of writing, quantum computers with about ten qubits have been constructed. ‘Scaling’ the technology to larger numbers is a tremendous challenge for quantum technology, but it is gradually being met.”
My own very modest attempt to explain quantum computation can be found where I discuss "The Beginning of Infinity" Chapter 11 "The Multiverse" - Part 3 of that series or ToKCast Episode 26 https://www.youtube.com/watch?v=RwJdhiMqIrU&list=PLsE51P_yPQCQqJDb65AIVLads8PKxYuPm&index=3
As I have said in episodes of ToKCast before this work on quantum computation is why David Deutsch is most famous among his peers and physicists and possibly the second reason I found the ideas of David Deutsch to be worth promoting (the first was the existence of his first book: The Fabric of Reality).
Whenever the question of “what do you do?” comes up these days, or whenever I am speaking to some group of younger people about the history of ideas and the present state of our knowledge - my “in” is typically computers. We see what they know about their origins. It allows me to explain the last name on that list above where the people at the Breakthrough Prize name check the luminaries: Einstein, Darwin and…Turing. There is indeed debate about whether it was Babbage, Lovelace, Church or Turing who was most central to the ultimate invention of the theory (as well as the implementation) of computers…or rather “computation” as a field of mathematics, computer science and engineering, software and hardware development and ultimately science. Many, if their hand is forced, nominate Turing as the real key. His approach was mathematical but assumed a physical device. He laid the most important groundwork for modern classical electronic digital computers that we know today as laptops, desktops, smartphones and watches, tablets and Teslas (well the onboard computers anyways…). Turing was an accomplished and unique thinker and he gifted us the ideas that led to an understanding of the universal classical computer often simply called the Universal Turing machine. And he is the Turing of the Church-Turing Conjecture: the hypothesis that any physical process can be computed. The first name on that list Einstein is the pre-eminent example of someone who redefined physics largely from the ground up. Gravity was not a force once Einstein was done with explaining it: it was the curvature of space time. Time was no longer a constant for everyone in the universe. How fast one moved through time depended on how fast one was moving through space. Lengths are not always the same, masses (or momenta) are not always constant for a given body. They too are relative to a velocity. But the speed of light is always and everywhere constant for observers. Light was no longer a wave but something more complex and more like a particle. Entanglement is a thing. So Einstein rightly deserves the reverence he has in the pantheon of names. And likewise Darwin - our third name there - undid the magic of creationism and explained how life can adapt and thus change over time through a process of natural selection.
Imagine if we could speak to Turing now? Someone who ushered in an entire multi-billion dollar industry of technology? Imagine if Einstein were still alive and we could further question him about disrupting the foundations of physics? Imagine if we could interrogate Darwin with what we know now about evolution? And let’s throw in Karl Popper who, like Darwin, utterly overturned the entire field he was working in by explaining knowledge was no about parochial “beliefs” people had in minds we “read from the book of nature” but rather was something truly objective and which could be out there in physical reality transforming objects?
This, I then go on to say, is why I am fascinated by the work of David Deutsch and in speaking to the man himself and trying to provide his ideas with more and more reach.
Like Turing, Deutsch has actually transformed a billion dollar industry: he laid the foundations of the field of quantum computation and this is why he won the Breakthrough Prize.
Like Einstein, Deutsch is beginning to transform the very foundations of physics - helping create an entire new mode of explanation: constructor theory.
And if anyone today is the intellectual successor to Karl Popper in philosophy, it is David Deutsch who has updated a number of Popper’s insights, refining and taking them further with, notably, his notion of good explanations and his exhalation of people as universal knowledge creators. And in doing this he has explained the unification of Darwin’s work in evolution with Popper’s as both being examples of knowledge: information that once instantiated somewhere, tends to cause itself to remain so - something both genes and good ideas have in common.
So it is wonderful to see David Deutsch winning The Breakthrough Prize. For me it brings some additional well deserved prominence to his ideas and hopefully to all his other ideas which can be world changing. The optimism of David’s perspective on Popperian epistemology as an unending steam of explanation creation that underpins potentially infinite progress needs to be far more widely known. It is the counter to a pervasive pessimism. His nascent Constructor Theory developed with Chiara Marletto and other collaborators needs to be explored more deeply - it could revolutionise physics and allow for more progress. He’s done it before. He’s done it with quantum computation. His books The Beginning of Infinity and The Fabric of Reality should still be at the top of best seller lists for their ideas are making an impact but not enough of an impact. David Deutsch is not a guru, nor is he omniscient - but he is modest and he knows his own fallibility because that is a trait shared by all humans. So he will say of Constructor Theory that it may fail. But it may not. It is worth trying. As he has wryly quipped before “String Theory was worth trying” - and it’s been given a few decades. We should at least have a generation of physicists, mathematicians, biologists, philosophers and other scientists and intellectuals to investigate where constructor theory might go. David Deutsch is such a modest fallibilist that he does not actively try to persuade anyone that he is right. He is not dogmatic, he will not force himself into conferences or into public speaking engagements. It is for those reasons, among others, his ideas do need something of a “promotions department” - which is what I am beginning to do here. After all, David is too busy coming up with the actual ideas which will transform the world so someone has to take on the task of outreach.
And David Deutsch is generous - but I will not say “generous to a fault” - because it’s not a fault. But his ideas are all out there in the public domain for free (all those papers on quantum computation) or next to free (his books) and they have already had a disproportionate impact given what a person can accomplish in a given lifetime. It is the age of speaking about “equality” and so forth: well if the world was “equal” Deutsch would be a billionaire, no?
It is so early on in explaining these ideas. Will they go on to have the impact the physics of Einstein in the 20th century did? Or classical computation of Turing did? Or 20th century philosophy did? Well he already has them all covered now in the 21st century with Constructor Theory, Quantum Computation and his improvements on Popper have. And have a mentioned his substantive reimagining of Everettian Quantum theory which, taken seriously, can foundational change our understanding of physical reality at the deepest levels - including that of personal identify and the notion of fungibility.
Most of us missed living at a time when we could have heard Einstein speaking - much less spoken to him ourselves. All of us missed the opportunity to hear Darwin. We can only wish to have spoken to or heard more from Turing. And while we can still hear Popper in his own words in recordings today, we cannot hear anymore from him.
But we have David Deutsch. This is something I have said to people for many years and I have the sense they have sometimes gone away with a shrug not really taking my implication seriously. Perhaps this award will help do some of that work for me from now on. It only acknowledges the advances in quantum computation and though that is a big part of his work - it is not all of it. The whole of it is extremely diverse. Almost as diverse as it can possibly be. For it covers the very “fabric” of reality. It is itself a beginning of infinity. If you’re fascinated with one part of it: explore the rest. There is literally no end to it once you begin. And if you’ve taken seriously the implications of what I’ve said here, then why aren’t you following David on Twitter @DavidDeutschOxf and why are you keeping up with what’s happening at the website “www.constructortheory.org" and why don’t you have copies of his books bought for family and friends? One day you might be able to say with a knowing smile and intellectual pride when the guy at the local phone store is trying to upsell you to the Apple Quantum qPhone Pro Max and begins to explain how it works using the multiverse as explained by that guy on the new £50 British banknote, “Yeah” you say “I knew of David Deutsch way before we all had quantum computers and universal constructors everywhere. I’ve even read his book.”
“Don’t you mean books?” says the salesperson.
Congratulations David Deutsch.