Chris is a physicist and mathematician, whose work focuses on quantum mechanics and quantum computing. He's the author of several highly successful science books, as well as cofounder of the quantum computing company, Eigensystems.
Topics:
The foundations of quantum computing
The state of quantum computing technology today
What impact quantum computers might have on the world
Quantum hype
… and other topics.
Watch on YouTube. Listen on Spotify, Apple Podcasts, or any other podcast platform. Read the full transcript here. Follow me on LinkedIn or Twitter/X for episodes and infrequent social commentary.
Episode links
Website: https://www.csferrie.com/
Books: https://www.csferrie.com/books
Timestamps
0:00 Intro
1:00 Should we still be using classical encryption?
2:58 How much faster will quantum computers be?
4:18 Did Google achieve quantum supremacy?
9:39 How does quantum computation work?
12:35 What's needed to get to commercial scale quantum computing?
16:12 Physical vs virtual qubits and fault-tolerant computers
18:25 How long until we have 'useful' quantum computers?
26:48 What's halting progress in quantum computing?
31:30 Applications of quantum computing
34:55 The Quantum Multiverse & David Deutsch
42:24 Decoherence (Evidence of a multiverse?)
47:46 Why is the quantum multiverse polarising?
49:50 Quantum bullsh*t
55:55 Eigensystems
1:01:45 Book recommendations
1:03:30 Advice for curious minds
1:06:26 Tommy Wiseau
Transcript
This transcript is AI-generated and may contain errors. It will be corrected and annotated with links and citations over time.
[00:00:12] Matt Geleta: I'm here with Chris Ferry. Chris, thanks for joining me.
[00:00:15] Chris Ferrie: Thanks for having me.
[00:00:16] Matt Geleta: Let's talk about quantum computing.
One of the most well known use cases of quantum computers is cryptography. Um, it's sort of well understood that that's a use case by the general public. Um, but I think that many things are not well understood. Um, I've always wondered, you know, once we get sufficiently large and robust quantum computers that we'll be able to crack our, uh, foundational encryption methods that we use today. Does this mean that existing, uh, encrypted content on the internet will no longer be safe in the future?
[00:00:46] Chris Ferrie: I mean, I think that's, that's true regardless of whether quantum computers exist or not. So this kind of cartoon imagery we have encryption is with like a lock and key, but it's not. physically impossible to decrypt a message. It's encoded with a math problem, if you have a big enough computer or enough time with pen and paper, you can always solve this problem.
Uh, so, yes, with a quantum computer we think we can solve the problem faster, it's not as if, you know, quantum computing is some magical key that unlocks current encryption. It can just solve those problems we think are keeping our secrets safe a lot faster. Anyone with the algorithm enough time and a big enough computer can crack any message.
You can set your computer churning away. It may take, you know, hundreds of years, thousands of years, depending on the level of security that message has. you, you will, you will crack the message eventually. Um, it's just, yeah, quantum computers, we think we'll be able to do it faster.
[00:01:57] Matt Geleta: Yeah. I mean, I guess it depends on just how much faster versus brute forcing it with, with classical computers, because, you know, if we believe it will be... faster, so fast that most encrypted content is basically unsafe, then it does pose the question should we be using any of these classical encryption methods at all for stuff that ends up on the internet publicly if it's, if it's sensitive material, how how much faster do you think we, we can get with quantum computing?
[00:02:25] Chris Ferrie: Well, it really depends on the problem. I think in terms of encryption, it's this, not, usually differentiate speedups between what's known as polynomial or exponential. Um, but the reality is this. There's, there's, there's problems that are somewhere, somewhere in between, if you had the magical box, the quantum computer and it worked perfectly, then it would be in for all intents and purposes instant for the kinds of.
encryption we do today. But for, for other problems that quantum computers could potentially be used for, it's a more modest advantage. And then of course there are problems for which we think quantum computers just won't be useful for at all.
[00:03:17] Matt Geleta: Hmm. Yeah, I guess the, um, the The concept of quantum computing, it's um, it has been in the public consciousness for many years now and I think it's not very well understood by the public. which problems it is good for and which it isn't. I mean, there is a lot of hype. Uh, there are even books coming out by people who are not quantum computing experts in, uh, in recent times, sort of opining on the, uh, the, the changes to come. Um, one, one area. That is often cited, uh, that happened relatively recently was when researchers at, uh, at Google made a bold claim that they had achieved something called quantum supremacy, which is a, a bit of a scary term, uh, with their Sycamore machine. Um, can you describe, uh, what, what happened there and if you feel this represents sort of truly meaningful advances in quantum computing?
[00:04:06] Chris Ferrie: Yeah, so I, it's not as impressive as it sounds. So I'll
[00:04:11] Matt Geleta: Ha ha ha ha
[00:04:12] Chris Ferrie: of the way. Um, it is a tech, what, what they've done is technologically impressive. It's a, certainly a step up from what we had previously and certainly superior to what we were doing a decade ago. But the, entire concept of quantum supremacy is a bit.
is a bit problematic because gives you this picture that there's this know kind of black and white boundary between quantum and classical when in reality it's just this big gray area. So now and certainly at the time It was like trying to define a line between black and white in this giant field of gray.
So, yeah, it, it, that's why there was at least some controversy about what it was they, what it was they achieved. Um, the idea is basically you want to find a problem for which, you know, a quantum computer solve that problem in some reasonable amount of time for which no conventional computer, which we call classical computers, digital computers could solve, you know, given all of the, all of the computing power that we have and, you know, and, and the age of the universe or some, some long, but, you know, finite amount of time.
So if you could find such a problem. Then you would say, well, look at, you know, the quantum computer is now something vastly superior to digital computers. But, you know, there isn't this kind of step transition, right? So the kinds of problems that we're looking at and the devices that we're building, it's more of this really gradual increase in capability.
and where you draw the line is somewhat arbitrary. So what they had said that they achieved was they could do something, device could do something that it would take the world's fastest conventional supercomputer thousands of years to solve. What it actually What they did was not useful for anything.
It was, uh, they basically created, um, some target random distribution and said that the device could sample numbers according to that distribution, whereas a computer would take a long time to figure out how to get it perfect to sample that distribution. it's somewhat arbitrary. problem. Uh, yeah.
So, I mean, for people, for us in the community, our point of view is usually something like, that's a, that's a great, you know, scientific achievement, uh, probably shouldn't have used that, that phrasing because it, you know, even though, you know, you can't blame them directly, they must've known
[00:07:19] Matt Geleta: Hmm.
[00:07:20] Chris Ferrie: it was going to be mis, misinterpreted,
[00:07:22] Matt Geleta: Yeah.
[00:07:23] Chris Ferrie: that's what they wanted, right?
That's what gets press.
[00:07:25] Matt Geleta: Well, it is an incredibly highly cited paper that they put out. Do you feel like it is at least a stepping stone towards meaningful progress? Meaningful progress en route to something like commercial scale quantum computing?
[00:07:40] Chris Ferrie: I don't know. I think, know, these, these, these papers, these research papers that come out there, they'll be lost to the annals of, uh,
academia at some point in time, like nobody will care when we transition from four to five cubits, right? Right now, it seems like an important technological achievement, but far down the future, it'll, it'll all be washed out in some more significant milestones that, that we reach.
So, you know, as we, as we're here living it, yes, it's a, it's an important step. Each time they come up with a new, a new chip design or, uh, a new kind of architecture, it, it is. It's a necessary and important step, but in the grand scheme of things, it probably won't be remembered.
[00:08:36] Matt Geleta: Hmm. Yeah. Okay, well, let's, uh, let's then warm up to the, what is more at the cutting edge of, of quantum technology, quantum computing technology and where we think it could go. Um, let's perhaps set the scene a little bit from, from square one. Um, at its most basic level, how does quantum computation work physically?
[00:08:55] Chris Ferrie: Okay, well, that's a, um, it's a, it's a bit of an unfair question,
I think, because, you know, we often have this expectation, and certainly The people within quantum computing that, you know, speak outside of, outside of our small community give themselves this gargantuan task of explaining something that took them 15 years of study to figure out in a matter of five minutes.
Because this is not how we explain conventional computing. When someone asks, how does your computer work? They tell you about how it's used and what it's useful for, right? They don't say, well, give me the physics of transistors. Um, which, by the way, if you, if this was a technical discussion, you said, how does a digital computer work?
I'd start with transistors and voltages and these sorts of things. every single computing device... uses the same technology, whereas quantum computers, there are many competing proposals and existing prototypes, they all work differently. So I can't just say, well, there's this thing, physical thing in the world, and here's, here's how it works and what it does, because each, each company or, or research group is doing something different.
Uh, the, the one thing that they do have in common is a bit more abstract. So transistors, the, the reason, well, there's lots of reasons we use them, but know, the core sort of computational reason is because it's very good at representing a bit, a zero or a one. So quantum computing, we need things that represent quantum bits.
So these are like lists of, of numbers that can be zero, one, then any other number, negative numbers. whatever it may be. So find a thing in the world that easily and naturally represents those numbers that you can manipulate with very high fidelity and finesse and you have something that represents a qubit and if you can manipulate that and in according to a sequence of steps which change qubits then you can call that a computing device.
So it's, uh, anything that, that can represent quantum information, and the sequences of qubits instead of bits, and can change that according to an algorithm, so a sequence of steps, is a quantum computer.
[00:11:34] Matt Geleta: So the, um, the progression from, from going from conceptual quantum computing and maybe simulating quantum algorithms on a classic computer to instantiating them in the real world, um, is what you're saying that, so the, the, the biggest advance there is, is really an engineering problem? Is it, is it? you know, developing these physical substrates to be able to represent quantum bits in, in the, in the real world. Or is, or is there technological, sorry, theoretical advance, uh, that needs to happen in order to get to quantum computing at, at scale?
[00:12:10] Chris Ferrie: It depends on, on, like, your precise definition of, of those words. I think at the highest level, we, we created these algorithms, and these algorithms are just steps to change lists of numbers to new lists of numbers. You could carry that out by hand if you wanted to. Of course, it'd be better if we built an automated machine to do that for us.
And... What we know from the theory of quantum physics is that there are degrees of freedom in the world, usually internal degrees of freedom of microscopic things, that naturally encode information in that way. So if we can access those, those things and have control over them, then that's what we should try to do.
Um, so from a theoretical perspective, this was worked out. You know, a hundred years ago, but to best do it, you know, that, that's like a design architecture design question. Right. And that's a theoretical question mathematicians tackle people that have never touched a laboratory machine. And so they would call themselves theorists.
and then, you know, there's, although the theory of quantum physics has been around for a hundred years. Actually, applying it to materials, things a difficult challenge because we have to make approximations and models and, and, and, you know, algorithms that work on the computers that we have now to simplify things.
And that. Involves a branch of probably the biggest branch of physics called condensed matter physics, which is really just the business of creating approximations to Schrodinger's equation that he wrote down in 1926. Again, those people would call themselves theorists, it's their job to say, someone says, here are the properties of matter that I want and need.
then those people go and try to design it, um, from their understanding of, of, of quantum theory. Now, in some sense, we don't know which questions ask. So it's a, it's a kind of back and forth between engineering. And theory. So the engineers make some progress. They say, uh, you know, this isn't, this sort of thing isn't working out.
Uh, we need these new parameters. We need something with the new set of parameters. Then the theorists come and try to try to work that out. So it's a, it's a, it's a back and forth, but you know, the basic theory is, is well understood. That's, that's quantum physics. Nothing is going to change at the fundamental level in terms of quantum physics.
[00:15:11] Matt Geleta: So then if, if we had to take something like a, a, a problem like RSA encryption, and, um, you know, looking at the point at which something like that becomes Essentially obsolete as an encryption method to be used in practice. Um, you know, What needs to be true for that to happen? How big does a quantum computer need to be?
Um, and, and where are we today versus, versus that level?
[00:15:38] Chris Ferrie: So, what, what we're trying to do is basically create what's known as a fault tolerant quantum computer. So, the actual quantum bits that will do the, carry out the computation will be virtual quantum bits. They won't be the real physical bits. things like real physical transistors, uh, and you kind of recode, encode these logical.
quantum bits redundantly across many physical qubits. And it really depends on how, how much error is going on, how many errors are happening, how much noise, how resilient your, your physical device is dictates the ratio of physical qubits to logical qubit. Uh, so that, you know, a typical number might be a thousand.
So you need a thousand physical qubits to create one Logical bit that actually encodes the information in a robust way that it will last a long time for to crack, like, um, you know, a typical, uh, you know, RSA key would require billions of bits, uh, qubits. you know, we're not, we're not there,
[00:16:59] Matt Geleta: Hmm.
[00:17:00] Chris Ferrie: We, we have no. have no fault tolerant qubits. We have no qubits that we, that we'll just, we can do whatever we want with and they'll last forever. We haven't created one of those yet. We're at the level of maybe a hundred physical qubits, not even enough to make one logical qubit. So it's a long, it's a long ways away.
[00:17:24] Matt Geleta: Yeah. Do you, uh, do you, are you optimistic that we will, we will get there in the foreseeable? When you say long ways away, um, how long, what is your mental picture of that number? Yeah.
[00:17:36] Chris Ferrie: Well, it's interesting. I think people, when we talk about, uh, like encryption and, and, and security and sensitivity of information, uh, we should really, you should really quantify that in terms of number of years, right? So, you know, is, does this secret I have, is it a one year secret? Is it a 50 year secret?
[00:17:54] Matt Geleta: Um,
[00:17:54] Chris Ferrie: I think for individuals, like your secret. Probably a sensible person that a secret is only as, it's only worth one lifetime.
[00:18:09] Matt Geleta: Uh, Yeah,
[00:18:09] Chris Ferrie: states have secrets, too, so that they need to last beyond a lifetime. Um, when we talk about quantum computers, you know, that, that, the time, the timescale there, really depends on the input into the problem.
So the inputs that we need are basically boiled down to money and people.
[00:18:35] Matt Geleta: Uh,
[00:18:35] Chris Ferrie: So there, there isn't a magic number that says, you know, it's definitely 50 years away. It really depends on how many people are involved, how organized they're and whatnot, and how much, how much, much money is, is being put into it.
Um, so it, it really depends. I think if at, I don't think that things will progress as they are now, as we progress, things will compound and. it becomes more interesting, more people will become involved, as it gets closer, more money will be put into it, so compound. If we... If, if we tried to extrapolate in the same way that digital technology progressed, then, you know, it'll, it'll grow exponentially in like some sort of quantum Moore's law.
[00:19:34] Matt Geleta: Um,
[00:19:34] Chris Ferrie: And then you can, if you, if you make that sort of model of, of progress and say, you know, we doubled the number of qubits that we have every year, then maybe it's only 25 years away. But, you know, if, if it takes two or three years to double. Then, it, that, that, uh, horizon extends.
[00:19:56] Matt Geleta: Yeah, there are certain technologies that are sort of infamous for having this nature of being just around the corner for decades and decades on end, and some of them are still not here, you know, nuclear fusion. Um, creation of synthetic life, things like that. Um, but people have also been very wrong in the past.
Um, I think the, the famous example that comes to mind is the former president of IBM in the 1940s said. that there was a global market for something like five computers and it turned out to be outrageously wrong. I mean, I've got five computers in this room with me as we speak. And he was really just thinking, you know, confined to the wrong paradigm and couldn't really see the full potential of. What, you know, personal computation could look like, um, and I do, I do wonder if, if we're in a similar paradigm as it pertains to quantum computers, do you think we might experience a similar phenomenon where at some point in the future, quantum computation is Thank you. Thanks. Is everywhere, you know, people have personal access to quantum computers
[00:20:56] Chris Ferrie: Well, I think that, you know, nuclear fusion is an interesting example. And synthetic life and nuclear fusion are two completely different, um, obviously they're different things, but they're different from the, in the following way, as it pertains to like progress, synthetic life. I mean, we don't even know what life is like argue about what life is.
And so the problem is it's just too vague to say, how would you even decide whether or not you achieved it? Whereas nuclear fusion, we've understood that for decades. Probably, again, the main reason why it, it's taken so long and, you know, we're not, you know, we're not quite there yet is again, money, money and people, but what is the purpose of nuclear fusion?
It's, it's, it's energy, right? But it's so much easier just to dig up fossil fuels and burn them. There was never really. Um, uh, there was no, there was no, it wasn't necessary, you know, necessary in
[00:21:59] Matt Geleta: Yeah, it's interesting the
[00:22:00] Chris Ferrie: right? Um, there's no economic incentive or political will to, to make it happen. If you had put people and money into it, then we would have it already.
physics very well understood, as opposed to synthetic life where, you know, we don't even know what question we're asking. Nuclear fusion is more like quantum computers. We understand... quantum physics to a remarkable degree, we know it can be done. It's just a matter of, of putting money and people on, on it.
And, you know, they'll answer the questions and solve the problems as they, as they come along. There's, there's nothing in, in the theory. And we're all going to assume that the theory is correct. That forbids this from happening. that, you know, I think that's why it's inevitable. I really do like that quote.
I use that quote quite often, but you know, there is a sense in which he was right. I probably there wasn't more than five of those devices, right? And if you compare quantum computing now to Maybe what, what was going on in the 1940s in terms of, um, of classical computing, you know, IBM sells quantum computer, right?
It's tens of millions of dollars. It has 27 qubits. There's a roughly five of them on the order of five. And I would, I would confidently say. They're not going to sell more than that, right? So what happened, right, is that didn't foresee basically miniaturization and the breakthroughs that You know, had, had he thought about it for a little bit longer and, you know, was convinced that it could be miniaturized, you know, it could be deployed at scale, then he might say, well, yeah, sure.
Um, you know, everybody might, might want. Spreadsheets calculated if it's cheap and free, right? so the same thing could be true with, with, with quantum computers. You know, there's no theoretical reason why we can't solve the problems which currently confine them to laboratories. And then put them in, you know, a wristwatch or something like that.
Uh, and so, you know, we, we don't know what exactly those breakthroughs will look like. Just to throw an example out there, right? If you, if you could. build a high temperature or room temperature superconductor, then you wouldn't need these massive refrigeration devices that hold liquid helium cool, you know, some vessel down to colder than outer space.
You could just put it out on the table, right? And that wouldn't really change, you know, that would be no different at a theoretical level, like someone who thinks about quantum computing from a theoretical point of view, they don't care what it looks like and where it is, right? But it would massively change, like how, how it affects society, because then it would, would be ubiquitous.
So we don't know, yeah. I mean, as it stands now, there's not going to be more than a few of them because you know, there's not enough liquid helium in the world to, uh, to cool them down, right? Um, but if we could do it without that, then yeah, they could be, they could be everywhere.
[00:25:48] Matt Geleta: the question of why is it then that um, you know funding and funding and minds are not focused on on the On this issue and this technology as much as they possibly could. I mean, the, the example of nuclear fusion, I think you're right. Um, you know, fossil fuels are easy to access and I don't think we'll run out anytime soon. Um, and so that makes sense. But if you look back at something like the Manhattan Project, you know, there was a, there was a strong. Uh, need, I guess, of sorts to create a very powerful nuclear weapon and, um, money and people followed and, and that problem was solved. And with something like the classical computer revolution, the, you know, the economic value, the impact of the world has been so enormous, um, it would be absurd not to invest, uh, in developing a technology like that. And then when I look at, you know, quantum computing, um, You know, what is, what is the difference? Is it that we actually don't believe that the applications could be impactful enough? Well, what is it that is, that is stopping that flow of, of, uh, of people and money into this, into this technology?
[00:26:54] Chris Ferrie: Yeah, I, I, I think that people don't see a need, a need for it, right? Um, You know, even, even the most fantastical applications we can think of, right, that we can design drugs quicker or, you know, create vaccines quicker, I, I don't think people actually really care that much about that. There seems to be more pressing problems.
So I do think that that's currently blocking it is that people can't see the desperate need for it. You know, have computational devices, they work pretty well for all the problems we can, you know, all the daily problems that we've given ourselves. Um, But yeah, I mean, there's some companies obviously that are investing in it, uh, investing at quite a high level, I would And they, they, they do see the need, but I, maybe we don't, we don't actually know the parameters, right? So, you know, suppose I said, well, we can solve all the world's problems. Um, and all it's going to take is, uh, everybody. has to live off food rations and work hours a day for the next 20 years, but I promise at the end and at the end of that, you know, we'll have solved all the world's problems.
I still don't. Even if everyone believed that promise, I still don't think it would happen. so I think, yeah, it's, you know, with, with the Manhattan project and then, and then with like the, then, uh, Apollo missions, which included like, you know, millions of people and trillions of dollars, um, It is an interesting, that those are interesting phenomenon, right, that so many people got behind it, uh, towards the same, the same goal.
Uh, I don't think you can find that of nationalism, uh, any, any more, certainly not, certainly not in Australia, anyway. Um, but yeah, there, there's, there was, I think, probably a lot of competing incentives and... probably a lot of propaganda that, you know, an ethical side to it that, It is more, would be more visible today, so yeah, it, I don't know, I couldn't, I couldn't put a number on it, but I would, I would say that it's on the same scale in, in terms of need of something like a Manhattan Project or, or the Apollo, the Apollo program.
that's really what we need to build a quantum computer and we're not, we're not doing that today. know, on the flip side, imagine that we tried to land someone on the moon in the same way that we're trying to build quantum computers today, right? So a bunch of like, you know, yeah, thousands of, of professors with PhD students that are competing for a small pot of money, uh, a few startup companies.
That put everything behind, um, you know, patents and intellectual property, um, mostly vacuous CEOs with just big egos and, and just a lot of money flowing around for completely vapid reasons. We would never have done it, right?
[00:30:30] Matt Geleta: Yeah. I guess, um, I guess maybe that it comes to the question of what we think, uh, the, the applications actually are. Um, you know, one we've, we've talked about is, is cryptography, but I think one of the motivations for developing. The theory behind quantum computers actually goes all the way back to Feynman and his colleagues in you know simulating quantum processes, simulating chemical reactions and I mean when I just say that that that sounds like a huge application space, you know, you can develop new materials Um, you mentioned condensed metaphysics is one of the biggest areas of physics This would have huge applications in condensed metaphysics.
So I mean what what are the Look, what is the scale of application? If we were to come to the point where quantum computers were a part of everyday life, how would the world change? What, what problems could we solve then that we can't solve today?
[00:31:21] Chris Ferrie: Well, we think there are applications for problems that, that we are solving, but not at the scale we think we might be able to solve them. So, you know, we design materials, we design drugs by using our understanding of chemistry, sometimes down at the quantum level, but with approximations. So, you know, we do this now, and we think that quantum computers would enhance these capabilities.
Uh, in those areas, I, I think that it will move, move slowly. Like we won't, again, we won't notice like this, like it won't be like a, uh, a switch has been flicked on and all of a sudden we'll be able to do something that we couldn't have done before. it, it'll be, you know, slow progress improving upon things that will probably.
Not feel as impressive as it is because everything is sort of increasing, right? Like the whole, all of our society and economy is, is built on this idea of constant growth. So, um, we would expect it, demand it. And that's what will be provided. Um, You know, so we, as of the same will happen, right? Like we, we're getting better materials, we're getting, um, medicine.
We're, you know, we, we can create vaccines in a matter of, you know, months new diseases. These things will just happen faster and at a, at a bigger scale, but, but maybe the problems come faster too, right? And these two things can, you know, just kind of wash each other out. I, you know, we, you can think of fantastical scenarios, but, uh, you know, even With digital technology, which is, you know, completely revolutionized society as you live it, it's pretty, it's pretty mundane, right?
you know, what did we do with it? We created Tik TOK so we can look at each other. filters on our faces. Um, so it'll be, it'll be kind of boring, I think. Um, but it will transform society, you know, in, in kind of the same way that digital technology has, will, will, will live and work and play in completely different, different ways.
Um, but for the people living it, it will just seem like everyday life.
[00:33:54] Matt Geleta: Hmm. Well, let's um, let's maybe then move on to some of the more speculative topics in this area. Um, I think, you know, quantum, quantum computing, um, and really quantum physics in general is, um, often subject of deep speculation and a generator of Weird sounding ideas, which I know you're very intimate with given, uh, given your recent book, which I've just finished and which I thought was, which was very entertaining and I actually, quite frankly, learned a lot from it.
So, um, I would, I would
recommend, uh, having a look. Um, I guess one of the, one of the most well known among these and something that, um, you commented on your book is the idea of a quantum multiverse and, um, quantum computing has been, uh, has been a, A, an area of physics or an application area that has actually generated some commentary on this topic. Um, I would love to get your, your take on this idea of the quantum multiverse. Um, and I, I have some follow up questions, but I would like to get your, your unfiltered views to start off with.
[00:34:59] Chris Ferrie: I, I don't find it useful. Um, I think, know, some people, like one of the most prominent proponent, of it is David, David Deutsch, who was one of the founders of quantum computing. And, you know, he likes to think about quantum computing as computations happening. And I don't know exactly how he thinks of it, but, you know, parallel worlds, whatever.
Um, but just because you use, An idea or a concept for something successful doesn't prove that, that it's true. So you know, if he likes to think about it that way, great, that's if he finds that useful, then, then so be it. But multiverse and all its incarnations is not a testable hypothesis.
And so. So, it, it doesn't, for me, it doesn't seem like it's that, that useful of a hypothesis. if you like it, by all means, you know, create, create some part of your personal story which includes it, but, uh, and if you find it useful, I, I think that that itself is. This is an interesting research question as to why, but in, in terms of, in terms of practical value, um, I, I think over the years it's shown not to have it.
Otherwise. You know, in the many decades since it, especially in the, in the context of like the many worlds theory in quantum, quantum physics, it would have been parts of the practical side of quantum computing, which the vast majority of people who study and use quantum computing are, you know, practicing applied physicists, right, uh, who don't use this, this concept of, of many worlds to their job done.
And I think that, you know, that in and of itself shows that it's actually not a very useful idea.
[00:37:10] Matt Geleta: I think, I think David Deutsch looks at it more as a prediction of, um, you know, quantum theory. I think, you know, he points to, for example, Shor's algorithm for factorizing prime numbers. And he, he says, you know, if this was done in a classical way... You know, it would take, it would consume more steps and more time than we have in the universe, and yet that doesn't happen. Um, and he asked the question, you know, where does the, where does the factorization happen? And um, you know, it is a bit of an odd question, but he, his answer is it happens across multiple universes and collapses into, into one of them. How do you then think about, you know, that algorithm, for example, where it does use superposition? As a, as a, um, you know, superposition is, is the sort of underlying basis of that algorithm. And, um, and it collapses at the end to a definite answer. Uh, how do you think about where that calculation then takes place?
[00:38:09] Chris Ferrie: Well, as I said before, I can do the calculation myself with pen and paper. So in that case, where does it happen? I guess it happens in the combination of mind and on on the paper itself And there's no the collapse is something I do with a pen piece of graphite and and some fiber That's been flattened So I Don't know what I mean, I don't know what he how he would respond to that right it seems like a bit of a non sequitur to bring up a quantum computer when you can do a quantum computation yourself by hand.
In, in the context of Shor's algorithm, like where does, where does the factorization happen? Actually, it doesn't actually happen in Shor's algorithm, right? So Shor's algorithm is mostly a classical algorithm. Like if you, if you, put all the steps together. Most of the steps are classical steps involving like, you know, Euclid's algorithm for, know, the greatest common divisor that was of years old.
So, um, the, what actually is happening At the quantum, in the quantum part, is it's just taking a function and trying to find a pattern in a function. And then once it finds that pattern, then it's kind of solved a sub problem in a bigger algorithm that's mostly classical. So you've designed this algorithm so that...
created a sub problem which the quantum computer is well suited for. Um, and then, you know, Deutsch's other algorithm, like the Deutsch Jozsa algorithm, the first, sort of the first quantum algorithm with a quantum speedup, was designed specifically to exploit, you know, the fact that there, there, there's interference when you do these calculations.
The negative numbers cancel the positive numbers. Um, so, you know, you, You can, you can write this all down. Like if you had a big enough pad of paper, you can write it all down and it's not happening in parallel universes. It's all on one piece of paper in this, in this universe, in this one right? So again, I think it, it's a bit, it's a bit cartoonish.
I often find it, it surprisingly. It's surprising how, how easy, how sticky it is, like how, given, just given how, how cartoonish it is. It's a, it's a very, um, it's not, it's not very, it's not very deep, right? You can, you just look at it and you think, oh, well, you know, look, I, I put the data in these terms and then I put an addition sign between them.
Uh, I'll interpret each of those as being in, its in its own separate world. It, it, it's a bit, yeah. It's a, for me, it's a, is a bit cartoonish.
[00:41:23] Matt Geleta: One of the, one of the, um, other phenomenon that, that David and many people point to is the phenomenon of decoherence, um, which is a big and important term in quantum computing. And I think many people, you know, there's sort of two camps of people. I think some think of decoherence as, uh, the, you know, quantum system, uh, interacting with the environment and kind of. Collapsing to, um, you know, one state or however you want to term that. And, and then there's the other camp who considers decoherence as the environment kind of getting entangled with. a quantum system in superposition. and and as you said, you know, there's different terms. Um, you know, there might be a term for Matt and a term for, for Chris in one state entangled with a quantum system.
And, and then they would then think of that as, um, you know, Matt and Chris entangled with one quantum system and then Matt and Chris entangled with another equally real quantum system. Um, both of those which have, have all right to be called, uh, you know, real and, and existing. Uh, how, how then do you think of, what do you, what do you think of the, the concept of, of decoherence physically, ontologically?
What is, what is happening in, in decoherence?
[00:42:37] Chris Ferrie: Yeah, so if you take a system and it's isolated, then the Schrodinger equation a very good equation to use to describe behavior of that system, and if you make predictions based on it, you'll right of the time. Um, that is interacting with another system, uh, the mathematics of quantum physics This you to describe it in a in a certain way and we give that a name.
It's called entanglement. They just become correlated And in the same way that classical correlations, you know render uncertain, you know, some properties of the system The same happens in, in, in quantum physics. so I don't think there's anything mysterious there. Uh, the, you know, the decoherence and superposition itself is a, what we call in quantum physics, basis dependent.
Um, so In some sense, the superposition is only meaningful because you define some preferred kind of states of the world. from, I would say, from the universe's perspective, those aren't special at all. I mean, you just chose to say that, say, the alive cat and the dead cat are special states of the world.
And so the superposition has some, some particular weird meaning for you. But, um. from the universe's perspective, it's just another vector in this space of a lot of vectors. Um, it, it's not it's not a sum of two things at all. It's just its own, its own thing. Um, so yeah, when you set up a model that includes the environment in, in setting that up, it's, it usually prefers some basis.
So the environment is, is in set up in such a way. prefer states of the system and create robust states of that system. if you imagine, like a dust particle floating around in a room, lots of air molecules around, and every time an air molecule hits the dust particle, it, you know, that air molecule now encodes the position of that dust particle.
So position space is this, one of these preferred states. Because you've stuck the thing in this environment, which is in, is constantly in, you know, encoding and copying the position. Um, and so when you put that thing in superposition of two, uh, of two position states, it will. So, you know, it will cease to be in such a superposition quite rapidly because position information is constantly being encoded and copied in the environment.
if you put it in a different environment, like, uh, it, it some very non, non-natural environment that was more conducive to Uh, then, then super positions of positions would, would, would be natural and remain. And then the momentum states would be the ones that, that deco here. So it, for me, it's all about.
So you know, the kind of environment that you're in defines what, states of the system are robust that in turn kind of sets up that this kind of, um, artificially paradoxical situation of, of, of superpositions they're not common. So when they do happen, when you try to engineer them, they seem unique and surprising, but that's only because of the context in which you've placed this system in.
[00:46:46] Matt Geleta: So why is it that you think then that, um, so many, that this is such a, like a divisive issue in, in physics today, both among, um, practicing physicists, but also just among, um, sort of physics lay people who, um, you know, know a bit, read a bit about physics, but not actively involved in the research. Why is there such a strong dividing line today?
Um, what, what are we, what are we not seeing that's providing clarity here?
[00:47:12] Chris Ferrie: I, I think it's not that important an issue for people to spend time thinking about. Uh, and it's what, and I guess what I mean by that is it's so far removed from everyday experience, right? Like resolving this question is. is not going to help you get a new job, right? It's, it's not going to tell you where to invest your money, you know, what you should have for dinner tonight.
Like your everyday concerns will never be related to details of what's, what's going on. Um, in this sort of, um, part of the world, so far removed from every, every experience and sensation you can have. So from that point of view, it's just not important enough for people to devote a lot of time to.
Um, you know, I guess it, I don't want to be too glib about it, but I, it would be hard for me to, to really think about what, what problems it would actually resolve if everyone came to an agreement about it. So you know, it's this. Um, it's, it's kind of like, uh, like, like fiction, right? You there, there are unanswered questions about a fictitious world.
People will, there's, uh, there's always room for interpretation. And so you'll get people arguing about it endlessly.
[00:48:51] Matt Geleta: Yeah, yeah, we've seen that. And I think we've also seen, and this leads very nicely to your, um, your book, your most recent book. I don't know how many books you have, more than, more than anyone has spoken to probably, but, um, uh, you know, there was also that, but then there's also deliberate misuse of, of quantum terminology, quantum ideas, or even not deliberate, but naive use of these ideas. And you've gone through several of them in, in your book, uh, Quantum Bullshit, which, um, which is, which is, which is good fun. Um, maybe let's start with, uh, let's start with the, the motivation for writing a book like that. What, what brought you to writing that book?
[00:49:30] Chris Ferrie: I was a combination of things. Um, of them was the fact that my, uh, my other books, which are, which are for children. Seem to hit a lot of different audiences except one. So, you know, obviously kids have the book, parents have the book, um, grandparents. Uh, I, I've even seen sort of, uh, adults but science enthusiasts pick up a copy because they, like, like, The way things are explained in it, the one sort of audience that I didn't, uh, it didn't resonate with was like, say the undergraduate physics audience.
So like, you know, people in their late teens, early twenties, um, right in that perfect of age where you know everything. Um, so I, I was missing that audience. And, and then there was a very sort of clear kind of moment in my mind that I remember I was walking through an airport and I was actually going to visit the publisher of my children's books,
[00:50:31] Matt Geleta: Mm
hmm.
[00:50:32] Chris Ferrie: for dinner.
And I remember seeing the airport, one of these airport bookstores, and it had the top 10 books. it was after the subtle art of not giving a fuck became popular. And then everybody put a swear word in the title of their book. Um, and I, I, I thought, well, you know, if I rename quantum physics for babies to quantum fucking physics for babies, maybe it'll, it'll start selling in airport bookstores.
And, you know, young professionals will, and undergraduate physicists will, will, will buy it. Uh, and so I joked about it with the publisher and they thought about it for a second. They said, Oh, that's not actually a bad idea. And so I thought. Okay, well, I'll, I'll write a book with a swear word in the title, um, and, you know, it just so happens that there is a lot of quantum bullshit out there, so it wasn't that difficult to fill the book.
[00:51:26] Matt Geleta: Yeah, I actually, I actually tested some of your claims by doing a Google search for, for quantum blank and, and you're totally right. It is, it is, it is a lot out there. Why is it that you think that it is such a misabused, um, you know, topic? You don't get, for example, statistical physics hype out there. You don't get, um, random chemistry hype, but there is a lot of quantum. Hype. And it's certainly overrepresented in, uh, in the general public and it's certainly the most represented, misrepresented sort of brand of physics that I've seen. What do you, what do you, what's your take on that? What is the cause of, of this phenomenon?
[00:52:05] Chris Ferrie: Well, I think, again, because it's so far removed from our everyday experience, it just leaves lots of room for interpretation, and so, you know, ev People are aware that there's this theory of quantum physics, and it's very successful. And it to explain the way the world works, and if, and it, you know, it's about a hidden, sort of, something hidden from our everyday experience.
Then you take some, you know, something else, right, that seems to be hidden, uh, but a part of the world, like love or something.
[00:52:40] Matt Geleta: Hmm.
[00:52:41] Chris Ferrie: so certainly some, God has to be some mechanism there, right? Um, but it's not observable. It's clearly not explained by engineering or statistics or Newton's laws. Um, What's left, right?
Um, so think that's, that, that's why, right? There's, it leaves, it leaves so much room for interpretation. And, uh, you know, people don't have the time, obviously, to, to get a, an undergraduate degree in physics to understand the limits of its application. it seems to be there free for the, free for the taking to apply to, to whatever unexplained thing that, you want to interpret.
[00:53:27] Matt Geleta: Hmm. Yeah. And, um, and in, in going through sort of the research, I mean, you, you, you work in this field, so I don't think you would have to do. All that much external research, but you know, looking at what's out there and trying to diagnose, you know, how much of this is. It's just naive and how much of this is actually malicious intent, um, it feels like a big mix.
Do you have a sense as to which side it skews?
[00:53:53] Chris Ferrie: Uh, I think the vast majority, like if you just quantified the amount, the number of bits, like the amount of information out there, most of it would be just innocuous nonsense, right? Somebody posts some meme of, um, you know, cosmic consciousness or whatever they want to think about in the moment.
Without any malicious intent. They don't really intend to deceive anyone. They're not selling anything. Uh, it's just a reshare meme that resonates with them. And because it has the word quantum in it, it sounds cool and exciting. That's the majority of it. Um, Obviously when things go wrong, then it gets more attention.
And so, yeah, you, you, you see more stories about the, the, the things that do involve malicious intent, but I don't think that makes up the majority of it.
[00:54:55] Matt Geleta: Yeah. Well, it's a, it's a, it's a, it's a worthwhile, it's a worthwhile read. I must say I did, I did learn a bit even though I've got a couple physics degrees and some background in it. It was, uh, it summarized things in a nice way. So I recommend it. Um, the other sort of back to quantum computing, the other interesting thing you've worked on is, um, You know, you've written several books on education and I know you're involved in a quantum computing education of a sort through Through a company called Eigen systems. Can you tell me a little bit about what you're what you're doing there?
[00:55:25] Chris Ferrie: Yeah, so the, the company is, is a quantum computing education company. And our goal is to
democratize access to, to quantum computing education. So we talked about briefly already quantum computers that are for sale. Like, you know, IBM will sell you one if you have a tens of millions of dollars, um, but you know, obviously not everyone can, can afford that.
So. What we wanted to do was provide the same sort of, uh, benefits of tangibility by creating a desktop quantum emulator that is accessible and affordable would allow people to, to engage in new and yeah, more, um,
Yeah, I think just, just engage in, in new ways with, with quantum computing that didn't exist before.
[00:56:25] Matt Geleta: Yeah, and and when you say engage with quantum computing, do you mean, you know algorithm design developing software? Is this is this something for developers to use?
[00:56:35] Chris Ferrie: Well, part of the, part of the motivation, you know, was we, we thought back to the early days of, of digital computing
[00:56:46] Matt Geleta: Hmm
[00:56:46] Chris Ferrie: and this hobbyist mentality, When you could buy like an Altair. And, uh, you know, there was some, some instructions for how to use it, that, you know, that was it. Obviously you couldn't use that device to, to program a web app, but.
you could how to develop some, some computing skills by, by using that. And the constraints of it forced you to do interesting things, like come up with an operating system for it. Um, so. We, that's what we wanted to like hearken back to, right? This hobbyist mentality. Now you can't develop, you know, you can't use it to say, develop more optimized subroutines to run Shor's algorithm.
Because as I said, you need billions of qubits and we can't simulate that with conventional technology and you're not going to be able to develop. Practical commercial applications because again, it's It's a small scale emulate, you know, device that emulates the industrial scale technology. But you could do the same things that hobbyists did with digital computers.
You could create quantum video games. You could, you know, uh, create, you know, quantum chatbots, right? You know, create your, yeah, create your quantum game that runs in parallel universes if you want. Um, so these are the sorts of things that you, that, that you can do with it. It, it's not about learning and learning development in the same way that you would learn development.
In a like software development, where the point is to someone into, into a commercial setting right away. because the, you know, we're still at a really fundamental level with this technology.
[00:58:52] Matt Geleta: Yeah. Great. Um, and, and, uh, you know, is, is this available? Can people, can people check this out or is this something in development? Um, what's the, what's the status?
[00:59:00] Chris Ferrie: Yeah, so the status, now is we, we have devices, uh, we have more customers than we can, we can fulfill orders for. Uh, they're kind of pilot customers at the moment. Um, we, we're, we're giving them to say other university professors. Uh, there's a couple of sort of more hands on pilot programs that we're running.
That, that are for clients that don't have any background in quantum computing. we're testing how we can, uh, deploy these things in that context. What sort of support people would need they didn't have a quantum computing background, the obvious. This application is for professors that are already teaching quantum computing that just want to enhance, um, the engagement with students to provide them with something tangible.
And where, you know, so the stage we're at is. is, is really, uh, looking at getting, getting some investment so that we can start to, to scale up and mass produce them so we can to meet all the demand that, that we're seeing for it.
[01:00:19] Matt Geleta: Amazing. Yeah. Well,
it's a wish.
[01:00:22] Chris Ferrie: maybe early, early next year. There'll be a website up where you can put your, uh, pre order in and, uh, by mid next year we're hoping we can, we can start to ship, um, every, for every order that we get.
[01:00:36] Matt Geleta: Fantastic. Well, um, I can retrospectively, once the website is up, I can add it to the, uh, the notes here.
Um,
[01:00:43] Chris Ferrie: Sure.
[01:00:44] Matt Geleta: let's, uh, to bring it to a close, I like asking my guests a couple sort of structured questions. Um, and the first I think relates very nicely to the work you do, you know, you've been involved in, in book writing and I assume book reading and book gifting for, uh, for many years. Um, and one of the questions I'd love to ask is what book have you most gifted to other people and why?
[01:01:05] Chris Ferrie: Okay, um, well, okay, this is gonna sound a bit silly. It's one of my books, because the publisher gives me so many, so um, so I get them for free, so they're easy for me to gift. Um, but the one I like to give away the most is, is called, There Was a Black Hole That Swallowed the Universe. Um, because I think it's a really fun book, kind of to the cadence of there was an old lady that swallowed a fly, so it's very easy, sort of easy to read and fun to read to kids.
And I, when I designed the book, I created a reverse story where, so the story is about a black hole that swallows up everything in the universe. there's a story that goes in reverse that puts everything back in the universe starting from the Big Bang. And that story is written in UV reactive ink. So you can't see it on the page, but if you shine a UV torch on it, a story that goes in reverse when you go back through the page.
So I like giving that book away with a UV torch, um, and then, uh, if it's in the context of, you know, some event or something, then I'll, I'll, I'll sign the book with, uh, you know, invisible, invisible UV, UV reactive ink and, and the kids really get a kick out of that. So that's the funnest one to, to give away for sure.
[01:02:23] Matt Geleta: Yeah, well, there's definitely no need to be embarrassed for giving that away. I think that's, that's unique. That's, that's amazing. Um, the next question I'll ask also relates to young people. You know, you've thought a lot about, uh, young people's learning journeys, both from a very young age, but also at undergraduate level and beyond. Um, and I think many people, when they enter... You know, these technical fields that enter physics, it's in a very undirected way. And uh, it's, it's almost, it's almost, you know, by chance they might end up following some route and go very, very deep. Um, and so my question is, you know, to, to a young person or potentially just any curious person wanting to get, uh, wanting to explore these fields, wanting to explore physics in general and not knowing where to start. What advice would you have for somebody like that?
[01:03:09] Chris Ferrie: Well, I think it would just be start. Um, it, people tend to over optimize and you get this sort of sense of stagnation or, or, or paralyzation you don't know if you're doing the right thing. Um, even today, the vast majority of things that I do are mistakes, right? If I, if I'm writing a book, there's.
You know, false starts. I have a whole, I have a folder, um, called the bad ideas bin and it's the biggest folder on my computer. Uh, so you just, you just go and then, and then as you go, you come up with questions. And in some sense, like you just have to trust the process that there'll be, there'll be interesting and useful questions and they'll eventually lead you down the right path.
And the, that process of making those mistakes will make you better prepared for the path further down. in, you know, it's, it's necessary. So, you know, making mistakes and, and what seems like wasting time is, is actually the most useful and productive thing that you can do. Um, so just get started. Um, I find, I don't, I don't.
passively learn information very well. it, it's the process of doing that, that allows me to understand the things that I'm working on. So, a lot of that involves writing and, and attempting to teach it to other people. You know, even if it, if it's just the void, I post a blog post, um, that, that process of least attempting to teach it to other people is what provides me with, with understanding.
So that would be my recommendation. Just, just. Pick something. Try to write it in your own words. Write it as if you were teaching it to someone else. Whether or not anyone else is going to read it, it doesn't really matter. Because that process is what will provide you with the understanding.
[01:05:23] Matt Geleta: Yeah, fantastic. Um, you know, the, the last question I have, we talked a bit about the advances in, in technology and in quantum computing. And one of the other areas that's also hyped up a lot, but is also bearing fruit is, is artificial intelligence. And something you hear a lot of is the prospect of a general artificial intelligence or an artificial super intelligence. Uh, and my question to you is, suppose one day we were to be visited by. A, an artificial super intelligence and we had to pick one person either past or present to represent us to this super intelligent other. Who would you pick?
[01:06:01] Chris Ferrie: Um,
uh, I feel like realistically , what would happen would be, uh, you know, some organization would create some sort of program of dubious, ethical
[01:06:18] Matt Geleta: Ha
[01:06:19] Chris Ferrie: uh, procedures that trains, trains someone, uh, to be the representative, right? , Um, I think the, I mean, that's, that, that sounds a bit cynical, I suppose. Uh, and it, you know, if you're cynical about, about AI, like this, so your picture of a AI or, you know, a super intelligence is like the Terminator, then probably you would want the, the inevitable.
To be over as quick as possible. So you should present like the worst example of a human so that,
[01:06:56] Matt Geleta: ha ha.
[01:06:57] Chris Ferrie: you get the, you get it over with as
[01:06:58] Matt Geleta: Ha ha ha. Ha ha.
[01:07:00] Chris Ferrie: So, uh, yeah, I don't know, Tom Cruise, I guess. Um,
[01:07:02] Matt Geleta: Ha
ha.
[01:07:03] Chris Ferrie: you know, insert, insert the, the political leader of your least favorite political party, for the listeners.
Um,
[01:07:11] Matt Geleta: Yeah.
[01:07:12] Chris Ferrie: I think I don't, I, I, yeah, I don't, singularity where.
Uh, tech, the progress in technology, we'll see some giant step transition. Um, that's not usually what happens. So I don't think that will happen with, with AI So I'll give it a fuck. So yeah, so I think it's a bit absurd to consider, but so I'll give you my final absurd answer, which is Tommy
[01:07:41] Matt Geleta: Ha ha ha. Fantastic. Okay, well, I won't, I won't open up this, this rabbit hole of Tommy Wiseau and whether we'll hit AGI, but um, it's been a fantastic conversation, Chris. Thank you. Thank you so much for, uh, for speaking with me today.
Chris Ferrie: Quantum computing & quantum hype