What on earth is quantum computing?

Welcome to Season 5 of the Hello World podcast. We're excited to be back, bringing you conversations about computing education. For our first episode, we're exploring an emerging field in computing and how we might approach it with students. We'll be asking our expert guests, "What on earth is quantum computing?"

Full show notes:
https://helloworld.raspberrypi.org/articles/what-on-earth-is-quantum-computing

Transcript

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Diane Dowling: 0:03

It will be able to solve problems that are way too complex for traditional computer systems.

Stefan Seegerer: 0:08

Quantum computers have been around for quite some time.

Andreas Woitzik: 0:11

How would you explain Quantum Computing to a ten-year-old?

James Robinson: 0:14

Quantum Computing, is going to shift the goalposts in terms of what we can break. Welcome back to Hello World a podcast for educators, interested in Computing and digital making. I'm James Robinson, Computing educator and professional development Pioneer.

Diane Dowling: 0:32

Hello, I'm Diane. I've been learning manager at the foundation and I consider myself a total novice in the field of quantum Computing. So I'm very excited for the chance to talk to our experts today. And as ever we really value your comments and feedback which you can share at helloworld.cc/podcastfeedback.

James Robinson: 0:51

This week, We're exploring how Computing might change and develop in the future and the impact of these changes and are by asking what on earth is quantum computing? Now whilst I'm in very much doubt we gonna be able to cover this topic in depth in 25 minutes. We can hopefully help demystify this emerging field. So Diane and there's no pressure here at all. But how would you explain Quantum Computing and its potential impact?

Diane Dowling: 1:17

I'm definitely feeling under pressure. So what do I know about Quantum Computing? Well, the main thing I know is, it's based on some really clever physics and that it will be able to solve problems that are way too complex for traditional computer systems. I know that it will pose a threat to our current encryption schemes and the last thing I know is that it involves something called qubits. So James, have you managed to get your head around qubits?

James Robinson: 1:45

Well, to an extent and I'm probably going to embarrass myself a little bit in front of our guests here. Now, interestingly, I was, I was thinking about this too for when I was researching the show. I remember reading probably about twenty years ago, I used to work for an organisation that had like a research journal. And I remember them publishing a thing about Quantum Computing being the future. And I remember at that point what I took away from the magazine article was that qubits were a thing and that whereas regular bits and Computing have two states on and off, qubits had more States and I at the time was like, oh, lots and lots of States, but I think, broadly, it's kind of three states. But I don't quite know. I think that superposition has something to do with the third state, but that's about the limit of my knowledge, but I think it's a really fascinating field and I think one that I'm really excited to kind of be corrected about, learn a bit more about as we explore this. We're really fortunate today to be joined by two Quantum Computing experts firstly, Andreas Woitzik a PhD student in Quantum information science at the University of Freiburg in Germany and as well as learning as much as possible about this topic, he is passionate about bringing Quantum Computing and Quantum information to schools. So Andreas, what do we mean by Quantum Computing and just how badly did Di and I do?

Andreas Woitzik: 3:15

Yes. Thanks a lot a lot at first for having us here. I'm actually very much looking forward to this episode especially now, since I heard about your question, what a qubit is and about the superposition State. I think we will get this figured out. So I'm talking about Quantum Computing, I think we have two terms here, one as Quantum, one is Computing. With Computing here at Hello World I think we are rather familiar. So we have some goal, we have some goal or if some problem, we want to solve and we're using some Machinery in order to do so. And in the case of quantum Computing the Machinery just follows the laws of quantum physics and saying just here I mean this might be complicated from time to time but kind of the Machinery you use is that what is changing and by that we hope that we can gain some potential.

James Robinson: 4:05

That's great. I love the use of the word just in that sentence. That covers a lot of a lot of ground there. Di, Do want to introduce our second guest.

Diane Dowling: 4:14

Yes, indeed, yes. So, our second guest is Dr. Stefan Seegerer, and he is a Quantum education manager at IQM, a European manufacturer of superconducting quantum computers. Stefan has designed a variety of teaching and learning materials in the field of quantum Computing. So Stefan, can you tell us if quantum computers exist right now? And if so, what are they being used for?

Stefan Seegerer: 4:39

That's a very good question to ask and thanks for having me on the show. So actually quantum computers is they exist right now. So we're all the way always speaking about quantum computers being the future of computing but actually, quantum computers have been around for quite some time. James I remember you mentioning that you have been working on this research magazine years ago where you were investigating qubits. So there are things that are not new to us but only in recent years we actually got to build quantum computers that would actually house a couple of qubits so we can do something with it. So for example, IQM the company I work in, we build quantum computers for research institution and supercomputing centers but truth is that at the moment a quantum computer is still used for research purposes for training people stuff like that because they are at the moment not really useful for the tasks we want to solve in the future with a quantum computer. But the thing is, it's a reality already now. And the hardware is hopefully getting better every year. And at some point, we can speak about the applications we mentioned in the beginning that could bring us as Humanity forward.

Diane Dowling: 5:56

Sounds really interesting. Stefan, how many quantum computers are there at the moment?

Stefan Seegerer: 6:01

How many supercomputers are there? I'd Guess that it's like a couple of hundreds worldwide, I guess, but this is just a rough estimate. So or we have like two digit numbers of quantum computers in our labs and other companies have like the similar amount of quantum computers in their labs and then there are a couple of them in universities around the world or in some supercomputing centers. So, for example, we've connected one to the LUMI supercomputer here in Finland where a quantum computer is integrated into a supercomputing center.

James Robinson: 6:36

That's really interesting. So it's not just necessarily that we have the quantum computer, like is just doing a job in isolation, but it's maybe supplementing the work of another traditional kind of computer in that sense. A question maybe to both of you and I think we have used this word a couple of times and like I'm still unsure whether I got the definition or the explanation correct. So we talked about qubit earlier on so can either of you help us understand what we're, when we're talking about a qubit, what is that? And how does it differ from regular Computing?

Andreas Woitzik: 7:08

I think we both should be able to since we published an article in Hello World about that. So and you can first have a read. I think it's the 18th episode. And there we explain what a qubit is by using a coin and I think this analogy analogy is used very often so when you have a coin then the classical States might be heads or tail so you can encode information as 0 or 1 with this but now people like use this picture of having the coin spinning and then being in a third state and you said already, this might be the third superposition State earlier that is, that is described that is describing a coin that is partially in zero State and partially in a one state. So it's not yet decided whether it's heads or tail and this changes when you really kind of measure or when you look at the coin, but it falls down and this is kind of an analog you can draw. I think with these metaphors, you have to be always a little careful because the the laws of quantum physics are not not really like our real world. So we are not really used to it our intuition is sometimes very bad for that. So there's not only this one superposition state but you have this spinning coin but you can also think of other superposition states. So when you use math as the former formalism to describe these states and it all gets a little more advanced, but I think just for getting an intuition, it's really nice to think of this rotating taking coin.

James Robinson: 8:38

That's really interesting and Stefan, Did you have anything you wanted to add to that explanation?

Stefan Seegerer: 8:43

Yes. So this coin metaphor is quite useful for us to get this understanding or this feeling that something can be in two states at the same time, that's always what we hear when we speak about quantum computer. A qubit. Well, it has the word Quantum in the word bit in it. So it's something like a Quantum bit. The bit can be either 0 or 1. And the quantum bit can be 0, can be 1 and can be both at the same time. And when we look at it, this measurement when the coin falls we have a certain probability of getting either 0 or 1. Well, this kind of sounds cool way. We have waiting way more states to use for computation, but in the end we just end up with those classical States. We are already used to the question is how can we use that for computation? Because I mean well we have this huge amount of states with one qubit we can be 0 and 1 at the same time with two qubits we can be like in four states at once, 0 0, 0 1, 1 0 and 1 1 with three qubits we can be in eight states at the same time with each having a specific probability of being measured as this and so on. You can kind of draw the line and see the same curve as we had with those covid infections. So an exponential increase in the amount of States we can be in at the same time but when we kind of look at the result we end up in just one of those States and to really make Quantum Computing useful. We need very clever algorithms that kind of eliminate the outcomes we don't want and emphasise the outcomes we would like to see. You can think about this like with waves. So if two waves hit each other there are some positions that get emphasised where the wave gets higher and some where the waves are lower so you will see a very specific pattern of two waves meeting each other. And this is kind of the idea how we can think about a Quantum algorithm also. So we emphasise or we increase the probability of measuring the outcome. We want the right result and we decrease the results which are less likely. Of course, speaking just with probabilities doesn't tell the complete truth. As a quantum computer or quantum physics has more than just probability to it. There is a phase and an amplitude attached to to each state, but that's a detail we don't want to dive into now. But I think now Andreas has something to add here as well. So over to you Andreas.

Andreas Woitzik: 11:44

Yeah I think I just want to elaborate a little on this wave picture because I think it is, it's very, It's a very good picture actually, because quantum mechanics is kind of wave mechanics. So here here speaks the physicist now and then in this regards, I do my PhD in physics and that's why we should really think about information and coding into waves. When we talk about States being two different state... two different other states at the same time, like in our superposition state of the coin, then what we mean is not actually that we are in parallel in these two states but we are partially in each of those States at the same time. That is a very important difference when it comes to complexity or when it comes to erm Computing machines, because one is the machine where you're really working in parallel. The other one is where you are working in what we call superposition when you do it on top of each other and you have this interference effect.

Diane Dowling: 12:43

You said that of these quantum computers are currently in sort of research settings, sort of in Academia or in organisations that are invested in the development of quantum computers. Where do you think we'll see the first actual practical application of quantum Computing? What kind of, what kind of task will we see solved by quantum computers.

Stefan Seegerer: 13:08

That's a very good question. First, I want to add that not or people that are currently investigating Quantum Computing are from the research side, there are also a lot of Industry players, companies that investigate how they can apply Quantum Computing to their field. So they kind of try to become Quantum ready to use quantum computers. When they are like good to be used for practical applications that actually generate business value. And there are different fields where people investigate Quantum Computing and it all comes down to those problems that current Hardware current computer hardware just reaches fundamental limits. So the computer I have in front of me, the computer you have in front of you and even the big super computers in those supercomputing centers, they are pretty pretty capable of doing things, they are good at rendering video games. They are good at doing math calculations and stuff. But actually, there are that some things, those computers will really struggle with. They can't just finish them in a reasonable amount of time. So, we just don't approach those problems. We try to like, water down the problem. Simplify it to be able to run it on the machines we currently have. And those problems are for example, simulation problems. In drug research and stuff like that we need to simulate how those molecules behave, how they interact and stuff like that. And this is something that is really, really hard to do with the computers we have at hand in our notebooks in the classical supercomputing centers. So simulation is one thing. The others are problems where we are trying to get an optimal solution. In a vast solution space trying to find the best way to collect all those people trying to do carpooling in a city or something like that. Optimisation problems, production planning, Logistics, all those areas. Those problems are also really hard to do because you need to investigate a lot of possible solutions. Those two areas are very interesting for Quantum Computing, especially the field of Quantum simulation is one that is heavily explored and where we might see applications in the future.

James Robinson: 15:43

If I'm understanding correctly, we're kind of saying that Quantum Computing fundamentally it is helping us address challenges, for which traditional means, we just don't have the computational capacity to solve them. And so one of the spaces, where comp Quantum Computing can be valuable is in those spaces, where traditional computing would take far too long or we don't have the Computing bandwidth to be able to do it in a reasonable amount of time. So there's probably some really positive things to that. I mean, the problems you suggested there, Stefan, are quite positive problems we can solve, but there are some potential risks that come along with that as well, I guess because like one of the questions from our audience, so from Steve Rich on Twitter asked, what effect will the availability of quantum computers have on the encryption algorithms that we use today and I can see that at moment the fact that that's a big problem to solve is a good thing because it keeps our data secure. But what's the impact there? And I don't mind if Stefan or Andreas want to come in on that.

Stefan Seegerer: 16:45

That's that's a very good question from the audience and it is true that current encryption relies on, mathematical problems that are actually quite easy to solve on a quantum computer at least potentially. So the quantum computer hardware is not at the stage that we can actually solve those problems but integer factorisation, or discrete logarithms, or elliptic curve discrete logarithm problems. The ones that are used for those public key cryptography systems that we've in use today, they can actually be solved by a quantum computer way more efficiently than with a classical one. Which would mean that we would be able to read a lot of the encrypted conversations we have online. And I mean all the internet communication is relying on that. But actually, a lot of researchers are also investigating so-called post Quantum cryptography, like Quantum safe cryptographic algorithms that are suitable even when we have capable quantum computers around us, then probably the only real, like danger. Is that we could do playback attacks like a record now, what is sent via the Internet and decrypted later and find out what was the communication about? Maybe there is some information, we want to store for longer time but the good news is that people are investigating post Quantum cryptography working classically and actually we have also cryptographic algorithms which work on a quantum computer which are actually very interesting to explore with students and in this Hello World magazine number 18. There is actually an article showing how to do one of those protocols with students. And I think that's a cool thing to explore in class.

Andreas Woitzik: 18:46

And let me just add to this. So, in Quantum cryptography I think there was already, there are already applications in the industry so you can buy encryption devices that use quantum cryptography, as of now. So in comparison to the field of quantum computation, when we talked about optimisation or a simulation of quantum systems. There, this is really still research but with Quantum cryptography, this is already industry applications.

James Robinson: 19:15

Okay. So, like Quantum Computing, is going to shift the goalposts in terms of what we can break the in terms of cryptography. But already people are thinking about how to address that either with new forms of encryption powered by Quantum, or with cryptographic algorithms that are resistant potentially to to Quantum cryptology to Quantum decryption techniques. Is that accurate?

Andreas Woitzik: 19:42

Yeah, yep. And it's it's a little ironic isn't it? That Quantum Computing is kind of a threat at least in theory too many of these encryption protocols and then at the same time because Quantum information is so fragile and we talked about the spinning coin and that if you look at it that it kind of alters its State and this property can be used actually to to invent these Quantum cryptography protocols. So for key distribution and so on. And this is what you can explore in this Hello world article.

Diane Dowling: 20:15

Yeah, I wanted to ask, just to pick up on something that Stefan said earlier. So I think you use the term quantum algorithms and I just wondered if we take a sort of classic hard problem, can we use the same algorithm but actually run it because the computers more capable or do we actually need a different algorithm and just to extend that a little bit. Will we need new programming languages you know so as a software developer will I need to learn you know some new tools to actually develop my programs with?

Stefan Seegerer: 20:47

That's a very very good question and to start with the first part you can't use the algorithm you would use in a classical machine so you would need a specific Quantum algorithm which is capable of canceling out the bad solutions and like emphasising the good Solutions. So we need a different way to approach the problem and actually that's quite interesting. So a quantum computer at the moment is kind of working in the megahertz range, so it's quite slow in that sense whereas like classical computer is kind of in the gigahertz range. Even my notebook here is probably a couple of gigahertz the processor is fast. So we actually need to approach the problem differently and actually we can't solve any problem that a classical computer can't solve with a quantum computer, those np-hard problems, still stay np-hard even with a quantum computer. So we just need to, we have a couple of problems where we can actually utilise a huge speed up with a quantum computer, which are very interesting for us as humanity and to come to the second part. If we need new tools or programming languages, most tools we have available now. They rely on programming languages we already know, like python or Julia. Just adding a bunch of APIs to that a bunch of functions and methods that we can utilise to write code for a quantum computer. And the truth is at the moment also that a lot of those algorithms are actually hybrid. So we utilise power on the quantum computer and we utilise power on a classical machine. So, like we have hybrid approaches to Computing and those are ones that are heavily explored right now.

James Robinson: 22:50

And that hybrid approach is quite interesting. I was having a chat with some colleagues who are doing some work on AI, and machine learning at the moment. And the fact that with machine learning you invariably there's a machine learning component which does the bit that it's good at and there's a classical Computing algorithm bit that does the bit that it's good at and the two kind of work together to solve a problem that neither methodology or Paradigm, whatever you are using could solve independently kind of thing. So it sounds like there's a similar kind of way of working between Quantum, Quantum and traditional Computing, that's really interesting.

Stefan Seegerer: 23:22

I mean, we see that Trend in general, I guess. So quantum processors are can be like accelerators to classical supercomputers and I guess Computing is moving in a way anyway that we, as end users kind of have communication devices. Our smartphone, doesn't have a huge capacity to calculate the route from London to Manchester. So, we just send a server request to somewhere to please get that route calculated. So there is in general, a trend, Outsourcing the huge computation power to some remote location where it shared and have only like a communication device with us.

Diane Dowling: 24:04

So what are the important Concepts about Quantum Computing that Learners or students will have to grasp?

Stefan Seegerer: 24:12

That's a very important question to ask and we have mentioned a lot of those Concepts already. One is the word of superposition that qubits can be in a superposition of 0 and 1 at the same time while having a certain probability of measuring, being measured as either 0 or 1. Then there is a concept, we haven't touched so far, which is called entanglement, which is also used quite heavily in computation in quantum computation and entanglement, is that the state of multiple entangled qubits cannot be described by specifying an individual state for each of those qubits which kind of means even if those qubits are far apart, they kind of know what the other is doing. So Einstein was referring to that as spooky action at a distance at a distance, you might have heard about that and that's another important concept that you'll explore while you do Quantum Computing with your students, then we have that quantum computers can solve can can solve certain but not all problems more efficiently than a traditional computer about Quantum algorithms that they use quantum gates to influence the state of those qubits in a way that the probability of measuring a correct solution increases. And like incorrect solution, the probability of measuring them decreases. This was kind of this wave analogy we were speaking about. And finally, this is more related to Quantum cryptography that we can actually use the information in qubits like Quantum information and the fragility of qubits which we haven't really spoken about. But those qubits are very sensitive to everything to environmental noise, to heed all those things but we can actually use their fragility to enable tap proof communication, which is a nice thing because we only know, like the one time pad which is completely tapped proof. But with quantum computer, we actually have with Quantum cryptography. We actually have other cryptography protocols which what it allows is to do tap proof communication and I think that's quite interesting for students to experience.

James Robinson: 26:41

That's really nice summary. And I think we've touched upon this a couple of times. And we've talked about analogy a few times and we've mentioned, this is this coin flip and analogy, you talked a little bit about kind of waves. And I think, you know, anyone that studied, I think that sort of GCSE or a level physics will understand constructive and destructive interference and that sort of, that's analogous, but maybe not 100% accurate. And I think that kind of leads on to this, like when we using analogies like this kind of infer or describe what's going on to a limited extent, there's the potential to introduce some misconceptions. Right? So what do we think? And maybe Andreas you could answer this one. What do we think are some of the common misconceptions that our students might have as we start talking about Quantum Computing?

Andreas Woitzik: 27:35

Yeah, absolutely. So there is always this risk and as I mentioned earlier, I think this risk is very big when it comes to Quantum Computing because we are not used to these phenomena that occur on on these scales usually. So I think the number one misconception that I come across is that quantum computers are just super fast computers that can solve everything much much faster than than actually is done on current Hardware. This is simply not true. So there we can prove that some tasks, for example, sorting a list will not be speed up sped up by quantum computers. So this is just the same amount of time as for classical computer. So we don't expect classic the quantum computers, taking over this part from the classical computer, especially since Stefan was mentioning the, the different rates, the megahertz versus gigahertz, with which they work. Then another common misconception is the one of parallel Computing which is kind of related to super fast computing I would say. So sometimes you read that quantum computers are just doing everything in parallel and that's why they're doing it so fast. And this is only kind of partially true. So there is a thing called Quantum parallelism, but this is really more to these to this wave property and not, you cannot just imagine that all the calculations are done in parallel. It's really about this creative interference of getting the right Solutions and out of your measurement and the wrong solutions of a problem canceling out by interference as Stefan also mentioned earlier. So I think yeah, these are kind of the, the most important misconceptions that I come across often, and I think they are also provoked by our metaphors, like, the coin, for example. But these are kind of the best we have, I would say.

James Robinson: 29:33

And Stefan because this, again, feeds into a really interesting conversation that we had last week when some colleagues of ours were talking about AI, and they have to be so careful with the language that they were using and I noticed earlier on, when you were talking about entanglement, you said you've got these two qubits and they kind of, and I think on-screen you'd use air quotes for like they know what's going on between them. Right? And I think one of the things we have in this space is when using analogies, we have to be so careful about the language because they clearly I mean I my understanding is they don't 'know' but there is some kind of information transfer going on between these entangled qubits, right? Is that, is that fair?

Stefan Seegerer: 30:13

They are, so for sure there is no information transfered between them because this information would travel faster than light. So that's definitely not the case that so still, we can't really explain why this is kind of taking place. So, this is kind of the explanation approach we use for it. And this also makes it difficult for students because this is quite unnatural to us to our everyday life to the objects we see and stuff. So it is really a spooky action as a distance at a distance.

Andreas Woitzik: 30:50

Yeah, I think physicists, so I think this is really something big in the field of physics. So there's a whole branch of philosophy about this and people are thinking of many world interpretations or collapse of a wave function or I think you have my maybe you've heard terms like this. So, these are still very big, and ongoing discussions and I get very excited, excited thinking about those but yes, as Stefan mentioned. So at the moment we really don't see faster-than-light information or faster-than-light communication, this is something. So there is some correlation between these few bits or between these states but it's not that you can use this for for signalling. So for sending information from A to B with faster than light.

James Robinson: 31:35

That's really interesting. And yeah I think that was a misconception that I think I'd I'd picked up from somewhere that there was this kind of communication, but that's cool. Yeah, and it's a very standard one. So you're definitely not the only one. And in time, I hope that some of the listeners also had this. And now they see, see this point differently. Thank you for making me feel better about that Andreas that's really good. So I guess I guess, I mean, we talked about this a little bit earlier on and I think, you know, the work that you've both done in terms of that, you know, you've written a Hello World article. You're coming on our podcast to try and expl... Help explain some of the ways that students can engage in Quantum Computing. What what learning resources exist out there? And in fact this is a question from our audience, from from Kevin McAleer, who asks, what resources are there out there to help explain Quantum Computing to our students, in a way that they will understand? And we've touched upon these little bit but maybe we can elaborate.

Stefan Seegerer: 32:31

So the good thing is there are a lot of resources out there already despite the field being not as used as, for example, AI and stuff. So, of course, I would recommend checking out the to hello world articles about Quantum Computing. That's the first. Try out the quantum Penny flip game with your students. I think that's quite fun and then you can check out our IQM Academy which is for everyone and it's free. So, this will be available very soon and will give you the chance to explore Quantum Computing even deeper without going into the finicky programming stuff. But of course, also, there is different programming languages that Frameworks programming Frameworks that we have PennyLane, or Qiskit. They offer quite good learning resources as well if you want to delve deeper into the programming aspect to it. And I guess there are also a couple of good YouTube videos that we can link in the show notes with a couple of other resources to to check out for you guys.

Andreas Woitzik: 33:35

Yeah, so one thing, I'm a little worried about many of the resources we have nowadays come from big industry companies. So no offense. Stefan, I'm sure that your, your material will be great, but at the same time, of course, these companies they have some interests and it's a little dangerous if companies, they, they create the learning content alone. So, I would really recommend also to watch out for critical videos. Go on YouTube. I think there's something like type Quantum hype or something in there and check out these videos. I think there, you can also learn a lot, of course.

James Robinson: 34:10

That's really great. I think just a quick follow-up and then, I'm going to suggest we have a final question. What age groups have you successfully, kind of had dialogue about Quantum Computing with, is there kind of a, you know, minimum kind of age that you would recommend or suggest.

Stefan Seegerer: 34:28

So, we together actually had a project with the university I was doing my PhD with where we developed and conducted a curriculum about Quantum Computing and we did it with 10th graders and above that. So 10th graders is like 15, 16 years old. Like the minimum age we tried. I Mean of course you can start lower but I guess so. You typically start with some understanding about the classical computer. The computers that they are used to and also about algorithms in general doesn't need to be that they are like familiar with writing algorithms in python or something. Just that they know how algorithms function that there are some limits to what you can do with the computer and that's kind of some prerequisites that are helpful to really discuss Quantum Computing.

Andreas Woitzik: 35:23

Yeah, I would fully we here with Stefan, I think you gave us a question and before this interview asking us, how would you explain Quantum Computing to a ten-year-old? And actually, this took two or three evenings for me to to get an answer for that? I mean, I have one, but I'm still not satisfied. So I won't read it out. I think actually a little math here, really helps. So, you can get a very nice understanding as soon as the people know, like what trigonometry is and sine, cosine or the unit circle this. But this is, of course, this is already a little advanced, but then I would say, you can do whatever you can also do on the University level. Then you can get really deep into the topic and when you talk about interference or kind of the most important properties of the theory of quantum Computing. I think you can do much much earlier on also. For cryptography like this bb84 protocol. I'm sure that you can do this with age group 10 already 10, 12, and 14. That's all doable. I would say.

James Robinson: 36:22

And probability and coin flipping is we could start talking about that at a bit of a younger age potentially, but that's interesting.

Stefan Seegerer: 36:29

I think, the question probably is not when we can, but when we should, I mean, we can potentially break things down to a level. We could do it in kindergarten but I guess it's more when the students discovered, like, for themselves that this Quantum Computing, really is a thing and I guess there is some age group that is actually exposed to those kind of newspaper articles or blog posts about Quantum Computing and then they really want to explore that and I think before that we have so much interesting things in computer science. We can discover, I mean, you mentioned AI and the stuff the Raspberry Pi Foundation is doing there. So, there is a lot of things that people are actually curious about, because they use those filters on their smartphone. They use their automatic detection of pic of hats in images of persons in images and stuff like that. So I think when it comes natural to them, we can definitely find something that they can, well, explore Quantum Computing with.

Diane Dowling: 37:37

Yeah, I wanted to ask another question, really. It's about the application of quantum Computing. So we've talked about, you know, the sort of hard problems that exist at the moment and some of the challenges over things like optimisation or route planning, those kind of things. What about the big challenges that face the planet today? Because obviously that's an area which it's really easy to engage young people and do you see any application for quantum computers or Quantum Computing in, you know, making the world a better place?

Andreas Woitzik: 38:10

Quantum Computing might help to save some resources. So when we think about climate change, then quite much of the energy at the moment for the high-performance Computing centers. The, this is used for these Quantum simulations, because designing chemicals and designing drugs is just such a bit big thing in our society. So, I think there, we could really have an environmental impact for sure. We don't have it at the moment because we are building all these fridges that are ver energy hungry, in order to do the research for that. But I think on the long run, this could really pay off. So then the quantum computer could gain us quite some of this energy back.

Stefan Seegerer: 38:52

I totally agree. But I also need to say that, of course, we need to be very sensitive with those claims because there might be very useful applications that help with climate change and stuff. But at the moment of course Quantum Computing is still in a stage of development where it's not used for those tasks. I mean, it might help us to understand how to design better batteries, how to design, or how to produce fertiliser with less energy. And also, a quantum computer might use less energy for some calculations than the supercomputers we currently use. This is all something we need to see in the future. I think no one knows where this will lead ultimately to. But I think we are all excited and happy to be able to watch in life, kind of.

Andreas Woitzik: 39:50

I find this question about the ethics of such technology, very interesting because when you think about kind of the last Quantum Revolution. So the quantum computer is often called kind of the second quantum Revolution and the first one comes from the device laser that we are all used to very much now. It would be hard for me to, to judge on how good or bad a laser is when it comes to to the history of our society. So I'm definitely we could have another full episode on this, I guess, but yeah, of course. So it's definitely exciting to see where the world goes and what we will be able to do with those quantum computers, or even, if we are not able to do anything with them, what we learned along the path.

James Robinson: 40:35

If you have a question or comment for us about our discussion today than you can email via podcast@helloworld.cc or you can tweet us at @HelloWorld_edu. My thanks to Andres and Stefan for sharing their time experience and expertise with us today and we'll be back in two weeks, exploring the role of philosophy in teaching Computing. So Di, what did we learn today?

Diane Dowling: 41:00

Well, I think my main takeaway is that I did manage to follow all of the conversations so well done to Stefan and Andreas for making it very, very accessible to a non physics person. And the main things I learned were that quantum computers do exist and that they are definitely not just super fast computers, and that I probably will still be able to use the same programming languages that I use at the moment. But some of the tasks that are done, will be delegated to quantum computers. So James, what about you? What did you learn?

James Robinson: 41:35

Well, I learned that I haven't forgotten all of my A-Level physics.