WEBVTT - What Is A Quantum Computer? 0:00:07.440 --> 0:00:10.119 So you know how sometimes in physics there's a word, 0:00:10.440 --> 0:00:13.039 and this word for people it's like magic. It means 0:00:13.080 --> 0:00:16.960 like a big leap forward. It's like a huge transformation, 0:00:17.120 --> 0:00:21.639 you mean, like dimensions, dimension is the worst, absolutely, and 0:00:21.680 --> 0:00:23.439 stuff like that. And the one I'm thinking of in 0:00:23.480 --> 0:00:27.200 particular is the word quantum. Quantum mechanics obviously a huge 0:00:27.240 --> 0:00:29.520 transformation the way we think about the world that it 0:00:29.560 --> 0:00:32.360 also seems to be a transformation and everything like you 0:00:32.400 --> 0:00:35.440 can find like quantum massage, and you know, there's that 0:00:35.520 --> 0:00:38.360 whole television show Quantum Leap, and like all this stuff 0:00:38.360 --> 0:00:40.879 has nothing to do with quantum mechanics at all. It's 0:00:40.920 --> 0:00:43.919 just the word quantum seems to represent some sort of 0:00:44.200 --> 0:00:49.479 high tech, next generation high tech fanciness. You know, sometimes 0:00:49.479 --> 0:00:53.280 it really does represent a transformative leap. Sometimes there really 0:00:53.400 --> 0:00:56.360 is an opportunity to convert a normal version of something 0:00:56.360 --> 0:00:59.560 into the quantum version and then take a huge step forward. 0:00:59.840 --> 0:01:02.600 And so that's what we wanted to talk about today. 0:01:02.800 --> 0:01:24.440 After my quantum massage hold on him and I'm Daniel 0:01:24.680 --> 0:01:27.520 and this is our podcast. Daniel and Jorge explained the 0:01:27.600 --> 0:01:30.280 universe in which we take the whole universe and chop 0:01:30.360 --> 0:01:32.520 it up in the little pieces, turn each of them 0:01:32.520 --> 0:01:35.959 into a quantum of understanding and download it into your 0:01:36.000 --> 0:01:38.960 brain and in which you feel like you understand and 0:01:39.040 --> 0:01:42.679 not understand at the same time. No, we're going for 0:01:42.800 --> 0:01:46.040 a hundred understanding. We don't want to be one of 0:01:46.080 --> 0:01:48.520 those podcasts where you feel like, oh, I heard a 0:01:48.600 --> 0:01:50.640 lot of smart people talking about it, but I didn't 0:01:50.680 --> 0:01:53.720 really get it right. Yeah. Yeah, because in this podcast 0:01:53.720 --> 0:01:58.400 you only listen to one intelligent person, Joe and I 0:01:58.520 --> 0:02:01.880 together making one intelligent person. We won't say which fraction 0:02:01.920 --> 0:02:04.360 of each, but together we are one smart guy. We 0:02:04.360 --> 0:02:08.600 are quantum entangled in our intelligence. That's right. That's right, 0:02:08.800 --> 0:02:11.239 And this is just the latest in our projects together. 0:02:11.280 --> 0:02:13.800 We also wrote a book called We Have No Idea, 0:02:14.160 --> 0:02:16.720 A Guide the Unknown Universe, where we explore all the 0:02:16.760 --> 0:02:19.799 big questions in the universe, what doesn't physics know yet 0:02:19.840 --> 0:02:22.160 and what could it mean for humanity? And if you 0:02:22.200 --> 0:02:24.440 search online on YouTube, you can also find a couple 0:02:24.520 --> 0:02:27.240 of the videos that we've made together about the Higgs boson, 0:02:27.440 --> 0:02:31.720 about dark matter, about gravitational waves. So check this out. Yeah, 0:02:32.040 --> 0:02:39.040 so today we wanted to talk about quantum computers because 0:02:39.040 --> 0:02:41.080 we feel like it's a word that's bandied around, and 0:02:41.120 --> 0:02:44.160 we wanted to make sure everybody understood what it actually means. 0:02:44.520 --> 0:02:47.480 Think about whether you know what a quantum computer is. So, 0:02:47.639 --> 0:02:50.400 as usual, I went out and I asked ten random 0:02:50.440 --> 0:02:52.720 people on the u c I campus if they knew 0:02:52.760 --> 0:02:55.080 what a quantum computer was and how it works. And remember, 0:02:55.400 --> 0:02:58.880 some of these people are computer science undergraduates, so they 0:02:58.919 --> 0:03:02.720 really should know. Here's what they had to say. Nope, nope, 0:03:03.160 --> 0:03:05.400 you never heard of a quantum computer? All right, cool, 0:03:05.960 --> 0:03:08.760 I have no idea. Have you heard of the quantum computer? 0:03:09.200 --> 0:03:11.119 This is the first time that I'm hearing it right now. 0:03:12.560 --> 0:03:15.560 I'm not sure about how does it work, but I 0:03:15.680 --> 0:03:21.440 know that it has four men bits or alphabet and 0:03:21.520 --> 0:03:25.760 it is said to revolutionalize the computer science. I don't 0:03:25.760 --> 0:03:28.520 know about a quantum computer, but you've heard of them. Um. 0:03:28.560 --> 0:03:31.160 I've heard the term, but I don't know much else 0:03:31.160 --> 0:03:33.440 about it other than that. Alright, So not a not 0:03:33.480 --> 0:03:37.640 an impressive performance here by uc I Underground. That's right. Well, hey, 0:03:37.680 --> 0:03:39.600 some of them understood it, right, at least most of 0:03:39.640 --> 0:03:42.000 them have heard of it. The one guy like heard 0:03:42.000 --> 0:03:44.960 about quantum computers. The moment I said the phrase, it 0:03:45.240 --> 0:03:48.760 exploded in his brain. Like, what, I've never heard of 0:03:48.760 --> 0:03:51.320 that until you mentioned it. I've never heard those two 0:03:51.360 --> 0:03:56.360 words together. You've probably spend the next six hours googling 0:03:56.360 --> 0:03:58.400 and reading about it. And maybe he's the next future 0:03:58.480 --> 0:04:01.240 quantum computing genius. We have changed the course of human 0:04:01.280 --> 0:04:03.960 history through this podcast or oh my god, it's possible. 0:04:04.440 --> 0:04:06.960 But most people seem to have very little understanding of 0:04:06.960 --> 0:04:10.000 what a quantum computer is. Um though, you know, somebody 0:04:10.000 --> 0:04:12.320 out there had had some idea at least, so we 0:04:12.400 --> 0:04:15.160 feel like this is a good topic for a podcast. 0:04:15.280 --> 0:04:18.320 Let's clear out the weeds of everybody's understanding and make 0:04:18.360 --> 0:04:20.720 sure everybody knows what we're talking about when we say 0:04:20.839 --> 0:04:23.239 quantum computer. I mean everyone has heard of a computer, 0:04:23.839 --> 0:04:27.440 but a quantum computer. That just sounds interesting, Right, What 0:04:27.480 --> 0:04:28.599 do you what do you what did you think of 0:04:28.640 --> 0:04:30.560 the first time you heard quantum computer? Do you think 0:04:30.560 --> 0:04:32.919 like a tiny computer the size of an atom? What 0:04:33.000 --> 0:04:35.320 did I think? I thought that it was? I think 0:04:35.360 --> 0:04:37.400 I just had that good reaction. Also, it's like a 0:04:37.839 --> 0:04:41.880 like a super new magic computer, right, Like I want 0:04:41.880 --> 0:04:46.760 a quantum Ferrari. We just said for my quantum mortgage 0:04:46.800 --> 0:04:50.719 to be paid first. I love how the word quantum 0:04:50.800 --> 0:04:54.040 is just like taken on this magical mystical power, you know, 0:04:54.240 --> 0:04:57.280 and it's not bad. There's like no nuance to quantum 0:04:57.279 --> 0:04:59.760 that's bad. It's not like dark or dangerous. It's just 0:04:59.800 --> 0:05:03.279 like the new, fancy, glittery, shiny version of something. The 0:05:03.320 --> 0:05:05.960 weird thing is is that it's not a new word, right, Like, 0:05:06.080 --> 0:05:10.160 it's a word that's been around for a hundred years nearly, right, Well, 0:05:10.200 --> 0:05:11.960 it's been around for a long time and it's been 0:05:12.000 --> 0:05:14.839 applied to this kind of thing for about a hundred years. Yeah, 0:05:14.920 --> 0:05:17.760 quantum mechanics is almost a hundred years old. To the idea, 0:05:18.360 --> 0:05:20.719 the very basic ideas of quantum mechanics, you know, that 0:05:20.760 --> 0:05:24.559 the universe is chopped into pieces and not continuous. That's 0:05:24.640 --> 0:05:30.600 not a very new idea, right, Well, let's break it down. 0:05:30.640 --> 0:05:33.360 What does it mean when you say the word quantum, 0:05:33.640 --> 0:05:36.960 like quantum physics or quantum particles? You know, what does 0:05:37.000 --> 0:05:40.039 it mean? Well, the word basically just means portion or 0:05:40.080 --> 0:05:44.400 packet or unit, you know, it's like a quantity, like, yeah, 0:05:44.600 --> 0:05:47.600 quant quantity, quantum is that where it comes from? Yeah, 0:05:47.839 --> 0:05:50.080 it's connected. Why I think Jorge just had a realization 0:05:50.120 --> 0:05:54.320 and live right there on the podcast. Um, Yes, it's 0:05:54.400 --> 0:05:57.240 related to quantities, right. It says things that are are 0:05:57.360 --> 0:06:01.560 quantized are things that are made out of little atomic pieces, 0:06:01.600 --> 0:06:05.000 things that can't be broken into smaller pieces. Right, So 0:06:05.080 --> 0:06:07.719 like our money is quantized. We don't have money less 0:06:07.720 --> 0:06:09.919 than a penny, right, you can't spend less than a penny. 0:06:09.960 --> 0:06:12.560 That's the basic unit. Everything is built out of that. 0:06:13.200 --> 0:06:15.760 And it's relevant to physics because it turns out the 0:06:15.880 --> 0:06:19.600 universe is quantized, like particles are made out of smaller particles. 0:06:19.600 --> 0:06:21.599 You can't have like half a particle or three quarter 0:06:21.680 --> 0:06:25.240 of a particle. And energy levels are quantized, you know, 0:06:25.320 --> 0:06:28.000 the way electrons move around in nucleus. They can't just 0:06:28.040 --> 0:06:30.240 have like any arbitrary amount of energy, just like a 0:06:30.720 --> 0:06:33.240 ladder of energy levels. They can be on and they 0:06:33.279 --> 0:06:35.800 can't be in between those steps. But it kind of 0:06:35.839 --> 0:06:39.520 means more than just the idea of chopping things up 0:06:39.520 --> 0:06:42.039 into a little bit. It's really more about what the 0:06:42.080 --> 0:06:45.119 world is like when you get down to those little 0:06:45.120 --> 0:06:48.800 little little bits. Quantum physics means the physics of those 0:06:48.839 --> 0:06:51.800 little little little particles, which is very different than the 0:06:51.800 --> 0:06:55.160 physics of like, you know, a basketball or a baseball 0:06:55.200 --> 0:06:57.880 that's right. Quantum. That's what quantum means. It's a little 0:06:57.880 --> 0:07:01.000 bit bits and quantum mechanics or quantum physics that deals 0:07:01.040 --> 0:07:03.640 with how those things interact with each other. And it 0:07:03.640 --> 0:07:06.279 turns out that those little tiny bits of the universe 0:07:06.320 --> 0:07:09.480 interact in ways that are very unfamiliar to us. There's 0:07:09.600 --> 0:07:13.280 very little intuitive understanding we can grasp the way those 0:07:13.280 --> 0:07:16.480 things work because they follow very different rules than the 0:07:16.520 --> 0:07:21.120 things than baseballs and basketballs follow. They follow more probabilistic rules, 0:07:21.600 --> 0:07:24.560 and and your intuition that you developed through observing the 0:07:24.600 --> 0:07:27.720 way baseballs and basketballs moved through the air doesn't work 0:07:27.760 --> 0:07:30.720 when you're talking about electrons or other little quantum particles 0:07:30.720 --> 0:07:34.000 because they follow different rules. Yeah, and those different rules 0:07:34.200 --> 0:07:36.560 lead to a very different kind of logic. You see, 0:07:36.560 --> 0:07:39.400 in normal logic, you can say something like a switch 0:07:39.480 --> 0:07:42.680 is either on or off, but not both, right, But 0:07:42.760 --> 0:07:46.400 in quantum logic it's different, which is why quantum computing 0:07:46.560 --> 0:07:49.640 turns out to also be different. Yeah, they don't behave 0:07:49.640 --> 0:07:52.520 like they do the big things behave, right, Like if 0:07:52.560 --> 0:07:55.440 you had a baseball the size of a quantum particle, 0:07:55.600 --> 0:07:58.200 you can just bounce it off of a wall, That's right. 0:07:58.400 --> 0:08:00.720 And the most important feature of these little quantum bits, 0:08:00.720 --> 0:08:02.920 and the one that's gonna be relevant for quantum mechanics, 0:08:03.480 --> 0:08:07.120 is that we don't know everything about them. Like a baseball, 0:08:07.440 --> 0:08:09.280 you know everything you need to know. You know it's 0:08:09.280 --> 0:08:11.480 direction and you know it's velocity. From that, you can 0:08:11.520 --> 0:08:13.800 predict its future. If you know where it is and 0:08:13.800 --> 0:08:16.240 where it's going, you know where it's going to be. Right. 0:08:16.680 --> 0:08:19.920 For a quantum particle, like an electron, you can't observe 0:08:19.920 --> 0:08:23.080 it directly, and so there's some uncertainty about where it is, 0:08:23.520 --> 0:08:25.760 which means that it can be like here or it 0:08:25.800 --> 0:08:28.360 can be there. But the crucial thing about a quantum 0:08:28.400 --> 0:08:31.840 particle is it's not actually in one place or the other, 0:08:31.960 --> 0:08:34.920 and you just don't know it. It has a probability 0:08:35.080 --> 0:08:37.680 to be in both places. Our lack of knowledge about 0:08:37.720 --> 0:08:41.840 it reflects the fact that it's location is not actually determined. 0:08:42.280 --> 0:08:44.719 It's like it could be over here and it could 0:08:44.760 --> 0:08:47.400 be over there, which means it's a little bit of both. 0:08:47.679 --> 0:08:49.040 And that's what I mean when I say the act 0:08:49.080 --> 0:08:51.400 in ways that are different from the ways that are 0:08:51.480 --> 0:08:53.840 normal things interact. You know, a baseball is either here 0:08:54.280 --> 0:08:56.280 or it's there, right, But when you get down to 0:08:56.320 --> 0:08:59.319 that size, it doesn't look like like an electron doesn't 0:08:59.320 --> 0:09:02.520 look like a little tiny baseball. Nobody knows what an 0:09:02.520 --> 0:09:05.440 electron looks like. Yeah, like when you try to zoom 0:09:05.440 --> 0:09:08.400 in and you zoom in, it just becomes fuzzy, right, 0:09:08.440 --> 0:09:11.440 like you see this little fuzziness right. Well, that's a 0:09:11.440 --> 0:09:13.679 whole other funny question, like what would an electron look like? 0:09:13.720 --> 0:09:17.520 Because an electron is has zero size, right, zero volume, 0:09:17.559 --> 0:09:20.960 and so it doesn't really look like anything. But about 0:09:20.960 --> 0:09:24.960 the electrons fuzziness, we say the electron has a probability 0:09:25.040 --> 0:09:27.920 to be in a few different places. That's the fuzziness. 0:09:27.920 --> 0:09:31.360 But it's not determined before you ask. But when you 0:09:31.400 --> 0:09:33.400 want to interact with the electron, like if you want 0:09:33.400 --> 0:09:37.240 to measure where it is, then those probabilities collapse into 0:09:37.240 --> 0:09:40.720 a specific outcome. We call that collapsing the wave function 0:09:40.800 --> 0:09:45.120 because remember electrons are particles, but they're controlled by wave equations, 0:09:45.160 --> 0:09:50.439 which determine the probability of being in various places, kind 0:09:50.440 --> 0:09:52.400 of like if you're not looking at it, it's sort 0:09:52.400 --> 0:09:54.360 of like a cloud almost, and then when you look 0:09:54.400 --> 0:09:56.720 at it, then boom, it's a little point. That's right, 0:09:56.920 --> 0:09:59.000 And this is the deep question of quantum mechanics that 0:09:59.200 --> 0:10:01.559 that a lot of people do and understand. Most people 0:10:01.679 --> 0:10:04.959 don't understand. I think maybe everybody doesn't understand. How does 0:10:05.000 --> 0:10:07.400 that make any sense? Right? How does it make sense 0:10:07.760 --> 0:10:10.160 that something can be in both places at once until 0:10:10.200 --> 0:10:12.280 you ask look at it? How does it make sense 0:10:12.320 --> 0:10:16.040 that you asking changes where it's going to be? Right? 0:10:16.240 --> 0:10:18.920 It's it's it's a situation, and that's all. There's a 0:10:19.000 --> 0:10:21.920 huge philosophical debate about that. You know, is it the 0:10:22.000 --> 0:10:24.120 asking that makes a decide where it's it going to be? 0:10:24.400 --> 0:10:27.280 Or does the universe split into two options where you know, 0:10:27.320 --> 0:10:28.719 on one hand it's on the left and then the 0:10:29.120 --> 0:10:32.120 other universe it's on the right. And different people argue 0:10:32.120 --> 0:10:35.200 about this stuff for for decades and decades. So it's 0:10:35.200 --> 0:10:37.240 certainly not something we can address in twenty minutes on 0:10:37.280 --> 0:10:39.280 a podcast. But the thing you need to know to 0:10:39.320 --> 0:10:42.560 understand quantum mechanics is that there's a probability for it 0:10:42.600 --> 0:10:44.680 to be in one place or the other, and that 0:10:44.760 --> 0:10:48.400 both probabilities exist simultaneously. So if I'm not if I'm 0:10:48.440 --> 0:10:50.120 not looking at the electron, it looks like a little 0:10:50.120 --> 0:10:52.880 fuzzy cloud and you're saying that cloud is it's it's 0:10:52.960 --> 0:10:54.920 kind of like it's in all those places at the 0:10:54.960 --> 0:10:58.040 same time with a certain probability. Yeah, I think the 0:10:58.080 --> 0:11:01.280 most correct statement would say it has a probability to 0:11:01.360 --> 0:11:03.520 be in all of those places. To say it actually 0:11:03.679 --> 0:11:06.080 is in all those places, I mean you don't. It's 0:11:06.080 --> 0:11:09.080 not actually anywhere. It just has a probability to be 0:11:09.120 --> 0:11:11.720 those things. It's like the answer is not determined or known. 0:11:11.800 --> 0:11:14.040 It's not like God has it written down on a 0:11:14.040 --> 0:11:17.679 golden tablet somewhere. We just don't know. It's not actually anywhere. 0:11:17.720 --> 0:11:19.680 It just has a probability to be this or that. 0:11:19.840 --> 0:11:22.280 It's like it's like a die you haven't ruled yet. 0:11:22.320 --> 0:11:23.880 It's not like it already is a four and you 0:11:23.960 --> 0:11:26.240 just haven't looked yet. You haven't rolled the die, so 0:11:26.280 --> 0:11:28.520 you don't There isn't an answer. The same way the 0:11:28.520 --> 0:11:32.400 electron has a probability distribution to be in various situations, 0:11:32.600 --> 0:11:35.040 but until you measure it, it's not in all of 0:11:35.080 --> 0:11:37.160 those at the same time. It just has a probability 0:11:37.200 --> 0:11:40.720 to be in those things. Man, So you're saying all 0:11:40.760 --> 0:11:43.880 of us, all of our particles are if you get 0:11:43.880 --> 0:11:49.199 down to that level, they're all unthrown die, yes, exactly, 0:11:49.800 --> 0:11:52.520 until you interact with them and forces the universe to 0:11:52.559 --> 0:11:54.240 throw the die. And that's one of the deep questions 0:11:54.280 --> 0:11:57.199 about about econom mechanics, is like where's that die? Who's 0:11:57.240 --> 0:12:00.800 doing those random number process you know? So when Einstein 0:12:00.840 --> 0:12:04.319 famously said God doesn't play dice, it's kind of true. 0:12:04.400 --> 0:12:07.920 It's like, really, things are all just unthrown dice. Yeah, 0:12:08.080 --> 0:12:10.240 he didn't like that description of it at all. He 0:12:10.280 --> 0:12:13.560 really believed that the dice was already thrown. We just 0:12:13.559 --> 0:12:17.280 didn't know the answer, right, That's a big difference. That's 0:12:17.280 --> 0:12:20.319 a big difference. And then eventually they proved that actually 0:12:20.440 --> 0:12:23.160 the dice is not yet thrown until you ask the question. 0:12:24.080 --> 0:12:26.040 And that's a whole other podcast. We can talk about 0:12:26.240 --> 0:12:29.400 how they proved that. It's called the bell inequality, and 0:12:29.440 --> 0:12:31.680 it's a whole other topic we can get into. But 0:12:31.760 --> 0:12:34.000 I think for today's episode, people just need to understand 0:12:34.040 --> 0:12:37.320 that a quantum particle can be different from a classical particle, 0:12:37.320 --> 0:12:39.679 from like a thing you're you're understand because it can 0:12:39.720 --> 0:12:42.160 be kind of a probability to be in two different 0:12:42.440 --> 0:12:46.240 situations at the same time. Okay, So that's that's what 0:12:46.400 --> 0:12:49.880 quantum means. And now let's get into quantum computers. But 0:12:50.000 --> 0:13:04.960 first let's take a break, all right. So that's what 0:13:05.040 --> 0:13:07.600 quantum means. It's like the how the world behaves when 0:13:07.640 --> 0:13:09.800 you get down to those little tiny pits of the universe, 0:13:10.040 --> 0:13:14.200 which is totally different and kind of fuzzy and probabilistic. Um. 0:13:14.240 --> 0:13:16.360 So now let's combined it with the word everyone knows, 0:13:16.360 --> 0:13:18.480 which is a computer. So what does it mean to 0:13:18.559 --> 0:13:22.760 like have a quantum computer. Yeah, so the idea there is, 0:13:23.240 --> 0:13:25.800 let's build a computer. Let's build out of pieces that 0:13:25.880 --> 0:13:28.920 can do these weird things, because then maybe you can 0:13:28.960 --> 0:13:32.000 solve problems that are otherwise hard. I mean, I think 0:13:32.320 --> 0:13:34.880 it's also important to think about how a normal computer works, 0:13:34.920 --> 0:13:36.840 and like what does it mean to say a computer 0:13:37.040 --> 0:13:39.920 before we think about what is a quantum computer um? 0:13:39.960 --> 0:13:42.040 And for those of you out there listening, you probably 0:13:42.040 --> 0:13:43.680 know what a computer is. You have one in your 0:13:43.880 --> 0:13:45.720 in your office or whatever. You're banging on it right 0:13:45.760 --> 0:13:49.200 you download stuff and play Mario card or whatever. But 0:13:49.320 --> 0:13:51.840 what it's doing on the inside is really is that 0:13:51.880 --> 0:13:55.400 it's doing calculations. Right, a program on your computer or 0:13:55.440 --> 0:13:58.040 something that does a calculation, Maybe that calculation is how 0:13:58.040 --> 0:14:00.600 do I draw Mario card on the screen? Or you know, 0:14:00.679 --> 0:14:03.880 how do I predict this the trajectory of this cannonball 0:14:03.920 --> 0:14:05.920 that I want to fire at my opponent's castle or whatever. 0:14:06.240 --> 0:14:08.520 In the end, it's doing a calculation. And the way 0:14:08.520 --> 0:14:11.240 it does that calculation is that it represents the problem 0:14:11.280 --> 0:14:13.560 that needs to be solved in terms of a bunch 0:14:13.600 --> 0:14:16.000 of numbers, because all the computer really, in the end 0:14:16.080 --> 0:14:19.200 is doing is manipulating numbers. I mean the memory and 0:14:19.240 --> 0:14:22.040 your computer is a bunch of ones and zeros. That's 0:14:22.080 --> 0:14:25.200 what we call bits, and those represent a number. And 0:14:25.360 --> 0:14:27.600 a computer is useful when you can take a problem 0:14:27.640 --> 0:14:30.440 you want to solve and represent it in a way 0:14:30.480 --> 0:14:33.320 that the computer knows how to solve it right. Right, So, 0:14:33.360 --> 0:14:35.680 for example, how do I hit my baseball in a 0:14:35.680 --> 0:14:37.640 way that goes over the fence? What angle is the 0:14:37.640 --> 0:14:39.440 best angle to do that? Right? Do? You want to 0:14:39.480 --> 0:14:41.360 solve that problem? But you first have to break it 0:14:41.400 --> 0:14:45.720 down into math and then have your computer basically act 0:14:45.760 --> 0:14:49.080 as a calculator and crunch those math equations. And the 0:14:49.200 --> 0:14:52.040 kind of math you use to break it down depends 0:14:52.040 --> 0:14:53.720 on the kind of computer you have and the kind 0:14:53.760 --> 0:14:57.160 of calculations that computer can do. So the kind of 0:14:57.160 --> 0:15:00.560 computers we use, classical computers have ones in zeros, and 0:15:00.640 --> 0:15:03.680 all they can do are a few basic logical operations 0:15:03.680 --> 0:15:06.400 on those ones and zeros they can do and they 0:15:06.440 --> 0:15:08.960 can do or they can do x or or nand 0:15:09.120 --> 0:15:11.160 and you can build those up to do all sorts 0:15:11.200 --> 0:15:15.080 of more complicated things like addition or subtraction or Mario 0:15:15.160 --> 0:15:17.280 Kard and other video games. Right, And the way it 0:15:17.320 --> 0:15:20.280 does that you're saying, is that it takes the problem, 0:15:20.320 --> 0:15:24.080 you know, whereas Mario and Mario card or how much 0:15:24.120 --> 0:15:27.960 is tu plus two and then breaks it down into bits, 0:15:28.040 --> 0:15:30.760 which is are which are ones and zeros. So everything that, 0:15:31.320 --> 0:15:33.560 like most of our language, all the math that we 0:15:33.600 --> 0:15:37.800 know about, all that can be essentially eventually breaking down 0:15:37.920 --> 0:15:41.680 into ones and zeros. That's right, and we'll see later. 0:15:41.800 --> 0:15:45.000 The quantum computers don't use ones and zeros, and they 0:15:45.040 --> 0:15:47.480 have a different kind of logic, so they can solve 0:15:47.600 --> 0:15:50.600 different kinds of problems. And in the end, it's all 0:15:50.600 --> 0:15:53.960 about efficiency. Which kind of computer is faster at which 0:15:54.040 --> 0:15:57.200 kind of problem running Mario cards or breaking into the 0:15:57.320 --> 0:15:59.400 n s A does it take one second or does 0:15:59.400 --> 0:16:01.480 it take a build in years? Well, let's talk a 0:16:01.480 --> 0:16:03.160 bit about why you want to break it down into 0:16:03.200 --> 0:16:05.400 ones and zeros, right, Like, why is why is that important? 0:16:05.400 --> 0:16:07.520 Because once you break it down to ones and zeros, 0:16:07.640 --> 0:16:11.680 then even like a simple computer can then add and 0:16:11.800 --> 0:16:14.480 subtract those, Right Like, if you can break the whole 0:16:14.520 --> 0:16:18.200 world into ones and zeros and everything into simple operations 0:16:18.200 --> 0:16:21.040 like plus or minus, then you can have a machine 0:16:21.120 --> 0:16:24.400 basically do it. Yeah, you can do simple logic operations 0:16:24.400 --> 0:16:27.080 on ones and zeros, and there's a theorem that shows 0:16:27.720 --> 0:16:30.440 that you can combine those to do any logical operation. 0:16:31.240 --> 0:16:33.600 So if you combine enough of those together, you can 0:16:33.640 --> 0:16:37.680 have any operation on your inputs. That doesn't mean necessarily 0:16:37.720 --> 0:16:40.960 the best way to do any problem. Like you might say, hey, 0:16:41.000 --> 0:16:43.040 I want to know where this baseball is going to go. 0:16:43.200 --> 0:16:45.560 So one way to do that is build a computer, 0:16:46.120 --> 0:16:48.400 have inside the computer a perfect model of how the 0:16:48.440 --> 0:16:51.440 baseball works, and do the calculation. Another way to do 0:16:51.520 --> 0:16:54.960 that is just hit the baseball. Right from that perspective, 0:16:55.040 --> 0:16:58.680 like a baseball is a computer that calculates one thing, 0:16:58.920 --> 0:17:02.680 how far does this base ball go? Right. It's very powerful, 0:17:02.760 --> 0:17:05.160 it's very fast, but it only does that one thing. 0:17:05.560 --> 0:17:08.160 The advantage of a classical computer with ones and zeros 0:17:08.640 --> 0:17:11.080 is that it can solve lots of different kinds of problems. 0:17:11.080 --> 0:17:12.879 They can do your baseball problem, and they can do 0:17:12.960 --> 0:17:17.159 Mario Kart right, Okay, So that's the basis of regular computers, 0:17:17.200 --> 0:17:20.159 Like even the computer and the phone that people are 0:17:20.160 --> 0:17:23.879 listening to this podcast on. It's taking our voices, breaking 0:17:23.920 --> 0:17:26.800 them down to one and zeros, chopping those up, mixing 0:17:26.800 --> 0:17:31.760 them up, and then basically recreating our voices and flappy bird. Right, 0:17:32.160 --> 0:17:35.520 that's right exactly. And so what is a quantum computer. Well, 0:17:35.520 --> 0:17:38.600 a quantum computer is a computer built out of different 0:17:38.640 --> 0:17:41.600 little pieces. Right. Whereas the normal computer uses ones and zeros, 0:17:41.600 --> 0:17:45.720 a quantum computer uses quantum mechanical objects that have different properties. 0:17:46.000 --> 0:17:48.960 They can be zero, they can be one, or they 0:17:48.960 --> 0:17:51.840 can be some combination of zero and one. The way 0:17:51.840 --> 0:17:55.640 a quantum particle is like, maybe it's here, maybe it's there. 0:17:55.920 --> 0:17:59.000 A quantum bit, what we call a cube bit, is 0:17:59.119 --> 0:18:02.359 maybe zero, maybe one, has a probability be zero and 0:18:02.359 --> 0:18:05.280 a probability to be one. And again it's not secretly 0:18:05.359 --> 0:18:08.520 zero and secretly one. Like a dice you've already rolled 0:18:08.600 --> 0:18:11.120 and you just haven't looked at. It's not determined. It's 0:18:11.280 --> 0:18:15.040 some combination of zero and some combination of Wow. I see, 0:18:15.040 --> 0:18:18.160 what if he had a computer that was fundamental little 0:18:18.200 --> 0:18:21.320 processing unit is not just black and white, but maybe 0:18:21.600 --> 0:18:24.760 like some something in between the shades of gray, shades 0:18:24.760 --> 0:18:26.639 of great, Like what would happen if you add and 0:18:26.680 --> 0:18:29.760 mix those up and try to make calculations with things 0:18:29.800 --> 0:18:32.919 that can be not just ones and zeros. Yeah, And 0:18:32.920 --> 0:18:34.480 so what happens is you get a very different kind 0:18:34.480 --> 0:18:38.840 of computer, one that's much better at things that classical 0:18:38.880 --> 0:18:42.560 computers find difficult, but also is worse at some things 0:18:42.560 --> 0:18:46.840 that classical computers find very easy. Like what, Yeah, just 0:18:46.880 --> 0:18:49.199 the way, like a baseball is a good computer for 0:18:49.240 --> 0:18:51.760 calculating what a baseball does, it's not very good at 0:18:51.920 --> 0:18:55.600 organizing your recipes or doing Mario Kart, right. A quantum 0:18:55.600 --> 0:18:58.480 computer is built differently, it's but it still runs in 0:18:58.520 --> 0:19:00.880 the physical universe, you know all the things. These computers 0:19:00.880 --> 0:19:05.119 are just ways to manipulate physical objects to represent calculations 0:19:05.119 --> 0:19:07.480 that we want done. That's what a computer is, right, 0:19:08.080 --> 0:19:10.359 And sometimes the classical computer is really good at that. 0:19:10.520 --> 0:19:13.600 A quantum computer, because it's made out of different things, 0:19:13.840 --> 0:19:16.159 is good at at different kind of calculations. It's like 0:19:16.359 --> 0:19:18.200 do you want to build your house out of wood 0:19:18.560 --> 0:19:20.480 or out of brick? Well, you know wood is good 0:19:20.520 --> 0:19:22.399 for some things and brick is good for other things. 0:19:22.560 --> 0:19:25.240 You get a pretty different kind of house. Um, so 0:19:25.280 --> 0:19:27.880 they're pretty different, but you know they're related, but they 0:19:27.880 --> 0:19:30.640 have different strengths, and those strengths and weaknesses come from 0:19:30.640 --> 0:19:34.399 the essential differences in how those bits work. Okay, so 0:19:34.480 --> 0:19:37.119 let's get into some of these differences from where they 0:19:37.119 --> 0:19:39.480 come from. So, like, what's happening now instead of when 0:19:39.480 --> 0:19:42.199 I'm mixing these cube bits that's what they're called, right, 0:19:42.240 --> 0:19:45.359 the quantum bits, they're called cube bids. Yeah, Um, so 0:19:45.359 --> 0:19:47.440 what's happened? What's happening when I mix them? Like if 0:19:47.440 --> 0:19:50.760 I do a calculation with these fuzzy bits. Right, So 0:19:50.800 --> 0:19:52.639 there's really two things you have to understand about how 0:19:52.720 --> 0:19:56.840 quantum calculations work. First of all, is that you when 0:19:56.840 --> 0:20:00.560 you have two cube bits, they're not independent. It't Okay, 0:20:00.600 --> 0:20:02.800 you have two bits and a computer, then they can 0:20:02.840 --> 0:20:06.920 have four different states zero zero, zero, one, one zero 0:20:07.119 --> 0:20:10.040 or one one. Right, So two bits means two to 0:20:10.080 --> 0:20:12.080 the end different states. But you really just need two 0:20:12.320 --> 0:20:15.399 numbers to specify that, right, you need the first number 0:20:15.400 --> 0:20:18.400 in the second number totally specifies the configuration. So it's 0:20:18.400 --> 0:20:21.359 really just two bits means two pieces of information for 0:20:21.400 --> 0:20:24.920 a classical computer. That's because those two bits are totally independent. 0:20:25.040 --> 0:20:29.639 For a quantum computer, the cubits are not independent. They're entangled, okay, 0:20:29.640 --> 0:20:32.880 so they're connected to each other. And so you can 0:20:32.920 --> 0:20:35.960 have different states. You can have zero zero, you can 0:20:36.000 --> 0:20:38.560 have one one. You can have some mixture of one 0:20:38.640 --> 0:20:41.360 zero and zero one. You can have other mixtures of zero, zero, 0:20:41.480 --> 0:20:46.320 zero one. There's four combinations there, and what you get 0:20:46.320 --> 0:20:49.840 are you need four piece of information to specify which 0:20:49.880 --> 0:20:53.480