WEBVTT - What can quantum computers do? 0:00:00.280 --> 0:00:02.960 Brought to you by the reinvented two thousand twelve Camray. 0:00:03.160 --> 0:00:08.880 It's ready. Are you get in touch with technology with 0:00:09.000 --> 0:00:17.560 tech Stuff from how stuff works dot com. Hello everyone, 0:00:17.600 --> 0:00:20.079 welcome to tech Stuff. My name is Chris Poulette and 0:00:20.079 --> 0:00:22.480 I am an editor at how stuff works dot com. 0:00:22.480 --> 0:00:25.759 Sitting across from me, or maybe he's not, or maybe 0:00:25.800 --> 0:00:28.840 all of the above, the senior writer, Jonathan Strickland, Darling, 0:00:29.120 --> 0:00:32.080 you've got to let me know should I stay or 0:00:32.120 --> 0:00:37.160 should I go? Excellent? Thank you. So today we wanted 0:00:37.200 --> 0:00:43.080 to tackle an incredibly complex subject, which is a quantum computers. 0:00:43.120 --> 0:00:46.080 We've talked a little bit about quantum computers in previous podcasts, 0:00:46.080 --> 0:00:48.720 but we haven't really dedicated a full episode to it, 0:00:49.200 --> 0:00:52.560 and part of that is because it scares us. Yeah, 0:00:52.640 --> 0:00:55.200 and you'll probably see why as soon as we get 0:00:55.360 --> 0:01:01.760 further into the discussion today. Yeah. The the the potential 0:01:01.960 --> 0:01:06.520 for quantum computers is phenomenal. Yes, it potentially could be 0:01:06.680 --> 0:01:12.560 a true breakthrough in computing for certain applications. But the 0:01:13.360 --> 0:01:16.080 actually describing what a quantum computer does and how it 0:01:16.160 --> 0:01:21.440 works is a pretty herculean task for for the layman. 0:01:21.600 --> 0:01:24.520 And this is where Chris and I both say, neither 0:01:24.560 --> 0:01:29.200 of us are quantum physicists. We are not experts in 0:01:29.360 --> 0:01:33.160 quantum mechanics by any stretch of the imagination. Although I 0:01:33.200 --> 0:01:36.960 do know that they used to work on VW midsize 0:01:36.959 --> 0:01:39.560 sedans in the eighties. It wasn't mid sized sedans, it 0:01:39.640 --> 0:01:43.160 was quantum size sedans. Yeah, because it doesn't work on 0:01:43.200 --> 0:01:47.080 the classical system. Um, we're gonna get into that. Actually. See, 0:01:47.400 --> 0:01:49.840 to really understand how a quantum computer works, you have 0:01:49.880 --> 0:01:53.000 to know a little bit about quantum mechanics. And this 0:01:53.080 --> 0:01:55.920 is a crazy kind of world for those of us 0:01:55.920 --> 0:01:59.880 who are accustomed to things working on the classical level. 0:02:00.720 --> 0:02:03.920 So for to kind of ease into this. For me, 0:02:04.160 --> 0:02:08.320 physics was an easy class in general. I was able 0:02:08.360 --> 0:02:12.320 to grasp the concepts of physics pretty quickly. And the 0:02:12.360 --> 0:02:18.000 reason I uh I give to that is because I 0:02:18.040 --> 0:02:21.200 am a fairly observant person, and physics really was just 0:02:21.240 --> 0:02:25.079 a way of explaining why the things I see work 0:02:25.160 --> 0:02:29.480 the way they work. Yeah, I I didn't split off 0:02:29.480 --> 0:02:34.280 on that vector very easily myself. Um, you know, I 0:02:34.320 --> 0:02:36.440 think I think my interests in high school when I 0:02:36.480 --> 0:02:39.480 took physics were not where they where they would have 0:02:39.520 --> 0:02:42.399 been now, maybe I should go back through it. Well, 0:02:42.400 --> 0:02:45.799 physics though, ultimately, I mean once you get past the 0:02:45.960 --> 0:02:50.079 equations and the formulas, once you get past that, that barrier, 0:02:50.400 --> 0:02:53.040 that mathematical barrier that exists for some of us. I mean, 0:02:53.080 --> 0:02:54.880 I know there are math whizz is out there that 0:02:54.960 --> 0:02:58.320 they they see mathematics as a beautiful expression of the universe, 0:02:58.320 --> 0:03:00.720 which is phenomenal to me. It's just that doesn't come 0:03:00.800 --> 0:03:04.440 naturally to me. However, the concepts behind it made perfect 0:03:04.440 --> 0:03:07.919 sense to me because it described the world I live in. Right, 0:03:08.360 --> 0:03:10.840 So so I'm like, well, of course, you know, the 0:03:10.919 --> 0:03:14.840 deceleration from gravity makes sense because of this. I mean 0:03:14.919 --> 0:03:18.520 I I can observe that and and draw conclusions from 0:03:18.560 --> 0:03:21.079 and in fact, that's where physics comes from. It are 0:03:21.120 --> 0:03:26.400 these observations of the universe, trying to make uh, explanations 0:03:26.440 --> 0:03:30.000 for those observations, and predictions based on those observations, and 0:03:30.000 --> 0:03:33.040 testing that out over time to make sure that they 0:03:33.120 --> 0:03:36.520 are relevant and and accurate. Right, I mean, that's that 0:03:36.640 --> 0:03:39.160 was the basis of that science. Well, right, I mean 0:03:39.200 --> 0:03:42.240 it's easy for you to you know, shove a book 0:03:42.320 --> 0:03:44.600 off the table and watch it hit the floor and 0:03:44.640 --> 0:03:47.080 be able to explain that because that's something that you 0:03:47.120 --> 0:03:49.920 can see, but quantum mechanics is not something that you 0:03:49.960 --> 0:03:53.520 can see exactly. Quantum mechanics deals with elements that are 0:03:53.680 --> 0:03:59.240 on the atomic or subatomic scale, So we're talking about 0:03:59.560 --> 0:04:02.840 things that are so tiny that it is very difficult 0:04:02.880 --> 0:04:07.040 to observe them in any classical sense. You can, you 0:04:07.080 --> 0:04:12.120 can observe some quantum effects using a classical system, but 0:04:12.360 --> 0:04:15.440 there are complications that will get into in a second. 0:04:15.440 --> 0:04:18.680 But on the quantum level, things behave in a really weird, 0:04:18.839 --> 0:04:22.840 funky way. And we don't fully understand all of the 0:04:23.720 --> 0:04:27.440 the aspects of quantum mechanics. And when I say we, 0:04:27.680 --> 0:04:31.280 I'm talking about super yeah, super smart people who make 0:04:31.360 --> 0:04:35.960 it their livelihood to study and try to understand quantum mechanics. 0:04:36.240 --> 0:04:39.279 We know bits and pieces. We don't know if there 0:04:39.440 --> 0:04:44.159 is an overall system that everything fits neatly into place. 0:04:45.240 --> 0:04:48.760 We we hope there is, so that we can explain everything, 0:04:49.240 --> 0:04:52.120 but we can't know that yet. We just don't have. 0:04:52.200 --> 0:04:54.680 You know, it's kind of like you've been given, uh, 0:04:54.920 --> 0:04:57.920 five or six little tiny, tiny pieces of a puzzle 0:04:58.320 --> 0:05:02.040 and you can't really be sure that they're all belonging 0:05:02.080 --> 0:05:05.120 to the same picture. And you're trying to put the 0:05:05.120 --> 0:05:08.880 picture together just based on those little tiny pieces, right right, Well, 0:05:09.240 --> 0:05:12.680 and the analogy holds for classical computers. It's hard to 0:05:12.680 --> 0:05:15.400 think of computers as being classical, but in this sense 0:05:15.760 --> 0:05:21.039 classical computers versus quantum computers because um, when you talk 0:05:21.120 --> 0:05:24.960 about the computers that we use every day, laptops, desktops, 0:05:25.520 --> 0:05:29.320 other kinds of computers, we're talking about things that are 0:05:29.400 --> 0:05:32.640 fairly standard. Now. I mean, we use materials like, uh, 0:05:32.800 --> 0:05:37.240 silicon and mercury and lead and glass and all sorts 0:05:37.240 --> 0:05:40.479 of other things that we are pretty familiar with. We 0:05:40.520 --> 0:05:43.719 know how the properties work. Now we have the semiconductors 0:05:43.760 --> 0:05:48.800 and transistors. You know, these things are are pretty common. 0:05:49.040 --> 0:05:52.920 I mean can basically you know, computer science as far 0:05:52.920 --> 0:05:55.800 as the hardware and software goes. And this also does 0:05:55.839 --> 0:05:58.000 apply to programming. We'll get into that in a few minutes. 0:05:58.360 --> 0:06:01.200 But um, you know, the the things are fairly standard 0:06:01.200 --> 0:06:03.680 to the point where you know, the layman is pretty 0:06:03.680 --> 0:06:07.359 familiar with the guts of a computer. But quantum computers 0:06:07.480 --> 0:06:12.320 use materials that we don't use in classical computers at all. 0:06:12.720 --> 0:06:16.160 And not only that, but in a system that is 0:06:16.400 --> 0:06:18.840 really complex to the sense in the sense that you 0:06:18.839 --> 0:06:22.760 have to you have to isolate the computing elements from 0:06:22.800 --> 0:06:28.040 the overall system, because if you don't, the computer breaks down. Um. 0:06:28.080 --> 0:06:30.359 But to understand that, we need to talk about some 0:06:30.440 --> 0:06:35.840 of the the features of the quantum mechanics world. One 0:06:35.880 --> 0:06:41.160 of those is the wave particle duality concept, which is 0:06:41.200 --> 0:06:46.799 that certain elements, certain things behave as both a wave 0:06:46.880 --> 0:06:51.720 and a particle. And the classic experiment to demonstrate this 0:06:51.800 --> 0:06:54.960 is called the double slit experiment. Now, this is an 0:06:54.960 --> 0:06:59.839 experiment where you have a thin sheet of material and 0:07:00.120 --> 0:07:02.560 in that thin sheet of material you cut two vertical 0:07:02.600 --> 0:07:05.679 slits that are close together, all right, and then behind 0:07:05.760 --> 0:07:09.200 the thin sheet of material you've got a a wall, 0:07:09.279 --> 0:07:13.840 essentially a target. You start to fire particles at this 0:07:14.160 --> 0:07:17.000 sheet of material it has these two slits, and detect 0:07:17.040 --> 0:07:20.400 where they hit on the on the target. Now, if 0:07:20.400 --> 0:07:24.480 you were to shine light at this at this double 0:07:24.520 --> 0:07:28.760 slitted material, you would observe on the other side, uh, 0:07:28.800 --> 0:07:31.560 some some little bands of light where the lights passing 0:07:31.560 --> 0:07:34.679 through the slits, and the bands would have little dark 0:07:34.920 --> 0:07:39.480 sections between them or within them even which would show 0:07:39.520 --> 0:07:43.240 where the waves of light are interfering with one another. 0:07:44.040 --> 0:07:48.320 All right, So so you see the interference pattern from light, 0:07:48.400 --> 0:07:51.720 And that's because light behaves, at least in part like 0:07:51.760 --> 0:07:53.840 a wave. It can also behave as a particle, but 0:07:53.840 --> 0:07:58.200 we'll get into that. So that's the wave behavior of 0:07:58.200 --> 0:08:02.320 of light. You see that those inference patterns um. Now 0:08:02.800 --> 0:08:06.600 let's say instead of light, you're firing electrons at these 0:08:06.640 --> 0:08:11.000 double slits. Now, presumably you've got something on that wall 0:08:11.040 --> 0:08:14.440 that's going to detect where the electron hits. After as 0:08:14.560 --> 0:08:18.800 an individual shot of an electron going through those double slits, 0:08:19.080 --> 0:08:21.560 you'll just see that it appears on one specific spot, 0:08:22.200 --> 0:08:24.400 all right, So you're like, oh, well, here's where the 0:08:24.400 --> 0:08:30.560 electron landed. Uh. After you've done repeated shots of electrons 0:08:30.680 --> 0:08:33.640 through those double slits over and over and over again. 0:08:34.120 --> 0:08:37.120 The interesting thing is when you look at the accumulation 0:08:37.440 --> 0:08:41.000 of those spots, they're going to fall within that same 0:08:41.040 --> 0:08:45.960 sort of uh pattern as the light did when the 0:08:46.000 --> 0:08:50.080 wave forms were interfering with one another. So you're gonna 0:08:50.080 --> 0:08:55.600 see those dark bands appear, showing that somehow the electron 0:08:55.720 --> 0:08:58.120 is behaving both as a particle in a wave, meaning 0:08:58.920 --> 0:09:02.600 that every time you fire an electron at that double 0:09:02.640 --> 0:09:07.079 slit of material, the electron is somehow passing through each 0:09:07.320 --> 0:09:12.280 of those slits, because it's only if there's an interference 0:09:12.320 --> 0:09:15.400 that those bands are going to appear. Otherwise you wouldn't 0:09:15.400 --> 0:09:18.720 expect to see the bands, like the dark bands within 0:09:18.840 --> 0:09:23.640 the collision area. You wouldn't expect to see those appear 0:09:23.640 --> 0:09:26.600 at all. Otherwise it would just be a continuous line 0:09:26.800 --> 0:09:30.240 within wherever the double slits would allow the electron to hit. 0:09:31.520 --> 0:09:35.240 That means that somehow the electron is in two places 0:09:35.280 --> 0:09:40.400 at one time, and it's only you know, it's doing 0:09:40.440 --> 0:09:42.880 that while it's moving through, but by the time it hits, 0:09:42.880 --> 0:09:45.760 when you look at it, it's clear that it's it 0:09:45.840 --> 0:09:47.720 had to be in one space because there's only one 0:09:47.760 --> 0:09:52.679 impact point per electron. Now, this is insane to someone 0:09:52.679 --> 0:09:55.000 who's looking at this on the classical level. How how 0:09:55.040 --> 0:09:57.760 can something be in two places at the same time 0:09:58.000 --> 0:10:00.360 and yet ultimately be in one place at the end 0:10:00.360 --> 0:10:02.960 of it. That would be a good time to pause 0:10:03.000 --> 0:10:07.040 the podcast and take some headache reliever medicine. Yeah, because 0:10:07.040 --> 0:10:09.760 it's gonna get weirder from here on out, all right. So, 0:10:09.800 --> 0:10:12.600 there were people who had been there's some people who 0:10:12.640 --> 0:10:15.760 had some problems with this idea of of the wave 0:10:15.840 --> 0:10:20.040 particle duality. Of this this idea of not just that 0:10:20.120 --> 0:10:23.640 something can behave as both wave and a particle, but 0:10:23.760 --> 0:10:26.800 that it could somehow be in two places at one time. 0:10:27.360 --> 0:10:30.679 Einstein had some issues with this um and created some 0:10:30.679 --> 0:10:34.640 thought experiments. But there's an UH and and and then 0:10:34.640 --> 0:10:38.959 there were There's a related concept, at least related within 0:10:39.040 --> 0:10:44.040 quantum mechanics called entanglement, which is this is also pretty complex, 0:10:44.080 --> 0:10:46.880 but the ideas essentially is that let's say you've got 0:10:46.880 --> 0:10:50.000 a particle and it has a certain number of states 0:10:50.240 --> 0:10:52.920 it can exist in. In other words, there's some sort 0:10:53.040 --> 0:10:57.560 of feature or behavior this particle can have or not have, 0:10:58.520 --> 0:11:02.560 and that that one way of describing this particle. Now 0:11:03.600 --> 0:11:06.640 we'll go with electrons and say that this electron could 0:11:06.679 --> 0:11:10.000 have one of two different spins, so it could be 0:11:10.040 --> 0:11:14.840 spinning up or it could be spinning down. Now UH. 0:11:14.920 --> 0:11:21.000 Within quantum mechanics, another, yet another UH concept is called superposition. 0:11:21.840 --> 0:11:28.520 Superposition describes a system's ability to to occupy multiple states 0:11:28.600 --> 0:11:31.520 at one time, like there's no way to determine until 0:11:31.600 --> 0:11:34.120 you measure it which state it's in, So therefore it's 0:11:34.160 --> 0:11:36.600 in all of those states at the same time. And 0:11:36.600 --> 0:11:41.240 the best part is if you observe this, you will 0:11:41.280 --> 0:11:46.359 affect what's actually happening. Yes, it it goes through decoherence. 0:11:46.400 --> 0:11:50.160 It decoheres, which means that the quantum state collapses and 0:11:50.240 --> 0:11:54.200 it becomes a classic system, not a quantum system, at 0:11:54.280 --> 0:11:57.720 least to the observer, which means that, so you have 0:11:57.800 --> 0:12:00.800 this electron that could be either spinning up or spinning down. 0:12:00.880 --> 0:12:03.880 From a quantum level, we would say it's doing both 0:12:03.920 --> 0:12:06.640 at the same time, which is because it's a Superposition's 0:12:06.640 --> 0:12:09.920 a superposition right Mathematically, if we were to describe the system, 0:12:09.920 --> 0:12:13.360 we would have to say it's doing both because we 0:12:13.440 --> 0:12:17.400 cannot determine at this time which one it is um 0:12:17.440 --> 0:12:24.040 and it behaves as if it's doing both in multiple experiments. 0:12:24.120 --> 0:12:29.520 So entanglement means that you could have another particle interact 0:12:29.520 --> 0:12:32.600 with that first one, and then its behavior is dependent 0:12:32.720 --> 0:12:36.360 there or their behaviors are dependent upon each other. So 0:12:36.400 --> 0:12:39.079 in the classic sense of the electron spinning up, you 0:12:39.160 --> 0:12:42.400 might have a second electron that you introduce into this system, 0:12:42.600 --> 0:12:44.600 and it's always going to spin down if the other 0:12:44.600 --> 0:12:48.920 one spinning up, and vice versa. Now again, if you 0:12:49.000 --> 0:12:52.400 haven't measured it yet, you cannot be certain which what 0:12:52.520 --> 0:12:55.840 electrons are doing what So both electrons are acting in superposition. 0:12:55.880 --> 0:12:58.960 They're both spinning up and down. There, that's what they're doing. 0:12:59.040 --> 0:13:01.640 They're spinning up and down. And it's only when you 0:13:01.679 --> 0:13:05.760 measure one that you determine that that the system collapses 0:13:05.840 --> 0:13:09.080 and you see, all right, it's spinning up. Well, by 0:13:09.080 --> 0:13:11.760 knowing that that spent that electron is spinning up, you 0:13:11.840 --> 0:13:15.920 then know the other electron, which has entangled with the 0:13:15.920 --> 0:13:18.480 first one, is spinning down and you don't have to 0:13:19.040 --> 0:13:20.840 mess with it. You're want to measure it. If you 0:13:20.840 --> 0:13:24.000 do measure it, you realize it's spinning down. So you've 0:13:24.000 --> 0:13:27.040 already determined the measurement by measuring the first one. Uh. 0:13:27.080 --> 0:13:30.600 Now this Einstein also had a big problem with because 0:13:30.880 --> 0:13:34.880 entanglement is uh there are certain types of entanglement that 0:13:34.960 --> 0:13:40.120 are have non locality. So locality is talking about how 0:13:40.160 --> 0:13:42.880 close these things are to one another. If you have 0:13:43.000 --> 0:13:46.160 a system that where you've got entangled particles that are 0:13:46.800 --> 0:13:50.920 non local, it means that it doesn't matter how far 0:13:50.960 --> 0:13:54.880 apart those two particles are, they're going to behave this way, 0:13:54.920 --> 0:13:56.920 so that if you measure one, you know the other one. 0:13:58.320 --> 0:14:01.760 This in theory gives us the ability to communicate over 0:14:02.040 --> 0:14:05.800 huge distances. Um, if we're able to manipulate this in 0:14:05.840 --> 0:14:09.760 such a way so that uh, the information, like you know, 0:14:09.840 --> 0:14:13.360 the information that exists in another location, no matter how 0:14:13.360 --> 0:14:14.720 far away it is, Like even if it's on the 0:14:14.720 --> 0:14:18.840 other side of the universe, you instantly know the state 0:14:19.040 --> 0:14:23.000 of that particle. That means that you the information has 0:14:23.040 --> 0:14:26.360 traveled faster than the speed of light. That's the problem 0:14:26.360 --> 0:14:30.560 Einstein had, because nothing travels faster than the speed of light, 0:14:30.640 --> 0:14:34.200 except possibly information. So if I've got a system here 0:14:34.200 --> 0:14:39.240 on Earth, and there's another system across the universe, perhaps 0:14:39.920 --> 0:14:43.400 set to a Beatles tune, uh felt that one coming. 0:14:43.560 --> 0:14:46.560 I can, I can, and and my system is entangled 0:14:46.600 --> 0:14:50.480 with that system. By by observing and measuring my system, 0:14:50.520 --> 0:14:53.520 I now know the state of the other system across 0:14:53.560 --> 0:14:56.080 the universe without having to be there to measure it. 0:14:56.680 --> 0:15:00.280 And and this is again kind of crazy for anyone 0:15:00.320 --> 0:15:02.960 who's thinking up from a classical point of view, because 0:15:03.000 --> 0:15:06.000 it's that's just not the way stuff appears to work 0:15:06.000 --> 0:15:09.120 to us on the macro level. Now, I wish I 0:15:09.160 --> 0:15:13.880 had remembered my pain reliever medication. I do, However, I 0:15:14.040 --> 0:15:19.800 hope to avoid any imperial entanglements. Nice, thank you, thank 0:15:19.800 --> 0:15:22.720 you made the Kessel running twelve post sex. It's fast 0:15:22.840 --> 0:15:27.160 enough for you, old man. Um. So yeah, so quantum 0:15:27.200 --> 0:15:32.960 computers rely on this idea on on multiple ideas, superpositions 0:15:32.960 --> 0:15:37.080 and entanglement in particular, and uh and just another aside. 0:15:37.080 --> 0:15:39.560 I know we've done a lot of prep works here 0:15:39.600 --> 0:15:41.640 in the sides, but it's it is really important to 0:15:41.720 --> 0:15:47.600 kind of get that that information about quantum mechanics across um. 0:15:47.640 --> 0:15:50.960 You may have heard of a thought experiment called Schrodinger's cat, 0:15:51.040 --> 0:15:53.880 and Chris actually alluded to it earlier in the podcast. 0:15:55.280 --> 0:15:59.560 Schrodinger's Cat was and uh, well, Schroedinger was using this 0:15:59.640 --> 0:16:02.800 as a thought experiment to kind of show the absurdity 0:16:02.840 --> 0:16:07.680 of the quantum world compared to the classical world um. 0:16:07.720 --> 0:16:11.400 And it wasn't necessarily to ever state that such an 0:16:11.400 --> 0:16:14.880 experiment is should be carried out, but rather just that 0:16:16.160 --> 0:16:20.440 it shows how how how insane to us this world is. 0:16:20.680 --> 0:16:24.160 Troanjer's thought experiment is this. You've got a steel box. 0:16:24.960 --> 0:16:28.880 You put a cat in the steel box. The steel 0:16:28.880 --> 0:16:33.200 box also has a Geiger counter which has some nuclear material, 0:16:33.520 --> 0:16:38.520 some radioactive material in it. That's undergoing radioactive decay um 0:16:38.560 --> 0:16:42.280 and within an hour and atom of this material within 0:16:42.320 --> 0:16:47.320 the Geiger counter may or may not decay into another element. 0:16:47.840 --> 0:16:52.280 All right, so you've got you've got uh this this uh, 0:16:52.360 --> 0:16:55.040 this uncertainty here. You don't know whether or not that 0:16:55.120 --> 0:16:57.960 adam is going to decay within an hour. The guy 0:16:57.960 --> 0:17:01.320 your counter is hooked up to a system where if 0:17:01.360 --> 0:17:06.160 it detects that an adom has decayed, it will break 0:17:06.200 --> 0:17:08.880 some glass and some acid will be released into the box, 0:17:08.920 --> 0:17:12.760 which will kill the cat. You seal the box and 0:17:12.840 --> 0:17:16.200 you wait an hour, so you don't know if the 0:17:16.280 --> 0:17:21.640 atom has decayed within that hour. Now, based upon the 0:17:21.640 --> 0:17:25.760 the traditional interpretation of quantum mechanics and this idea of superposition, 0:17:27.000 --> 0:17:29.639 you would say that the cat before you open the 0:17:29.680 --> 0:17:34.480 box to observe it, is both alive and dead. It 0:17:34.800 --> 0:17:37.280 has to exist in both states at the same time. 0:17:37.560 --> 0:17:40.120 And only by opening the box and observing it will 0:17:40.200 --> 0:17:45.560 this quantum state collapse. It'll decohere and you will see 0:17:45.960 --> 0:17:49.960 definitively whether the cat is alive or dead. Now, there 0:17:50.000 --> 0:17:54.560 are a lot of philosophical objections to this. Not not 0:17:55.280 --> 0:17:57.479 I mean, it's all thought experiment anyway, right, It's not 0:17:57.520 --> 0:17:59.879 like people are actually gonna do this, but philosophical in 0:17:59.920 --> 0:18:03.200 the sense of, wait a minute, So from the cat's perspective, 0:18:03.960 --> 0:18:06.320 it's going to know whether or not it was dead. Well, 0:18:06.359 --> 0:18:08.320 if it's dead, it doesn't know anything. If it's alive, 0:18:08.359 --> 0:18:13.160 then it knows it didn't die. So the point being 0:18:13.200 --> 0:18:15.359 that how can you say it is both alive or 0:18:15.359 --> 0:18:17.879 dead because it's going to have no memory of such 0:18:18.119 --> 0:18:21.280 a being in such a state. Others have said that. 0:18:21.760 --> 0:18:25.280 Another objection is that, well, we talk about measuring a system, 0:18:25.280 --> 0:18:28.920 and that's what causes it to collapse. Some people would 0:18:29.000 --> 0:18:32.879 argue that it that opening up the box isn't necessary 0:18:32.960 --> 0:18:36.119 for that system to be measured. The Geiger counter inside 0:18:36.160 --> 0:18:39.680 the system is already a measuring device and is measuring 0:18:39.800 --> 0:18:42.720 part of that system, and just by measuring part of 0:18:42.720 --> 0:18:45.320 the system, it deco hears and becomes a classical system, 0:18:45.800 --> 0:18:48.960 so that the cat, the cat's life or death is 0:18:49.000 --> 0:18:52.399 not It's never a superposition thing in the first place. 0:18:52.640 --> 0:18:55.399 But this is one of those thought experiments that is 0:18:55.480 --> 0:18:58.000 meant to kind of make people think about this and 0:18:58.040 --> 0:18:59.919 try and figure out, all, right, well, how do we 0:19:00.080 --> 0:19:05.240 resolve this problem of our description of how the universe 0:19:05.280 --> 0:19:07.879 works and we don't have all the answers yet. There 0:19:07.880 --> 0:19:10.879 are a lot of different interpretations two quantum mechanics, and 0:19:10.920 --> 0:19:14.000 they some of them are fairly contradictory to one another. 0:19:14.400 --> 0:19:19.840 And you've got adherence to multiple different approaches and we 0:19:19.880 --> 0:19:24.720 don't have the full solution yet. This finally brings us 0:19:24.720 --> 0:19:29.520 to quantum computers. So here's another crazy thing about innovation. 0:19:29.760 --> 0:19:33.360 Sometimes we find out that something really cool happens when 0:19:33.359 --> 0:19:37.160 we do a certain action and we don't really know 0:19:37.280 --> 0:19:39.720 the mechanism behind it, but we go ahead and build 0:19:39.760 --> 0:19:45.560 stuff anyway. Yeah, a lot of sometimes great things happen 0:19:45.600 --> 0:19:49.040 because of this. Sometimes bombs happen because of this. But 0:19:49.920 --> 0:19:53.560 quantum computers almost fits into that realm because we don't have, 0:19:53.800 --> 0:19:57.439 like I said, a full understanding of quantum mechanics. But 0:19:57.480 --> 0:20:01.320 the idea behind the quantum computer is that you create 0:20:02.200 --> 0:20:06.000 some sort of system that uses sub atomic particles that 0:20:06.080 --> 0:20:08.680 have a particular feature, Like I was talking with the 0:20:08.720 --> 0:20:11.959 electron spin. That could be an example. It's not the 0:20:12.000 --> 0:20:15.119 only one, but it is an example of this. And 0:20:15.160 --> 0:20:19.840 you know that because of superposition, the electrons spin is 0:20:20.240 --> 0:20:24.199 all every every type of spin that it can be. Well, 0:20:24.480 --> 0:20:28.800 if you translate this into the classical computer system, which 0:20:28.840 --> 0:20:31.439 relies on bits. And if you've listened to our Logic 0:20:31.480 --> 0:20:34.600 Gates episode, we talked a lot about this. There are 0:20:35.080 --> 0:20:41.560 two states a bit can be in orffe yeah, or 0:20:41.640 --> 0:20:43.680 one or zero. Yes, exactly, because you said on or off, 0:20:43.720 --> 0:20:46.760 I was going to confuse everybody. Yes, or true or false. 0:20:47.040 --> 0:20:49.080 That would be the other way of looking at it, right. 0:20:49.200 --> 0:20:53.880 It can't be both true and false, right, right, So yeah, 0:20:53.920 --> 0:20:57.760 an individual bit is either going to be true or false, 0:20:57.920 --> 0:21:03.000 one or zero, on or off in a classical classical computer. Now, 0:21:03.240 --> 0:21:07.399 quantum computers use something called cubits. They're also great for 0:21:07.440 --> 0:21:13.919 measuring an arc. Actually, cub i t. The cub it 0:21:13.960 --> 0:21:16.439 in a quantum bit is a qub it, which is 0:21:16.440 --> 0:21:21.359 a little orange guy who hops up and down pyramids. 0:21:22.000 --> 0:21:25.399 Uh no, wait, that's cue Bert. So cube bit is 0:21:25.480 --> 0:21:30.760 a is is the fundamental element of information within a 0:21:30.840 --> 0:21:35.840 quantum computer system, and unlike a regular classical computer bit, 0:21:36.240 --> 0:21:39.640 a cubit is able to be a zero or a one, 0:21:40.240 --> 0:21:43.919 or any value of zero or one or all of them, 0:21:44.080 --> 0:21:46.760 or all of the values of zero or one. Yeah, 0:21:46.960 --> 0:21:52.040 that's not confusing. It exists in superposition, and so if 0:21:52.080 --> 0:21:56.280 you have two cubits together, then you've got all the 0:21:56.320 --> 0:21:59.119 different combinations of zero and one that two bits would have. 0:21:59.880 --> 0:22:03.119 H three cubits, you've got all the different combinations of 0:22:03.200 --> 0:22:06.959 zero and one that three bits would have. So exponentially 0:22:07.080 --> 0:22:11.600 it becomes a more powerful computer for certain computing problems. 0:22:13.800 --> 0:22:17.680 Haircut two. Yeah. So you you keep on adding more 0:22:17.720 --> 0:22:22.720 and more cubits, You've just created an incredibly powerful theoretical computer. 0:22:23.200 --> 0:22:26.879 And there have been some some advances in creating computers 0:22:26.880 --> 0:22:30.679 that use cubit technology. Uh, although we still have a 0:22:30.720 --> 0:22:33.560 lot of ground to cover in order to really make 0:22:33.600 --> 0:22:38.320 one that is um, that is practical. Yes, as a 0:22:38.359 --> 0:22:41.879 matter of fact, you listed some of those I believe 0:22:42.080 --> 0:22:45.800 that I I might have there. Well, there is a 0:22:45.880 --> 0:22:49.880 list in the article how quantum computers work on the website. 0:22:49.960 --> 0:22:52.919 Kevin Vonsa and I both worked on this article, and 0:22:52.960 --> 0:22:56.600 it's yeah, it's there have been several the first being 0:22:56.800 --> 0:23:02.640 back in where am I t researchers and Lost Alamos 0:23:02.680 --> 0:23:07.440 researchers were able to create a single cube it across 0:23:07.840 --> 0:23:12.800 three nuclear spins in a molecule of or in in molecules, 0:23:12.920 --> 0:23:16.840 I should say, of a liquid solution of of alanine, 0:23:17.200 --> 0:23:19.960 which is an amino acid. Yeah, this is what I 0:23:20.000 --> 0:23:23.800 was talking about before. We're not using the traditional materials, 0:23:23.800 --> 0:23:29.920 the silicon and metals that we use to manipulate information 0:23:30.200 --> 0:23:34.240 in a classical computer. This this kind of computer is 0:23:34.240 --> 0:23:39.320 going to require a brand new style of physical architecture. Yes, 0:23:39.440 --> 0:23:45.000 And remember when I mentioned about superposition and entanglement and decoherents. 0:23:45.000 --> 0:23:46.760 That's the reason why you have to be able to 0:23:46.840 --> 0:23:50.000 isolate the actual computing element from the system it's end, 0:23:50.040 --> 0:23:52.000 because if it comes into contact with the system, it's 0:23:52.040 --> 0:23:56.920 and you you have that problem of decoherens and quantum collapse, 0:23:57.880 --> 0:24:00.679 or you have a problem of entanglement where the system 0:24:00.720 --> 0:24:04.359 is getting entangled with the actual environment it's in and 0:24:04.440 --> 0:24:08.120 it's no longer able to do what you needed to do. Uh. 0:24:08.160 --> 0:24:13.200 These are real problems and it's it's there's no easy 0:24:13.240 --> 0:24:15.520 way to describe the solution to it. And there are 0:24:15.520 --> 0:24:18.520 a lot of different approaches that that scientists are are 0:24:18.560 --> 0:24:23.280 taking to try and create quantum computers, including a creating 0:24:23.359 --> 0:24:28.080 quantum computers that operate at a temperature close to absolute zero, yes, 0:24:28.160 --> 0:24:30.600 which is very very cold absolute zero by the way, 0:24:30.640 --> 0:24:32.800 In case you do not know that is the point 0:24:32.840 --> 0:24:37.520 where you have no molecular movement whatsoever. Uh, And even 0:24:37.760 --> 0:24:42.240 deep space usually be is a few uh kelvin over 0:24:42.400 --> 0:24:46.439 absolute zero because it's it's not easy to create a 0:24:46.480 --> 0:24:50.080 system where every single molecule in that system is is 0:24:50.520 --> 0:24:54.120 completely motionless. Yeah, that's that's one of the troubles here 0:24:54.240 --> 0:24:56.760 is that this is not something that's easy to achieve, 0:24:56.960 --> 0:25:03.080 no or cheap. It's really expensive that too. So what 0:25:03.200 --> 0:25:06.240 kind of problems could a quantum computer solve. Let's say 0:25:06.240 --> 0:25:08.720 that we've created a quantum computer and it exists with 0:25:08.760 --> 0:25:12.440 these cubits that can have any sort of value of zero, one, 0:25:12.880 --> 0:25:15.000 or all of those values all at the same time. 0:25:15.560 --> 0:25:18.520 What would you use that for? Well, you wouldn't use 0:25:18.560 --> 0:25:22.119 it to play doom. No. One of the advantages of 0:25:22.200 --> 0:25:28.400 quantum computers is that the superposition of the cubits would theoretically, 0:25:28.480 --> 0:25:30.399 assuming that you know, we get to the point where 0:25:30.840 --> 0:25:37.879