1 00:00:10,520 --> 00:00:17,059 Hey. So. My name is Fran. I'm a Ph.D. student here at Oxford, and I work in a department who quantum materials. 2 00:00:17,060 --> 00:00:20,900 So we work with very special materials, not just you normal word or, you know, metal. 3 00:00:21,900 --> 00:00:25,400 And they can only be described using quantum mechanics. 4 00:00:25,910 --> 00:00:31,280 And so I want to start off with a question. Has anyone ever been on a train and wished it was going a little bit faster? 5 00:00:33,120 --> 00:00:41,100 Yeah. No, I feel you. So I grew up in London, so I spent a lot of time waiting for the tube to just kind of slowly drive along. 6 00:00:41,450 --> 00:00:44,610 And does anyone know why trains can't go any faster? 7 00:00:44,850 --> 00:00:50,690 Does anyone know what limits the speed of a train? Any ideas? 8 00:00:51,530 --> 00:00:59,610 Yeah. So so that that's a good speed limit that trains by some can go a little bit faster but you know why is 60. 9 00:01:00,660 --> 00:01:09,530 Why can't trains go any faster? Yeah. They could be really dangerous if they hit something. 10 00:01:09,860 --> 00:01:14,149 Any other ideas? Yeah. Um, if it has to stop. 11 00:01:14,150 --> 00:01:18,820 Because there might be a fire. In the as well. 12 00:01:19,430 --> 00:01:27,110 Yeah that so imagine kind of you in kind of the perfect safe situation where you just have a truck and there wouldn't be any fires, 13 00:01:27,110 --> 00:01:31,759 you wouldn't have to hit something. What would limit the speed of a train then? 14 00:01:31,760 --> 00:01:35,210 What would kind of give it maximum possible speed? Yeah. 15 00:01:35,660 --> 00:01:38,989 If it went in Berkeley, it come off, right. Yeah. 16 00:01:38,990 --> 00:01:44,270 It might come off the rails. That's right. But the reason trains can't go extremely, 17 00:01:44,270 --> 00:01:51,530 extremely fast is because of friction between the train and the tracks and also because the engine 18 00:01:51,530 --> 00:01:57,260 has kind of only a small amount of or a limited thrust they can use to power the train forward. 19 00:01:57,560 --> 00:02:01,040 So there is a way we could actually make trains go a little bit faster. 20 00:02:01,430 --> 00:02:07,400 Does anyone have any idea how you might be able to get rid of one of these things to be able to make the train go faster? 21 00:02:08,620 --> 00:02:12,049 Any ideas? Yes. Vacuums. 22 00:02:12,050 --> 00:02:15,260 One idea. Another idea. Imagine, right? 23 00:02:15,410 --> 00:02:22,760 If there was no friction between the train and the track and the train would just go up and levitate above the track, that'd be pretty cool, right? 24 00:02:23,910 --> 00:02:27,480 Then I think it would be cool. This is my hope. 25 00:02:27,950 --> 00:02:32,060 HD To be too high. 26 00:02:33,480 --> 00:02:36,889 You get you could get a ladder or something to get onto the train. Trust me, it works. 27 00:02:36,890 --> 00:02:43,370 It works. So imagine that we're all very enthused about Levitating Train. 28 00:02:43,700 --> 00:02:49,280 And does anyone have any idea how we might be able to get a train to levitate in the first place? 29 00:02:49,390 --> 00:02:55,340 Yes. So we actually. Yeah, that's exactly right. 30 00:02:55,850 --> 00:02:59,900 If we're going to use magnets to try and levitate things, I've got t ball magnets here. 31 00:03:00,320 --> 00:03:04,910 And so if you have a North Pole, South Pole comes together, right? They attract they really like that sort of thing. 32 00:03:05,660 --> 00:03:10,250 But if I put you North Poles together or two South Poles together, they're not going to like it. 33 00:03:10,250 --> 00:03:15,140 They're going to repel. So imagine you kind of use this repelling force, right, to make them levitate. 34 00:03:15,440 --> 00:03:19,729 So I've got North Pole, South Pole here and then North Pole, South Pole here. 35 00:03:19,730 --> 00:03:23,660 Who thinks that they're going to levitate when I drop one onto the other? 36 00:03:24,350 --> 00:03:27,640 Yeah. Yeah. Okay. 37 00:03:27,820 --> 00:03:31,410 Well, moment of truth. Three, two, one. Oh. 38 00:03:31,880 --> 00:03:37,990 Oh, well, that's that. And the reason why it doesn't work is because these levitating. 39 00:03:38,440 --> 00:03:42,069 So these are just regular ball magnets and they're actually metastable. 40 00:03:42,070 --> 00:03:46,809 So they're not very stable. If you have them perfectly one on top of the other, it'll be stable. 41 00:03:46,810 --> 00:03:54,040 But as soon as it slips a tiny amount, then they're just going to kind of snap together and fall over, just like you saw there. 42 00:03:54,070 --> 00:03:58,120 So that's quite a big problem because obviously you want your train to be moving. 43 00:03:58,120 --> 00:04:03,070 So as soon as the train moves a little bit, that's going to stop being stable and then it just going to flip around and fall over. 44 00:04:03,670 --> 00:04:07,990 Does anyone know how we might be able to overcome this problem? Yeah. 45 00:04:08,470 --> 00:04:10,810 There is one against one. 46 00:04:12,940 --> 00:04:19,720 I think we still got the same problem here because this is one magnet and this is one and then we still have one without the. 47 00:04:20,740 --> 00:04:24,610 So that's a very interesting idea to use. Just a North Pole on its own, just the South Pole. 48 00:04:24,610 --> 00:04:28,870 And we think in physics they should exist. But actually physicists haven't even been able to find them yet. 49 00:04:29,320 --> 00:04:33,730 So we're going to have to try and work with things at the moment that we've already discovered. 50 00:04:34,030 --> 00:04:40,390 Anyone have any other idea? Well, how about using a different kind of Mac now? 51 00:04:40,870 --> 00:04:46,120 Has anyone ever heard of a superconductor before? Yes. 52 00:04:46,540 --> 00:04:51,819 Someone has heard of a superconductor. Now, superconductors are really interesting because they are a quantum magnet. 53 00:04:51,820 --> 00:04:57,219 So you cannot describe these magnets with normal classical mechanics that kind 54 00:04:57,220 --> 00:05:00,940 of describe both rolling down hills and kind of normal trains moving along. 55 00:05:01,180 --> 00:05:05,590 You have to use quantum mechanics. And they've got some very interesting properties. 56 00:05:05,830 --> 00:05:13,540 So superconductors have no electrical resistance. So who's ever touched a wire when it's part of a circuit and it's got a little bit warm? 57 00:05:14,590 --> 00:05:21,459 So anyone felt that. Yeah. So actually that's because the wire has resistance and superconductors, they have no resistance. 58 00:05:21,460 --> 00:05:24,520 So if you put a current through a superconducting wire, 59 00:05:24,550 --> 00:05:30,430 the current will keep going round and round and it won't lose any energy to heats and it would just keep going. 60 00:05:30,430 --> 00:05:35,080 And so there have been experiments where this kind of this current has been going for tens of years. 61 00:05:35,710 --> 00:05:40,900 So that's pretty neat. But the thing that's really important for us today is that it acts like a magnetic mirror. 62 00:05:41,080 --> 00:05:46,389 So if you get a superconductor so I've got I have got a superconductor here and you put it in as a magnets. 63 00:05:46,390 --> 00:05:52,090 I've got some magnets here. If you put one on top of the other, the electrons from the atoms, 64 00:05:52,090 --> 00:05:57,879 they're going to rearrange themselves inside the superconductor in such a way that it will become a magnet, 65 00:05:57,880 --> 00:06:03,040 but it will be a magnet that perfectly repels these magnets, which is pretty neat. 66 00:06:04,540 --> 00:06:07,170 So I've got some magnets for some nice magnets here. 67 00:06:07,180 --> 00:06:11,860 I've got a superconductor who thinks this is going to levitate when I put one on top of the other. 68 00:06:13,590 --> 00:06:18,270 Okay. Well, you got big expectations, so. Three, two, one. 69 00:06:18,520 --> 00:06:21,660 Oh, well, this is just a talk full of disappointment. 70 00:06:23,040 --> 00:06:29,670 So does anyone know why that didn't work? Any ideas why it didn't work? 71 00:06:30,090 --> 00:06:33,100 Yes, that's reflected. It's kind of perfected. 72 00:06:33,140 --> 00:06:36,180 The opposites do it. Not quite. 73 00:06:36,210 --> 00:06:41,190 No. So it is kind of. It's. It's reflective so that it perfectly repels so. 74 00:06:41,520 --> 00:06:44,610 Actually, the reason is because this is at room temperature. 75 00:06:44,940 --> 00:06:47,890 So this is this is a superconductor. 76 00:06:47,910 --> 00:06:54,420 It's kind of at the moment a bit like a ceramic, like something you get in a fancy bathroom or fancy place and it's pretty boring. 77 00:06:54,600 --> 00:06:58,590 So we need to cool it down. We need it to be really, really, really, really, really cold. 78 00:06:58,920 --> 00:07:06,630 And we need it to be below its critical temperature. And when the temperatures below the critical temperature, then it's superconducting. 79 00:07:06,930 --> 00:07:11,640 And so this one has a critical temperature of, I don't know, like -150 degrees. 80 00:07:12,480 --> 00:07:15,730 So then, you know, how are we going to get down to that sort of low temperature? 81 00:07:15,750 --> 00:07:18,990 Yeah. Bingo. And there is. 82 00:07:20,470 --> 00:07:24,660 But so has everybody heard of liquid nitrogen before? 83 00:07:26,140 --> 00:07:34,030 Yeah. Liquid nitrogen is a wicked is you basically you take nitrogen from the air and that means is actually pretty cheap. 84 00:07:34,030 --> 00:07:37,870 It's about the same price per litre as milk, but it's a lot less weird to throw around. 85 00:07:40,060 --> 00:07:48,010 And so I just take a little bit. It never gets old is very, very cool. 86 00:07:48,340 --> 00:07:59,079 And so you get nitrogen, you take it from the earth. So that means if I put a balloon full of air in here, the air inside will also liquefy. 87 00:07:59,080 --> 00:08:02,680 Right. So these are balloons I blew up earlier. 88 00:08:05,230 --> 00:08:08,470 And so who thinks they're going to explode? 89 00:08:10,510 --> 00:08:14,440 They're only going to explode if they're low quality balloons. I think they work fine earlier. 90 00:08:14,860 --> 00:08:21,099 It's just stuck together. That's fine, because I blew them up with a certain amount of air. 91 00:08:21,100 --> 00:08:26,170 I put them in here and then the air condensed down and became a liquid and the balloon shrank. 92 00:08:26,410 --> 00:08:32,950 But now the air is going to evaporate, hopefully, and then hope they all go back to being the same size. 93 00:08:35,210 --> 00:08:39,430 I think it's okay. I think it's okay. So, yeah, so that's very cool. 94 00:08:39,440 --> 00:08:46,340 And the main point of that is that liquid nitrogen, when you turn it from a gas to a liquid, it actually condenses down quite a lot. 95 00:08:46,350 --> 00:08:50,690 So I've got a a little what is the tiniest amount of nitrogen in there? 96 00:08:50,700 --> 00:08:54,590 And I'm going to stick a balloon over it and I'm going to try and work out how much. 97 00:08:56,090 --> 00:09:02,450 Yes. That's going to produce. So give a little shake. 98 00:09:03,590 --> 00:09:08,210 So you see there that tiny amount of nitrogen is blowing up that entire balloon. 99 00:09:08,450 --> 00:09:16,130 And in fact, the nitrogen, when it goes from being a liquid to being a gas, it increases by 700 times in volume. 100 00:09:17,300 --> 00:09:20,690 So it's actually a little bit dangerous and you've got to be a little bit careful. Okay. 101 00:09:20,690 --> 00:09:25,110 I'm just going to intervene. Okay. 102 00:09:26,070 --> 00:09:35,459 I'm glad that's the highlight of the talk. So yes, I increases by 700 times in volume when it goes from being a liquid to being gas. 103 00:09:35,460 --> 00:09:40,080 So it's a little bit dangerous. You might have heard a story a few years ago now. 104 00:09:41,010 --> 00:09:45,780 So it became very fashionable for a while to pour liquid nitrogen inside drinks because I mean, it's really neat to look at. 105 00:09:45,780 --> 00:09:54,660 It is really cool. And you can put it in drinks and it freezes things really quickly and it is really interesting. 106 00:09:56,160 --> 00:09:59,819 But obviously if you have a drink which has got something which is like -200 degrees 107 00:09:59,820 --> 00:10:03,230 and then you generally wait for the -200 degrees bit to evaporate outright. 108 00:10:03,600 --> 00:10:09,630 I mean, it's not just me, but someone in the news a few years ago drank a cocktail which still had the liquid nitrogen in it, 109 00:10:09,930 --> 00:10:15,329 and then the liquid nitrogen went down her throat, expanded 700 times, and her stomach blew off her stomach. 110 00:10:15,330 --> 00:10:18,420 She had to have an operation to have a stomach for me. She's still alive, so it's okay. 111 00:10:19,380 --> 00:10:23,460 But the point is, don't drink. This is what I'm trying to say here. 112 00:10:23,880 --> 00:10:32,040 And so I've got some nitrogen and I've got my superconductor here and I'm going to try cooling it down, see what happens. 113 00:10:33,540 --> 00:10:38,070 And so now the little superconductor, the little puck in there is cooling down. 114 00:10:38,370 --> 00:10:42,960 And what happens when it goes through the critical temperature? It goes through something called a phase transition. 115 00:10:43,230 --> 00:10:49,860 A phase transition is basically when you get something and it changes its properties after a certain temperature. 116 00:10:50,280 --> 00:10:55,980 And there are lots of different examples when you have water boiling 100 degrees, that's an example of a phase transition. 117 00:10:56,250 --> 00:11:00,180 When you have water freezing at zero degrees, that's an example of a phase transition. 118 00:11:00,510 --> 00:11:03,600 And so I'm going to show you another phase transition. 119 00:11:03,600 --> 00:11:07,169 So I've got this rubber rod. And can you tell me, how does it feel? 120 00:11:07,170 --> 00:11:11,880 Does it feel brittle or so? Yes, I soft and bendy. 121 00:11:12,000 --> 00:11:18,420 And if I hit this with a hammer, I mean, no, particularly exciting, but whatever. 122 00:11:18,990 --> 00:11:25,469 And so I'm going to put in the nitrogen. What happens up in the nitrogen is that it heats up the nitrogen that's immediately 123 00:11:25,470 --> 00:11:31,200 around it because the rod is about 200 degrees hotter than the liquid nitrogen. 124 00:11:31,890 --> 00:11:39,299 And so when he's set up, it turns into a gas and then that pushes more liquid nitrogen through the rod and now it's stopped, 125 00:11:39,300 --> 00:11:48,740 which means it's at -200 degrees. And the rod is going through a phase transition which changes material properties and now it's like grass cool. 126 00:11:50,880 --> 00:11:54,720 And so it's not just that, it's not just your rod. You can also do with flowers. 127 00:11:55,140 --> 00:11:59,070 So flowers, they're made from from plant cells which are mainly water. 128 00:11:59,400 --> 00:12:04,170 And so obviously water's going to be frozen at -200 degrees. 129 00:12:05,190 --> 00:12:13,440 So just give a little moment. So we are a shadow like lost. 130 00:12:13,710 --> 00:12:17,310 So this is really good if you're having a really bad Valentine's Day friend told me that. 131 00:12:19,380 --> 00:12:21,660 So that's pretty neat. I mean, you can smash a lot of things, 132 00:12:21,660 --> 00:12:27,810 but let's try and be a little bit constructive now with our phase transitions and see how it goes for our superconductor. 133 00:12:28,320 --> 00:12:33,510 So I'm hoping I superconductor is pretty cool now and I'm going to put it on here. 134 00:12:34,560 --> 00:12:39,360 We see that is levitating. That's pretty neat. 135 00:12:40,970 --> 00:12:46,250 And so it's going to be heating up now because it's obviously in the air, which is much hotter than the superconductor. 136 00:12:46,580 --> 00:12:53,510 And once it goes above the critical temperature, goes through the phase transition and then stop, superconducting becomes boring again. 137 00:12:54,080 --> 00:12:59,330 So that's pretty neat I think anyway. So this is what it acts like, a magnetic mare. 138 00:12:59,340 --> 00:13:02,360 So you get a superconductor, you cool it down, it starts superconducting. 139 00:13:02,660 --> 00:13:10,670 And then what happens is arranges the electrons inside itself so that it pushes all the magnetic field out and it perfectly repels it. 140 00:13:11,810 --> 00:13:15,110 So that's quite good, but it's not particularly stable. It can fall off quite easily. 141 00:13:15,120 --> 00:13:19,700 So we need something a little bit better in order to make our superconducting train. 142 00:13:19,910 --> 00:13:24,320 But fortunately, we've got science on our side here. 143 00:13:24,590 --> 00:13:27,770 So if I actually cooled down the superconductor. 144 00:13:29,310 --> 00:13:33,900 Inside the magnetic field, it's going to be something a little bit different. 145 00:13:36,180 --> 00:13:45,550 So. There's a more nitrogen. 146 00:13:56,860 --> 00:14:01,150 Alex, coach. And now we're superconducting again. 147 00:14:01,210 --> 00:14:03,730 But this time it trapped the magnetic field inside itself. 148 00:14:03,730 --> 00:14:08,020 So now you can I superconducting rollercoaster which I basically the reason I'm doing a Ph.D. so I can do a 149 00:14:08,020 --> 00:14:13,540 superconducting rollercoaster and now it heats up is through the phase transition and stop superconducting. 150 00:14:13,810 --> 00:14:18,940 So that's a different kind of superconductivity and that's called quantum locking. 151 00:14:19,150 --> 00:14:24,129 So what happens there? You get your superconductors at like super boring and then you put it in the magnetic 152 00:14:24,130 --> 00:14:29,470 field and then it pretty much holds on to the magnetic field inside the superconductor, 153 00:14:29,710 --> 00:14:31,060 and then it's stuck inside. 154 00:14:31,240 --> 00:14:40,150 So it's basically the same as kind of, I don't know if I would hold this pocket like this for the, for the first one, the magnetic mirror. 155 00:14:40,330 --> 00:14:44,770 But then if I put my arm through the bucket for the quantum locking, it's a little bit more stable. 156 00:14:45,190 --> 00:14:52,030 So that's the sort of thing we want to be using with our train and loop history. 157 00:14:52,270 --> 00:14:56,920 Superconductors were discovered by this guy coming on us in Leiden in the Netherlands in 1911, 158 00:14:57,220 --> 00:15:01,660 and he discovered Mercury Superconducting at -269 degrees. 159 00:15:02,140 --> 00:15:09,040 So that's a little bit colder than liquid nitrogen. Does anyone know how we're going to be able to get to a temperature colder than liquid nitrogen? 160 00:15:09,260 --> 00:15:13,659 Yeah, dry ice is actually not going to work in this case, I'm afraid. 161 00:15:13,660 --> 00:15:17,810 I think draw us a little bit warmer than liquid nitrogen. Any other ideas? 162 00:15:20,630 --> 00:15:23,750 Yeah, that's true. That's a very good idea. 163 00:15:23,780 --> 00:15:28,580 So these days we actually use liquid helium because that's really safe and it doesn't react with things. 164 00:15:29,510 --> 00:15:33,020 But back in Camerlengo Onassis day, they did use liquid hydrogen. 165 00:15:33,260 --> 00:15:37,010 But as you probably know, if you have hydrogen and then you have a flame, 166 00:15:37,010 --> 00:15:41,780 it will set on fire and blow up enormously as soon as it reacts with the oxygen in the air. 167 00:15:42,110 --> 00:15:49,490 And so it's not particularly safe. So there were a few of the early students in in superconductivity did die because they were smoking that. 168 00:15:49,730 --> 00:15:55,040 This is all back in the day where people like to wear suits and smoking pipes in the lab and they were smoking that pipe. 169 00:15:55,040 --> 00:15:59,390 And then the the flame from that pipe caught on to some of the hydrogen and blew up the lab. 170 00:16:00,560 --> 00:16:04,520 But generally, this doesn't happen anymore. I mean, I don't like taking risks. 171 00:16:04,520 --> 00:16:10,070 I don't even go ice skating. So I think I wouldn't do this if this is very dangerous. 172 00:16:11,210 --> 00:16:15,770 And so superconductors are really exciting, but they're actually they're actually useful. 173 00:16:15,970 --> 00:16:21,740 And so it's very important when you're doing science to think about why why these things will be useful for society, 174 00:16:21,740 --> 00:16:28,040 not only to justify it yourself, but also to get funding. So does anyone recognise that thing up in the corner? 175 00:16:28,400 --> 00:16:33,190 Has anyone seen that before? Yeah. Do you know what it is? 176 00:16:35,740 --> 00:16:40,350 Anyone know what it could be? Yes. 177 00:16:40,370 --> 00:16:45,560 Has anyone heard of the Large Hadron Collider before? That was big in the news of the Higgs boson. 178 00:16:45,800 --> 00:16:50,510 Well, in the Large Hadron Collider, they got loads of particles and they got really, really, really fast in circles. 179 00:16:50,870 --> 00:16:55,069 And the way you get the particles to go round in circles is by using magnets. 180 00:16:55,070 --> 00:16:58,969 And we've got to use the superconducting magnets because they you can make really, 181 00:16:58,970 --> 00:17:03,550 really big magnets that are able to push the really fast particles round in circles. 182 00:17:04,190 --> 00:17:12,310 Then you can also use them in telescopes. So you can use superconductors and very special detectors that allow you to see very dim and faraway stars. 183 00:17:12,830 --> 00:17:16,790 You can obviously you can use them in trains. So train, train one is really neat. 184 00:17:17,240 --> 00:17:19,700 Has anyone ever been to Birmingham Airport before? 185 00:17:20,360 --> 00:17:25,999 There is a maglev train between Birmingham International Station and Birmingham Airport, which is pretty neat. 186 00:17:26,000 --> 00:17:29,860 So I went on that for the first time recently, was definitely more excited than any of the kids on there. 187 00:17:31,580 --> 00:17:36,830 And so the Birmingham airport doesn't go very fast, but maglev trains can go incredibly fast. 188 00:17:36,830 --> 00:17:41,479 They can go up to 600 kilometres an hour, which I think might be the land speed record. 189 00:17:41,480 --> 00:17:45,500 So pretty quick you can also use them in quantum computers. 190 00:17:45,500 --> 00:17:51,590 So quantum computers are a very special kind of computer that allow you to calculate things really, really, really quickly. 191 00:17:51,600 --> 00:17:56,929 So no more waiting for the computer to load. You can use them, obviously, because there's no resistance. 192 00:17:56,930 --> 00:18:04,070 You can use them and wires to transmit enormous amounts of current over long distances without losing any energy. 193 00:18:04,280 --> 00:18:08,960 So that would be amazing. Imagine if you could get high transmission lines that don't lose any energy. 194 00:18:09,230 --> 00:18:12,170 And finally, MRI scan is need a very big magnet. 195 00:18:12,290 --> 00:18:17,240 And if you have a very make, if you want to have a very big magnet, what are you going to use as a superconductor? 196 00:18:18,020 --> 00:18:23,899 So superconductors, they're basically everywhere. And one question I get a lot of free with the train is how does it hold the train off? 197 00:18:23,900 --> 00:18:29,270 And that's really interesting because because superconductors can actually hold up to 70, 198 00:18:29,450 --> 00:18:35,090 70,000 times their own weight just with the force of repulsion. 199 00:18:35,900 --> 00:18:36,889 So I think that's pretty neat. 200 00:18:36,890 --> 00:18:42,620 So I'm going to finish off with one final example of how you can use superconductors, and that's to make a levitating sumo wrestler. 201 00:18:42,890 --> 00:18:45,980 So as you see there, it can even hold up the sumo wrestler. 202 00:18:45,980 --> 00:18:54,490 So thank you very much for listening. I have got a little train down here, the front, if any of the kids parents would like to have a go, 203 00:18:54,510 --> 00:18:58,760 pushing it around, seeing how stable it is and you want to have a go. 204 00:19:02,210 --> 00:19:16,640 Yeah. Just come down to the front. It's fine. And does anyone have any questions? 205 00:19:19,640 --> 00:19:23,570 I'm just going to cool this down. Just. 206 00:19:31,450 --> 00:19:40,730 You're it. Another moment. Next to the. 207 00:19:40,820 --> 00:19:51,130 The droplets of the liquid nitrogen that. So you see the levitating train. 208 00:19:51,190 --> 00:19:55,360 Does anyone to give it a little push? See, they can just go for it. 209 00:19:57,010 --> 00:20:01,150 Just be gentle. Yeah. 210 00:20:01,180 --> 00:20:06,970 Cool. Well, thank you very much for coming. I think if you don't want to stay for the other talks, please go out of the store. 211 00:20:07,810 --> 00:20:10,150 Apart from that, I hope you have a nice rest of your day.