WEBVTT 1 00:00:07.679 --> 00:00:10.880 - Hello, and welcome to the Physics World weekly 2 00:00:10.880 --> 00:00:11.380 - podcast, 3 00:00:11.839 --> 00:00:14.740 - which is supported by American Elements. 4 00:00:15.824 --> 00:00:20.244 - Simulating quantum systems is something that classical computers 5 00:00:20.785 --> 00:00:21.765 - struggle with. 6 00:00:22.464 --> 00:00:23.204 - Not surprisingly, 7 00:00:23.984 --> 00:00:26.864 - quantum computers are expected to do a much 8 00:00:26.864 --> 00:00:27.765 - better job, 9 00:00:28.289 --> 00:00:30.629 - particularly when a quantum computer's 10 00:00:30.929 --> 00:00:31.429 - architecture 11 00:00:31.809 --> 00:00:35.170 - is designed to solve a specific type of 12 00:00:35.170 --> 00:00:36.070 - physics problem. 13 00:00:37.250 --> 00:00:39.829 - My guest in this episode of the Physics 14 00:00:39.890 --> 00:00:41.189 - World Weekly podcast 15 00:00:41.649 --> 00:00:42.869 - is Ross Jenkinson 16 00:00:43.505 --> 00:00:44.405 - of The UK's 17 00:00:44.864 --> 00:00:46.164 - University of Manchester. 18 00:00:46.945 --> 00:00:49.604 - He talks about the challenges and rewards 19 00:00:50.064 --> 00:00:51.844 - of using quantum computers 20 00:00:52.225 --> 00:00:53.604 - in particle physics, 21 00:00:54.384 --> 00:00:56.164 - a field where classical 22 00:00:56.545 --> 00:00:57.045 - supercomputers 23 00:00:57.920 --> 00:00:58.579 - can struggle 24 00:00:58.960 --> 00:01:01.059 - to simulate simple systems. 25 00:01:02.159 --> 00:01:02.979 - That conversation 26 00:01:03.439 --> 00:01:07.219 - is coming up after this message from American 27 00:01:07.439 --> 00:01:07.939 - Elements. 28 00:01:09.854 --> 00:01:12.515 - This podcast is brought to you by American 29 00:01:12.814 --> 00:01:13.314 - Elements, 30 00:01:13.935 --> 00:01:14.994 - the world's leading 31 00:01:15.454 --> 00:01:15.954 - manufacturer 32 00:01:16.494 --> 00:01:18.354 - of engineered and advanced 33 00:01:18.655 --> 00:01:19.155 - materials. 34 00:01:19.935 --> 00:01:23.155 - With a catalog of over 35,000 35 00:01:23.454 --> 00:01:23.954 - products 36 00:01:24.480 --> 00:01:28.260 - available in both industrial bulk and laboratory 37 00:01:28.719 --> 00:01:29.219 - quantities, 38 00:01:29.920 --> 00:01:33.280 - American Elements is the largest supplier of its 39 00:01:33.280 --> 00:01:33.780 - kind. 40 00:01:34.560 --> 00:01:37.534 - For more than twenty five years, its research 41 00:01:37.594 --> 00:01:38.334 - and development 42 00:01:38.715 --> 00:01:39.215 - programs 43 00:01:39.515 --> 00:01:41.055 - have been a vital resource 44 00:01:41.355 --> 00:01:42.174 - for innovation 45 00:01:42.715 --> 00:01:43.694 - across corporate, 46 00:01:44.155 --> 00:01:44.655 - government, 47 00:01:45.034 --> 00:01:46.655 - and academic sectors. 48 00:01:47.435 --> 00:01:50.174 - The company's ability to scale laboratory 49 00:01:50.635 --> 00:01:51.135 - breakthroughs 50 00:01:51.609 --> 00:01:53.149 - to industrial production 51 00:01:53.530 --> 00:01:56.109 - has contributed to many of the most significant 52 00:01:56.729 --> 00:01:57.229 - technological 53 00:01:57.689 --> 00:01:58.189 - advancements 54 00:01:58.649 --> 00:02:00.189 - since 1990, 55 00:02:00.810 --> 00:02:02.509 - including LED lighting, 56 00:02:02.890 --> 00:02:03.390 - smartphones, 57 00:02:03.929 --> 00:02:05.310 - and electric vehicles. 58 00:02:06.045 --> 00:02:10.384 - To learn more, visit americanelements.com. 59 00:02:11.085 --> 00:02:12.305 - American Elements, 60 00:02:12.925 --> 00:02:14.064 - now invent. 61 00:02:22.610 --> 00:02:24.550 - Hi, Ross. Welcome to the podcast. 62 00:02:25.409 --> 00:02:26.849 - Hi, Hamish. Thank you very much for having 63 00:02:26.849 --> 00:02:27.349 - me. 64 00:02:27.730 --> 00:02:30.290 - Yeah. I'm really looking forward to talking about, 65 00:02:30.610 --> 00:02:32.550 - applications for quantum computing 66 00:02:33.090 --> 00:02:35.990 - in particle physics and, beyond. 67 00:02:36.305 --> 00:02:36.805 - So 68 00:02:37.105 --> 00:02:39.344 - maybe we could start off with, sort of 69 00:02:39.344 --> 00:02:40.485 - a basic question. 70 00:02:41.025 --> 00:02:43.525 - Why are quantum computers useful 71 00:02:43.905 --> 00:02:44.724 - for simulating 72 00:02:45.025 --> 00:02:46.805 - particle physics collisions? 73 00:02:47.264 --> 00:02:49.205 - And, you know, in comparison to 74 00:02:49.504 --> 00:02:50.004 - conventional 75 00:02:50.385 --> 00:02:50.885 - supercomputers. 76 00:02:52.330 --> 00:02:54.490 - Yeah. It's it's a great question. So but 77 00:02:54.490 --> 00:02:56.509 - first of all, how are quantum computers different? 78 00:02:56.889 --> 00:02:58.889 - So classical computers are kind of written in 79 00:02:58.889 --> 00:03:02.169 - this language of of binary bits. So zeros 80 00:03:02.169 --> 00:03:03.449 - and ones you might have seen in the 81 00:03:03.449 --> 00:03:05.530 - movies. Lots of zeros, lots of ones. But 82 00:03:05.530 --> 00:03:06.030 - crucially, 83 00:03:06.344 --> 00:03:08.905 - it's a zero or a one for any 84 00:03:08.905 --> 00:03:12.185 - given bit. Whereas a quantum computer, because of 85 00:03:12.185 --> 00:03:13.485 - the principle of superposition, 86 00:03:14.425 --> 00:03:16.745 - a quantum bit or a qubit as we 87 00:03:16.745 --> 00:03:18.985 - call it, can be in zero and one 88 00:03:18.985 --> 00:03:20.610 - at the same time. So what that means 89 00:03:20.610 --> 00:03:22.550 - is that we can evolve two possibilities 90 00:03:23.009 --> 00:03:25.889 - at once. And if you have two qubits, 91 00:03:25.889 --> 00:03:28.870 - then there's four possibilities. You have zero zero, 92 00:03:28.930 --> 00:03:31.409 - one one, zero one, and one zero. So 93 00:03:31.409 --> 00:03:32.469 - you have four possibilities 94 00:03:32.930 --> 00:03:34.229 - that you can evolve simultaneously. 95 00:03:34.844 --> 00:03:37.085 - And, actually, as you keep growing this number 96 00:03:37.085 --> 00:03:39.185 - of qubits, so you have n qubits, 97 00:03:39.965 --> 00:03:42.044 - then that scales as two to the power 98 00:03:42.044 --> 00:03:45.264 - of n. So that's mathematically, that's an exponential. 99 00:03:45.564 --> 00:03:47.324 - So when we say it grows exponentially, we 100 00:03:47.324 --> 00:03:49.610 - really we're not saying that colloquially. We mean 101 00:03:49.610 --> 00:03:52.030 - it really does mathematically grow exponentially. 102 00:03:52.569 --> 00:03:54.909 - The number of possibilities that you can simulate 103 00:03:55.290 --> 00:03:57.450 - and evolve at the same time. So this 104 00:03:57.450 --> 00:03:59.129 - is where a lot of the power of 105 00:03:59.129 --> 00:04:00.830 - quantum computing comes from. 106 00:04:01.129 --> 00:04:03.465 - And the reason why it's particularly good 107 00:04:03.864 --> 00:04:04.444 - at simulating 108 00:04:05.064 --> 00:04:07.724 - quantum field theories or or quantum mechanical systems 109 00:04:08.264 --> 00:04:09.004 - is because 110 00:04:09.384 --> 00:04:12.185 - when you have some quantum mechanical system, you 111 00:04:12.185 --> 00:04:14.205 - may have heard that things can happen simultaneously 112 00:04:14.504 --> 00:04:16.120 - to a particle. If it wants to go 113 00:04:16.120 --> 00:04:18.199 - from a to b, it might take one 114 00:04:18.199 --> 00:04:19.479 - path, but it might take a different one 115 00:04:19.479 --> 00:04:21.560 - and a different one. And actually what quantum 116 00:04:21.560 --> 00:04:23.079 - mechanics says is that it takes all of 117 00:04:23.079 --> 00:04:24.459 - these paths simultaneously. 118 00:04:25.240 --> 00:04:27.639 - And if something has a certain energy level, 119 00:04:27.639 --> 00:04:29.319 - it can be in multiple energy levels at 120 00:04:29.319 --> 00:04:31.125 - the same time. So when we start doing 121 00:04:31.125 --> 00:04:32.504 - quantum mechanics calculations, 122 00:04:33.365 --> 00:04:36.404 - you very quickly realize that this system size 123 00:04:36.404 --> 00:04:37.705 - called the Hilbert space 124 00:04:38.085 --> 00:04:41.285 - grows exponentially as well. So it's really, really 125 00:04:41.285 --> 00:04:43.064 - difficult for a classical computer 126 00:04:43.444 --> 00:04:46.459 - to simulate these things. Whereas, as I was 127 00:04:46.459 --> 00:04:48.539 - just saying, this is the natural language of 128 00:04:48.539 --> 00:04:50.539 - a quantum computer. It can simulate these things 129 00:04:50.539 --> 00:04:52.800 - in exactly the same way, also grows exponentially. 130 00:04:53.180 --> 00:04:54.699 - So they're really good. They're kind of a 131 00:04:54.699 --> 00:04:57.579 - natural way to simulate quantum mechanics. Perhaps that's 132 00:04:57.579 --> 00:05:00.394 - unsurprising that a quantum computer is really good 133 00:05:00.394 --> 00:05:01.134 - at simulating 134 00:05:01.754 --> 00:05:02.735 - quantum physics. 135 00:05:03.194 --> 00:05:05.355 - So that's the goal. That's what we're trying 136 00:05:05.355 --> 00:05:08.074 - to we're trying to do with using quantum 137 00:05:08.074 --> 00:05:09.134 - computers. Yeah. 138 00:05:10.074 --> 00:05:12.475 - And and what's the the the state of 139 00:05:12.475 --> 00:05:14.394 - the art at the moment? So, you know, 140 00:05:14.394 --> 00:05:16.550 - quantum computing is a fairly 141 00:05:17.330 --> 00:05:17.990 - new technology. 142 00:05:18.689 --> 00:05:21.350 - Are the the quantum processors that are available 143 00:05:21.490 --> 00:05:21.990 - today, 144 00:05:22.770 --> 00:05:24.689 - are they up for the job? Are they 145 00:05:24.689 --> 00:05:25.589 - able to, 146 00:05:26.610 --> 00:05:28.870 - to sim to simulate meaningful 147 00:05:29.595 --> 00:05:32.314 - particle physics systems, or do we still have 148 00:05:32.314 --> 00:05:33.295 - a way to go, 149 00:05:34.074 --> 00:05:35.194 - in terms of getting, 150 00:05:35.675 --> 00:05:36.814 - practical results 151 00:05:37.194 --> 00:05:39.194 - out of a quantum computer when it comes 152 00:05:39.194 --> 00:05:40.254 - to particle physics? 153 00:05:41.675 --> 00:05:43.595 - Yeah. So there's kind of a few different 154 00:05:43.595 --> 00:05:44.639 - things there. I mean, so 155 00:05:45.199 --> 00:05:46.720 - the current state of the art will depend 156 00:05:46.720 --> 00:05:49.040 - who you ask. Specifically, it depends which company 157 00:05:49.040 --> 00:05:51.040 - you ask. But if you wanted just to 158 00:05:51.040 --> 00:05:52.960 - get a large array of cubits, I think 159 00:05:52.960 --> 00:05:55.280 - there's a a company that has done 6,000 160 00:05:55.280 --> 00:05:56.800 - cubits all in a all in a large 161 00:05:56.800 --> 00:05:58.584 - collection, and that's all well and good, but 162 00:05:58.584 --> 00:06:00.345 - they're not interacting. You can't use them to 163 00:06:00.345 --> 00:06:02.845 - calculate. In terms of a benchmark calculation, 164 00:06:03.944 --> 00:06:06.264 - so, yeah, chips are already being developed. You 165 00:06:06.264 --> 00:06:08.264 - have Google who have developed a chip that 166 00:06:08.264 --> 00:06:11.004 - they've called Willow, which is a 105 167 00:06:11.064 --> 00:06:11.564 - qubits. 168 00:06:12.600 --> 00:06:14.439 - So that's pretty powerful. I mean, if you 169 00:06:14.439 --> 00:06:16.520 - think about that in terms of classical bits, 170 00:06:16.520 --> 00:06:18.360 - that's not very lot at all. A 105 171 00:06:18.360 --> 00:06:18.860 - bits 172 00:06:19.240 --> 00:06:21.240 - of information isn't a lot. But when you 173 00:06:21.240 --> 00:06:23.080 - do two to the power of a 105 174 00:06:23.080 --> 00:06:24.620 - and think about the kind of possibilities 175 00:06:25.175 --> 00:06:27.495 - there, that is actually really powerful. In fact, 176 00:06:27.495 --> 00:06:28.555 - they did a calculation, 177 00:06:29.095 --> 00:06:30.455 - and this is kind of cheating a little 178 00:06:30.455 --> 00:06:32.375 - bit because they deliberately built the chip to 179 00:06:32.375 --> 00:06:34.455 - do the specific calculation. So I don't want 180 00:06:34.455 --> 00:06:36.375 - to oversell it, but it was built to 181 00:06:36.375 --> 00:06:38.055 - do a calculation, and it did it in 182 00:06:38.055 --> 00:06:40.910 - five minutes. And they calculated that the world's 183 00:06:40.910 --> 00:06:43.970 - largest, most powerful classical computer 184 00:06:44.590 --> 00:06:46.529 - would have done it in ten septillion 185 00:06:46.830 --> 00:06:47.330 - years. 186 00:06:47.790 --> 00:06:49.949 - So it would have taken a a huge 187 00:06:49.949 --> 00:06:52.185 - amount of time for a normal computer to 188 00:06:52.185 --> 00:06:53.165 - do the same calculation. 189 00:06:53.544 --> 00:06:56.824 - So they are already doing really powerful, interesting 190 00:06:56.824 --> 00:06:57.324 - calculations 191 00:06:58.024 --> 00:07:00.365 - using quantum computing chips. But how 192 00:07:00.904 --> 00:07:03.870 - relevant is that for the particle physics stuff? 193 00:07:04.269 --> 00:07:05.629 - Well, we're still a while off. I I 194 00:07:05.629 --> 00:07:07.790 - would say from both a theoretical and an 195 00:07:07.790 --> 00:07:09.470 - engineering point of view, we're kind of in 196 00:07:09.470 --> 00:07:12.449 - the foothills of this really exciting journey. 197 00:07:13.069 --> 00:07:14.449 - We're we're starting to do 198 00:07:14.750 --> 00:07:15.250 - benchmark 199 00:07:15.870 --> 00:07:17.009 - example calculations, 200 00:07:17.794 --> 00:07:19.074 - But in order to actually get them to 201 00:07:19.074 --> 00:07:21.254 - simulate real particle interactions, 202 00:07:21.714 --> 00:07:23.495 - that's quite difficult. And, actually, 203 00:07:24.514 --> 00:07:26.834 - the classical methods we have are really powerful. 204 00:07:26.834 --> 00:07:29.154 - We've been we've been developing them for for 205 00:07:29.154 --> 00:07:31.154 - decades. I say we have been in development 206 00:07:31.154 --> 00:07:32.399 - since before I was born. 207 00:07:33.360 --> 00:07:35.620 - So really, really well tested stuff. In fact, 208 00:07:36.160 --> 00:07:37.060 - quantum electrodynamics, 209 00:07:37.519 --> 00:07:38.819 - which is one of the 210 00:07:39.360 --> 00:07:42.240 - basically applications of our of our quantum mechanical 211 00:07:42.240 --> 00:07:42.740 - methods 212 00:07:43.279 --> 00:07:45.539 - is one of the most well experimentally 213 00:07:45.919 --> 00:07:46.979 - verified methods 214 00:07:47.345 --> 00:07:50.564 - in all of science. It's it's experimentally verified 215 00:07:50.865 --> 00:07:53.185 - at the Large Hadron Collider to about one 216 00:07:53.185 --> 00:07:54.725 - part in 1,000,000,000,000. 217 00:07:55.024 --> 00:07:56.944 - So that's I mean, just to give some 218 00:07:56.944 --> 00:07:58.004 - scale as to how 219 00:07:58.464 --> 00:08:01.169 - unbelievably accurate that is. That's like measuring the 220 00:08:01.169 --> 00:08:03.649 - length of The United Kingdom from from Lands' 221 00:08:03.649 --> 00:08:04.949 - End, Saviano Groats, 222 00:08:05.329 --> 00:08:07.250 - down to the width of a red blood 223 00:08:07.250 --> 00:08:09.649 - cell. In fact, it's more accurate than that. 224 00:08:09.649 --> 00:08:11.430 - So one part in a 1,000,000,000,000. 225 00:08:11.729 --> 00:08:13.705 - So really, really good methods. And so we 226 00:08:13.705 --> 00:08:15.625 - don't have to just get quantum computing to 227 00:08:15.625 --> 00:08:17.064 - work. We have to get it to be 228 00:08:17.064 --> 00:08:18.685 - even better than that, basically. 229 00:08:19.465 --> 00:08:20.824 - And so this is where that kind of 230 00:08:20.824 --> 00:08:22.045 - power of this simultaneously 231 00:08:22.824 --> 00:08:25.944 - evolving things. And, actually, what classical methods do 232 00:08:25.944 --> 00:08:27.944 - is they kind of do slight approximations because 233 00:08:27.944 --> 00:08:30.420 - they they can't do that. So there's certain 234 00:08:30.420 --> 00:08:32.919 - regimes where they can do calculations very well. 235 00:08:33.059 --> 00:08:35.620 - But to actually evolve a quantum system in 236 00:08:35.620 --> 00:08:37.620 - real time and kind of, like, press play, 237 00:08:37.620 --> 00:08:40.419 - press pause, inspect it, we can't do that. 238 00:08:40.419 --> 00:08:42.360 - Whereas a quantum computer perhaps could. 239 00:08:43.644 --> 00:08:45.184 - And and Ross, you mentioned, 240 00:08:46.524 --> 00:08:48.605 - a a quantum computer that was created to 241 00:08:48.605 --> 00:08:50.304 - solve a specific problem, 242 00:08:50.924 --> 00:08:53.644 - and it did so very well. Is that 243 00:08:53.644 --> 00:08:55.024 - is that sort of the idea 244 00:08:55.404 --> 00:08:58.850 - in how quantum computers would be used, at 245 00:08:58.850 --> 00:09:02.710 - least initially, to to solve particle physics problems? 246 00:09:03.170 --> 00:09:04.230 - The the architecture 247 00:09:04.610 --> 00:09:06.790 - of the quantum computer would be designed 248 00:09:07.250 --> 00:09:08.550 - such that it was 249 00:09:08.930 --> 00:09:10.070 - somehow similar 250 00:09:10.370 --> 00:09:10.870 - to 251 00:09:11.490 --> 00:09:12.629 - a particle collision 252 00:09:13.044 --> 00:09:15.125 - that you were interested in? Is is is 253 00:09:15.125 --> 00:09:17.125 - that one way of, you know, sort of 254 00:09:17.125 --> 00:09:17.625 - accelerating 255 00:09:18.004 --> 00:09:19.845 - the use of of, 256 00:09:20.325 --> 00:09:22.184 - of quantum computers? Actually, 257 00:09:22.565 --> 00:09:23.544 - making the architecture 258 00:09:24.245 --> 00:09:25.384 - fit the problem. 259 00:09:25.850 --> 00:09:27.370 - Yeah. I mean, that's a really, really good 260 00:09:27.370 --> 00:09:28.830 - point. And that that is exactly 261 00:09:29.370 --> 00:09:31.450 - the the way forward, I think. So the 262 00:09:31.450 --> 00:09:32.809 - era that we're in at the moment is 263 00:09:32.809 --> 00:09:35.129 - called the NISQ era, n I s q, 264 00:09:35.129 --> 00:09:38.750 - stands for noisy intermediate scale quantum era. 265 00:09:39.095 --> 00:09:41.254 - So the noisy is really the the the 266 00:09:41.254 --> 00:09:42.695 - main part about that. And what that means 267 00:09:42.695 --> 00:09:44.855 - is that we can't error correct. So we 268 00:09:44.855 --> 00:09:46.535 - can't we take a bunch of qubits and 269 00:09:46.535 --> 00:09:48.315 - they're really susceptible to 270 00:09:48.855 --> 00:09:51.434 - changes because of their interaction with the environment. 271 00:09:51.495 --> 00:09:52.955 - They're really hard to isolate. 272 00:09:53.330 --> 00:09:54.450 - So what we have to do is we 273 00:09:54.450 --> 00:09:55.649 - have to kind of get a group of 274 00:09:55.649 --> 00:09:57.990 - qubits to all fact check each other constantly. 275 00:09:58.450 --> 00:10:00.450 - That's how we do quantum error correction, but 276 00:10:00.450 --> 00:10:02.690 - that is currently the engineering challenge that everyone 277 00:10:02.690 --> 00:10:03.990 - is trying to to overcome. 278 00:10:04.450 --> 00:10:06.049 - So we're kind of in that era at 279 00:10:06.049 --> 00:10:07.794 - the moment, and what that means is that 280 00:10:07.794 --> 00:10:10.595 - we don't have fault tolerant quantum computing, but 281 00:10:10.595 --> 00:10:12.914 - we also don't have we're not really close 282 00:10:12.914 --> 00:10:15.394 - to. We're probably twenty, thirty years away from 283 00:10:15.394 --> 00:10:17.794 - a fully programmable quantum computer. So if you 284 00:10:17.794 --> 00:10:19.519 - think about your laptop, you can do all 285 00:10:19.519 --> 00:10:22.259 - sorts on your laptop. It's it's very programmable. 286 00:10:22.639 --> 00:10:23.139 - Right? 287 00:10:23.679 --> 00:10:26.159 - So because that's so far away, you're exactly 288 00:10:26.159 --> 00:10:28.159 - right. We can instead build devices that are 289 00:10:28.159 --> 00:10:29.699 - kind of purpose built. Imagine 290 00:10:30.000 --> 00:10:32.079 - like a calculator. A calculator is a really 291 00:10:32.079 --> 00:10:34.735 - useful device. A calculator is really good at 292 00:10:34.735 --> 00:10:36.415 - maths, but it's not gonna tell you the 293 00:10:36.415 --> 00:10:38.654 - weather. You know? So if you wanted to 294 00:10:38.654 --> 00:10:40.894 - have a purpose built device, you can exactly 295 00:10:40.894 --> 00:10:43.535 - do that. Firstly, with the architecture, so, yeah, 296 00:10:43.535 --> 00:10:45.054 - so you can you can design it in 297 00:10:45.054 --> 00:10:45.870 - such a way 298 00:10:46.350 --> 00:10:48.750 - using a certain medium that it might be 299 00:10:48.750 --> 00:10:49.809 - specifically good 300 00:10:50.190 --> 00:10:51.629 - at. So, for example, when I talk about 301 00:10:51.629 --> 00:10:53.789 - these qubits, they seem like quite abstract ideas, 302 00:10:53.789 --> 00:10:55.950 - but the actual candidates for qubits are things 303 00:10:55.950 --> 00:10:57.250 - like cold atoms, 304 00:10:57.789 --> 00:10:58.690 - trapped ions, 305 00:10:59.309 --> 00:10:59.809 - photons. 306 00:11:00.355 --> 00:11:02.674 - Each one of them has pros and cons. 307 00:11:02.674 --> 00:11:05.075 - And so for specific calculations, you might want 308 00:11:05.075 --> 00:11:06.215 - to use different ones. 309 00:11:06.595 --> 00:11:08.835 - So there's lots of investment in which one's 310 00:11:08.835 --> 00:11:11.254 - gonna be the best for a fully programmable 311 00:11:11.554 --> 00:11:13.394 - quantum computer, but actually they all have their 312 00:11:13.394 --> 00:11:14.134 - own advantages. 313 00:11:15.300 --> 00:11:16.660 - So yeah. And and one of the things 314 00:11:16.660 --> 00:11:18.519 - that I do in my research is 315 00:11:19.059 --> 00:11:20.660 - I say, well, it's all well and good 316 00:11:20.660 --> 00:11:22.660 - trying to build a quantum computer, but if 317 00:11:22.660 --> 00:11:24.340 - you put one in front of me, the 318 00:11:24.340 --> 00:11:24.840 - world 319 00:11:25.379 --> 00:11:27.884 - at the moment doesn't have a set of 320 00:11:27.884 --> 00:11:29.725 - algorithms to run on it, to actually do 321 00:11:29.725 --> 00:11:31.565 - the stuff that we want to do. So 322 00:11:31.565 --> 00:11:32.784 - I'm coming up with 323 00:11:33.164 --> 00:11:35.644 - architecture in the theoretical sense. I'm coming up 324 00:11:35.644 --> 00:11:38.684 - with circuits and algorithms that we could actually 325 00:11:38.684 --> 00:11:41.230 - put onto a quantum computer to get it 326 00:11:41.230 --> 00:11:42.830 - to do the stuff we want to do. 327 00:11:42.830 --> 00:11:44.590 - And so that's the kind of stuff that 328 00:11:44.590 --> 00:11:45.410 - we have to build 329 00:11:46.110 --> 00:11:49.230 - kind of in parallel to the engineering challenges 330 00:11:49.230 --> 00:11:51.009 - for lots of companies are trying to overcome. 331 00:11:52.190 --> 00:11:54.565 - And and what about the idea of, you 332 00:11:54.565 --> 00:11:56.985 - know, you mentioned that conventional supercomputing 333 00:11:57.365 --> 00:11:58.425 - is very advanced 334 00:11:58.965 --> 00:12:00.985 - when it comes to, understanding 335 00:12:01.445 --> 00:12:04.884 - particle physics or doing simulations on particle physics. 336 00:12:04.884 --> 00:12:06.644 - Is I mean, is part of the way 337 00:12:06.644 --> 00:12:10.090 - forward to to only use the quantum processor 338 00:12:10.790 --> 00:12:12.809 - to do a specific calculation 339 00:12:13.110 --> 00:12:15.930 - that would take ages on the supercomputer, 340 00:12:16.550 --> 00:12:19.190 - and then sort of feed that information back 341 00:12:19.190 --> 00:12:21.590 - into the supercomputer, and back and forth, and 342 00:12:21.590 --> 00:12:23.745 - back and forth. So you would use the 343 00:12:23.745 --> 00:12:24.725 - quantum computer 344 00:12:25.184 --> 00:12:27.684 - as a sort of, well, auxiliary 345 00:12:28.865 --> 00:12:31.664 - processor or something that can do one thing 346 00:12:31.664 --> 00:12:32.404 - very well. 347 00:12:34.225 --> 00:12:36.245 - Yeah. Is that a way forward? 348 00:12:36.669 --> 00:12:38.669 - Yeah. 100%. So it's kind of a hybrid 349 00:12:38.669 --> 00:12:42.210 - computing, part quantum, part classical. That's really important. 350 00:12:42.350 --> 00:12:43.870 - Firstly, because there's a bunch of stuff that 351 00:12:43.870 --> 00:12:45.549 - classical computers are very good at, and we've 352 00:12:45.549 --> 00:12:47.549 - already got them to do. And, actually, the 353 00:12:47.549 --> 00:12:49.149 - quantum computer, we don't need it to do 354 00:12:49.149 --> 00:12:50.904 - and it and actually quite difficult. So for 355 00:12:50.904 --> 00:12:51.965 - example, readout, 356 00:12:52.424 --> 00:12:54.424 - reading out a measurement, we know how to 357 00:12:54.424 --> 00:12:56.345 - do that classically. It might be quite hard 358 00:12:56.345 --> 00:12:58.345 - to do quantum mechanically. So as long as 359 00:12:58.345 --> 00:12:59.945 - we get the kind of hard part of 360 00:12:59.945 --> 00:13:00.605 - the calculation 361 00:13:01.544 --> 00:13:02.365 - kind of bootstrapped 362 00:13:02.709 --> 00:13:04.789 - onto a quantum computer, then that's where the 363 00:13:04.789 --> 00:13:07.830 - real advantage lies. It's also worth saying, again, 364 00:13:07.830 --> 00:13:09.509 - there's a lot of hype and and rightly 365 00:13:09.509 --> 00:13:11.029 - so, and I'm very excited about it. It's 366 00:13:11.029 --> 00:13:12.709 - why I've chosen to research it for my 367 00:13:12.709 --> 00:13:15.909 - my job. Right? But it's important not to 368 00:13:15.909 --> 00:13:16.815 - overstate that 369 00:13:17.294 --> 00:13:21.154 - quantum computers will never completely replace classical computers. 370 00:13:21.615 --> 00:13:22.894 - I don't think we will ever live in 371 00:13:22.894 --> 00:13:25.774 - a world where no one has phones, laptops, 372 00:13:25.774 --> 00:13:28.254 - whatever equivalent there is that's running on this 373 00:13:28.254 --> 00:13:30.914 - kind of classical baseline of digital bits, 374 00:13:31.490 --> 00:13:33.169 - and everything is quantum. I don't think that 375 00:13:33.169 --> 00:13:35.089 - would be the case. I think the most 376 00:13:35.089 --> 00:13:37.169 - optimal way will be a hybrid of the 377 00:13:37.169 --> 00:13:38.549 - two, exactly like you say. 378 00:13:39.490 --> 00:13:41.750 - And and what in terms of, 379 00:13:42.450 --> 00:13:45.169 - sort of general areas of particle physics that 380 00:13:45.169 --> 00:13:48.495 - could benefit from quantum computing. You you mentioned 381 00:13:48.554 --> 00:13:49.054 - quantum 382 00:13:49.595 --> 00:13:50.095 - electrodynamics, 383 00:13:51.595 --> 00:13:53.134 - but then there's quantum chromodynamics, 384 00:13:53.675 --> 00:13:54.415 - which is 385 00:13:54.875 --> 00:13:55.375 - extraordinarily 386 00:13:56.075 --> 00:13:56.575 - difficult 387 00:13:57.115 --> 00:13:59.774 - to to do any calculations, really. 388 00:14:00.419 --> 00:14:02.340 - You know, this is the the the physics 389 00:14:02.340 --> 00:14:03.159 - that describes, 390 00:14:04.019 --> 00:14:07.399 - how quarks behave inside protons and neutrons. 391 00:14:09.339 --> 00:14:12.200 - It that is a very difficult problem, computationally. 392 00:14:13.434 --> 00:14:13.934 - Will 393 00:14:14.394 --> 00:14:16.894 - quantum computing help with that? 394 00:14:17.674 --> 00:14:19.774 - Is it is that sort of a quantum 395 00:14:20.315 --> 00:14:23.995 - computing friendly problem where lots of progress could 396 00:14:23.995 --> 00:14:24.654 - be made? 397 00:14:25.720 --> 00:14:28.300 - Yeah. Absolutely. So for a few different reasons. 398 00:14:28.360 --> 00:14:29.580 - So so firstly, 399 00:14:30.040 --> 00:14:30.540 - quantum 400 00:14:30.920 --> 00:14:31.420 - chromodynamics 401 00:14:32.200 --> 00:14:33.980 - quite often in certain energy limits 402 00:14:34.440 --> 00:14:36.600 - doesn't play well with perturbation theory, which is 403 00:14:36.600 --> 00:14:39.240 - our usual toolbox for quantum mechanics, which basically 404 00:14:39.240 --> 00:14:40.634 - just means that if you have a small 405 00:14:40.634 --> 00:14:42.654 - enough coupling constant, you can 406 00:14:44.554 --> 00:14:48.235 - expand your maths in different terms that are 407 00:14:48.235 --> 00:14:49.615 - in less and less important. 408 00:14:50.074 --> 00:14:52.074 - Whereas in quantum chromodynamics, that's often not the 409 00:14:52.074 --> 00:14:53.274 - case, and so what they do is they 410 00:14:53.274 --> 00:14:55.375 - call they do something called lattice QCD, 411 00:14:56.370 --> 00:14:58.210 - which is really interesting in and of its 412 00:14:58.210 --> 00:15:00.769 - own right and very, very well experimentally tested, 413 00:15:00.769 --> 00:15:01.269 - and 414 00:15:01.649 --> 00:15:03.190 - the theory there is really good. 415 00:15:03.570 --> 00:15:05.090 - But wouldn't it be great if we could 416 00:15:05.090 --> 00:15:07.330 - real time evolve of these these quarks and 417 00:15:07.330 --> 00:15:09.269 - these quantum chromodynamic particles 418 00:15:09.774 --> 00:15:12.414 - and actually inspect it in real time, real 419 00:15:12.414 --> 00:15:14.414 - time quantum field theory. That's the kind of 420 00:15:14.414 --> 00:15:16.254 - the stuff that I'm interested in. And it's 421 00:15:16.254 --> 00:15:18.014 - also worth saying that there's lots of other 422 00:15:18.014 --> 00:15:20.434 - things in quantum chromodynamics that expand 423 00:15:21.054 --> 00:15:22.740 - massively. So, for example, color 424 00:15:23.539 --> 00:15:25.459 - color flow. So color, this red, green, or 425 00:15:25.459 --> 00:15:27.459 - blue, is how we label quarks. Each one 426 00:15:27.459 --> 00:15:29.379 - of them has their own color. It's the 427 00:15:29.379 --> 00:15:30.519 - charge of QCD, 428 00:15:31.139 --> 00:15:32.899 - kind of like how electric charge is the 429 00:15:32.899 --> 00:15:35.299 - charge of QED. Right? So you have this 430 00:15:35.299 --> 00:15:36.039 - this color, 431 00:15:36.375 --> 00:15:37.975 - And the number of color states as as 432 00:15:37.975 --> 00:15:40.934 - as your your your gluons and your quarks 433 00:15:40.934 --> 00:15:43.174 - and all of these, they explode in these 434 00:15:43.174 --> 00:15:43.674 - jets. 435 00:15:44.134 --> 00:15:46.695 - That grows factorially. So it's actually even worse 436 00:15:46.695 --> 00:15:49.195 - than exponentially. So it's it's impossible 437 00:15:49.575 --> 00:15:50.879 - impossible to do 438 00:15:51.679 --> 00:15:53.220 - on a classical computer 439 00:15:53.600 --> 00:15:56.080 - a 100% accurately. Again, there's a lot of 440 00:15:56.080 --> 00:15:58.240 - really good work that's being done to try 441 00:15:58.240 --> 00:16:01.039 - and model these parton showers. But if we 442 00:16:01.039 --> 00:16:03.759 - can get a a quantum computer to attack 443 00:16:03.759 --> 00:16:05.279 - this problem, I think it would be really, 444 00:16:05.279 --> 00:16:06.225 - really useful. Yeah? 445 00:16:07.504 --> 00:16:11.105 - And and another, sort of computational technique that, 446 00:16:12.144 --> 00:16:14.704 - I suppose is of great interest to, 447 00:16:15.105 --> 00:16:16.884 - particle physicists is 448 00:16:17.264 --> 00:16:19.250 - artificial intelligence. Can 449 00:16:20.350 --> 00:16:22.289 - you talk a bit about how, 450 00:16:22.669 --> 00:16:23.889 - artificial intelligence 451 00:16:24.990 --> 00:16:26.990 - is is being used and could be used 452 00:16:26.990 --> 00:16:27.490 - by, 453 00:16:28.190 --> 00:16:29.169 - particle physicists, 454 00:16:29.629 --> 00:16:31.730 - you know, maybe in the context of quantum 455 00:16:31.789 --> 00:16:32.289 - computing? 456 00:16:33.195 --> 00:16:35.995 - Yeah. Absolutely. I mean, firstly, just at the 457 00:16:35.995 --> 00:16:37.915 - the kind of easy level of, like, how 458 00:16:37.915 --> 00:16:39.355 - do I use AI on a day to 459 00:16:39.355 --> 00:16:41.055 - day basis and the way that it's transformed 460 00:16:41.115 --> 00:16:43.355 - my life. I mean, throughout my PhD, I 461 00:16:43.355 --> 00:16:45.675 - didn't have access to AI. And so when 462 00:16:45.675 --> 00:16:48.095 - I coded something that would be time consuming 463 00:16:48.440 --> 00:16:50.440 - or doing a literature review, obviously, I still 464 00:16:50.440 --> 00:16:51.959 - go away and read lots of papers. But 465 00:16:51.959 --> 00:16:54.220 - finding papers, I would essentially just be using 466 00:16:54.279 --> 00:16:55.980 - Google or looking in journals. 467 00:16:56.519 --> 00:16:58.519 - AI right now is really useful for physicists 468 00:16:58.519 --> 00:17:01.720 - across the world for accelerating the coding process. 469 00:17:01.720 --> 00:17:03.399 - You still have to double check it because 470 00:17:03.399 --> 00:17:06.274 - it can often be be incorrect, but also 471 00:17:06.654 --> 00:17:08.174 - giving you a group of papers to go 472 00:17:08.174 --> 00:17:09.855 - away and read, and you can decide whether 473 00:17:09.855 --> 00:17:11.694 - they're relevant. And often, it does a pretty 474 00:17:11.694 --> 00:17:13.454 - good job of giving you a batch of 475 00:17:13.454 --> 00:17:16.335 - papers to familiarize yourself with the field. So 476 00:17:16.335 --> 00:17:19.049 - that's kind of the the low entry level 477 00:17:19.049 --> 00:17:20.970 - way that AIB is used by me at 478 00:17:20.970 --> 00:17:22.809 - least on a day to day basis. They're 479 00:17:22.809 --> 00:17:24.809 - kind of like blue skies idea, the stuff 480 00:17:24.809 --> 00:17:27.609 - that I'm also working on in terms of 481 00:17:27.609 --> 00:17:29.150 - AI and machine learning. 482 00:17:29.734 --> 00:17:32.234 - Is can we apply these to kind 483 00:17:33.575 --> 00:17:35.894 - of fit quantum algorithms in a way that 484 00:17:35.894 --> 00:17:38.234 - often quantum mechanics is is really counterintuitive. 485 00:17:39.174 --> 00:17:41.654 - So maybe we're thinking about it in the 486 00:17:41.654 --> 00:17:43.529 - wrong way when we try and come up 487 00:17:43.529 --> 00:17:46.269 - with quantum circuits. In fact, it is very 488 00:17:46.730 --> 00:17:49.049 - common that someone comes up with a quantum 489 00:17:49.049 --> 00:17:51.869 - algorithm that is essentially just a classical algorithm, 490 00:17:52.170 --> 00:17:54.090 - but written in the language of qubits and 491 00:17:54.090 --> 00:17:54.990 - actually isn't 492 00:17:55.304 --> 00:17:58.504 - using things like superposition and entanglement to actually 493 00:17:58.504 --> 00:18:00.125 - gain any kind of advantage. 494 00:18:00.504 --> 00:18:03.404 - And so that circuit is never gonna actually 495 00:18:03.704 --> 00:18:05.565 - be better than a classical computer. 496 00:18:05.865 --> 00:18:06.365 - So 497 00:18:06.744 --> 00:18:07.884 - maybe AI 498 00:18:08.440 --> 00:18:10.200 - can work to kind of come up with 499 00:18:10.200 --> 00:18:12.119 - new quantum circuits. And in fact, that is 500 00:18:12.119 --> 00:18:14.200 - being done. There are research groups around the 501 00:18:14.200 --> 00:18:16.119 - world that are kind of trying to come 502 00:18:16.119 --> 00:18:18.359 - up with almost a large language model, but 503 00:18:18.359 --> 00:18:19.740 - for quantum algorithms. 504 00:18:20.085 --> 00:18:22.404 - So that's a really interesting and a niche 505 00:18:22.404 --> 00:18:23.704 - area that that 506 00:18:24.085 --> 00:18:26.804 - excites me a lot. But also machine learning 507 00:18:26.804 --> 00:18:28.005 - says something that I want to try and 508 00:18:28.005 --> 00:18:28.744 - do is 509 00:18:29.125 --> 00:18:31.284 - when we evolve these quantum systems and there's 510 00:18:31.284 --> 00:18:33.065 - there's infinite number of possibilities, 511 00:18:34.085 --> 00:18:35.784 - and formally, you have to 512 00:18:36.140 --> 00:18:38.460 - sum up every single possibility. So how do 513 00:18:38.460 --> 00:18:39.980 - you do an infinite sum? Well, it's very 514 00:18:39.980 --> 00:18:40.480 - difficult. 515 00:18:40.940 --> 00:18:42.080 - And so often, 516 00:18:42.460 --> 00:18:45.259 - computationally, that's impossible. So you have to come 517 00:18:45.259 --> 00:18:47.900 - up with tricks and you have to think, 518 00:18:47.900 --> 00:18:50.140 - okay. Well, which paths are actually important and 519 00:18:50.140 --> 00:18:51.440 - which ones aren't important? 520 00:18:51.904 --> 00:18:53.664 - Or maybe a machine learning model could learn 521 00:18:53.664 --> 00:18:55.585 - that for us. And maybe in the process 522 00:18:55.585 --> 00:18:57.825 - of doing that, it will reveal something about 523 00:18:57.825 --> 00:19:00.544 - quantum mechanics that we don't yet know. So 524 00:19:00.544 --> 00:19:01.904 - these are the kind of ways I want 525 00:19:01.904 --> 00:19:04.164 - to apply AI and machine learning. 526 00:19:05.230 --> 00:19:07.089 - And what what about your colleagues, 527 00:19:07.549 --> 00:19:10.429 - you know, who run particle physics experiments? I 528 00:19:10.429 --> 00:19:11.569 - would imagine that 529 00:19:12.029 --> 00:19:13.490 - AI and machine learning 530 00:19:14.109 --> 00:19:15.889 - is becoming really important 531 00:19:16.349 --> 00:19:19.125 - in in helping them deal with the the 532 00:19:19.125 --> 00:19:21.605 - sort of deluge of data that comes out 533 00:19:21.605 --> 00:19:21.845 - of, 534 00:19:22.724 --> 00:19:25.684 - an experiment on the Large Hadron Collider, for 535 00:19:25.684 --> 00:19:26.184 - example? 536 00:19:26.884 --> 00:19:29.125 - Yeah. I mean, this is, again, great question, 537 00:19:29.125 --> 00:19:31.525 - brilliant point, and and actually quite relevant to 538 00:19:31.525 --> 00:19:33.900 - another thing that I'm working on, actually. So, 539 00:19:34.279 --> 00:19:34.779 - basically, 540 00:19:35.799 --> 00:19:37.559 - Abelard, Hadron Collider, for those who don't know, 541 00:19:37.559 --> 00:19:40.759 - it it's billions of particle interactions per second 542 00:19:40.759 --> 00:19:43.079 - when it when it's running. So these datasets 543 00:19:43.079 --> 00:19:44.920 - are some of the biggest datasets in the 544 00:19:44.920 --> 00:19:47.465 - world, and it's not just one bit of 545 00:19:47.465 --> 00:19:49.945 - data for each particle. You you get its 546 00:19:49.945 --> 00:19:51.705 - momentum. You can get scattering angles. You get 547 00:19:51.705 --> 00:19:53.865 - all all sorts of things. So this dataset 548 00:19:53.865 --> 00:19:55.404 - is really massive. And so 549 00:19:55.865 --> 00:19:58.365 - scouring through it and trying to find interesting 550 00:19:58.585 --> 00:20:00.765 - bumps in the data that you weren't predicting 551 00:20:00.825 --> 00:20:02.160 - that might reveal new physics, 552 00:20:02.720 --> 00:20:04.640 - That's a really difficult thing. Again, it has 553 00:20:04.640 --> 00:20:06.080 - been done very well. I mean, the Higgs 554 00:20:06.080 --> 00:20:09.539 - particle in 2012 was discovered using classical techniques. 555 00:20:10.000 --> 00:20:10.500 - So 556 00:20:11.039 --> 00:20:11.539 - it's 557 00:20:11.840 --> 00:20:12.740 - doing really well, 558 00:20:13.119 --> 00:20:15.855 - but machine learning absolutely is being used 559 00:20:16.815 --> 00:20:18.595 - to essentially try and spot patterns 560 00:20:18.974 --> 00:20:20.275 - in the data 561 00:20:20.654 --> 00:20:22.894 - in a much quicker, much more efficient way, 562 00:20:22.894 --> 00:20:24.755 - and perhaps in a in a novel way 563 00:20:24.815 --> 00:20:27.134 - using techniques that we might not have thought 564 00:20:27.134 --> 00:20:27.634 - of 565 00:20:27.980 --> 00:20:28.720 - in order 566 00:20:29.019 --> 00:20:29.680 - to discover 567 00:20:30.140 --> 00:20:32.000 - new particles or new structures 568 00:20:32.380 --> 00:20:34.700 - in the standard model. So, for example, something 569 00:20:34.700 --> 00:20:36.859 - I'm working on is, can we map this 570 00:20:36.859 --> 00:20:38.859 - to a quantum computer? So can we take 571 00:20:38.859 --> 00:20:39.519 - the final 572 00:20:39.900 --> 00:20:41.184 - state particles, 573 00:20:41.484 --> 00:20:42.545 - take their momenta, 574 00:20:43.404 --> 00:20:45.105 - map it onto a bunch of qubits, 575 00:20:45.724 --> 00:20:47.884 - and then entangle those qubits in such a 576 00:20:47.884 --> 00:20:50.684 - way that we try to mirror some of 577 00:20:50.684 --> 00:20:53.325 - the correlations that you might expect between these 578 00:20:53.325 --> 00:20:54.384 - final state particles. 579 00:20:55.250 --> 00:20:56.309 - So we entangle 580 00:20:57.089 --> 00:20:59.809 - pairwise entangle the final state particles, and then 581 00:20:59.809 --> 00:21:02.529 - we run a machine learning code on this 582 00:21:02.529 --> 00:21:03.589 - network of qubits. 583 00:21:03.970 --> 00:21:04.470 - And 584 00:21:04.849 --> 00:21:07.809 - can this quantum computing and machine learning work 585 00:21:07.809 --> 00:21:10.595 - together to potentially give us an advantage over 586 00:21:10.595 --> 00:21:12.535 - traditional machine learning methods. 587 00:21:12.994 --> 00:21:15.554 - So some really exciting stuff there, but absolutely 588 00:21:15.554 --> 00:21:17.494 - machine learning and AI is being used 589 00:21:17.954 --> 00:21:21.234 - and being used increasingly more in particle physics 590 00:21:21.234 --> 00:21:22.595 - and a lot of my colleagues at the 591 00:21:22.595 --> 00:21:23.095 - LHC. 592 00:21:24.710 --> 00:21:25.909 - So it sounds like, 593 00:21:26.389 --> 00:21:28.549 - so so the LHC at the moment, I'm 594 00:21:28.549 --> 00:21:30.710 - I'm not sure if it's is it shut 595 00:21:30.710 --> 00:21:33.049 - down for the high luminosity 596 00:21:33.509 --> 00:21:35.529 - upgrade or is it Yeah. It's about to. 597 00:21:35.589 --> 00:21:38.815 - About to. Right. So, you know, that's going 598 00:21:38.815 --> 00:21:41.294 - to take a few years. And, I mean, 599 00:21:41.294 --> 00:21:43.934 - I would imagine that when the LHC is 600 00:21:43.934 --> 00:21:45.554 - back and up and running, 601 00:21:46.894 --> 00:21:48.174 - I mean, is it going to be a 602 00:21:48.174 --> 00:21:51.214 - different world for particle physicists? Because all these 603 00:21:51.214 --> 00:21:53.400 - machine learning and AI techniques 604 00:21:53.940 --> 00:21:54.839 - will have been 605 00:21:55.220 --> 00:21:55.720 - developed 606 00:21:56.179 --> 00:21:56.679 - and, 607 00:21:57.140 --> 00:21:57.640 - matured. 608 00:21:58.339 --> 00:22:01.079 - And also, you know, we we've got another 609 00:22:01.140 --> 00:22:02.839 - few years of quantum computing 610 00:22:03.380 --> 00:22:05.380 - progress to be made. I mean, you I 611 00:22:05.380 --> 00:22:07.214 - I mean, it sounds to me like you, 612 00:22:07.694 --> 00:22:10.115 - and your colleagues should be very excited 613 00:22:11.054 --> 00:22:11.554 - about, 614 00:22:12.095 --> 00:22:14.894 - a new sort of paradigm in how you 615 00:22:14.894 --> 00:22:15.375 - can, 616 00:22:15.855 --> 00:22:18.894 - interpret data from the LHC, and lots more 617 00:22:18.894 --> 00:22:19.394 - data, 618 00:22:20.490 --> 00:22:22.250 - that that is a result of the of 619 00:22:22.250 --> 00:22:24.250 - the upgrade. I mean, it it must be 620 00:22:24.250 --> 00:22:25.070 - very exciting. 621 00:22:25.609 --> 00:22:27.769 - Yeah. Well, exactly. And that point, if I 622 00:22:27.769 --> 00:22:28.970 - made it there at the end, is is 623 00:22:28.970 --> 00:22:30.330 - the crucial one. I mean, it's coming at 624 00:22:30.330 --> 00:22:32.170 - the right time. There's this high luminosity upgrade 625 00:22:32.170 --> 00:22:34.164 - is gonna give even more data. So that 626 00:22:34.164 --> 00:22:36.085 - would almost be quite scary if we weren't 627 00:22:36.085 --> 00:22:38.404 - equipped with the right tools to combat that, 628 00:22:38.404 --> 00:22:40.404 - and that's exactly what AI and machine learning 629 00:22:40.404 --> 00:22:42.404 - give us access to. And also, it's worth 630 00:22:42.404 --> 00:22:43.525 - saying that, I mean, a lot of my 631 00:22:43.525 --> 00:22:46.210 - work, I don't work directly with datasets of 632 00:22:46.210 --> 00:22:47.970 - a large Hadron Collider often, and the kind 633 00:22:47.970 --> 00:22:49.190 - of stuff that interests me 634 00:22:49.650 --> 00:22:53.430 - in parallel is this simulation using quantum computers 635 00:22:53.730 --> 00:22:54.309 - to simulate 636 00:22:54.690 --> 00:22:55.670 - particle interactions. 637 00:22:56.210 --> 00:22:57.730 - So we can build that on a a 638 00:22:57.730 --> 00:22:58.789 - tabletop experiment. 639 00:22:59.794 --> 00:23:02.434 - Obviously, we need probably thousands and thousands at 640 00:23:02.434 --> 00:23:03.815 - least of qubits. 641 00:23:04.275 --> 00:23:05.634 - So that might be a little while away, 642 00:23:05.634 --> 00:23:07.474 - but I can think of the algorithms now 643 00:23:07.474 --> 00:23:09.075 - and say one day when you give me 644 00:23:09.075 --> 00:23:11.154 - a tabletop of qubits, this is what I'm 645 00:23:11.154 --> 00:23:12.775 - gonna run and I'm gonna simulate 646 00:23:13.079 --> 00:23:15.079 - a particle interaction. And so we can kind 647 00:23:15.079 --> 00:23:17.339 - of attack it from two angles, top down 648 00:23:17.400 --> 00:23:19.400 - at the LHC. Look at all this data. 649 00:23:19.400 --> 00:23:21.880 - Let's go deep diving into it. And bottom 650 00:23:21.880 --> 00:23:24.539 - up from tabletop quantum computing experiments. 651 00:23:24.839 --> 00:23:27.400 - Let's try and build a simulation of these 652 00:23:27.400 --> 00:23:28.804 - and see if we can expect it from 653 00:23:28.804 --> 00:23:31.065 - below. So we can kind of pincer movement, 654 00:23:31.444 --> 00:23:33.605 - the the standard model of the universe, and 655 00:23:33.605 --> 00:23:35.384 - try and understand more about it. 656 00:23:36.724 --> 00:23:39.125 - And, Ross, I wanted to to shift gears 657 00:23:39.125 --> 00:23:41.224 - a bit and and talk about 658 00:23:41.529 --> 00:23:44.829 - how quantum computers could be used to 659 00:23:45.609 --> 00:23:48.190 - to, I suppose, solve one of the the 660 00:23:48.410 --> 00:23:49.470 - the biggest challenges 661 00:23:49.769 --> 00:23:52.750 - facing physicists at the moment, and that is 662 00:23:52.890 --> 00:23:53.390 - developing 663 00:23:53.769 --> 00:23:54.589 - a viable 664 00:23:55.454 --> 00:23:55.954 - quantum 665 00:23:56.255 --> 00:23:58.815 - theory of gravity. You know, at the moment, 666 00:23:58.815 --> 00:24:00.194 - quantum mechanics is 667 00:24:00.494 --> 00:24:01.234 - an extraordinarily 668 00:24:02.494 --> 00:24:03.714 - successful theory. 669 00:24:04.174 --> 00:24:05.394 - And, Einstein's 670 00:24:05.934 --> 00:24:08.755 - general theory of relativity does a great job 671 00:24:09.259 --> 00:24:10.559 - at describing gravity. 672 00:24:10.940 --> 00:24:14.159 - But, it has proven very difficult to bring 673 00:24:14.619 --> 00:24:17.259 - those two things together in a in a 674 00:24:17.259 --> 00:24:20.960 - theory that works. So how could quantum computers 675 00:24:21.099 --> 00:24:21.599 - help, 676 00:24:22.139 --> 00:24:23.119 - with that challenge? 677 00:24:24.015 --> 00:24:25.775 - Yeah. I mean, exactly like you say that 678 00:24:25.775 --> 00:24:28.815 - they're kind of fundamentally incompatible despite being two 679 00:24:28.815 --> 00:24:31.295 - of the most well verified theories in all 680 00:24:31.295 --> 00:24:34.174 - science. It is quite counterintuitive, but general relativity 681 00:24:34.174 --> 00:24:36.734 - speaks in this language of continuous space and 682 00:24:36.734 --> 00:24:38.355 - time and deterministic 683 00:24:38.734 --> 00:24:39.234 - results. 684 00:24:39.750 --> 00:24:42.070 - And quantum mechanics speaks in this language of 685 00:24:42.070 --> 00:24:43.769 - discretized space, quantized 686 00:24:44.070 --> 00:24:46.890 - space, and energy levels, and and not deterministic 687 00:24:46.950 --> 00:24:49.349 - at all. It's it's inherently probabilistic, and so 688 00:24:49.349 --> 00:24:52.150 - they're completely different languages. The mathematical toolbox that 689 00:24:52.150 --> 00:24:54.009 - you use for them both are completely different. 690 00:24:54.285 --> 00:24:55.965 - So for that reason, they're incompatible, but they're 691 00:24:55.965 --> 00:24:57.884 - also if you try and quantize gravity or 692 00:24:57.884 --> 00:24:59.965 - gravitize quantum, you end up with a bunch 693 00:24:59.965 --> 00:25:00.625 - of divergences, 694 00:25:00.924 --> 00:25:02.144 - so infinite terms. 695 00:25:02.525 --> 00:25:03.025 - So 696 00:25:03.325 --> 00:25:06.285 - for example, if you try to quantize gravity 697 00:25:06.285 --> 00:25:07.884 - and think of a particle, call it the 698 00:25:07.884 --> 00:25:08.384 - graviton, 699 00:25:08.799 --> 00:25:10.259 - it's infamously unrenormalizable. 700 00:25:10.960 --> 00:25:12.240 - I know there are some people who might 701 00:25:12.240 --> 00:25:13.440 - take issue with that, but that's kind of 702 00:25:13.440 --> 00:25:16.500 - general consensus. Right? So it's it's really difficult. 703 00:25:16.799 --> 00:25:18.640 - So this is where I'm gonna come back 704 00:25:18.640 --> 00:25:20.500 - to trying to do the bottom up approach 705 00:25:20.960 --> 00:25:21.460 - because 706 00:25:22.125 --> 00:25:23.265 - there are some theories 707 00:25:23.644 --> 00:25:26.525 - that are dual theories of quantum and gravity. 708 00:25:26.525 --> 00:25:28.684 - Now they're not theories of our universe. They're 709 00:25:28.684 --> 00:25:30.464 - theories of kind of toy models, 710 00:25:31.005 --> 00:25:32.065 - but it's this idea 711 00:25:32.445 --> 00:25:33.265 - called the holographic 712 00:25:33.565 --> 00:25:34.065 - principle. 713 00:25:34.605 --> 00:25:36.285 - And the idea is if you come up 714 00:25:36.285 --> 00:25:36.900 - with some 715 00:25:37.460 --> 00:25:39.700 - quantum theory and you calculate a bunch of 716 00:25:39.700 --> 00:25:41.880 - quantities in this quantum theory, 717 00:25:42.980 --> 00:25:44.200 - it's actually equivalent 718 00:25:44.820 --> 00:25:48.279 - to a gravitational theory that's not quantum whatsoever 719 00:25:48.900 --> 00:25:50.599 - in one dimension higher, 720 00:25:50.974 --> 00:25:52.755 - so an extra space time dimension, 721 00:25:53.695 --> 00:25:55.535 - and you calculate the same quantities, you get 722 00:25:55.535 --> 00:25:56.515 - the same results. 723 00:25:57.134 --> 00:25:59.855 - So, again, one is not contingent on the 724 00:25:59.855 --> 00:26:02.575 - other, but two different theories give the same 725 00:26:02.575 --> 00:26:04.195 - results, almost to imply 726 00:26:04.700 --> 00:26:06.640 - that if you have a gravitational theory, 727 00:26:07.180 --> 00:26:10.299 - the more fundamental version is this quantum mechanical 728 00:26:10.299 --> 00:26:12.240 - theory that exists in fewer dimensions. 729 00:26:12.619 --> 00:26:14.460 - So, for example, something you could do on 730 00:26:14.460 --> 00:26:16.875 - a tabletop is something called the SYK model, 731 00:26:17.035 --> 00:26:18.894 - the SAC devier Kitaev model. 732 00:26:19.275 --> 00:26:21.775 - And that's actually a zero plus one dimensional 733 00:26:21.835 --> 00:26:24.335 - theory, which means a zero space dimensions 734 00:26:24.875 --> 00:26:27.035 - and one time dimension. So it starts to 735 00:26:27.035 --> 00:26:29.289 - get very wacky, very hard to picture. It 736 00:26:29.289 --> 00:26:31.130 - says, imagine you have a bunch of particles, 737 00:26:31.130 --> 00:26:33.150 - essentially. They're called Majorana fermions. 738 00:26:33.849 --> 00:26:35.230 - You have a bunch of these particles. 739 00:26:35.769 --> 00:26:37.849 - They don't exist in space because space doesn't 740 00:26:37.849 --> 00:26:39.769 - exist, but we can still label them in 741 00:26:39.769 --> 00:26:40.829 - the kind of abstract, 742 00:26:41.625 --> 00:26:42.445 - and they do 743 00:26:42.984 --> 00:26:45.545 - change with time and their correlation has changed 744 00:26:45.545 --> 00:26:46.664 - with time. And all you do is you 745 00:26:46.664 --> 00:26:48.845 - randomly couple different groups of these particles. 746 00:26:49.144 --> 00:26:50.984 - And then there's your quantum theory and you 747 00:26:50.984 --> 00:26:52.664 - calculate a few things and it's quite a 748 00:26:52.664 --> 00:26:53.404 - simple theory, 749 00:26:53.865 --> 00:26:56.345 - something that we could try and build using 750 00:26:56.345 --> 00:26:57.669 - qubits in a lab. 751 00:26:58.690 --> 00:27:01.089 - What actually happens is really interesting is that 752 00:27:01.089 --> 00:27:03.029 - the results you get are equivalent 753 00:27:03.410 --> 00:27:06.130 - to something called j t gravity. So this 754 00:27:06.130 --> 00:27:07.910 - is this is a one plus one dimensional 755 00:27:08.450 --> 00:27:11.305 - theory. So one dimension of space, so it 756 00:27:11.305 --> 00:27:12.924 - exists on a line basically 757 00:27:13.305 --> 00:27:14.605 - and varies in time. 758 00:27:15.144 --> 00:27:16.205 - So you have this 759 00:27:16.585 --> 00:27:19.164 - baseline quantum model, this SYK model, 760 00:27:19.945 --> 00:27:22.744 - almost giving rise to gravity and giving rise 761 00:27:22.744 --> 00:27:24.424 - to a dimension of space because the two 762 00:27:24.424 --> 00:27:25.724 - theories give the same results. 763 00:27:26.570 --> 00:27:28.410 - So this is really interesting. Obviously, we don't 764 00:27:28.410 --> 00:27:30.089 - live on a line. We don't live in 765 00:27:30.089 --> 00:27:32.170 - a one plus one dimensional universe, so it's 766 00:27:32.170 --> 00:27:34.329 - not useful for us in our understanding of 767 00:27:34.329 --> 00:27:36.490 - our universe. But if we can build a 768 00:27:36.490 --> 00:27:37.470 - tabletop experiment 769 00:27:38.009 --> 00:27:39.769 - that doesn't have gravity in it at all, 770 00:27:39.769 --> 00:27:41.595 - just has entanglement and cubits, 771 00:27:41.994 --> 00:27:45.454 - and from that get results that mimic gravity, 772 00:27:46.154 --> 00:27:48.315 - then perhaps we can make the argument that 773 00:27:48.315 --> 00:27:50.734 - gravity and actually space itself 774 00:27:51.115 --> 00:27:52.654 - and perhaps even time 775 00:27:53.115 --> 00:27:56.015 - are emergent properties of quantum entanglement. 776 00:27:56.460 --> 00:27:58.539 - So this is the idea of emergent space 777 00:27:58.539 --> 00:28:00.400 - time, and this is the kind of way 778 00:28:00.460 --> 00:28:02.880 - that we could attack quantum gravity. Rather than 779 00:28:02.940 --> 00:28:05.919 - gravitize quantum or quantize gravity, let's 780 00:28:06.220 --> 00:28:09.500 - use fundamental quantum building blocks to build space 781 00:28:09.500 --> 00:28:10.480 - and time itself. 782 00:28:12.315 --> 00:28:15.274 - And that that takes me nicely to to 783 00:28:15.274 --> 00:28:18.315 - my final question for you, Ross. And I 784 00:28:18.315 --> 00:28:19.294 - I suppose it's 785 00:28:20.474 --> 00:28:23.534 - a more general question about the intersection between 786 00:28:23.835 --> 00:28:24.654 - quantum mechanics 787 00:28:25.115 --> 00:28:26.894 - and, general relativity. 788 00:28:28.519 --> 00:28:31.079 - Quantum information theory, which is the sort of 789 00:28:31.079 --> 00:28:32.619 - the conceptual framework 790 00:28:33.160 --> 00:28:33.660 - behind 791 00:28:34.200 --> 00:28:36.220 - quantum computers, is being used 792 00:28:36.519 --> 00:28:37.259 - to study 793 00:28:37.640 --> 00:28:38.940 - that interface. 794 00:28:40.454 --> 00:28:40.954 - And 795 00:28:41.255 --> 00:28:42.775 - it it it seems to be throwing up 796 00:28:42.775 --> 00:28:44.394 - some really interesting things. 797 00:28:45.015 --> 00:28:47.494 - I mean, I I wrote an article probably 798 00:28:47.494 --> 00:28:50.555 - about a year ago about something called, 799 00:28:51.575 --> 00:28:52.075 - indefinite 800 00:28:52.639 --> 00:28:55.519 - causal order, which is a really strange thing 801 00:28:55.519 --> 00:28:57.119 - when you when you start, 802 00:28:57.599 --> 00:28:58.099 - combining, 803 00:28:58.880 --> 00:28:59.779 - quantum mechanics 804 00:29:00.079 --> 00:29:01.460 - and general relativity. 805 00:29:03.359 --> 00:29:03.859 - And, 806 00:29:04.795 --> 00:29:06.714 - quantum information theory is, you know, it's been 807 00:29:06.714 --> 00:29:08.575 - shedding light on the nature of 808 00:29:08.875 --> 00:29:09.775 - space time, 809 00:29:10.154 --> 00:29:12.474 - black holes, and, you know, all those sort 810 00:29:12.474 --> 00:29:14.875 - of wonderful things. Can you talk a bit 811 00:29:14.875 --> 00:29:15.375 - about 812 00:29:15.914 --> 00:29:18.875 - what sort of insights quantum information theory can 813 00:29:18.875 --> 00:29:21.429 - give us into the, you know, the universe 814 00:29:21.429 --> 00:29:23.210 - in general, I suppose, beyond 815 00:29:23.509 --> 00:29:26.069 - the quantum world. Yeah. And it's really, really 816 00:29:26.069 --> 00:29:28.549 - interesting. So information is kind of this abstract 817 00:29:28.549 --> 00:29:29.929 - concept, but it's 818 00:29:30.309 --> 00:29:33.190 - often proposed as being fundamental in the universe 819 00:29:33.190 --> 00:29:35.210 - and and information is always conserved. 820 00:29:35.664 --> 00:29:37.265 - And so when you have information about, for 821 00:29:37.265 --> 00:29:38.244 - example, a thermodynamic 822 00:29:39.265 --> 00:29:42.305 - room of particles, you you apply something called 823 00:29:42.305 --> 00:29:44.464 - statistical mechanics to that, and you can get 824 00:29:44.464 --> 00:29:46.384 - some conclusions about the information in the room, 825 00:29:46.384 --> 00:29:48.545 - often this thing called entropy. Right? So may 826 00:29:48.545 --> 00:29:51.289 - have heard of entropy before. There's quantum mechanical 827 00:29:51.289 --> 00:29:53.450 - equivalent. Imagine you have lots of quantum particles 828 00:29:53.450 --> 00:29:54.890 - and you can do this the field of 829 00:29:54.890 --> 00:29:55.869 - quantum information. 830 00:29:56.490 --> 00:29:59.210 - And within that, there are definitions of entropy 831 00:29:59.210 --> 00:30:00.890 - about how much we know about this quantum 832 00:30:00.890 --> 00:30:02.595 - system, how much we don't know, what if 833 00:30:02.595 --> 00:30:03.954 - we only look at part of it, what 834 00:30:03.954 --> 00:30:06.515 - does that teach us about potentially entanglement between 835 00:30:06.515 --> 00:30:08.835 - different regions, things like that. And this toolbox 836 00:30:08.835 --> 00:30:10.355 - has been developed for a little while and 837 00:30:10.355 --> 00:30:12.515 - it's really interesting, and it kind of can 838 00:30:12.515 --> 00:30:13.634 - give us a bunch of stuff to do 839 00:30:13.634 --> 00:30:14.730 - with quantum computers. 840 00:30:15.210 --> 00:30:16.730 - But then in parallel, the field of black 841 00:30:16.730 --> 00:30:19.450 - holes was developing their own little toolbox to 842 00:30:19.450 --> 00:30:22.089 - try and understand the event horizon and what 843 00:30:22.089 --> 00:30:24.009 - happens to things that falls inside a black 844 00:30:24.009 --> 00:30:26.029 - hole. And then really surprisingly, 845 00:30:26.970 --> 00:30:27.795 - some of the results 846 00:30:28.275 --> 00:30:29.875 - again seem to match. It seemed to be 847 00:30:29.875 --> 00:30:31.475 - that, actually, we can start using these ideas 848 00:30:31.475 --> 00:30:34.674 - of quantum information theory on black holes themselves. 849 00:30:34.674 --> 00:30:35.414 - And, actually, 850 00:30:36.035 --> 00:30:38.515 - our current understanding, and this is really bleeding 851 00:30:38.515 --> 00:30:40.355 - edge physics at the moment, so this might 852 00:30:40.355 --> 00:30:42.059 - change, but But our current understanding is if 853 00:30:42.059 --> 00:30:44.079 - something falls into a black hole, that information 854 00:30:44.140 --> 00:30:45.200 - isn't lost forever. 855 00:30:45.819 --> 00:30:48.299 - It's actually encoded in some sense on the 856 00:30:48.299 --> 00:30:49.759 - surface of the black hole 857 00:30:50.220 --> 00:30:52.859 - on the event horizon. And Leonard Susskind would 858 00:30:52.859 --> 00:30:55.039 - be an advocate for saying it goes inside 859 00:30:55.394 --> 00:30:57.154 - and outside the black hole. This is the 860 00:30:57.154 --> 00:30:58.695 - idea of black hole complementarity. 861 00:30:59.154 --> 00:31:00.914 - So there's some really interesting stuff here, but 862 00:31:00.914 --> 00:31:03.955 - the idea is it's preserved. It's encoded, almost 863 00:31:03.955 --> 00:31:06.055 - encrypted, and it's done so redundantly. 864 00:31:06.434 --> 00:31:08.355 - So you don't need the entire surface of 865 00:31:08.355 --> 00:31:10.769 - the black hole to reconstruct all of the 866 00:31:10.769 --> 00:31:13.329 - information, almost as if it's error correcting in 867 00:31:13.329 --> 00:31:16.069 - some way. And then that information is slowly 868 00:31:16.130 --> 00:31:18.609 - released back into the universe over billions of 869 00:31:18.609 --> 00:31:19.669 - billions of years 870 00:31:19.970 --> 00:31:22.450 - through Hawking radiation. So some really interesting stuff, 871 00:31:22.450 --> 00:31:24.684 - and all of this has been found out 872 00:31:24.684 --> 00:31:27.024 - by applying this toolbox of quantum information 873 00:31:27.565 --> 00:31:30.865 - to black hole physics and to these extreme 874 00:31:30.924 --> 00:31:34.605 - environments where there's interesting quantum mechanical effects and 875 00:31:34.605 --> 00:31:36.960 - strong gravitational effects. So this could be a 876 00:31:36.960 --> 00:31:39.859 - good playground to understand quantum gravity, for example. 877 00:31:40.160 --> 00:31:41.920 - So this is a kind of idea that 878 00:31:41.920 --> 00:31:45.460 - we can apply quantum information to perhaps surprising 879 00:31:45.599 --> 00:31:48.224 - areas of physics and learn quite a lot. 880 00:31:50.304 --> 00:31:52.464 - Yeah. That that that is really interesting. I 881 00:31:52.464 --> 00:31:53.765 - mean, is this this, 882 00:31:56.065 --> 00:31:57.924 - black hole? Is it that firewall? 883 00:31:58.304 --> 00:32:00.065 - I I I remember there's a lot of 884 00:32:00.065 --> 00:32:00.930 - work about that. 885 00:32:01.410 --> 00:32:03.570 - Maybe five years ago, there was a flurry 886 00:32:03.570 --> 00:32:03.890 - of, 887 00:32:04.610 --> 00:32:06.950 - of papers. And, yeah, I remember 888 00:32:07.410 --> 00:32:08.390 - really struggling 889 00:32:08.930 --> 00:32:10.309 - to get my head around, 890 00:32:10.930 --> 00:32:13.009 - exactly what was going on. But, yeah, I 891 00:32:13.009 --> 00:32:15.375 - mean, that is a really interesting it's is 892 00:32:15.375 --> 00:32:18.115 - that is that the black hole information paradox? 893 00:32:18.255 --> 00:32:20.575 - Exactly. So the information paradox originally was when 894 00:32:20.575 --> 00:32:21.715 - when Stephen Hawking 895 00:32:22.174 --> 00:32:23.775 - came up with, oh, hold on. That there's 896 00:32:23.775 --> 00:32:25.934 - some kind of radiation that's leading out. But 897 00:32:25.934 --> 00:32:27.980 - he said that radiation cannot 898 00:32:28.440 --> 00:32:30.759 - contain the information. The information's inside the black 899 00:32:30.759 --> 00:32:31.580 - hole. Right? 900 00:32:31.960 --> 00:32:33.799 - So but the problem is if if a 901 00:32:33.799 --> 00:32:36.700 - black hole is radiating, it's it's slowly shrinking. 902 00:32:37.000 --> 00:32:38.984 - So eventually, that black hole will disappear. So 903 00:32:39.144 --> 00:32:40.684 - if the information is not in the radiation 904 00:32:40.825 --> 00:32:42.984 - and it's the black hole is gone, where's 905 00:32:42.984 --> 00:32:43.565 - the information? 906 00:32:43.865 --> 00:32:46.025 - So this was the information paradox. And he 907 00:32:46.025 --> 00:32:48.684 - actually had a bet, with with, with Preskill 908 00:32:48.825 --> 00:32:49.464 - about this. 909 00:32:50.025 --> 00:32:52.549 - And he said, Preskill said that, no. The 910 00:32:52.549 --> 00:32:54.789 - information must be in in in your radiation, 911 00:32:54.789 --> 00:32:57.349 - in the Hawking radiation. And Stephen Hawking disagreed, 912 00:32:57.349 --> 00:32:59.830 - but eventually conceded that that he was correct. 913 00:32:59.830 --> 00:33:01.430 - And that that is where we're at at 914 00:33:01.430 --> 00:33:04.390 - the moment. We think the information is indeed 915 00:33:04.390 --> 00:33:07.034 - in the Hawking radiation. So it is really 916 00:33:07.034 --> 00:33:09.514 - interesting. Really interesting. And, again, this could change, 917 00:33:09.835 --> 00:33:11.355 - but this is what's so exciting about the 918 00:33:11.355 --> 00:33:11.855 - field. 919 00:33:12.234 --> 00:33:14.714 - Yeah. Yeah. Yeah. It it it's all coming 920 00:33:14.714 --> 00:33:16.474 - back to me now. And then you've got 921 00:33:16.474 --> 00:33:19.294 - this no is it the no hair theorem? 922 00:33:19.779 --> 00:33:21.539 - Yeah. Is that is that at the heart 923 00:33:21.539 --> 00:33:23.400 - of the paradox that the black hole 924 00:33:23.940 --> 00:33:24.440 - can't 925 00:33:25.140 --> 00:33:27.859 - hold this information or that it shouldn't be 926 00:33:27.859 --> 00:33:29.779 - there or Yeah. There can't be kind of, 927 00:33:29.940 --> 00:33:31.700 - this kind of fuzzy thing that happens on 928 00:33:31.700 --> 00:33:33.315 - the edge. But this is all all kind 929 00:33:33.315 --> 00:33:35.315 - of intertwined, and and the firewall that you 930 00:33:35.315 --> 00:33:37.315 - mentioned earlier is kind of, again, up for 931 00:33:37.315 --> 00:33:39.654 - debate. So some people would would believe that 932 00:33:39.714 --> 00:33:41.954 - you can't cross the event horizon because you 933 00:33:41.954 --> 00:33:43.474 - would you would tear up. It would kind 934 00:33:43.474 --> 00:33:46.259 - of become infinite temperature. That isn't really the 935 00:33:46.259 --> 00:33:48.019 - prevailing theory at the moment. I think it's 936 00:33:48.019 --> 00:33:50.340 - slightly more common to say that if you 937 00:33:50.340 --> 00:33:52.420 - invoke the equivalence principle, which means that if 938 00:33:52.420 --> 00:33:53.860 - you're in free fall, you're not supposed to 939 00:33:53.860 --> 00:33:55.299 - be able to tell if that you're in 940 00:33:55.299 --> 00:33:57.620 - a particularly special environment, including that of the 941 00:33:57.620 --> 00:33:59.934 - event horizon. So for us if it was 942 00:33:59.934 --> 00:34:02.095 - a small black hole, the tidal effects would 943 00:34:02.095 --> 00:34:03.934 - rip you apart, so you could definitely tell. 944 00:34:03.934 --> 00:34:05.534 - But if it was a really supermassive black 945 00:34:05.534 --> 00:34:07.454 - hole, you could pass the event horizon and 946 00:34:07.454 --> 00:34:09.054 - not even notice. We could be doing it 947 00:34:09.054 --> 00:34:10.574 - right now. The Earth could be falling into 948 00:34:10.574 --> 00:34:13.074 - some supermassive black hole, and we wouldn't know. 949 00:34:13.135 --> 00:34:13.739 - So this is 950 00:34:14.300 --> 00:34:15.920 - kind of what we think 951 00:34:16.300 --> 00:34:18.320 - is happening. Obviously, if you look at someone 952 00:34:18.460 --> 00:34:19.280 - from afar 953 00:34:19.579 --> 00:34:22.079 - because of general relativity and different different 954 00:34:22.699 --> 00:34:25.579 - perspectives, different frames, you would see something different. 955 00:34:25.579 --> 00:34:27.420 - You would never see them pass the event 956 00:34:27.420 --> 00:34:30.224 - horizons black of the black hole because time 957 00:34:30.224 --> 00:34:32.244 - dilates infinitely. So that light 958 00:34:32.545 --> 00:34:34.464 - is never gonna reach you of them of 959 00:34:34.464 --> 00:34:36.464 - them passing the black hole. So this is 960 00:34:36.464 --> 00:34:38.964 - kind of, again, leading back into the Susskind 961 00:34:39.025 --> 00:34:39.844 - view of complementarity. 962 00:34:40.224 --> 00:34:42.559 - You you you almost pass the event horizon 963 00:34:42.559 --> 00:34:44.559 - and don't pass the event horizon, and something 964 00:34:44.559 --> 00:34:46.260 - is also true for information. 965 00:34:46.559 --> 00:34:48.179 - So really, really cool stuff. 966 00:34:48.719 --> 00:34:50.739 - Yeah. It is I mean, it is astonishing, 967 00:34:50.800 --> 00:34:52.640 - or at least I find it astonishing that 968 00:34:52.640 --> 00:34:54.974 - you can you can have these sort of 969 00:34:54.974 --> 00:34:56.194 - quantum conversations 970 00:34:56.574 --> 00:34:58.655 - about a black hole, which is, you know, 971 00:34:58.655 --> 00:35:01.074 - something that's huge and, you know, 972 00:35:01.494 --> 00:35:01.994 - the 973 00:35:02.414 --> 00:35:03.714 - incredibly violent 974 00:35:04.335 --> 00:35:04.835 - gravitational 975 00:35:05.534 --> 00:35:07.295 - field that it has. You would have thought 976 00:35:07.295 --> 00:35:09.150 - it would it would be the least quantum 977 00:35:09.150 --> 00:35:10.130 - thing in the world. 978 00:35:10.429 --> 00:35:12.750 - Yet, you know, you've got all these subtle 979 00:35:12.750 --> 00:35:13.250 - effects, 980 00:35:14.109 --> 00:35:16.670 - that you that I suppose quantum mechanics forces 981 00:35:16.670 --> 00:35:18.849 - you Yeah. To to think about. 982 00:35:19.309 --> 00:35:20.449 - Well, that's what I mean. 983 00:35:20.829 --> 00:35:22.190 - Everywhere. Even in the the vacuum of empty 984 00:35:22.190 --> 00:35:22.394 - spaces, 985 00:35:28.875 --> 00:35:32.255 - motivation to explain Hawking radiation. Even the vacuum, 986 00:35:32.554 --> 00:35:33.994 - right at the boundary of a black hole 987 00:35:33.994 --> 00:35:36.179 - at the event horizon, There's interesting stuff happening 988 00:35:36.179 --> 00:35:38.179 - there. There's an interaction between these really cool 989 00:35:38.179 --> 00:35:38.679 - environments. 990 00:35:40.900 --> 00:35:43.139 - Well, that's great, Ross. Thanks so much for 991 00:35:43.139 --> 00:35:45.539 - for coming on the podcast and and talking 992 00:35:45.539 --> 00:35:48.440 - to us about quantum computing and particle physics, 993 00:35:49.265 --> 00:35:52.485 - quantum gravity, and black holes as well. 994 00:35:53.184 --> 00:35:54.465 - So so what's some 995 00:35:55.585 --> 00:35:57.684 - you mentioned some of your research, 996 00:35:57.985 --> 00:36:00.565 - at the moment. Is there anything in particular 997 00:36:00.625 --> 00:36:02.545 - that you're working on now that you'd like 998 00:36:02.545 --> 00:36:04.429 - to share with our audience? 999 00:36:05.289 --> 00:36:06.730 - Yeah. So, I mean, so I I finished 1000 00:36:06.730 --> 00:36:09.309 - my PhD last year, actually, and it was 1001 00:36:09.369 --> 00:36:12.010 - mostly related in kind of causality for quantum 1002 00:36:12.010 --> 00:36:14.730 - field theory. So the mathematical framework of of 1003 00:36:14.730 --> 00:36:16.944 - our best theory of quantum mechanics. And now 1004 00:36:16.944 --> 00:36:18.085 - I'm pivoting into 1005 00:36:18.385 --> 00:36:20.864 - actually kind of more applications for quantum computers. 1006 00:36:20.864 --> 00:36:22.784 - So hopefully later this year, I'll have some 1007 00:36:22.784 --> 00:36:25.025 - papers out that are gonna be about the 1008 00:36:25.025 --> 00:36:26.944 - kind of algorithms that we can use to 1009 00:36:26.944 --> 00:36:27.444 - simulate 1010 00:36:27.984 --> 00:36:29.284 - quantum field theories 1011 00:36:29.585 --> 00:36:32.324 - on qubits. So hopefully, stay tuned for that. 1012 00:36:33.059 --> 00:36:34.340 - And I think, I mean, I think we've 1013 00:36:34.340 --> 00:36:36.660 - got a good careers message here. I mean, 1014 00:36:36.660 --> 00:36:38.760 - we we love to talk about careers 1015 00:36:39.140 --> 00:36:40.680 - on the Physics World podcast. 1016 00:36:41.219 --> 00:36:41.719 - And, 1017 00:36:42.099 --> 00:36:43.860 - you know, it sounds to me that, 1018 00:36:44.980 --> 00:36:47.079 - you you can do particle physics. 1019 00:36:47.565 --> 00:36:50.125 - And then, I mean, maybe you're not going 1020 00:36:50.125 --> 00:36:52.125 - to do this or maybe you will, that 1021 00:36:52.125 --> 00:36:53.905 - you can move into a career 1022 00:36:54.605 --> 00:36:56.144 - in quantum computing 1023 00:36:56.605 --> 00:36:58.925 - fairly seamlessly. I mean, is that right? Would 1024 00:36:58.925 --> 00:37:00.570 - you I mean, if somebody came to you 1025 00:37:00.570 --> 00:37:02.170 - and said, well, you know, I'm really interested 1026 00:37:02.170 --> 00:37:03.309 - in particle physics, 1027 00:37:03.610 --> 00:37:05.450 - but I wanna get a job at a 1028 00:37:05.450 --> 00:37:08.170 - quantum computing company. I mean, it sounds to 1029 00:37:08.170 --> 00:37:08.809 - me like, 1030 00:37:09.369 --> 00:37:11.784 - doing a PhD in particle physics be a 1031 00:37:11.784 --> 00:37:12.445 - good idea. 1032 00:37:12.824 --> 00:37:15.224 - Yeah. Yeah. I mean, the the boundaries are 1033 00:37:15.224 --> 00:37:16.905 - definitely getting more and more blurred as time 1034 00:37:16.905 --> 00:37:19.085 - goes on, as we've discussed the ideas of 1035 00:37:19.385 --> 00:37:21.945 - AI, machine learning, even qubits starting to be 1036 00:37:21.945 --> 00:37:24.760 - applied in particle physics. And so it becomes 1037 00:37:24.760 --> 00:37:25.500 - very interdisciplinary. 1038 00:37:25.880 --> 00:37:27.719 - And, actually, my my masters that I did 1039 00:37:27.719 --> 00:37:28.699 - before my PhD 1040 00:37:29.159 --> 00:37:31.319 - was half in quantum computing and half in 1041 00:37:31.319 --> 00:37:33.819 - particle physics. And so I always kind of 1042 00:37:34.119 --> 00:37:35.960 - balanced it because I'm interested in both. And 1043 00:37:35.960 --> 00:37:37.605 - so I've I've managed to be be very 1044 00:37:37.605 --> 00:37:39.445 - lucky in that I get to study both 1045 00:37:39.445 --> 00:37:41.625 - fields simultaneously. But, yeah, you can absolutely 1046 00:37:41.925 --> 00:37:42.985 - absolutely pivot. 1047 00:37:44.244 --> 00:37:45.925 - Well, that's great, Ross. Well, thanks again for 1048 00:37:45.925 --> 00:37:48.085 - coming on the podcast. Thank you very much 1049 00:37:48.085 --> 00:37:48.985 - for having me. 1050 00:37:56.519 --> 00:37:59.400 - That was Ross Jenkinson of the University of 1051 00:37:59.400 --> 00:37:59.900 - Manchester. 1052 00:38:00.440 --> 00:38:02.940 - Thanks, Ross, for a fascinating discussion. 1053 00:38:03.744 --> 00:38:06.144 - This podcast is brought to you by American 1054 00:38:06.144 --> 00:38:06.644 - Elements, 1055 00:38:07.105 --> 00:38:08.164 - the world's leading 1056 00:38:08.545 --> 00:38:09.045 - manufacturer 1057 00:38:09.425 --> 00:38:11.764 - of engineered and advanced materials. 1058 00:38:12.385 --> 00:38:15.204 - With a catalog of over 35,000 1059 00:38:15.344 --> 00:38:19.349 - products available in both industrial bulk and laboratory 1060 00:38:19.650 --> 00:38:20.150 - quantities, 1061 00:38:20.769 --> 00:38:23.809 - American Elements is the largest supplier of its 1062 00:38:23.809 --> 00:38:24.309 - kind. 1063 00:38:24.849 --> 00:38:27.410 - For more than twenty five years, its research 1064 00:38:27.410 --> 00:38:30.715 - and development programs have been a vital resource 1065 00:38:30.715 --> 00:38:31.534 - for innovation 1066 00:38:31.994 --> 00:38:35.295 - across corporate, government, and academic sectors. 1067 00:38:35.914 --> 00:38:38.574 - The company's ability to scale laboratory 1068 00:38:38.875 --> 00:38:40.974 - breakthroughs to industrial production 1069 00:38:41.355 --> 00:38:43.855 - has contributed to many of the most significant 1070 00:38:44.480 --> 00:38:44.980 - technological 1071 00:38:45.280 --> 00:38:47.460 - advances since 1990, 1072 00:38:48.079 --> 00:38:49.699 - including LED lighting, 1073 00:38:50.079 --> 00:38:50.579 - smartphones, 1074 00:38:50.960 --> 00:38:52.260 - and electric vehicles. 1075 00:38:52.880 --> 00:38:56.980 - To learn more, visit americanelements.com. 1076 00:38:57.440 --> 00:38:57.940 - American 1077 00:38:58.239 --> 00:38:58.739 - Elements. 1078 00:38:59.344 --> 00:39:00.484 - Now invent. 1079 00:39:01.824 --> 00:39:04.224 - I'm afraid that's all the time we have 1080 00:39:04.224 --> 00:39:05.525 - for this week's podcast. 1081 00:39:05.984 --> 00:39:08.944 - I'm Hamish Johnston, and our producer is Fred 1082 00:39:08.944 --> 00:39:09.444 - Iles. 1083 00:39:09.904 --> 00:39:12.804 - The music you hear in Physics World's podcasts 1084 00:39:13.130 --> 00:39:15.769 - is called one three seven, and it was 1085 00:39:15.769 --> 00:39:18.349 - composed and performed by the physicist 1086 00:39:18.969 --> 00:39:19.869 - Philip Moriarty. 1087 00:39:20.570 --> 00:39:22.429 - We'll be back again next week.