1 00:00:08,720 --> 00:00:11,039 Hello. I'm Matin Durrani, and welcome to a 2 00:00:11,039 --> 00:00:13,359 very special edition of the Physics World weekly 3 00:00:13,359 --> 00:00:13,859 podcast, 4 00:00:14,414 --> 00:00:16,175 where we're going to be revealing the top 5 00:00:16,175 --> 00:00:18,914 10 breakthroughs in physics for 2025. 6 00:00:19,614 --> 00:00:21,375 Every year here at Physics World, we pick 7 00:00:21,375 --> 00:00:23,314 what we think have been the biggest breakthroughs 8 00:00:23,375 --> 00:00:25,454 over the last twelve months, and we've had 9 00:00:25,454 --> 00:00:27,774 chosen some amazing successes over the years that 10 00:00:27,774 --> 00:00:28,994 include the Higgs boson, 11 00:00:29,480 --> 00:00:31,960 gravitational waves, and the shadow around a black 12 00:00:31,960 --> 00:00:34,439 hole. With last year, the top prize going 13 00:00:34,439 --> 00:00:37,000 to work on quantum error correction at Google 14 00:00:37,000 --> 00:00:37,739 and elsewhere. 15 00:00:38,920 --> 00:00:41,559 So taking you through our choices for 2025, 16 00:00:41,559 --> 00:00:44,219 I'm joined by my colleagues Margaret Harris, 17 00:00:44,674 --> 00:00:47,814 Tammy Freeman, Michael Banks, and Hamish Johnson. 18 00:00:48,914 --> 00:00:51,395 The physics world breakthrough the year 2025 19 00:00:51,395 --> 00:00:54,054 is sponsored by Reports on Progress in Physics. 20 00:00:54,754 --> 00:00:57,795 Celebrating the most significant advances across the physical 21 00:00:57,795 --> 00:00:58,295 sciences, 22 00:00:58,899 --> 00:01:01,880 this award highlights discoveries that reshape our understanding 23 00:01:01,940 --> 00:01:04,359 of the universe and inspire future innovation. 24 00:01:05,380 --> 00:01:07,540 Reports on Progress in Physics is the leading 25 00:01:07,540 --> 00:01:08,680 journal for authoritative 26 00:01:08,980 --> 00:01:09,480 research, 27 00:01:09,939 --> 00:01:13,380 connecting researchers worldwide with cutting edge insights across 28 00:01:13,380 --> 00:01:14,520 every field of physics. 29 00:01:15,114 --> 00:01:17,134 From quantum technologies to astrophysics, 30 00:01:17,754 --> 00:01:20,015 it provides the depth and clarity that drive 31 00:01:20,075 --> 00:01:21,134 scientific progress. 32 00:01:21,914 --> 00:01:24,394 Search reports on progress in physics on your 33 00:01:24,394 --> 00:01:27,694 favorite browser to explore the ideas transforming science 34 00:01:27,834 --> 00:01:28,334 today. 35 00:01:29,489 --> 00:01:31,569 So let's get cracking on the top 10 36 00:01:31,569 --> 00:01:34,549 physics world breakthroughs in physics for 2025, 37 00:01:35,090 --> 00:01:37,329 which, just to remind you, we pick based 38 00:01:37,329 --> 00:01:38,229 on three 39 00:01:38,609 --> 00:01:41,489 criteria. So in addition to having been reported 40 00:01:41,489 --> 00:01:44,069 in physics world in 2025, 41 00:01:44,534 --> 00:01:47,974 our selections have to represent a significant advance 42 00:01:47,974 --> 00:01:49,594 in knowledge or understanding, 43 00:01:50,295 --> 00:01:53,594 be important for scientific progress and or development 44 00:01:53,655 --> 00:01:54,875 of real world applications, 45 00:01:55,814 --> 00:01:58,510 and be of general interest to Physics World 46 00:01:58,510 --> 00:01:59,010 readers. 47 00:02:00,989 --> 00:02:02,269 So we're gonna start with a bit of 48 00:02:02,269 --> 00:02:05,069 astronomy, with astronomers creating what they say is 49 00:02:05,069 --> 00:02:06,129 a weather map 50 00:02:06,430 --> 00:02:08,689 for a gas giant exoplanet. 51 00:02:09,405 --> 00:02:11,084 Now it's hard enough for trying to predict 52 00:02:11,084 --> 00:02:12,844 the weather here in on Earth, although I 53 00:02:12,844 --> 00:02:14,444 know it's been a pretty dry year in 54 00:02:14,444 --> 00:02:16,925 Bristol in the Southwest corner of England where 55 00:02:16,925 --> 00:02:19,004 we are. So this sounds pretty cool to 56 00:02:19,004 --> 00:02:21,805 me. Hamish, you're gonna explain this breakthrough for 57 00:02:21,805 --> 00:02:22,080 us. 58 00:02:22,639 --> 00:02:25,460 That's right, Matin. This this first, breakthrough is 59 00:02:25,520 --> 00:02:28,080 astronomy related breakthrough, and it has to do 60 00:02:28,080 --> 00:02:28,819 with exoplanets. 61 00:02:29,599 --> 00:02:32,560 Now it's only been thirty years since the 62 00:02:32,560 --> 00:02:33,540 first exoplanet, 63 00:02:34,574 --> 00:02:37,134 orbiting a star, that's a planet orbiting a 64 00:02:37,134 --> 00:02:39,634 star other than the sun, was discovered. 65 00:02:39,935 --> 00:02:43,794 And today, astronomers know of more than 6,000 66 00:02:44,254 --> 00:02:45,235 such objects. 67 00:02:46,270 --> 00:02:49,009 And this breakthrough, it's been made by Lisa 68 00:02:49,069 --> 00:02:49,569 Nortman 69 00:02:49,949 --> 00:02:50,689 at Germany's 70 00:02:50,990 --> 00:02:51,490 University 71 00:02:51,870 --> 00:02:52,610 of Gottingen 72 00:02:53,229 --> 00:02:54,050 and colleagues, 73 00:02:54,430 --> 00:02:55,889 and they've used the European 74 00:02:56,189 --> 00:02:57,250 Southern Observatory's 75 00:02:57,949 --> 00:02:59,169 Very Large Telescope 76 00:02:59,865 --> 00:03:02,125 to create what they're saying 77 00:03:02,425 --> 00:03:05,245 is the first weather map of an exoplanet. 78 00:03:06,025 --> 00:03:08,844 Now this exoplanet is a hot Jupiter. 79 00:03:09,305 --> 00:03:12,044 It's a gas giant called WASP 80 00:03:12,500 --> 00:03:14,199 one twenty seven b, 81 00:03:14,500 --> 00:03:17,319 and it orbits very near to its star. 82 00:03:17,379 --> 00:03:19,299 So this is not something that we have 83 00:03:19,299 --> 00:03:21,459 in a in in the solar system. It's 84 00:03:21,459 --> 00:03:22,680 a very sort of exotic 85 00:03:22,979 --> 00:03:25,914 thing as far as we we're concerned. And 86 00:03:25,914 --> 00:03:28,314 what Nortman and colleagues did is they studied 87 00:03:28,314 --> 00:03:29,534 the absorption 88 00:03:29,914 --> 00:03:33,275 spectrum of starlight that had passed through the 89 00:03:33,275 --> 00:03:33,775 exoplanet's 90 00:03:34,155 --> 00:03:34,655 atmosphere. 91 00:03:35,675 --> 00:03:36,175 And 92 00:03:36,555 --> 00:03:40,349 by, looking at the Doppler shift of this, 93 00:03:41,150 --> 00:03:42,210 transmission spectrum, 94 00:03:42,590 --> 00:03:45,810 they could deduce that the winds on WASP 95 00:03:45,950 --> 00:03:48,830 one twenty seven b can reach as as 96 00:03:48,830 --> 00:03:51,170 high as 33,000 97 00:03:51,629 --> 00:03:52,930 kilometers per hour, 98 00:03:53,375 --> 00:03:55,854 which is pretty fast. That's quick. It it 99 00:03:55,854 --> 00:03:58,334 it is. Yeah. Yeah. And and what's more, 100 00:03:58,334 --> 00:04:00,514 by looking at the, sort of, the distribution 101 00:04:01,375 --> 00:04:02,354 of of how, 102 00:04:03,055 --> 00:04:04,914 the light is Doppler shifted, 103 00:04:05,375 --> 00:04:08,400 they could create a rough weather map of 104 00:04:08,400 --> 00:04:11,120 the exoplanet. Now, it's important to say that 105 00:04:11,120 --> 00:04:13,840 they weren't actually able to look at different 106 00:04:13,840 --> 00:04:14,340 points 107 00:04:14,800 --> 00:04:15,620 on the exoplanet 108 00:04:15,920 --> 00:04:18,420 and say the weather is like this there. 109 00:04:18,560 --> 00:04:20,319 What they did is they they looked at 110 00:04:20,319 --> 00:04:21,139 this distribution 111 00:04:22,035 --> 00:04:24,455 and somehow used that information to 112 00:04:24,835 --> 00:04:26,835 infer what the weather was like from the 113 00:04:26,835 --> 00:04:28,935 pole down to the Equator 114 00:04:29,555 --> 00:04:32,295 and, back again to to the other pole. 115 00:04:33,074 --> 00:04:34,615 So they were able to conclude, 116 00:04:35,250 --> 00:04:37,009 along with looking at the winds, they were 117 00:04:37,009 --> 00:04:37,910 able to conclude 118 00:04:38,290 --> 00:04:41,029 that the exoplanet's poles are cooler 119 00:04:41,330 --> 00:04:43,270 than the rest of the exoplanet, 120 00:04:43,730 --> 00:04:44,230 where, 121 00:04:44,770 --> 00:04:46,069 temperatures can exceed, 122 00:04:46,529 --> 00:04:49,250 over a thousand degrees Celsius. So, again, a 123 00:04:49,250 --> 00:04:50,550 very strange place. 124 00:04:51,314 --> 00:04:53,975 Imagine Jupiter, but it's a thousand degrees Celsius, 125 00:04:54,675 --> 00:04:56,134 sort of a weird world. 126 00:04:56,435 --> 00:04:59,794 And they also, detected water vapor in the 127 00:04:59,794 --> 00:05:00,294 atmosphere, 128 00:05:00,675 --> 00:05:04,134 and that raises the possibility of very exotic 129 00:05:04,274 --> 00:05:06,449 forms of rain on the planet. 130 00:05:06,930 --> 00:05:07,910 So rain, 131 00:05:08,290 --> 00:05:09,110 other than 132 00:05:09,889 --> 00:05:11,830 how we know it, I suppose. 133 00:05:12,210 --> 00:05:14,050 And, you know, I think we picked this 134 00:05:14,050 --> 00:05:17,830 one. Really, there's lots of really fantastic exoplanet 135 00:05:18,050 --> 00:05:20,470 research out there, thousands that have been discovered. 136 00:05:21,404 --> 00:05:22,384 But this was 137 00:05:22,845 --> 00:05:24,064 a a a really interesting, 138 00:05:24,605 --> 00:05:26,685 example of how we can we can now 139 00:05:26,685 --> 00:05:27,904 actually see the atmosphere 140 00:05:28,444 --> 00:05:29,425 of these exoplanets 141 00:05:29,964 --> 00:05:32,384 using, you know, the very latest telescopes. 142 00:05:33,139 --> 00:05:35,699 So very hot, very windy, and exotic rain. 143 00:05:35,699 --> 00:05:37,540 I don't think I wanna live there. Thanks, 144 00:05:37,540 --> 00:05:40,819 Hamish. Now from exoplanets out in space down 145 00:05:40,819 --> 00:05:42,819 to our planet here on Earth, our next 146 00:05:42,819 --> 00:05:44,839 breakthrough through of the year is a fascinating 147 00:05:44,899 --> 00:05:45,399 study 148 00:05:45,834 --> 00:05:47,995 about using the phones we all carry around 149 00:05:47,995 --> 00:05:50,074 with us to create an early warning system 150 00:05:50,074 --> 00:05:50,894 for earthquakes 151 00:05:51,435 --> 00:05:53,834 or at least using Android phones. Michael, can 152 00:05:53,834 --> 00:05:55,995 you tell us about this breakthrough, which seems 153 00:05:55,995 --> 00:05:58,759 like a great example of citizen science? Yeah. 154 00:05:58,759 --> 00:06:00,759 So this is all about using mobile phones 155 00:06:00,759 --> 00:06:02,939 to detect earthquakes. So traditional 156 00:06:03,319 --> 00:06:06,680 earthquake early warning systems usually use networks of 157 00:06:06,680 --> 00:06:07,660 seismic sensors 158 00:06:08,040 --> 00:06:10,680 that rapidly detect earthquakes in areas close to 159 00:06:10,680 --> 00:06:11,339 the epicenter. 160 00:06:12,165 --> 00:06:15,464 They also issue warnings to, people also across 161 00:06:15,524 --> 00:06:16,665 the affected region. 162 00:06:17,125 --> 00:06:19,125 Yet the issue is that building such networks 163 00:06:19,125 --> 00:06:20,904 of bulky sensors, it's expensive, 164 00:06:21,444 --> 00:06:23,464 you know, and this means that many earthquake 165 00:06:23,524 --> 00:06:26,069 prone regions do not have them. So to 166 00:06:26,069 --> 00:06:28,470 get around this problem, researchers in The US 167 00:06:28,470 --> 00:06:31,670 utilized the accelerometer housed in millions of mobile 168 00:06:31,670 --> 00:06:32,730 phones worldwide 169 00:06:33,189 --> 00:06:36,629 to create an app based Android earthquake alert 170 00:06:36,629 --> 00:06:37,129 system. 171 00:06:37,875 --> 00:06:41,814 So testing the app between 2021 and 2024 172 00:06:42,355 --> 00:06:44,275 led to the detection of an average of 173 00:06:44,275 --> 00:06:45,235 312 174 00:06:45,235 --> 00:06:49,314 earthquakes a month with magnitudes ranging from 1.9 175 00:06:49,314 --> 00:06:51,415 to 7.8 on the Richter scale. 176 00:06:52,300 --> 00:06:53,819 But what is more, the app could also 177 00:06:53,819 --> 00:06:55,980 alert people in the area. So for earthquakes 178 00:06:55,980 --> 00:06:57,759 of magnitude 4.5 179 00:06:57,819 --> 00:06:58,560 or higher, 180 00:06:58,939 --> 00:07:01,660 the system sent so called take action alerts 181 00:07:01,660 --> 00:07:02,400 to users. 182 00:07:02,860 --> 00:07:05,354 It also delivered lesser be aware alerts to 183 00:07:05,354 --> 00:07:08,394 regions expected to experience a shaking intensity of 184 00:07:08,394 --> 00:07:09,294 three or four. 185 00:07:09,914 --> 00:07:11,514 So the team now aimed to build on 186 00:07:11,514 --> 00:07:14,574 this earthquake early warning system based on Android 187 00:07:14,714 --> 00:07:17,754 mobile phones by producing maps of ground shaking 188 00:07:17,754 --> 00:07:18,300 as well. 189 00:07:18,779 --> 00:07:21,019 And this could all help assist the emergency 190 00:07:21,019 --> 00:07:23,439 response services when an earthquake occurs. 191 00:07:24,139 --> 00:07:27,099 Thanks, Michael. So from communicating with mobiles to 192 00:07:27,099 --> 00:07:29,339 communicating via the cables that make up the 193 00:07:29,339 --> 00:07:29,839 Internet, 194 00:07:30,220 --> 00:07:33,039 which is the almost invisible technology that underpins 195 00:07:33,180 --> 00:07:35,605 modern life. Now it seems the researchers have 196 00:07:35,605 --> 00:07:38,024 developed a new kind of fiber that loses 197 00:07:38,324 --> 00:07:39,865 that lose less data 198 00:07:40,165 --> 00:07:42,404 as the signals get sent down them. Tammy, 199 00:07:42,404 --> 00:07:43,545 what's this one about? 200 00:07:44,245 --> 00:07:47,045 So optical fibers form the backbone of the 201 00:07:47,045 --> 00:07:49,944 Internet carrying light signals across the globe. 202 00:07:50,430 --> 00:07:52,830 But sunlight is always lost as it travels 203 00:07:52,830 --> 00:07:55,230 through the fiber, which means that these signals 204 00:07:55,230 --> 00:07:57,730 must be amplified every few dozen kilometers. 205 00:07:58,430 --> 00:08:01,230 Now amazingly, the performance of even the best 206 00:08:01,230 --> 00:08:04,430 fibers has remained largely unchanged for nearly four 207 00:08:04,430 --> 00:08:04,930 decades 208 00:08:05,475 --> 00:08:06,375 until now. 209 00:08:07,235 --> 00:08:09,254 Physicists at the University of Southampton 210 00:08:09,875 --> 00:08:12,194 have developed a new type of fiber that 211 00:08:12,194 --> 00:08:13,714 exhibits 35% 212 00:08:13,714 --> 00:08:14,535 less attenuation 213 00:08:15,154 --> 00:08:18,854 while transmitting signals faster than standard glass fibers, 214 00:08:19,490 --> 00:08:21,810 and they achieved this by replacing the glass 215 00:08:21,810 --> 00:08:24,389 core of a conventional fiber with air. 216 00:08:25,250 --> 00:08:27,329 To guide the light through this hollow core, 217 00:08:27,329 --> 00:08:29,029 it's surrounded by a microstructure 218 00:08:29,490 --> 00:08:33,110 of ultrathin glass membranes that reflect certain frequencies 219 00:08:33,514 --> 00:08:35,434 to trap the light and keep it moving 220 00:08:35,434 --> 00:08:36,414 through the fiber. 221 00:08:37,434 --> 00:08:39,914 So to test this design, the team, which 222 00:08:39,914 --> 00:08:43,294 also included researchers from Microsoft Azure Fiber, 223 00:08:43,754 --> 00:08:46,315 they measured the transmission through a full spool 224 00:08:46,315 --> 00:08:48,450 of fiber, then they cut it into shorter 225 00:08:48,450 --> 00:08:49,990 lengths and compared the results. 226 00:08:50,610 --> 00:08:52,850 And they found that their hollow fibers reduced 227 00:08:52,850 --> 00:08:53,509 the attenuation 228 00:08:53,970 --> 00:08:56,389 to just naught point naught nine one decibels 229 00:08:56,450 --> 00:08:59,649 per kilometer at fifteen fifty nanometers, which is 230 00:08:59,649 --> 00:09:01,190 a wavelength used for telecoms. 231 00:09:01,784 --> 00:09:04,184 And this means that long cables would need 232 00:09:04,184 --> 00:09:05,164 fewer amplifiers, 233 00:09:05,625 --> 00:09:07,644 lowering the costs and the energy use. 234 00:09:08,345 --> 00:09:11,065 The new hollow fiber also supports a higher 235 00:09:11,065 --> 00:09:11,565 bandwidth 236 00:09:11,944 --> 00:09:13,084 than a normal fiber, 237 00:09:13,464 --> 00:09:15,464 which means that a single strand can carry 238 00:09:15,464 --> 00:09:16,919 far more channels at once. 239 00:09:17,480 --> 00:09:19,559 And because the speed of light's faster in 240 00:09:19,559 --> 00:09:22,039 air than in glass, the data could travel 241 00:09:22,039 --> 00:09:24,600 the same distance up to 45% 242 00:09:24,600 --> 00:09:25,100 faster. 243 00:09:26,120 --> 00:09:28,919 Now Microsoft has begun testing the new fibers 244 00:09:28,919 --> 00:09:29,980 in real systems, 245 00:09:30,575 --> 00:09:33,294 installing segments in its network and sending live 246 00:09:33,294 --> 00:09:34,355 traffic through them. 247 00:09:34,815 --> 00:09:37,215 And these trials prove that the hollow core 248 00:09:37,215 --> 00:09:40,654 design works with existing telecoms equipment and opens 249 00:09:40,654 --> 00:09:42,654 the door to a gradual rollout of this 250 00:09:42,654 --> 00:09:43,715 new source of fiber. 251 00:09:44,639 --> 00:09:48,000 And as team leader Francesco Paletti suggests, one 252 00:09:48,000 --> 00:09:51,220 day, they could even replace existing undersea cables. 253 00:09:51,920 --> 00:09:53,759 So that's the first three of our physics 254 00:09:53,759 --> 00:09:56,080 world breakthroughs of the year for 2025 255 00:09:56,080 --> 00:09:56,414 done. 256 00:09:56,894 --> 00:09:59,054 Now next up is some cool condensed matter 257 00:09:59,054 --> 00:10:00,834 physics that's involved superfluidity 258 00:10:01,375 --> 00:10:04,355 spotted in molecular hydrogen for the first time. 259 00:10:04,654 --> 00:10:07,315 Now, Margaret, physicists are pretty familiar with superfluidity 260 00:10:07,695 --> 00:10:09,794 in helium three and helium four 261 00:10:10,259 --> 00:10:12,660 atoms, but now we're talking about molecules, aren't 262 00:10:12,660 --> 00:10:13,160 we? 263 00:10:13,540 --> 00:10:15,940 Yeah. We're talking about specifically about molecular hydrogen, 264 00:10:15,940 --> 00:10:17,779 which is the simplest and lightest of all 265 00:10:17,779 --> 00:10:19,779 molecules. You take one hydrogen atom, you take 266 00:10:19,779 --> 00:10:21,800 another hydrogen atom, you link them together. 267 00:10:22,375 --> 00:10:25,735 And theorists predicted that this molecular hydrogen would 268 00:10:25,735 --> 00:10:28,394 enter a superfluid state at a temperature between 269 00:10:28,535 --> 00:10:30,795 one to two Kelvin above absolute zero, 270 00:10:31,254 --> 00:10:32,394 which is pretty cold. 271 00:10:32,855 --> 00:10:34,535 But the real problem with that is that 272 00:10:34,535 --> 00:10:37,175 molecular hydrogen freezes at 13.8 273 00:10:37,175 --> 00:10:39,190 Kelvin, So, obviously, it's not going to be 274 00:10:39,190 --> 00:10:41,269 behaving like a superfluid if it's further than 275 00:10:41,269 --> 00:10:41,769 solid. 276 00:10:42,629 --> 00:10:45,210 So before they could verify this prediction, Takamasa 277 00:10:45,350 --> 00:10:47,670 Momosa and colleagues at the University of British 278 00:10:47,670 --> 00:10:48,809 Columbia in Canada, 279 00:10:49,269 --> 00:10:50,790 they first had to develop a way to 280 00:10:50,790 --> 00:10:52,455 keep the hydrogen in a liquid state. 281 00:10:53,014 --> 00:10:55,095 And they did that by confining clusters of 282 00:10:55,095 --> 00:10:59,115 hydrogen molecules inside nanodroplets of helium and supercooling 283 00:10:59,254 --> 00:11:01,835 them to below their freezing point, which, 284 00:11:02,215 --> 00:11:03,735 I mean, I've never done it, but I 285 00:11:03,735 --> 00:11:06,134 imagine that isn't exactly easy. Certainly, it sounds 286 00:11:06,134 --> 00:11:07,434 like an impressive feat. 287 00:11:07,940 --> 00:11:10,259 And then once they've done that, they faced 288 00:11:10,259 --> 00:11:12,179 a further barrier, which was figure out how 289 00:11:12,179 --> 00:11:14,579 to detect whether the hydrogen was superfluid or 290 00:11:14,579 --> 00:11:15,079 not. 291 00:11:15,459 --> 00:11:17,459 And to do that, they stuck a methane 292 00:11:17,459 --> 00:11:19,799 molecule in with the cluster of hydrogen molecules 293 00:11:20,179 --> 00:11:21,399 and watched it rotate. 294 00:11:21,914 --> 00:11:24,495 And when it started to rotate without friction, 295 00:11:24,955 --> 00:11:26,495 they knew they'd seen superfluidity. 296 00:11:27,434 --> 00:11:29,274 Apparently, it took them nearly twenty years to 297 00:11:29,274 --> 00:11:31,034 sort of develop this experiment at this point, 298 00:11:31,034 --> 00:11:33,195 so this breakthrough was a long time coming. 299 00:11:33,195 --> 00:11:35,195 And it's a testament to the dedication and 300 00:11:35,195 --> 00:11:36,794 ingenuity of the team that they were able 301 00:11:36,794 --> 00:11:38,129 to do it at all. This is a 302 00:11:38,129 --> 00:11:40,549 real physicist experiment on my view at least. 303 00:11:41,329 --> 00:11:43,329 They now plan to study larger clusters of 304 00:11:43,329 --> 00:11:45,409 hydrogen with the aim of exploring the boundary 305 00:11:45,409 --> 00:11:48,549 between classical and quantum behavior in this system. 306 00:11:48,929 --> 00:11:51,250 So, I mean, they've seen superfluidity with 10 307 00:11:51,250 --> 00:11:52,725 hydrogen molecules. Great. 308 00:11:53,284 --> 00:11:54,964 Can I see it with a 100? What 309 00:11:54,964 --> 00:11:57,365 about a thousand or a million? We don't 310 00:11:57,365 --> 00:11:59,204 know the answer, but it'll be really exciting 311 00:11:59,204 --> 00:12:01,444 to find out. Like you say, Margaret, definitely 312 00:12:01,444 --> 00:12:03,204 one for the fit the hardcore physicist, I 313 00:12:03,204 --> 00:12:05,764 think, especially something that's taken twenty years to 314 00:12:05,764 --> 00:12:06,424 get through. 315 00:12:07,049 --> 00:12:09,129 So amazing achievement, that one. And speaking of 316 00:12:09,129 --> 00:12:12,910 molecules, research have found some pretty interesting molecules 317 00:12:13,049 --> 00:12:15,690 on the asteroid Bennu, which has caught our 318 00:12:15,690 --> 00:12:17,549 eye, hasn't it, Margaret? What have they found? 319 00:12:18,009 --> 00:12:20,090 Well, Matin, it's almost a case of asking 320 00:12:20,090 --> 00:12:21,950 what haven't they found on Bennu. 321 00:12:22,295 --> 00:12:24,134 I mean, they might be looking for not 322 00:12:24,134 --> 00:12:26,535 finding Jimmy Hoffa or Bigfoot, but they found 323 00:12:26,535 --> 00:12:28,934 almost everything else. So back in February, we 324 00:12:28,934 --> 00:12:31,254 reported that two teams had found salt and 325 00:12:31,254 --> 00:12:33,815 certain amino acids in samples of the asteroid 326 00:12:33,815 --> 00:12:34,315 Bennu, 327 00:12:34,639 --> 00:12:37,919 which NASA's OSIRIS REx spacecraft visited back in 328 00:12:37,919 --> 00:12:38,659 2020. 329 00:12:39,279 --> 00:12:41,360 These samples got parachuted back to Earth in 330 00:12:41,360 --> 00:12:44,320 2023, and ever since then, various groups of 331 00:12:44,320 --> 00:12:46,799 scientists have been studying them, hoping to answer 332 00:12:46,799 --> 00:12:49,184 questions about what was around in the earliest 333 00:12:49,184 --> 00:12:51,745 solar system, chemically speaking, and how it led 334 00:12:51,745 --> 00:12:53,264 to the kinds of stuff we see around 335 00:12:53,264 --> 00:12:53,845 us today. 336 00:12:54,784 --> 00:12:57,424 Now finding salt and amino acids on an 337 00:12:57,424 --> 00:13:00,225 asteroid is interesting because they're both important for 338 00:13:00,225 --> 00:13:01,204 living organisms. 339 00:13:01,769 --> 00:13:04,089 Lots of animals, including us, need salt to 340 00:13:04,089 --> 00:13:04,589 survive, 341 00:13:04,970 --> 00:13:06,970 and amino acids are the building blocks of 342 00:13:06,970 --> 00:13:09,289 the DNA and RNA that provide the instructions 343 00:13:09,289 --> 00:13:10,269 for making life. 344 00:13:10,730 --> 00:13:13,449 So finding these fairly complex molecules on an 345 00:13:13,449 --> 00:13:15,149 asteroid is a pretty big deal. 346 00:13:16,105 --> 00:13:17,625 Then just a few days ago, we got 347 00:13:17,625 --> 00:13:20,504 some new results about Bennu's composition showing that 348 00:13:20,504 --> 00:13:23,704 the asteroid also contains traces of glucose and 349 00:13:23,704 --> 00:13:25,804 ribose, which are both essential sugars, 350 00:13:26,345 --> 00:13:28,664 plus a bunch of different nitrogen and oxygen 351 00:13:28,664 --> 00:13:31,440 containing organic compounds plus supernova 352 00:13:32,139 --> 00:13:34,220 dust. And this is all really adding to 353 00:13:34,220 --> 00:13:36,620 this idea that asteroids could have delivered some 354 00:13:36,620 --> 00:13:39,259 of the, quote, ingredients for life to the 355 00:13:39,259 --> 00:13:40,000 early Earth 356 00:13:40,300 --> 00:13:42,779 while it was still essentially a smoldering ball 357 00:13:42,779 --> 00:13:43,840 of empty rock, 358 00:13:44,274 --> 00:13:46,514 and thereby kick starting the process that led 359 00:13:46,514 --> 00:13:47,815 to the evolution of life. 360 00:13:48,434 --> 00:13:50,514 This is a hypothesis that's been kicking around 361 00:13:50,514 --> 00:13:52,855 for decades, but thanks to our OSIRIS REx 362 00:13:53,154 --> 00:13:55,875 and other sample return missions, we're finally getting 363 00:13:55,875 --> 00:13:58,455 some answers about how plausible it really is. 364 00:13:59,509 --> 00:14:01,350 However, if I could add just a little 365 00:14:01,350 --> 00:14:03,669 down note here, several of the scientists involved 366 00:14:03,669 --> 00:14:06,230 in this particular breakthrough are or were affiliated 367 00:14:06,230 --> 00:14:08,309 with NASA, which is the US National Air 368 00:14:08,309 --> 00:14:09,289 and Space Administration. 369 00:14:10,149 --> 00:14:12,894 NASA's facing massive budget cuts and layoff due 370 00:14:12,894 --> 00:14:14,975 to the anti science attitude of the current 371 00:14:14,975 --> 00:14:15,714 US government, 372 00:14:16,095 --> 00:14:18,514 and NASA's Goddard Space Flight Center in particular 373 00:14:18,815 --> 00:14:21,315 is looking at significant reductions in staffing. 374 00:14:21,855 --> 00:14:24,014 It's perhaps indicative of the situation that at 375 00:14:24,014 --> 00:14:25,774 least one of the scientists who led this 376 00:14:25,774 --> 00:14:27,154 research is in this breakthrough 377 00:14:27,500 --> 00:14:29,419 and was employed at NASA Goddard at the 378 00:14:29,419 --> 00:14:31,120 beginning of 02/2025 379 00:14:31,419 --> 00:14:32,639 is no longer there. 380 00:14:33,339 --> 00:14:35,339 So we like to celebrate breakthroughs, but this 381 00:14:35,339 --> 00:14:37,019 is kind of the reverse. It's a breakdown 382 00:14:37,019 --> 00:14:38,779 of the year in terms of our ability 383 00:14:38,779 --> 00:14:40,945 to discover things like this because if it 384 00:14:40,945 --> 00:14:42,865 continues, then we're gonna lose the people and 385 00:14:42,865 --> 00:14:45,284 skills we need to make these discoveries happen. 386 00:14:45,504 --> 00:14:47,184 In fact, we already are losing them, and 387 00:14:47,184 --> 00:14:48,945 we'd be remiss not to mention that somewhere 388 00:14:48,945 --> 00:14:49,764 in this podcast. 389 00:14:50,544 --> 00:14:52,945 Yeah. Very good point, Margaret. Breakdown of the 390 00:14:52,945 --> 00:14:54,625 year. Yeah. That's something we didn't want hope 391 00:14:54,625 --> 00:14:56,840 we wouldn't think think would have happened. But, 392 00:14:57,220 --> 00:14:59,639 very good point. But, you know, sending asteroid 393 00:15:00,019 --> 00:15:01,539 samples back to Earth and studying them, I 394 00:15:01,539 --> 00:15:02,980 mean, how cool is that for getting people 395 00:15:02,980 --> 00:15:05,220 into physics and astronomy and science and getting 396 00:15:05,220 --> 00:15:06,820 them excited? It's the kind of thing, especially 397 00:15:06,820 --> 00:15:08,894 younger people will be, you know, fascinated about. 398 00:15:08,894 --> 00:15:10,335 Yeah. If we only keep if we can 399 00:15:10,335 --> 00:15:12,274 only keep them there, it'd be fantastic. Yeah. 400 00:15:12,335 --> 00:15:14,095 So we're now halfway through our list of, 401 00:15:14,335 --> 00:15:16,014 the top 10 breakthroughs of the year for 402 00:15:16,014 --> 00:15:18,654 2025 in physics. We're gonna switch gear and 403 00:15:18,654 --> 00:15:20,274 move over to medical physics. 404 00:15:20,654 --> 00:15:22,735 And, Tammy, we've gone for some new work 405 00:15:22,735 --> 00:15:24,355 using what's known as proton 406 00:15:25,080 --> 00:15:25,820 arc therapy, 407 00:15:26,120 --> 00:15:28,680 which involves using protons to treat patients with 408 00:15:28,680 --> 00:15:30,279 cancer, but in a better manner than has 409 00:15:30,279 --> 00:15:31,420 been possible before. 410 00:15:32,279 --> 00:15:35,340 Yes. So this study is about proton therapy, 411 00:15:35,720 --> 00:15:38,304 a cancer treatment in which beams of protons 412 00:15:38,365 --> 00:15:41,164 are precisely directed onto a tumor to destroy 413 00:15:41,164 --> 00:15:42,225 targeted cells. 414 00:15:42,845 --> 00:15:45,964 Now currently, proton therapy is mostly performed using 415 00:15:45,964 --> 00:15:48,684 a technique called pencil beam scanning, in which 416 00:15:48,684 --> 00:15:50,845 a narrow beam of protons is scanned over 417 00:15:50,845 --> 00:15:52,769 the target to match the tumor shape 418 00:15:53,250 --> 00:15:55,410 with different beam energies used to build up 419 00:15:55,410 --> 00:15:58,290 depth layers and effectively paint the dose onto 420 00:15:58,290 --> 00:15:59,429 the tumor volume. 421 00:15:59,730 --> 00:16:03,009 Now this this approach provides highly conformal dose 422 00:16:03,009 --> 00:16:03,509 distributions, 423 00:16:04,050 --> 00:16:06,690 which means that the proton dose matches really 424 00:16:06,690 --> 00:16:08,389 well with the shape of the tumor. 425 00:16:08,855 --> 00:16:10,454 But it can be limited by the small 426 00:16:10,454 --> 00:16:12,615 number of beam directions that it can deliver 427 00:16:12,615 --> 00:16:14,714 in an acceptable treatment time. 428 00:16:16,134 --> 00:16:18,694 Now a team at the Trento Proton Therapy 429 00:16:18,694 --> 00:16:21,014 Center in Italy is working on a new 430 00:16:21,014 --> 00:16:22,315 type of treatment delivery 431 00:16:22,620 --> 00:16:24,399 called proton arc therapy. 432 00:16:25,340 --> 00:16:27,899 Here, the proton beams are irradiated onto the 433 00:16:27,899 --> 00:16:30,320 target at a large number of beam angles 434 00:16:30,379 --> 00:16:32,799 while the gantry moves in an arc trajectory 435 00:16:33,100 --> 00:16:34,080 around the patient. 436 00:16:34,460 --> 00:16:35,679 And during this rotation, 437 00:16:36,095 --> 00:16:38,674 the beam energy and intensity are adjusted 438 00:16:38,975 --> 00:16:41,455 to map the required dose onto the target 439 00:16:41,455 --> 00:16:41,955 volume. 440 00:16:43,535 --> 00:16:46,815 Now working with researchers at research laboratories in 441 00:16:46,815 --> 00:16:47,315 Sweden, 442 00:16:47,934 --> 00:16:51,190 the team compared proton arc therapy plans with 443 00:16:51,190 --> 00:16:53,610 state of the art pencil beam scanning plans 444 00:16:53,750 --> 00:16:55,850 for 10 patients with head and neck cancers. 445 00:16:56,709 --> 00:16:59,209 And they found that proton arc therapy improved 446 00:16:59,269 --> 00:17:01,829 the dose conformality compared with the pencil beam 447 00:17:01,829 --> 00:17:04,869 plans. So it did it delivered equivalent dose 448 00:17:04,869 --> 00:17:07,265 to the tumor target, but less dose to 449 00:17:07,265 --> 00:17:10,065 the nearby organs at risk, with the largest 450 00:17:10,065 --> 00:17:12,544 impact seen in reducing dose to the brain 451 00:17:12,544 --> 00:17:13,044 stem. 452 00:17:13,744 --> 00:17:16,384 And the team also ran a feasibility test 453 00:17:16,384 --> 00:17:19,184 that confirmed that it's actually possible to deliver 454 00:17:19,184 --> 00:17:21,444 this proton arc therapy in the clinic. 455 00:17:22,880 --> 00:17:25,759 The big breakthrough here is that following these 456 00:17:25,759 --> 00:17:29,039 initial tests, the researchers then performed the world's 457 00:17:29,039 --> 00:17:32,099 first clinical treatments using proton arc therapy. 458 00:17:32,960 --> 00:17:34,960 At the time of writing their paper, they 459 00:17:34,960 --> 00:17:36,740 treated nine cancer patients, 460 00:17:37,244 --> 00:17:39,325 five with head and neck tumors, three with 461 00:17:39,325 --> 00:17:41,585 brain tumors, and one with thoracic cancer. 462 00:17:42,365 --> 00:17:44,924 Now importantly, all of these treatments were performed 463 00:17:44,924 --> 00:17:48,305 using the medical center's existing proton therapy system 464 00:17:48,525 --> 00:17:50,545 and using the same clinical workflow. 465 00:17:51,565 --> 00:17:54,069 Looking ahead, the researchers aim to use this 466 00:17:54,069 --> 00:17:57,029 protonark therapy to treat tumors in other regions 467 00:17:57,029 --> 00:17:57,769 of the body. 468 00:17:58,630 --> 00:18:00,630 So a technique that potentially could really be 469 00:18:00,630 --> 00:18:02,650 of great benefit to, to people, 470 00:18:03,109 --> 00:18:04,724 with cancer. That sounds great, 471 00:18:05,605 --> 00:18:08,265 and really promising work. And over in biophysics, 472 00:18:08,404 --> 00:18:10,085 Tammy, if I can stick with you, this 473 00:18:10,085 --> 00:18:12,244 year, we reported on some really interesting work 474 00:18:12,244 --> 00:18:13,944 using a quantum bit 475 00:18:14,244 --> 00:18:16,424 that was formed from a fluorescent protein 476 00:18:16,900 --> 00:18:18,579 that could be used as a sensor that 477 00:18:18,579 --> 00:18:21,700 can be directly produced inside living cells. Now 478 00:18:21,700 --> 00:18:23,859 to me, this sounds really fascinating. It's quantum 479 00:18:23,859 --> 00:18:25,000 physics and biophysics 480 00:18:25,299 --> 00:18:27,220 and a new kind of sensor. So do 481 00:18:27,220 --> 00:18:29,240 you wanna tell us about this one? Sure. 482 00:18:30,144 --> 00:18:32,704 So this breakthrough is from researchers at the 483 00:18:32,704 --> 00:18:36,244 University of Chicago, Pritzker School of Molecular Engineering. 484 00:18:37,025 --> 00:18:40,065 And they designed a protein quantum bit or 485 00:18:40,065 --> 00:18:40,565 qubit 486 00:18:40,945 --> 00:18:43,365 that can be produced inside living cells. 487 00:18:43,730 --> 00:18:45,890 And this protein qubit can be used as 488 00:18:45,890 --> 00:18:48,849 a quantum sensor that can detect tiny changes 489 00:18:48,849 --> 00:18:50,230 in magnetic fields. 490 00:18:51,089 --> 00:18:53,650 So many of today's quantum sensors are based 491 00:18:53,650 --> 00:18:56,230 on nitrogen vacancy or NV 492 00:18:56,884 --> 00:18:58,024 sensors in diamond. 493 00:18:58,484 --> 00:19:01,204 And when excited with laser pulses, these crystal 494 00:19:01,204 --> 00:19:03,845 defects emit a fluorescent signal that can be 495 00:19:03,845 --> 00:19:06,664 used to monitor slight changes in the magnetic 496 00:19:06,724 --> 00:19:08,585 properties of a nearby sample. 497 00:19:09,630 --> 00:19:13,089 For biological applications, however, these sensors are relatively 498 00:19:13,150 --> 00:19:16,990 large, and they're difficult to precisely position inside 499 00:19:16,990 --> 00:19:17,890 living cells. 500 00:19:18,750 --> 00:19:21,869 So instead, the team, led by Peter Maurer 501 00:19:21,869 --> 00:19:22,930 and David Avshalom, 502 00:19:23,615 --> 00:19:26,015 took a biological system and turned it into 503 00:19:26,015 --> 00:19:26,674 a qubit. 504 00:19:27,455 --> 00:19:29,775 They used fluorescent proteins that are just three 505 00:19:29,775 --> 00:19:30,994 nanometers in diameter 506 00:19:31,455 --> 00:19:33,234 and can be genetically encoded 507 00:19:33,535 --> 00:19:35,695 such that they're produced by cells at a 508 00:19:35,695 --> 00:19:38,035 desired location with atomic precision. 509 00:19:39,430 --> 00:19:41,670 What's special about these proteins is that they 510 00:19:41,670 --> 00:19:43,849 possess similar optical and spin properties 511 00:19:44,150 --> 00:19:46,410 to those of NV center based qubits, 512 00:19:46,950 --> 00:19:48,250 in that they have a metastable 513 00:19:48,630 --> 00:19:49,690 triplet state. 514 00:19:51,285 --> 00:19:53,525 So to demonstrate that their idea worked, the 515 00:19:53,525 --> 00:19:57,285 researchers created an optically addressable spin qubit in 516 00:19:57,285 --> 00:19:58,984 a yellow fluorescent protein, 517 00:19:59,285 --> 00:20:01,365 and they used a near infrared laser pulse 518 00:20:01,365 --> 00:20:03,285 to read out its triplet state with up 519 00:20:03,285 --> 00:20:05,065 to 20% spin contrast. 520 00:20:06,484 --> 00:20:09,670 Next, they genetically modified the protein so that 521 00:20:09,670 --> 00:20:12,710 it was expressed in bacterial cells, and they 522 00:20:12,710 --> 00:20:15,750 measured signals in this case with a, contrast 523 00:20:15,750 --> 00:20:16,970 of up to 8%. 524 00:20:17,750 --> 00:20:18,970 So while this performance 525 00:20:19,269 --> 00:20:22,170 doesn't match that of the NV quantum sensors, 526 00:20:22,914 --> 00:20:26,375 These fluorescent proteins could enable magnetic resonance measurements 527 00:20:26,595 --> 00:20:30,035 directly inside living cells, which NV centers simply 528 00:20:30,035 --> 00:20:30,855 cannot do. 529 00:20:31,954 --> 00:20:34,035 And because of this, Maurer suggests that the 530 00:20:34,035 --> 00:20:35,174 new protein qubits 531 00:20:35,579 --> 00:20:37,599 could transform medical and biochemical 532 00:20:37,900 --> 00:20:38,400 studies 533 00:20:39,019 --> 00:20:43,099 by probing protein folding, monitoring redox states, or 534 00:20:43,099 --> 00:20:45,679 detecting drug binding at the molecular scale. 535 00:20:46,059 --> 00:20:48,779 So thanks, Tammy. That's some fascinating, biophysics and 536 00:20:48,779 --> 00:20:51,054 quantum physics. And we're down to the final 537 00:20:51,054 --> 00:20:52,815 three picks for the breakthrough of the year 538 00:20:52,815 --> 00:20:54,674 in physics for 2025. 539 00:20:54,734 --> 00:20:56,255 Hamish, I'm gonna come back to you now 540 00:20:56,255 --> 00:20:58,835 for some imaging and condensed matter physicists, 541 00:20:59,294 --> 00:21:01,694 with physicists saying that they've recorded the highest 542 00:21:01,694 --> 00:21:02,514 ever resolution 543 00:21:02,894 --> 00:21:04,595 images of a single atom. 544 00:21:05,099 --> 00:21:06,779 Well, we do like breaking records here at 545 00:21:06,779 --> 00:21:08,460 Physics World. So, do you wanna tell us 546 00:21:08,460 --> 00:21:09,980 about this one? And can you pronounce the 547 00:21:09,980 --> 00:21:10,480 technique? 548 00:21:10,779 --> 00:21:13,099 It's got a funny name. Well, we'll see. 549 00:21:13,099 --> 00:21:14,240 Yeah. So, 550 00:21:14,539 --> 00:21:17,019 yes, this this is a a breakthrough in 551 00:21:17,019 --> 00:21:17,819 terms of, 552 00:21:18,605 --> 00:21:20,545 resolution with an electron micros- 553 00:21:20,845 --> 00:21:23,884 with an electron microscope. But there's much much 554 00:21:23,884 --> 00:21:26,205 more to it, which is why we selected 555 00:21:26,205 --> 00:21:27,984 it. This is related to twisted 556 00:21:28,445 --> 00:21:30,224 materials, this idea of twistronics. 557 00:21:31,005 --> 00:21:32,305 When you take two 558 00:21:32,609 --> 00:21:33,009 atomic, 559 00:21:33,569 --> 00:21:34,069 atomically 560 00:21:34,369 --> 00:21:34,869 thin 561 00:21:35,250 --> 00:21:38,130 lattice layers and twist them with respect to 562 00:21:38,130 --> 00:21:39,490 each other, and you can get some really 563 00:21:39,490 --> 00:21:39,990 strange, 564 00:21:41,009 --> 00:21:43,509 properties in these, twisted systems. 565 00:21:44,369 --> 00:21:47,109 The result is something called a moire superlattice 566 00:21:47,804 --> 00:21:49,984 of atoms. And you can by 567 00:21:50,524 --> 00:21:51,904 adjusting the twist angle, 568 00:21:52,204 --> 00:21:55,484 you can adjust this superlattice, the distance between 569 00:21:55,484 --> 00:21:56,065 the atoms, 570 00:21:56,524 --> 00:21:59,184 and then you can also adjust the electronic 571 00:21:59,244 --> 00:22:00,625 properties of the system, 572 00:22:01,480 --> 00:22:04,380 which researchers have found to be very useful. 573 00:22:05,000 --> 00:22:06,779 And in this, study, 574 00:22:07,079 --> 00:22:10,059 Yichao Zhang at the University of Maryland 575 00:22:10,519 --> 00:22:12,059 and Pinshain Huang 576 00:22:12,359 --> 00:22:14,140 of the University of Illinois 577 00:22:14,519 --> 00:22:15,179 at Urbana 578 00:22:15,644 --> 00:22:16,144 Champaign, 579 00:22:16,605 --> 00:22:18,224 have used a technique called 580 00:22:18,684 --> 00:22:19,904 electron tachygraphy 581 00:22:20,924 --> 00:22:22,945 to capture the highest resolution 582 00:22:23,404 --> 00:22:24,545 images ever 583 00:22:24,924 --> 00:22:25,664 of atoms, 584 00:22:26,285 --> 00:22:28,224 and they've done so in a moire 585 00:22:28,799 --> 00:22:29,299 superlattice 586 00:22:29,840 --> 00:22:30,900 made of tungsten 587 00:22:31,279 --> 00:22:31,779 diselenide. 588 00:22:32,799 --> 00:22:33,299 Now, 589 00:22:33,600 --> 00:22:34,660 electron ticography, 590 00:22:34,960 --> 00:22:36,420 it's an electron microscopy 591 00:22:36,720 --> 00:22:37,220 technique 592 00:22:37,600 --> 00:22:38,980 that uses diffraction 593 00:22:39,440 --> 00:22:42,884 to boost the resolution of electron microscopy. Now, 594 00:22:43,125 --> 00:22:46,404 electron microscopy has got pretty high resolution already, 595 00:22:46,404 --> 00:22:49,765 and you can see individual atoms with, some 596 00:22:49,765 --> 00:22:50,744 electron microscopes. 597 00:22:51,125 --> 00:22:54,184 But diffraction is used to to improve this. 598 00:22:54,484 --> 00:22:56,759 And they were able to look 599 00:22:57,240 --> 00:22:58,619 at this moire superlattice 600 00:22:59,160 --> 00:23:00,059 at a resolution 601 00:23:00,440 --> 00:23:01,259 of 15 602 00:23:01,720 --> 00:23:02,220 picometers. 603 00:23:03,400 --> 00:23:05,880 And that's pretty good when you consider that 604 00:23:05,880 --> 00:23:06,700 the size 605 00:23:07,000 --> 00:23:08,920 of an atom. Okay, what's the size of 606 00:23:08,920 --> 00:23:11,345 an atom? It's a bit wooly, the definition. 607 00:23:11,644 --> 00:23:14,525 But typically, you know, it's defined to be 608 00:23:14,525 --> 00:23:15,505 about a 100 609 00:23:16,365 --> 00:23:16,865 picometres, 610 00:23:17,164 --> 00:23:19,884 a 150 picometres, so they're you know, the 611 00:23:19,884 --> 00:23:22,464 resolution is much much smaller 612 00:23:22,765 --> 00:23:24,944 than the actual size of the atoms 613 00:23:25,289 --> 00:23:26,509 that they're looking at. 614 00:23:27,289 --> 00:23:28,670 And I suppose 615 00:23:29,130 --> 00:23:30,410 a a very interesting thing, 616 00:23:30,970 --> 00:23:33,789 that they used this technique to do 617 00:23:34,090 --> 00:23:37,150 is they looked at collective lattice vibrations 618 00:23:37,769 --> 00:23:39,630 called moire phasons. 619 00:23:40,505 --> 00:23:42,424 And so these are a bit like, the 620 00:23:42,424 --> 00:23:43,565 familiar phonons, 621 00:23:44,424 --> 00:23:44,924 collective 622 00:23:45,304 --> 00:23:48,204 sound waves that occur in normal lattices. 623 00:23:48,744 --> 00:23:51,565 But they occur in these moire superlattices, 624 00:23:51,865 --> 00:23:54,909 and they're actually much lower energy and much 625 00:23:54,909 --> 00:23:55,409 weaker, 626 00:23:56,509 --> 00:23:57,809 but they do have, 627 00:23:58,190 --> 00:24:01,970 a very important effect on the electronic properties 628 00:24:02,269 --> 00:24:03,970 of these twisted materials. 629 00:24:04,750 --> 00:24:05,389 And so, 630 00:24:05,869 --> 00:24:08,690 by using this technique to observe these phasons, 631 00:24:11,125 --> 00:24:11,605 physicists, 632 00:24:11,924 --> 00:24:14,984 have the chance to really understand why 633 00:24:15,285 --> 00:24:18,805 these twisted materials have these really strange and 634 00:24:18,805 --> 00:24:19,305 exotic 635 00:24:19,684 --> 00:24:23,990 electronic properties. Because often these electronic properties arise 636 00:24:23,990 --> 00:24:27,349 because of interactions between the electrons and the 637 00:24:27,349 --> 00:24:28,330 lattice vibrations, 638 00:24:28,710 --> 00:24:30,809 you know, the classic example being superconductivity. 639 00:24:31,990 --> 00:24:32,390 So, 640 00:24:33,589 --> 00:24:35,609 yeah, a very a very high resolution 641 00:24:36,070 --> 00:24:36,404 elect, 642 00:24:36,884 --> 00:24:38,505 electron microscopy technique 643 00:24:38,884 --> 00:24:41,125 that opens up a new field, a new 644 00:24:41,125 --> 00:24:42,025 way of studying, 645 00:24:42,884 --> 00:24:45,765 these materials. So, yep, very exciting, and that's 646 00:24:45,765 --> 00:24:48,644 why it's in our top 10. Brilliant stuff, 647 00:24:48,644 --> 00:24:50,309 Hamish. Thanks very much. And if I can 648 00:24:50,309 --> 00:24:52,069 stick with you, now we always do know 649 00:24:52,069 --> 00:24:54,950 that particle physics gets, people very excited. And 650 00:24:54,950 --> 00:24:57,190 our penultimate pick for this year is some 651 00:24:57,190 --> 00:24:58,409 work done at CERN, 652 00:24:58,789 --> 00:25:01,429 where researchers at the base experiments have measured 653 00:25:01,429 --> 00:25:05,154 the magnetic properties of antimatter with record breaking 654 00:25:05,214 --> 00:25:05,714 precision. 655 00:25:06,575 --> 00:25:08,734 Tell us about this one, Hamish. Well, this 656 00:25:08,734 --> 00:25:10,255 is I mean, this has to do with 657 00:25:10,255 --> 00:25:11,875 one of the biggest mysteries 658 00:25:12,494 --> 00:25:13,154 of physics. 659 00:25:13,775 --> 00:25:16,974 And that mystery is why is there much 660 00:25:16,974 --> 00:25:17,795 more matter 661 00:25:18,319 --> 00:25:21,519 than antimatter in the visible universe? The the 662 00:25:21,519 --> 00:25:22,980 standard model says 663 00:25:23,359 --> 00:25:23,680 that, 664 00:25:24,240 --> 00:25:26,819 when the universe began in the big bang, 665 00:25:26,960 --> 00:25:28,960 there would have been roughly equal amounts of 666 00:25:28,960 --> 00:25:30,259 matter and antimatter. 667 00:25:30,664 --> 00:25:32,744 But when we look around us well, you 668 00:25:32,744 --> 00:25:34,664 know, look around the room that you're in, 669 00:25:34,664 --> 00:25:38,265 it's all matter. There's very little antimatter. Really, 670 00:25:38,265 --> 00:25:41,244 the only antimatter that we see comes from, 671 00:25:41,784 --> 00:25:43,484 you know, sort of nuclear processes, 672 00:25:44,105 --> 00:25:46,524 you know, both in in stars and in 673 00:25:47,440 --> 00:25:49,680 in, colliders here on Earth. There there's not 674 00:25:49,680 --> 00:25:51,539 a lot of antimatter out there. 675 00:25:53,039 --> 00:25:55,840 And so there are, there's a series of 676 00:25:55,840 --> 00:25:58,100 experiments, base is one of them at CERN, 677 00:25:58,320 --> 00:25:59,539 where they create, 678 00:26:00,320 --> 00:26:00,820 antimatter 679 00:26:01,365 --> 00:26:01,724 in, 680 00:26:02,164 --> 00:26:03,224 in an accelerator, 681 00:26:03,924 --> 00:26:05,065 and they do 682 00:26:05,365 --> 00:26:07,785 really, really precise measurements on it. 683 00:26:08,404 --> 00:26:09,625 And in this case, 684 00:26:10,005 --> 00:26:11,944 researchers on the base experiment 685 00:26:12,244 --> 00:26:14,345 managed to trap a single 686 00:26:14,724 --> 00:26:15,224 antiproton 687 00:26:16,130 --> 00:26:17,029 in an electromagnetic 688 00:26:17,890 --> 00:26:18,390 trap 689 00:26:18,690 --> 00:26:21,269 and use quantum control techniques 690 00:26:21,809 --> 00:26:22,950 to measure the 691 00:26:23,330 --> 00:26:26,630 antiproton's magnetic properties, basically, its spin, 692 00:26:27,809 --> 00:26:28,630 very precisely. 693 00:26:29,170 --> 00:26:31,830 In fact, 16 times more precise 694 00:26:32,945 --> 00:26:33,684 than before. 695 00:26:34,945 --> 00:26:37,285 And, you know, this is very difficult because 696 00:26:37,424 --> 00:26:39,585 first, you have to create the antiprotons, and 697 00:26:39,585 --> 00:26:41,825 that's done in a collider, and they come 698 00:26:41,825 --> 00:26:44,065 out at very high energy. You have to 699 00:26:44,065 --> 00:26:45,125 slow them down. 700 00:26:46,250 --> 00:26:48,109 You have to sort of store them 701 00:26:48,649 --> 00:26:50,190 at very, very low temperatures 702 00:26:50,649 --> 00:26:53,289 and then do your experiments. And at any 703 00:26:53,289 --> 00:26:54,589 point in this process, 704 00:26:54,970 --> 00:26:57,929 if that anti piece of antimatter comes into 705 00:26:57,929 --> 00:27:00,509 contact with matter, which is, of course, everywhere, 706 00:27:01,244 --> 00:27:04,045 it'll annihilate and you lose it. So it's 707 00:27:04,045 --> 00:27:06,545 a really, really difficult process accumulating 708 00:27:07,244 --> 00:27:08,305 all this antimatter. 709 00:27:08,924 --> 00:27:11,244 And then amazingly, you know, they hold it 710 00:27:11,244 --> 00:27:12,144 in their trap 711 00:27:12,445 --> 00:27:14,785 for long enough to do these quantum manipulations 712 00:27:15,269 --> 00:27:15,769 and, 713 00:27:16,630 --> 00:27:17,450 and measure 714 00:27:18,070 --> 00:27:20,009 the, the its properties. 715 00:27:20,470 --> 00:27:22,230 And and and the reason they want to 716 00:27:22,230 --> 00:27:23,029 do this is, 717 00:27:23,990 --> 00:27:25,450 the the standard model, 718 00:27:26,070 --> 00:27:28,809 basically says that matter and antimatter 719 00:27:29,684 --> 00:27:32,404 should be roughly the same except, you know, 720 00:27:32,404 --> 00:27:35,044 for the the obvious that one's matter and 721 00:27:35,044 --> 00:27:35,865 one's antimatter. 722 00:27:36,404 --> 00:27:39,444 So what what the ultimate goal is to 723 00:27:39,444 --> 00:27:42,265 measure the magnetic properties of the antiproton 724 00:27:43,000 --> 00:27:45,559 and compare it to the magnetic properties of 725 00:27:45,559 --> 00:27:46,299 the proton. 726 00:27:46,839 --> 00:27:49,019 And these should be, well, identical 727 00:27:49,400 --> 00:27:51,740 with the exception of a flip in, 728 00:27:52,599 --> 00:27:54,859 in the side the charge on the particle. 729 00:27:55,325 --> 00:27:57,244 And so if they can find even the 730 00:27:57,244 --> 00:27:57,984 most minute 731 00:27:58,285 --> 00:28:00,944 differences between the proton and the antiproton, 732 00:28:01,644 --> 00:28:03,025 that could lead to physics 733 00:28:03,565 --> 00:28:05,105 beyond the standard model 734 00:28:05,565 --> 00:28:08,065 and also tell us why there's more matter 735 00:28:08,365 --> 00:28:09,265 than antimatter 736 00:28:09,700 --> 00:28:10,519 in the universe. 737 00:28:11,220 --> 00:28:11,720 So 738 00:28:12,259 --> 00:28:15,299 exciting experiment, and who knows? Hopefully, they'll they'll 739 00:28:15,299 --> 00:28:17,380 find a difference between the proton and the 740 00:28:17,380 --> 00:28:17,880 antiproton. 741 00:28:18,180 --> 00:28:20,019 I always think with antimatter, we need another 742 00:28:20,019 --> 00:28:22,340 Dan Brown novel to follow angels and demons 743 00:28:22,340 --> 00:28:24,259 when they used antimatter, and that was the 744 00:28:24,259 --> 00:28:25,214 the plot hook. 745 00:28:26,174 --> 00:28:28,335 Now completing our list of the top 10 746 00:28:28,335 --> 00:28:30,015 breakthroughs of the year in physics as picked 747 00:28:30,015 --> 00:28:31,154 by Physics World, 748 00:28:31,534 --> 00:28:33,855 we've gone some for some condensed matter physics 749 00:28:33,855 --> 00:28:36,335 that seems pretty straightforward in principle, but, 750 00:28:36,894 --> 00:28:38,335 it seems to have taken quite a lot 751 00:28:38,335 --> 00:28:40,599 of effort, and that is in making two 752 00:28:40,599 --> 00:28:41,819 dimensional metals. 753 00:28:42,519 --> 00:28:44,119 So, Michael, can you tell us more about 754 00:28:44,119 --> 00:28:44,779 this one? 755 00:28:45,079 --> 00:28:46,759 Yeah. So this breakthrough is about the first 756 00:28:46,759 --> 00:28:48,700 creation of two d sheets of metal. 757 00:28:49,000 --> 00:28:50,440 So since 2004, 758 00:28:50,440 --> 00:28:52,359 we know that some materials can form flat 759 00:28:52,359 --> 00:28:54,059 sheets known as two d materials, 760 00:28:54,464 --> 00:28:56,244 graphene being one prime example. 761 00:28:56,785 --> 00:28:59,105 Such materials are about one atom thick, and 762 00:28:59,105 --> 00:29:01,345 in the case of graphene occur because you 763 00:29:01,345 --> 00:29:03,444 have a layer of atoms that are separated 764 00:29:03,505 --> 00:29:05,924 by gaps between neighboring layers. 765 00:29:06,539 --> 00:29:08,860 This means that you can effectively shave off 766 00:29:08,860 --> 00:29:10,880 layers to make two d sheets. 767 00:29:11,420 --> 00:29:13,660 Things are a bit different, however, for metals. 768 00:29:13,660 --> 00:29:16,140 In the case of metals, atoms are strongly 769 00:29:16,140 --> 00:29:19,019 bounded to surrounding atoms in all directions, which 770 00:29:19,019 --> 00:29:20,559 makes cleaving difficult. 771 00:29:21,274 --> 00:29:23,034 To get around this problem and create two 772 00:29:23,034 --> 00:29:25,274 d sheets of metal, the researchers who are 773 00:29:25,274 --> 00:29:28,075 based in China heated powders of pure metals 774 00:29:28,075 --> 00:29:29,534 and melted them into droplets. 775 00:29:30,075 --> 00:29:32,474 They then applied a pressure of around 200 776 00:29:32,474 --> 00:29:33,774 megapascal, effectively 777 00:29:34,075 --> 00:29:37,440 squeezing the opposite sides of these anvils until 778 00:29:37,440 --> 00:29:39,539 two d sheets of metals were formed. 779 00:29:40,079 --> 00:29:42,799 The team managed to produce five atomically thin 780 00:29:42,799 --> 00:29:45,140 two d metals. That's bismuth, 781 00:29:45,440 --> 00:29:48,799 tin, lead, indium, and gallium, with the thinnest 782 00:29:48,799 --> 00:29:50,320 being around 6.3 783 00:29:50,320 --> 00:29:50,820 angstrom. 784 00:29:51,654 --> 00:29:53,335 The researchers say their work is just a 785 00:29:53,335 --> 00:29:55,255 tip of the iceberg, and they now aim 786 00:29:55,255 --> 00:29:57,755 to study fundamental physics with the new materials. 787 00:29:58,055 --> 00:29:59,194 So watch this space. 788 00:30:00,855 --> 00:30:03,035 So that's all of our top 10 breakthroughs 789 00:30:03,174 --> 00:30:05,319 for this year as picked by Physics World. 790 00:30:05,319 --> 00:30:07,419 We've had some astronomy, some geoscience, 791 00:30:07,880 --> 00:30:08,859 condensed matter, 792 00:30:09,240 --> 00:30:12,119 a bit of particle physics, biophysics, medical physics, 793 00:30:12,119 --> 00:30:13,339 and optical physics. 794 00:30:13,880 --> 00:30:15,720 But to find out who's bagged the overall 795 00:30:15,720 --> 00:30:17,960 top prize for Physics World's breakthrough of the 796 00:30:17,960 --> 00:30:19,500 year for 2025, 797 00:30:20,144 --> 00:30:22,805 Check back on Thursday, December 18, 798 00:30:23,025 --> 00:30:25,184 where we'll reveal the winner in a new 799 00:30:25,184 --> 00:30:27,105 story and in the next episode of the 800 00:30:27,105 --> 00:30:28,805 Physics World weekly podcast. 801 00:30:29,825 --> 00:30:32,644 So a big thank you to Tammy, Margaret, 802 00:30:32,865 --> 00:30:35,045 Michael, and Hamish for joining me today. 803 00:30:35,460 --> 00:30:38,359 And a special thanks to producer Fred Isles. 804 00:30:38,419 --> 00:30:40,419 And thanks for listening, and do join us 805 00:30:40,419 --> 00:30:42,500 again next week for the big reveal of 806 00:30:42,500 --> 00:30:45,720 Physics World's breakthrough of the year for 2025.