1 00:00:07,919 --> 00:00:10,719 Hello, and welcome to the Physics World weekly 2 00:00:10,719 --> 00:00:12,660 podcast. I'm Hamish Johnston. 3 00:00:13,044 --> 00:00:15,625 In this episode, I'm joined by my colleagues 4 00:00:15,685 --> 00:00:18,804 Margaret Harris and Matin Durrani to talk about 5 00:00:18,804 --> 00:00:20,824 what's new in the world of physics. 6 00:00:21,445 --> 00:00:24,265 But first, a message from IOP Publishing, 7 00:00:24,725 --> 00:00:27,989 which brings you Physics World and also publishes 8 00:00:28,050 --> 00:00:32,070 an impressive range of scholarly journals, conference proceedings, 9 00:00:32,450 --> 00:00:33,350 and ebooks. 10 00:00:34,130 --> 00:00:35,989 As part of IOP Publishing's 11 00:00:36,289 --> 00:00:40,549 ongoing support for the early career researcher community, 12 00:00:41,125 --> 00:00:44,664 it's created a comprehensive guide to assist researchers 13 00:00:45,045 --> 00:00:46,585 in publishing their work. 14 00:00:46,885 --> 00:00:49,384 The guide includes valuable information 15 00:00:49,844 --> 00:00:52,265 about funding, peer review, ethics, 16 00:00:52,645 --> 00:00:53,145 accessibility, 17 00:00:54,090 --> 00:00:56,909 and strategies for maximizing the visibility 18 00:00:57,530 --> 00:00:58,589 of your work 19 00:00:58,890 --> 00:00:59,710 post publication. 20 00:01:00,570 --> 00:01:02,509 Search for IOP science 21 00:01:03,129 --> 00:01:06,670 researcher publishing guide and sign up to receive 22 00:01:06,729 --> 00:01:08,754 your copy, which will be emailed 23 00:01:09,454 --> 00:01:10,995 directly to your inbox. 24 00:01:19,055 --> 00:01:21,614 So first up, we've got Margaret who's going 25 00:01:21,614 --> 00:01:22,834 to take us to Mars 26 00:01:23,359 --> 00:01:25,619 and talk about the first observation 27 00:01:25,920 --> 00:01:26,979 of an aurora 28 00:01:27,359 --> 00:01:28,340 from the surface 29 00:01:28,719 --> 00:01:30,900 of the red planet. Hi, Margaret. 30 00:01:31,280 --> 00:01:32,019 Hi, Hamish. 31 00:01:32,799 --> 00:01:34,340 So Margaret, can you 32 00:01:34,799 --> 00:01:37,439 first remind us what an aurora is? I 33 00:01:37,439 --> 00:01:39,765 mean, people have been seeing lots of them 34 00:01:39,765 --> 00:01:40,564 here on Earth, 35 00:01:41,045 --> 00:01:42,965 over the over the past few months. But 36 00:01:42,965 --> 00:01:44,344 what what are people seeing? 37 00:01:44,884 --> 00:01:46,984 Well, what you're seeing is the 38 00:01:47,524 --> 00:01:48,024 manifestation 39 00:01:48,405 --> 00:01:51,465 of an interaction between our planet's magnetosphere 40 00:01:52,165 --> 00:01:53,924 and the solar wind. Okay. So what's the 41 00:01:53,924 --> 00:01:54,424 magnetosphere? 42 00:01:54,939 --> 00:01:55,599 The magnetosphere 43 00:01:55,979 --> 00:01:58,859 is sort of an envelope that surrounds Earth, 44 00:01:58,859 --> 00:02:01,119 and it's caused by the Earth being, 45 00:02:02,140 --> 00:02:03,819 basically, a big gigantic magnet. So there's a 46 00:02:03,819 --> 00:02:05,739 magnetic dynamo in the center of the Earth. 47 00:02:05,739 --> 00:02:07,579 It's probably due to the fact that we 48 00:02:07,579 --> 00:02:09,514 have a liquid iron core, 49 00:02:09,915 --> 00:02:11,215 creating a magnetic field. 50 00:02:11,835 --> 00:02:14,074 And so this is great. This is great 51 00:02:14,074 --> 00:02:16,074 because it protects us from the solar wind, 52 00:02:16,074 --> 00:02:17,935 which is a stream of charged particles 53 00:02:18,474 --> 00:02:19,694 coming from the sun. 54 00:02:20,155 --> 00:02:22,789 And when that stream of charged particles from 55 00:02:22,789 --> 00:02:24,969 the sun slams into our planet's magnetosphere, 56 00:02:25,509 --> 00:02:28,069 it it it produces the aurora borealis if 57 00:02:28,069 --> 00:02:29,830 the if you're in the Northern Hemisphere and 58 00:02:29,909 --> 00:02:32,330 or the aurora australis if you're down south. 59 00:02:33,444 --> 00:02:35,444 Okay. And and so what what has been 60 00:02:35,444 --> 00:02:37,205 seen on Mars? I think we when we 61 00:02:37,205 --> 00:02:39,685 were first discussing this paper a few weeks 62 00:02:39,685 --> 00:02:41,685 ago, we were really hoping that there was 63 00:02:41,685 --> 00:02:42,824 going to be a fantastic 64 00:02:43,444 --> 00:02:44,985 image of, you know, the classic 65 00:02:45,300 --> 00:02:45,800 shimmering 66 00:02:46,500 --> 00:02:48,120 red and green lights, 67 00:02:49,459 --> 00:02:50,919 above the Martian surface. 68 00:02:51,539 --> 00:02:52,520 Is that essentially 69 00:02:52,979 --> 00:02:53,479 what 70 00:02:54,099 --> 00:02:55,239 what what has been seen 71 00:02:55,539 --> 00:02:56,280 on Mars? 72 00:02:56,900 --> 00:02:59,300 Okay. Well, so first things, in order to 73 00:02:59,300 --> 00:03:00,759 see something really 74 00:03:01,115 --> 00:03:02,955 shimmering and gorgeous, you need a couple things. 75 00:03:02,955 --> 00:03:04,555 One, you need a solar storm that's big 76 00:03:04,555 --> 00:03:06,735 enough because not every time, 77 00:03:07,435 --> 00:03:09,194 not every solar storm is big enough to 78 00:03:09,194 --> 00:03:10,495 create the, you know, tremendous 79 00:03:11,034 --> 00:03:13,115 sort of light show that we've been seeing 80 00:03:13,115 --> 00:03:14,655 recently here on Earth because, 81 00:03:15,034 --> 00:03:16,635 we're at a solar maximum, as in the 82 00:03:16,635 --> 00:03:17,009 maximum of 83 00:03:20,849 --> 00:03:23,409 So first off, the solar storm that produced 84 00:03:23,409 --> 00:03:24,930 the aurora that was seen on Mars was 85 00:03:24,930 --> 00:03:27,569 a really minor one. It may have turned 86 00:03:27,569 --> 00:03:29,955 the sky just sort of, like, faintly greenish. 87 00:03:31,155 --> 00:03:33,155 So that's hard to detect even for for 88 00:03:33,155 --> 00:03:35,314 for the naked eye. It's hard even to 89 00:03:35,314 --> 00:03:37,335 detect for cameras. And the other thing is 90 00:03:37,634 --> 00:03:39,715 that this was seen on the surface of 91 00:03:39,715 --> 00:03:41,495 Mars by the Perseverance rover. 92 00:03:42,270 --> 00:03:44,270 And the Perseverance rover is a great little 93 00:03:44,270 --> 00:03:46,770 instrument, but it's mostly designed to be looking 94 00:03:46,990 --> 00:03:47,490 down. 95 00:03:47,870 --> 00:03:50,430 It's designed to do geology on Mars and 96 00:03:50,430 --> 00:03:52,590 to do all sorts of fantastic stuff associated 97 00:03:52,590 --> 00:03:54,110 with, you know, trying to work out whether 98 00:03:54,110 --> 00:03:55,889 life ever existed on Mars. 99 00:03:56,215 --> 00:03:58,474 It's not really designed to look up. 100 00:03:59,014 --> 00:04:00,854 And it's not designed to do observations in 101 00:04:00,854 --> 00:04:02,454 the dark. You don't do much geology in 102 00:04:02,454 --> 00:04:03,034 the dark. 103 00:04:03,655 --> 00:04:04,155 So 104 00:04:04,775 --> 00:04:07,014 the cameras there were not really optimized to 105 00:04:07,014 --> 00:04:09,674 pick up, you know, a really fantastic aurora, 106 00:04:10,069 --> 00:04:11,830 but they did pick up something. They picked 107 00:04:11,830 --> 00:04:13,990 up the fact that the sky turned from 108 00:04:13,990 --> 00:04:15,990 being its normal subdark color to being sort 109 00:04:15,990 --> 00:04:19,370 of vaguely grayish green. And that's important because 110 00:04:19,990 --> 00:04:22,790 we'd never seen an aurora from the surface 111 00:04:22,790 --> 00:04:24,649 of another world before. 112 00:04:25,055 --> 00:04:25,955 We'd seen auroras 113 00:04:26,415 --> 00:04:27,475 from orbits 114 00:04:28,014 --> 00:04:30,014 on all sorts of of planets in the 115 00:04:30,014 --> 00:04:31,694 in the solar system, any any, 116 00:04:32,415 --> 00:04:33,634 planet that has a magnetosphere, 117 00:04:34,415 --> 00:04:37,154 which interestingly, Mars doesn't really have its magnetosphere 118 00:04:37,295 --> 00:04:39,439 in the same sense that Earth does, but 119 00:04:39,439 --> 00:04:41,300 it does have a weak magnetosphere. 120 00:04:41,759 --> 00:04:43,060 It's called a hybrid magnetosphere 121 00:04:43,759 --> 00:04:46,740 that's generated not by this in interior planetary 122 00:04:46,800 --> 00:04:50,894 dynamo, but by some weakly, residually magnetic rocks, 123 00:04:51,134 --> 00:04:52,595 I believe in its southern hemisphere, 124 00:04:53,134 --> 00:04:54,974 and by just the fact that Mars is 125 00:04:54,974 --> 00:04:55,875 a big object. 126 00:04:56,254 --> 00:04:58,274 And so it tends to sort of warp 127 00:04:58,574 --> 00:05:00,735 the solar wind into and the magnetic fields 128 00:05:00,735 --> 00:05:02,175 that come from there sort of get warped 129 00:05:02,175 --> 00:05:04,134 around it and kinda gathered around it like 130 00:05:04,134 --> 00:05:06,514 a like a sort of gauzy summer shawl. 131 00:05:07,110 --> 00:05:09,189 So it has this very, very weak magnetic 132 00:05:09,189 --> 00:05:11,430 field. It's although it's not strong enough to 133 00:05:11,430 --> 00:05:11,930 protect, 134 00:05:12,870 --> 00:05:15,689 objects on the surface of Mars from intense 135 00:05:15,750 --> 00:05:17,589 radiation, from the cosmic rays, and from the 136 00:05:17,589 --> 00:05:20,654 solar wind, it is strong enough to produce 137 00:05:20,654 --> 00:05:22,995 an aurora. And that's what Perseverance saw. 138 00:05:23,375 --> 00:05:25,055 I see. And, I mean, it sounds to 139 00:05:25,055 --> 00:05:26,894 me that this was was was this sort 140 00:05:26,894 --> 00:05:28,115 of an accidental 141 00:05:28,415 --> 00:05:29,394 or a serendipitous 142 00:05:30,654 --> 00:05:32,814 observation that I don't know. They they just 143 00:05:32,814 --> 00:05:34,709 happened to leave the cameras on at night 144 00:05:35,430 --> 00:05:37,669 and, and and they caught this, you know, 145 00:05:37,669 --> 00:05:39,430 this is sort of the equivalent of the 146 00:05:39,430 --> 00:05:42,310 of the doorbell cam here on Earth or 147 00:05:42,310 --> 00:05:42,810 or, 148 00:05:43,990 --> 00:05:45,750 were they actually looking for it? Oh, they 149 00:05:45,750 --> 00:05:47,750 were definitely looking for it. They were definitely 150 00:05:47,750 --> 00:05:49,824 looking very hard for it. And the thing 151 00:05:49,824 --> 00:05:51,824 is that, you know, Perseverance is a busy 152 00:05:51,824 --> 00:05:53,425 little dude. You know? It can't just keep 153 00:05:53,425 --> 00:05:55,345 its cameras looking up just in case there 154 00:05:55,345 --> 00:05:57,824 might be an aurora up there. Mhmm. They 155 00:05:57,824 --> 00:05:59,764 had to have some really good predictions 156 00:06:00,464 --> 00:06:00,964 of 157 00:06:01,425 --> 00:06:03,699 when this to first for actually, first, go 158 00:06:03,699 --> 00:06:05,220 back a little bit. First, they had to 159 00:06:05,220 --> 00:06:06,519 see the solar storm 160 00:06:07,060 --> 00:06:08,279 that produced the aurora, 161 00:06:08,660 --> 00:06:10,899 and then they had to, work with some 162 00:06:10,899 --> 00:06:14,439 scientists at NASA's Goddard flight Space Flight Center 163 00:06:14,685 --> 00:06:15,185 to, 164 00:06:16,205 --> 00:06:18,605 understand when that aurora was gonna hit Mars. 165 00:06:18,605 --> 00:06:20,764 It takes about three days, but they can 166 00:06:20,764 --> 00:06:22,865 kinda predict it to within a few hours. 167 00:06:23,485 --> 00:06:25,324 And then they had to make a decision, 168 00:06:25,324 --> 00:06:27,824 like, is this aurora big enough that, 169 00:06:28,845 --> 00:06:31,850 Perseverance is not very optimized for looking at 170 00:06:31,850 --> 00:06:34,250 the sky cameras could see something. And then 171 00:06:34,250 --> 00:06:36,250 they had to request time and Perseverance, get 172 00:06:36,250 --> 00:06:37,770 it to stop doing whatever else it was 173 00:06:37,770 --> 00:06:39,709 doing and to look up at the sky. 174 00:06:40,569 --> 00:06:42,330 And then they had to be lucky, basically. 175 00:06:42,330 --> 00:06:43,149 They had to 176 00:06:43,504 --> 00:06:45,425 have all those things happen at just the 177 00:06:45,425 --> 00:06:47,105 right time. And I think it took him 178 00:06:47,105 --> 00:06:47,425 about, 179 00:06:48,464 --> 00:06:50,064 I think it took him about four goes 180 00:06:50,064 --> 00:06:52,245 before they managed to actually capture an aurora 181 00:06:52,464 --> 00:06:54,064 on Mars. But this is important. It's the 182 00:06:54,064 --> 00:06:56,144 first one to be done, and it's also 183 00:06:56,144 --> 00:06:57,660 the first aurora to be seen 184 00:06:58,139 --> 00:07:00,860 anywhere other than the Earth that's been measured 185 00:07:00,860 --> 00:07:01,680 in visible 186 00:07:01,980 --> 00:07:04,319 light wavelength rather than in UV light. 187 00:07:04,699 --> 00:07:07,180 And that's important because visible light cameras are 188 00:07:07,180 --> 00:07:08,000 a lot cheaper 189 00:07:08,459 --> 00:07:09,680 than UV cameras. 190 00:07:10,060 --> 00:07:11,819 So if we can do these observations with 191 00:07:11,819 --> 00:07:12,879 nice cheap cameras, 192 00:07:13,305 --> 00:07:15,144 then we should be able to do do 193 00:07:15,144 --> 00:07:16,444 more of them, essentially. 194 00:07:17,225 --> 00:07:19,464 Right. And, it is I mean, it does 195 00:07:19,464 --> 00:07:21,625 seem to be a very good time here 196 00:07:21,625 --> 00:07:24,425 on Earth to be to be out looking 197 00:07:24,425 --> 00:07:26,430 for Aurora. I mean, I've seen reports 198 00:07:26,910 --> 00:07:29,550 in North America where, you know, even this 199 00:07:29,550 --> 00:07:30,370 time of year, 200 00:07:30,750 --> 00:07:32,209 aurora have been spotted, 201 00:07:34,269 --> 00:07:36,669 further south than forty five degrees north, which 202 00:07:36,669 --> 00:07:39,069 is, you know, that's closer to the Equator 203 00:07:39,069 --> 00:07:41,064 than the North Pole, which, you know, is 204 00:07:41,064 --> 00:07:43,625 is pretty impressive. And I'm guessing that has 205 00:07:43,625 --> 00:07:45,805 to do with some increased solar activity 206 00:07:46,345 --> 00:07:47,564 at the time. So, 207 00:07:48,024 --> 00:07:48,524 are 208 00:07:48,985 --> 00:07:51,324 the the people who who use Perseverance, 209 00:07:51,625 --> 00:07:54,044 are are they geared up for more observations? 210 00:07:54,589 --> 00:07:57,170 And I'm guessing they're probably looking for time 211 00:07:57,310 --> 00:07:59,170 when they know there's gonna be a big 212 00:07:59,550 --> 00:08:00,770 solar storm, 213 00:08:02,270 --> 00:08:03,889 that that to to turn 214 00:08:04,430 --> 00:08:07,310 the the the rover's cam cameras skyward. Is 215 00:08:07,310 --> 00:08:08,590 that is that the sort of thing that 216 00:08:08,670 --> 00:08:09,764 that's going to be next 217 00:08:10,324 --> 00:08:11,944 for, for people there? 218 00:08:12,564 --> 00:08:14,245 I think they certainly want to do that. 219 00:08:14,245 --> 00:08:16,085 Whether they'll be able to get time on 220 00:08:16,085 --> 00:08:19,365 on perseverance is, you know, another question. It 221 00:08:19,444 --> 00:08:20,725 it's as I said, it has lots of 222 00:08:20,725 --> 00:08:21,384 other priorities. 223 00:08:22,240 --> 00:08:24,879 But, definitely, this is probably gonna be hopefully 224 00:08:24,879 --> 00:08:26,899 the first of many detections of aurora, 225 00:08:28,159 --> 00:08:29,699 by robots that are 226 00:08:30,079 --> 00:08:31,620 by robots that are exploring, 227 00:08:32,240 --> 00:08:34,740 the surfaces and the atmospheres by the planets. 228 00:08:35,360 --> 00:08:37,139 Oh, that's great. That's really interesting. 229 00:08:38,575 --> 00:08:41,215 And staying in space, but sort of looking 230 00:08:41,215 --> 00:08:43,154 into the far, far future, 231 00:08:43,934 --> 00:08:46,495 you've also got an update for us about 232 00:08:46,495 --> 00:08:48,995 the ultimate fate of the universe 233 00:08:49,789 --> 00:08:52,129 and the news that it might 234 00:08:52,429 --> 00:08:55,730 not be as long lived as previously expected. 235 00:08:56,269 --> 00:08:57,789 And I think this has something to do 236 00:08:57,789 --> 00:08:59,329 with white dwarf stars, 237 00:08:59,789 --> 00:09:01,809 which are expected to persist 238 00:09:02,235 --> 00:09:03,615 for an extraordinarily 239 00:09:04,235 --> 00:09:05,054 long time. 240 00:09:05,434 --> 00:09:05,934 And 241 00:09:06,315 --> 00:09:08,554 when I say extraordinarily long, I think we're 242 00:09:08,554 --> 00:09:10,575 talking about ten to the 243 00:09:11,514 --> 00:09:14,575 thousands or even tens of thousands of years. 244 00:09:15,034 --> 00:09:17,534 So so why are white dwarfs 245 00:09:18,059 --> 00:09:18,559 important 246 00:09:18,860 --> 00:09:21,759 when it comes to understanding the the future 247 00:09:22,299 --> 00:09:23,120 of the universe? 248 00:09:24,059 --> 00:09:27,679 Okay. So white dwarfs are lower mass stars 249 00:09:27,740 --> 00:09:29,820 in the final stage of their lives. They 250 00:09:29,820 --> 00:09:32,165 weren't massive enough to collapse into a neutron 251 00:09:32,165 --> 00:09:34,725 star star or a black hole. They're just 252 00:09:34,725 --> 00:09:37,205 kinda hanging out, gently glowing from the residual 253 00:09:37,205 --> 00:09:39,684 heat. They're not doing any thermonuclear fusion or 254 00:09:39,684 --> 00:09:40,585 anything exciting. 255 00:09:41,285 --> 00:09:43,044 And that means that as long as they 256 00:09:43,044 --> 00:09:45,720 don't get cannibalized by a companion star or 257 00:09:45,720 --> 00:09:47,720 fall into a black hole or something weird 258 00:09:48,120 --> 00:09:49,560 and, also, I should say, as long as 259 00:09:49,560 --> 00:09:51,800 our universe doesn't undergo some sort of big 260 00:09:51,800 --> 00:09:53,720 crunch, this is not this this story is 261 00:09:53,720 --> 00:09:55,720 not to do with the sort of grand 262 00:09:55,720 --> 00:09:58,279 scale cosmology. It's really about white dwarf stars, 263 00:09:58,279 --> 00:10:00,404 the physics of white dwarf stars. So as 264 00:10:00,404 --> 00:10:02,164 long as those things don't happen, they can 265 00:10:02,164 --> 00:10:03,465 last a really long time. 266 00:10:04,485 --> 00:10:06,565 But crucially, a really long time is not 267 00:10:06,565 --> 00:10:08,404 the same thing as forever. There is a 268 00:10:08,404 --> 00:10:10,325 few things that could make a white dwarf 269 00:10:10,325 --> 00:10:11,065 star disappear. 270 00:10:11,924 --> 00:10:14,220 So one of them is if protons decay. 271 00:10:15,419 --> 00:10:18,000 Various theories predict that protons should decay, 272 00:10:18,699 --> 00:10:21,100 but nobody's ever seen that happen, and it's 273 00:10:21,100 --> 00:10:22,779 not for lack of trying. There were several 274 00:10:22,779 --> 00:10:24,860 experiments looking for proton decay, I think, in 275 00:10:24,860 --> 00:10:26,559 the nineteen eighties and nineteen nineties. 276 00:10:27,835 --> 00:10:29,355 But the best we can say that if 277 00:10:29,355 --> 00:10:30,815 if protons do decay, 278 00:10:31,434 --> 00:10:33,115 they do it on a time scale that's 279 00:10:33,115 --> 00:10:35,514 longer than our experiments so far have been 280 00:10:35,514 --> 00:10:38,335 able to measure. Okay. That's proton decay. 281 00:10:39,035 --> 00:10:40,980 The other way of making a white dwarf 282 00:10:41,059 --> 00:10:43,879 star disappear is via process called piconuclear 283 00:10:44,259 --> 00:10:44,759 fusion. 284 00:10:45,299 --> 00:10:46,820 I had never heard of this before I 285 00:10:46,820 --> 00:10:48,740 saw this story, but it's derived from the 286 00:10:48,740 --> 00:10:50,759 Greek word pyknos, meaning dense. 287 00:10:51,220 --> 00:10:52,360 So piconuclear 288 00:10:52,740 --> 00:10:55,379 fusion is nuclear fusion that only happens in 289 00:10:55,379 --> 00:10:56,679 extremely dense material 290 00:10:57,514 --> 00:10:59,615 like you get inside a white dwarf star. 291 00:11:00,315 --> 00:11:02,875 And it's kind of a complicated process, but, 292 00:11:02,875 --> 00:11:05,514 essentially, what's happening is that the nuclei inside 293 00:11:05,514 --> 00:11:08,715 white dwarfs are oscillating around their zero point 294 00:11:08,715 --> 00:11:09,179 energy. 295 00:11:09,899 --> 00:11:12,620 And sometimes these oscillations are actually enough to 296 00:11:12,620 --> 00:11:14,940 allow them to fuse. There's some quantum tunneling 297 00:11:14,940 --> 00:11:15,440 involved. 298 00:11:15,980 --> 00:11:17,980 And if that happened to matter under normal 299 00:11:17,980 --> 00:11:18,480 conditions, 300 00:11:18,860 --> 00:11:20,700 like, stuff would be fusing all over the 301 00:11:20,700 --> 00:11:22,795 place. But fortunately, that doesn't happen. It only 302 00:11:22,795 --> 00:11:25,355 happens really in inside white dwarf stars, or 303 00:11:25,355 --> 00:11:28,154 it's only important, let's say, inside white dwarf 304 00:11:28,154 --> 00:11:28,654 stars. 305 00:11:29,514 --> 00:11:30,014 And 306 00:11:30,955 --> 00:11:33,274 the consequence of pyronuclear fusion is that it 307 00:11:33,274 --> 00:11:35,774 turns the carbon and white dwarf star cores 308 00:11:36,269 --> 00:11:39,230 into nickel, which then decays to, I think 309 00:11:39,230 --> 00:11:41,709 it's iron 56. Don't quote me on that. 310 00:11:41,709 --> 00:11:43,169 I think it's iron 56 311 00:11:43,309 --> 00:11:44,529 by emitting a positron. 312 00:11:45,389 --> 00:11:47,230 And once you've got that iron core, you've 313 00:11:47,230 --> 00:11:48,990 no longer got a white dwarf star. You've 314 00:11:48,990 --> 00:11:50,315 got a black dwarf star, 315 00:11:50,695 --> 00:11:53,014 which is a theoretical object that's never before 316 00:11:53,014 --> 00:11:53,754 been seen, 317 00:11:54,134 --> 00:11:56,634 not just because it's dark, but because 318 00:11:57,095 --> 00:11:59,115 the time required for that to happen 319 00:11:59,575 --> 00:12:01,414 is actually longer than the lifetime of the 320 00:12:01,414 --> 00:12:02,634 universe so far. 321 00:12:03,014 --> 00:12:05,095 So even if it's possible, it hasn't happened 322 00:12:05,095 --> 00:12:05,340 yet. 323 00:12:06,779 --> 00:12:08,940 I see. And and so the idea here 324 00:12:08,940 --> 00:12:10,879 is that the the end of the universe 325 00:12:11,019 --> 00:12:13,980 that we're talking about is when all is 326 00:12:13,980 --> 00:12:16,399 when these white dwarf stars go 327 00:12:17,100 --> 00:12:19,019 that they don't produce any more light. They 328 00:12:19,019 --> 00:12:19,759 go dark. 329 00:12:20,095 --> 00:12:22,495 It's even weirder than that because so while 330 00:12:22,495 --> 00:12:23,615 we're going out on a out on a 331 00:12:23,615 --> 00:12:27,695 speculative limb here, turning carbon into iron leads 332 00:12:27,695 --> 00:12:29,634 to a loss of electron degeneracy 333 00:12:30,014 --> 00:12:31,475 pressure, which is what's keeping 334 00:12:31,855 --> 00:12:34,289 the black door from collapsing in on itself. 335 00:12:35,089 --> 00:12:37,649 And eventually I mean, we're talking very, very 336 00:12:37,649 --> 00:12:38,149 eventually. 337 00:12:38,929 --> 00:12:41,190 That will reduce the maximum mass 338 00:12:41,570 --> 00:12:44,049 that the black dwarf star can have before 339 00:12:44,049 --> 00:12:44,629 it collapses. 340 00:12:45,250 --> 00:12:46,470 It's called the Chandrasekhar 341 00:12:46,929 --> 00:12:47,429 limit. 342 00:12:47,754 --> 00:12:49,434 Right. And so that will actually make the 343 00:12:49,434 --> 00:12:50,894 black dwarf star unstable. 344 00:12:51,914 --> 00:12:53,595 So this is the other process that could 345 00:12:53,595 --> 00:12:56,574 cause otherwise stable white dwarf stars to disappear, 346 00:12:56,875 --> 00:12:59,294 and it's it's really slow. It's you mentioned 347 00:12:59,674 --> 00:13:02,074 it would take somewhere between ten to the 348 00:13:02,074 --> 00:13:03,360 eleven hundred years 349 00:13:03,839 --> 00:13:06,339 and ten to the thirty two thousand years 350 00:13:06,959 --> 00:13:09,059 depending on the mass of the black dwarf. 351 00:13:09,120 --> 00:13:10,879 So higher masses would be quicker because they 352 00:13:10,879 --> 00:13:12,899 would reach the Chandrasekhar limit quicker. 353 00:13:13,600 --> 00:13:16,019 Right. Okay. And that that is a very 354 00:13:16,079 --> 00:13:17,759 long time. That is a very long time. 355 00:13:17,759 --> 00:13:19,875 So those those are the so, 356 00:13:21,295 --> 00:13:23,535 proton decay, if it happens, is actually relatively 357 00:13:23,535 --> 00:13:26,254 quick. If you're if protons don't decay and 358 00:13:26,254 --> 00:13:28,654 piconuclear fusion is your only mechanism, that's really, 359 00:13:28,654 --> 00:13:29,475 really slow. 360 00:13:30,014 --> 00:13:30,514 Right. 361 00:13:31,055 --> 00:13:32,995 But there's some new research now, 362 00:13:33,950 --> 00:13:36,850 where some physicists have looked at a process, 363 00:13:37,789 --> 00:13:40,370 or a phenomenon called Hawking radiation. 364 00:13:41,309 --> 00:13:41,629 And, 365 00:13:42,269 --> 00:13:45,950 they've they've applied this to, white dwarf stars 366 00:13:45,950 --> 00:13:48,294 in the in the far future, and and 367 00:13:48,294 --> 00:13:50,615 they've come up with a a much, much, 368 00:13:50,615 --> 00:13:51,115 much 369 00:13:51,495 --> 00:13:51,995 shorter 370 00:13:52,375 --> 00:13:53,915 lifetime. Still very long, 371 00:13:54,375 --> 00:13:56,455 but much, much shorter. So so what is 372 00:13:56,455 --> 00:13:59,335 Hawking radiation? How does it fit in to, 373 00:13:59,815 --> 00:14:02,634 to the life's lifetime of, of these stars? 374 00:14:03,460 --> 00:14:06,100 Okay. So if you've heard of Hawking radiation, 375 00:14:06,100 --> 00:14:08,500 it's probably in the context of black holes 376 00:14:08,500 --> 00:14:10,899 because that's where it was first formulated by 377 00:14:10,899 --> 00:14:11,720 Stephen Hawking, 378 00:14:12,419 --> 00:14:14,740 building on some ideas of another theorist called 379 00:14:14,740 --> 00:14:15,559 Jacob Bekenstein. 380 00:14:16,855 --> 00:14:20,134 The idea is that particle antiparticle pairs are 381 00:14:20,134 --> 00:14:22,295 popping in and out of the quantum vacuum 382 00:14:22,295 --> 00:14:24,934 all the time. They borrow energy from the 383 00:14:24,934 --> 00:14:27,254 vacuum to to appear, and then they almost 384 00:14:27,254 --> 00:14:29,754 immediately give it back again because they annihilate 385 00:14:29,815 --> 00:14:30,450 and they disappear. 386 00:14:31,649 --> 00:14:32,149 However, 387 00:14:33,090 --> 00:14:35,490 if one half of that pair happens to 388 00:14:35,490 --> 00:14:38,070 drop over a black hole's event horizon 389 00:14:38,610 --> 00:14:41,190 in that brief period between coming into existence 390 00:14:41,490 --> 00:14:42,230 and annihilating, 391 00:14:42,850 --> 00:14:44,690 then it won't ever be able to recombine 392 00:14:44,690 --> 00:14:46,975 with its partner, so it'll take away some 393 00:14:46,975 --> 00:14:49,214 energy. And this is the mechanism by which 394 00:14:49,214 --> 00:14:51,955 black holes radiate away their mass energy 395 00:14:52,334 --> 00:14:53,154 and shrink 396 00:14:53,455 --> 00:14:54,995 rather than continually growing. 397 00:14:56,014 --> 00:14:58,199 But, obviously, a black hole is not the 398 00:14:58,199 --> 00:14:59,500 same thing as a white dwarf. 399 00:14:59,879 --> 00:15:02,600 But the kicker is that Hawking radiation doesn't 400 00:15:02,600 --> 00:15:04,299 just happen to black holes. 401 00:15:05,720 --> 00:15:07,399 A couple of years ago, the black hole 402 00:15:07,399 --> 00:15:11,579 expert Heino Falke, quantum physicist Michael von Drac, 403 00:15:11,735 --> 00:15:14,855 and mathematician Walter von Sudekum. Apologies. Their Dutch 404 00:15:14,855 --> 00:15:16,335 names I don't know speak Dutch. So if 405 00:15:16,335 --> 00:15:18,215 I pronounce those incorrectly, I'm very sorry. Don't 406 00:15:18,215 --> 00:15:20,555 even try, Margaret. Don't even try. Try. 407 00:15:20,935 --> 00:15:22,455 I'll do my best. I'll do my best. 408 00:15:23,175 --> 00:15:25,570 So they worked out that this whole particle 409 00:15:25,570 --> 00:15:27,590 falling over the event horizon scenario 410 00:15:28,129 --> 00:15:30,710 is really just an extreme case of particles 411 00:15:30,769 --> 00:15:33,889 not being able to annihilate because gravitational tidal 412 00:15:33,889 --> 00:15:35,970 forces have pulled them far away from each 413 00:15:35,970 --> 00:15:36,470 other. 414 00:15:37,009 --> 00:15:37,909 And in principle, 415 00:15:38,725 --> 00:15:39,544 that kind of 416 00:15:40,004 --> 00:15:41,705 gravitational tidal force separation 417 00:15:42,565 --> 00:15:44,664 can happen at least some of the time 418 00:15:45,125 --> 00:15:47,125 in the vicinity of any object with a 419 00:15:47,125 --> 00:15:48,345 gravitational field, 420 00:15:48,725 --> 00:15:51,284 and that includes white dwarf stars. In fact, 421 00:15:51,284 --> 00:15:52,350 it includes humans 422 00:15:52,829 --> 00:15:54,589 because you and I, we also have a 423 00:15:54,589 --> 00:15:57,250 gravitational field. It's very tiny, but it exists. 424 00:15:57,949 --> 00:15:58,449 And 425 00:15:59,230 --> 00:15:59,730 so 426 00:16:00,190 --> 00:16:02,350 this trio worked out it would take a 427 00:16:02,350 --> 00:16:04,909 white dwarf star around ten to the seventy 428 00:16:04,909 --> 00:16:05,569 eight years 429 00:16:05,949 --> 00:16:07,889 to dissipate via Hawking radiation, 430 00:16:08,804 --> 00:16:10,325 which is it's a hell of a long 431 00:16:10,325 --> 00:16:11,845 time, but it's a lot shorter than ten 432 00:16:11,845 --> 00:16:13,764 to eleven to the eleven hundred years or 433 00:16:13,764 --> 00:16:15,285 ten to the thirty two thousand years you 434 00:16:15,285 --> 00:16:17,065 get with piconuclear fusion reactions. 435 00:16:18,165 --> 00:16:20,264 And as a side note, they also calculated, 436 00:16:20,325 --> 00:16:21,945 you know, somewhat tongue in cheek, 437 00:16:22,325 --> 00:16:22,919 that if 438 00:16:23,559 --> 00:16:26,039 Hawking radiation was the only process involved, you 439 00:16:26,039 --> 00:16:27,639 know, you got rid of all of chemistry 440 00:16:27,639 --> 00:16:30,039 and biology and all sort of various physical 441 00:16:30,039 --> 00:16:30,919 events that could, 442 00:16:31,480 --> 00:16:33,259 cause them interrupt this process, 443 00:16:33,959 --> 00:16:34,459 then 444 00:16:34,759 --> 00:16:35,980 it would take a human, 445 00:16:36,785 --> 00:16:38,384 which is obviously less dense than a white 446 00:16:38,384 --> 00:16:39,125 dwarf star, 447 00:16:39,504 --> 00:16:42,245 around ten to the ninety years to 448 00:16:42,625 --> 00:16:45,125 dissipate entirely via Hawking radiation. 449 00:16:45,665 --> 00:16:47,985 Now I don't think that's there's gonna be 450 00:16:47,985 --> 00:16:50,610 much of an interesting universe around in ten 451 00:16:50,610 --> 00:16:52,129 to the ninety years. After all, we've just 452 00:16:52,129 --> 00:16:54,290 shown that white dwarf stars, even white dwarf 453 00:16:54,290 --> 00:16:55,990 stars, will have winked out of existence 454 00:16:56,450 --> 00:16:59,090 in, ten to the seventy eight years. But 455 00:16:59,090 --> 00:16:59,750 in principle, 456 00:17:00,210 --> 00:17:02,389 that is how long a a a human 457 00:17:02,529 --> 00:17:04,690 could or a human sized object made of 458 00:17:04,690 --> 00:17:07,304 water, let's say, could, could last in the 459 00:17:07,304 --> 00:17:07,804 universe. 460 00:17:08,505 --> 00:17:10,585 And, of course, that that doesn't take into 461 00:17:10,585 --> 00:17:11,085 consideration 462 00:17:11,384 --> 00:17:12,684 these sort of cosmological 463 00:17:13,304 --> 00:17:15,704 Oh, yeah. Issues Yeah. Yeah. About whether whether 464 00:17:15,704 --> 00:17:17,644 the universe is going to keep on 465 00:17:17,960 --> 00:17:20,519 keep on expanding or if it's going to 466 00:17:20,519 --> 00:17:22,759 sort of bounce back or this is just 467 00:17:22,759 --> 00:17:23,500 how long 468 00:17:24,279 --> 00:17:26,299 stuff in the universe can actually 469 00:17:26,680 --> 00:17:29,720 exist. Yeah. Exactly. Exactly. Yeah. Which is still 470 00:17:29,720 --> 00:17:31,815 interesting to think about. I mean Oh, yeah. 471 00:17:31,815 --> 00:17:34,054 Yeah. Yeah. Well, I mean, it is very 472 00:17:34,054 --> 00:17:36,694 interesting because, you know, I'm guessing that by 473 00:17:36,694 --> 00:17:39,035 doing these calculations on Hawking radiation, 474 00:17:39,815 --> 00:17:42,474 they're, you know, sort of moving our knowledge 475 00:17:42,535 --> 00:17:43,035 forward 476 00:17:43,559 --> 00:17:44,059 of, 477 00:17:45,000 --> 00:17:47,179 you know, the sort of the interplay between 478 00:17:47,480 --> 00:17:48,919 quantum mechanics and, 479 00:17:50,200 --> 00:17:51,339 and general relativity 480 00:17:51,799 --> 00:17:54,440 Yeah. Which is always very interesting. Well, thanks, 481 00:17:54,440 --> 00:17:56,779 Margaret. Thanks for coming on and talking about 482 00:17:57,325 --> 00:18:00,845 about Aurora on Mars and the age of, 483 00:18:01,244 --> 00:18:03,744 objects in the universe. And you can find, 484 00:18:04,445 --> 00:18:07,005 both of those articles written by Margaret. They're 485 00:18:07,005 --> 00:18:09,005 both written by you, Margaret. Is that right? 486 00:18:09,005 --> 00:18:11,565 Yep. Yeah. Both articles written by Margaret about 487 00:18:11,565 --> 00:18:12,065 these, 488 00:18:12,730 --> 00:18:15,710 subjects on the Physics World website. Thanks. 489 00:18:16,490 --> 00:18:17,309 Thanks, Hamish. 490 00:18:25,210 --> 00:18:27,609 Now let's move from the future to the 491 00:18:27,609 --> 00:18:29,224 past and an important 492 00:18:29,525 --> 00:18:31,464 moment in physics history. 493 00:18:32,085 --> 00:18:34,505 Matin, you'll soon be traveling to the German 494 00:18:34,565 --> 00:18:35,785 island of Helgoland 495 00:18:36,484 --> 00:18:38,105 for a hundredth anniversary 496 00:18:38,644 --> 00:18:39,144 celebration. 497 00:18:39,924 --> 00:18:41,545 What happened in Helgoland 498 00:18:42,190 --> 00:18:44,049 back in 1925? 499 00:18:44,750 --> 00:18:47,630 Well, it was in June 1925 that Werner 500 00:18:47,630 --> 00:18:48,130 Heisenberg, 501 00:18:48,430 --> 00:18:50,609 who at the time was a young postdoc 502 00:18:50,670 --> 00:18:51,970 at the University of Gottingen, 503 00:18:52,590 --> 00:18:54,750 he suffered from a really bad bout of 504 00:18:54,750 --> 00:18:55,570 hay fever. 505 00:18:55,904 --> 00:18:58,945 But he famously asked his supervisor, Max Born, 506 00:18:58,945 --> 00:19:00,865 if he could go to this island for 507 00:19:00,865 --> 00:19:02,565 two weeks to recover 508 00:19:03,345 --> 00:19:05,184 from the allergies that he had because it's 509 00:19:05,184 --> 00:19:06,805 an island in the North Sea. 510 00:19:07,184 --> 00:19:09,420 I've looked on Google Maps. It's probably about, 511 00:19:09,900 --> 00:19:11,980 an hour off the coast of Germany. And, 512 00:19:11,980 --> 00:19:13,119 you know, it's very windswept, 513 00:19:13,500 --> 00:19:14,799 and it's very isolated. 514 00:19:15,180 --> 00:19:17,500 There's no trees in the sea, so no 515 00:19:17,500 --> 00:19:18,000 pollen. 516 00:19:18,460 --> 00:19:20,539 Exactly. Yeah. Yeah. So he went he went 517 00:19:20,539 --> 00:19:22,539 there, and it was on this island in 518 00:19:22,539 --> 00:19:24,285 June 1925 that 519 00:19:24,845 --> 00:19:25,345 he, 520 00:19:25,884 --> 00:19:26,684 had this, 521 00:19:27,085 --> 00:19:29,325 amazing insights. His ideas that he'd been working 522 00:19:29,325 --> 00:19:31,505 on came together, and he formulated 523 00:19:31,805 --> 00:19:33,664 the ideas of quantum mechanics, 524 00:19:34,205 --> 00:19:36,539 you know, proper mathematical framework for 525 00:19:37,100 --> 00:19:39,180 all these weird quantum effects that people were 526 00:19:39,180 --> 00:19:39,680 seeing. 527 00:19:40,779 --> 00:19:42,220 And so, yeah, that was a hundred years 528 00:19:42,220 --> 00:19:42,720 ago. 529 00:19:43,259 --> 00:19:45,500 So a very famous moment in history of 530 00:19:45,500 --> 00:19:47,980 physics that is being celebrated this year. That's 531 00:19:47,980 --> 00:19:50,480 right. In the the international year the UN's 532 00:19:50,539 --> 00:19:53,005 international year. UNESCO, is it? Yeah. 533 00:19:53,545 --> 00:19:55,085 UNESCO, which is a UN agency, 534 00:19:55,465 --> 00:19:58,684 the International Year of Quantum Science and Technology. 535 00:19:59,384 --> 00:20:02,025 And and so this was matrix mechanics that 536 00:20:02,025 --> 00:20:04,345 he came up with. This is this this 537 00:20:04,345 --> 00:20:05,865 idea of, of, 538 00:20:08,259 --> 00:20:08,759 representing, 539 00:20:09,940 --> 00:20:11,299 reality in terms of, 540 00:20:11,940 --> 00:20:15,320 vectors and and matrices and multiplying them together 541 00:20:15,380 --> 00:20:17,299 and, and all that sort of stuff that 542 00:20:17,299 --> 00:20:19,400 you learn, I suppose, as an undergraduate. 543 00:20:20,054 --> 00:20:20,294 And, 544 00:20:20,855 --> 00:20:22,214 and and that was a big deal, wasn't 545 00:20:22,214 --> 00:20:25,014 it? Because before that, wasn't there the, I 546 00:20:25,014 --> 00:20:26,855 mean, I might have the the lingo wrong, 547 00:20:26,855 --> 00:20:30,375 but the old quantum mechanics where people didn't 548 00:20:30,375 --> 00:20:32,855 really understand what was going on. They knew 549 00:20:32,855 --> 00:20:35,470 that physics was really weird. And it was 550 00:20:35,470 --> 00:20:37,470 only when Heisenberg sort of wrote down this 551 00:20:37,470 --> 00:20:39,089 matrix mechanics that, 552 00:20:39,950 --> 00:20:42,369 it all start started to make sense or 553 00:20:42,509 --> 00:20:44,750 well, started to make sense. It still doesn't 554 00:20:44,750 --> 00:20:46,769 make sense, does it? Quantum mechanics, 555 00:20:47,149 --> 00:20:47,649 famously. 556 00:20:48,029 --> 00:20:49,964 If you think you understand it, you don't. 557 00:20:50,924 --> 00:20:53,585 But, yeah. So so a very, very exciting, 558 00:20:54,845 --> 00:20:55,744 a very exciting, 559 00:20:56,365 --> 00:20:57,884 time, 1925 560 00:20:57,884 --> 00:21:00,865 in Helgoland. So Helgoland is it's an island. 561 00:21:01,325 --> 00:21:03,484 It's off the the West Coast Of Germany, 562 00:21:03,484 --> 00:21:05,505 so it's in the North Sea. 563 00:21:06,690 --> 00:21:07,009 And, 564 00:21:07,490 --> 00:21:08,230 so you're 565 00:21:08,609 --> 00:21:11,509 you're going there, very exciting, to this conference, 566 00:21:12,049 --> 00:21:13,190 that's been organized 567 00:21:13,569 --> 00:21:14,309 in Helgoland 568 00:21:14,609 --> 00:21:15,910 to commemorate this. 569 00:21:16,609 --> 00:21:18,690 But you're starting in Hamburg, is that right? 570 00:21:18,690 --> 00:21:20,150 Which I suppose is the nearest 571 00:21:20,674 --> 00:21:23,714 big city to Helgoland. So what's going to 572 00:21:23,714 --> 00:21:24,615 happen in Hamburg, 573 00:21:25,554 --> 00:21:27,335 the the preconference event? 574 00:21:27,875 --> 00:21:29,634 So on the Monday so it's the it's 575 00:21:29,634 --> 00:21:31,474 quite soon, coming up soon. So it's Monday, 576 00:21:31,474 --> 00:21:31,974 the, 577 00:21:32,914 --> 00:21:35,734 June 9. There's a preconference 578 00:21:36,490 --> 00:21:39,149 banquet dinner at a hotel in in Hamburg, 579 00:21:39,609 --> 00:21:41,609 and there are three speakers talking about the 580 00:21:41,609 --> 00:21:42,669 history of, 581 00:21:43,529 --> 00:21:45,450 the subject. And one of them is actually 582 00:21:45,450 --> 00:21:47,690 Phil Ball, Philip Ball, who's an old friend, 583 00:21:47,690 --> 00:21:50,250 dare I say, Physics World. Listeners may remember 584 00:21:50,250 --> 00:21:51,644 he's written quite a lot for us, 585 00:21:52,205 --> 00:21:54,045 and, he's a bit of an expert in 586 00:21:54,045 --> 00:21:55,424 the history of quantum mechanics. 587 00:21:56,445 --> 00:21:58,365 And he's one of those unusual journalists who's 588 00:21:58,365 --> 00:22:00,924 kind of reached almost, like, the status of 589 00:22:00,924 --> 00:22:02,924 a knowledgeable expert in this area. He's at 590 00:22:02,924 --> 00:22:05,404 that really a crossover between being a journalist, 591 00:22:05,404 --> 00:22:07,570 science journalist, and the sort of experts on 592 00:22:07,570 --> 00:22:09,170 this area. So he's doing one of the 593 00:22:09,170 --> 00:22:11,029 talks at the conference dinner 594 00:22:11,650 --> 00:22:13,809 on the Monday. And then the next day, 595 00:22:13,809 --> 00:22:16,609 we get this ferry, which takes about four 596 00:22:16,609 --> 00:22:18,789 hours to get. You go up the Elbe. 597 00:22:19,009 --> 00:22:20,769 That's right. Yeah. Because Hamburg is actually a 598 00:22:20,769 --> 00:22:22,464 long way from the sea. It is. It's 599 00:22:22,464 --> 00:22:24,085 on a big river called the Elbe. 600 00:22:24,384 --> 00:22:26,144 And then so you go out the Elbe, 601 00:22:26,144 --> 00:22:27,825 and then do you turn right? Or does 602 00:22:27,825 --> 00:22:29,684 it turn left? You turn 603 00:22:31,024 --> 00:22:32,944 up up. I'm sure I'm sure the captain 604 00:22:32,944 --> 00:22:34,565 will know which way to go to Helgoland. 605 00:22:34,784 --> 00:22:36,304 So the Elbe, it's a Hamburg is a 606 00:22:36,304 --> 00:22:38,930 seaport and very, you know, important for Germany, 607 00:22:38,930 --> 00:22:40,470 but, it's quite a way 608 00:22:40,850 --> 00:22:42,289 inland. And so you go up the Elbe 609 00:22:42,289 --> 00:22:44,690 and then turn right, I think, as you 610 00:22:44,690 --> 00:22:46,309 say, and then you get to Helgoland 611 00:22:46,610 --> 00:22:49,269 after about four hours. Right. And and Helgoland 612 00:22:49,410 --> 00:22:51,509 itself, we're we're talking about this yesterday. 613 00:22:51,944 --> 00:22:53,865 And you said it's it's about the same 614 00:22:53,865 --> 00:22:56,204 size as the Bristol suburb of Clifton, 615 00:22:56,825 --> 00:22:58,505 which is not very big. It's not very 616 00:22:58,505 --> 00:23:00,345 big. I think it's about there's about 1,500 617 00:23:00,345 --> 00:23:01,865 people live on it. So suddenly, at this 618 00:23:01,865 --> 00:23:04,284 conference, there are gonna be 300 physicists 619 00:23:05,190 --> 00:23:07,429 turning up. So the population will increase by, 620 00:23:07,909 --> 00:23:09,049 is that 20%? 621 00:23:10,149 --> 00:23:12,869 And, yes, about one it's about 1.7 kilometers 622 00:23:12,869 --> 00:23:14,549 long and maybe a kilometer wide. There's actually 623 00:23:14,549 --> 00:23:16,250 a second island next to it, 624 00:23:16,630 --> 00:23:17,849 so not very big. 625 00:23:18,984 --> 00:23:21,325 These days, it's a kind of holiday resort, 626 00:23:21,384 --> 00:23:22,764 and there are a lot of beach 627 00:23:23,384 --> 00:23:25,884 villas and cottages and that sort of thing. 628 00:23:25,944 --> 00:23:28,664 Right. So I suppose it hasn't changed much 629 00:23:28,664 --> 00:23:31,750 because Heisenberg was on holiday there. So, 630 00:23:32,470 --> 00:23:34,390 Well, there is that famous story that after 631 00:23:34,390 --> 00:23:36,390 the second World War, the British ally and 632 00:23:36,390 --> 00:23:39,130 the allies, they collected all their unexploded bombs 633 00:23:39,269 --> 00:23:41,589 and put them on Helgoland. Oh, dear. Practically 634 00:23:41,589 --> 00:23:42,730 blew the island up. 635 00:23:43,029 --> 00:23:45,029 So that didn't do much for tourism. No. 636 00:23:45,029 --> 00:23:47,954 So anything that is connected with where Heisenberg 637 00:23:48,014 --> 00:23:50,254 stayed doesn't exist anymore. All the all the 638 00:23:50,254 --> 00:23:52,595 housing was blown up. So there's no sort 639 00:23:53,214 --> 00:23:55,214 of this is the room that Heisenberg stayed 640 00:23:55,214 --> 00:23:56,835 in that you can see, I don't think. 641 00:23:57,134 --> 00:23:59,714 Okay. Although there is a, a little 642 00:24:00,839 --> 00:24:02,299 sculpture statue thing, 643 00:24:03,319 --> 00:24:04,960 in honor of Heisenberg, so I'll make sure 644 00:24:04,960 --> 00:24:06,039 I have a look at that. Oh, yeah. 645 00:24:06,039 --> 00:24:08,440 I'll get some pictures. Definitely. Yeah. And and 646 00:24:08,440 --> 00:24:11,259 one of the big worries about going is 647 00:24:12,679 --> 00:24:13,179 accommodation. 648 00:24:14,204 --> 00:24:14,444 And, 649 00:24:15,005 --> 00:24:16,684 I I think am I right in thinking 650 00:24:16,684 --> 00:24:19,744 that you've you've sort of got a somebody 651 00:24:19,884 --> 00:24:22,365 probably canceled and you've got a last minute 652 00:24:22,365 --> 00:24:22,865 booking, 653 00:24:23,644 --> 00:24:25,404 so you're actually lucky enough to be able 654 00:24:25,404 --> 00:24:26,944 to go out to Halgo Land, 655 00:24:27,619 --> 00:24:30,180 where I'm guessing accommodation is pretty scarce. Yeah. 656 00:24:30,180 --> 00:24:32,019 There was instructions for anyone who wanted to 657 00:24:32,019 --> 00:24:33,539 go to, you might have to camp on 658 00:24:33,539 --> 00:24:34,119 the beach. 659 00:24:34,900 --> 00:24:37,700 I didn't really fancy doing that. And, luckily, 660 00:24:37,700 --> 00:24:38,600 there is a 661 00:24:39,795 --> 00:24:41,394 a, yeah, a place that I'll be staying 662 00:24:41,394 --> 00:24:43,634 in, which is very, very fortunate. But, yeah, 663 00:24:43,634 --> 00:24:44,934 all the hotels are booked 664 00:24:45,235 --> 00:24:47,414 out, have been for quite some time, 665 00:24:47,795 --> 00:24:50,035 like I say, with these 300 physicists turning 666 00:24:50,035 --> 00:24:51,955 up. So, yeah, it should be, and then, 667 00:24:51,955 --> 00:24:53,980 yeah, it's four days on the island. Yeah. 668 00:24:53,980 --> 00:24:55,980 And then come back to Hamburg. So it's 669 00:24:55,980 --> 00:24:57,440 a really unusual event, 670 00:24:57,819 --> 00:24:59,339 and there are some, you know, big big 671 00:24:59,339 --> 00:25:01,099 names going on. Am I am I right 672 00:25:01,099 --> 00:25:03,419 in thinking speaking of big names that Bob 673 00:25:03,419 --> 00:25:03,919 Kreese, 674 00:25:05,349 --> 00:25:05,849 longtime 675 00:25:06,445 --> 00:25:09,484 Physics World, contributor. Is he is he speaking 676 00:25:09,484 --> 00:25:11,325 there? I know he's written about how Golang 677 00:25:11,325 --> 00:25:11,825 Forest. 678 00:25:12,285 --> 00:25:14,525 He no. He is not going, but there 679 00:25:14,525 --> 00:25:18,125 are, some eminent people going, including I think 680 00:25:18,125 --> 00:25:19,265 I've counted four 681 00:25:19,990 --> 00:25:21,049 Nobel Prize winners, 682 00:25:22,710 --> 00:25:24,230 and I think all the Nobel Prize winners 683 00:25:24,230 --> 00:25:26,230 get must get tons of invitations, but there 684 00:25:26,230 --> 00:25:27,929 are four on the list there. Mhmm. 685 00:25:28,390 --> 00:25:29,210 Serge Haroche, 686 00:25:29,509 --> 00:25:30,409 Anton Sailinger, 687 00:25:31,109 --> 00:25:33,369 David Wineland, and Alan Aspect. 688 00:25:33,704 --> 00:25:36,184 Wow. So so some pretty strong connections to 689 00:25:36,184 --> 00:25:38,585 quantum physics there as well. Yeah. And then 690 00:25:38,585 --> 00:25:40,345 the rest of the people is it is 691 00:25:40,345 --> 00:25:41,944 a kind of who's who. I mentioned Phil 692 00:25:41,944 --> 00:25:44,265 Ball. There's people like Charles Bennett who came 693 00:25:44,265 --> 00:25:45,644 up with one of the algorithms. 694 00:25:47,789 --> 00:25:49,329 Michelle Simmons from Australia, 695 00:25:50,029 --> 00:25:50,849 Carla Ravelli, 696 00:25:52,109 --> 00:25:54,829 Michelle Lukin who won the Yeah. Yeah. Our 697 00:25:54,829 --> 00:25:57,230 favorite is on the podcast Exactly. Not too 698 00:25:57,230 --> 00:26:00,349 long ago. Yeah. And there's also Elisa Krill 699 00:26:00,349 --> 00:26:02,505 who's appearing in, Physics World. 700 00:26:03,545 --> 00:26:06,105 Oh, that's right. Yeah. She's a philosopher. Yeah. 701 00:26:06,105 --> 00:26:07,785 So so there will be a philosopher. It 702 00:26:07,785 --> 00:26:10,025 won't be Bob. Yeah. Not him. Right. There'll 703 00:26:10,025 --> 00:26:11,644 be a New York based philosopher. 704 00:26:12,505 --> 00:26:14,744 That's what you need at every conference. Yeah. 705 00:26:14,744 --> 00:26:16,678 Right. So, So, yeah, it's, you know, it's 706 00:26:16,678 --> 00:26:18,726 a real who's who. And there's other people 707 00:26:18,726 --> 00:26:21,849 like John Preskill Oh, right. Yeah. Sandhu Pippescu 708 00:26:21,910 --> 00:26:24,309 from the University of Bristol, Janeway Pan is 709 00:26:24,309 --> 00:26:24,809 invited, 710 00:26:25,509 --> 00:26:26,490 Nicholas Guissaint 711 00:26:27,109 --> 00:26:28,009 from Geneva, 712 00:26:29,029 --> 00:26:29,930 Bill Unruh, 713 00:26:30,295 --> 00:26:32,315 Canadian Yeah. Yeah. Person. 714 00:26:32,855 --> 00:26:33,755 Peter Zola. 715 00:26:35,095 --> 00:26:36,454 You know, if you're if you're into your 716 00:26:36,454 --> 00:26:38,535 quantum physics, this list of people I'm just 717 00:26:38,535 --> 00:26:40,335 looking at So it's a who's who, definitely. 718 00:26:40,695 --> 00:26:43,095 Pretty, yeah, you know, some big big shots, 719 00:26:43,095 --> 00:26:44,634 dare I say. Big big cheeses. 720 00:26:44,934 --> 00:26:47,630 Right. Okay. Well, that's that's great. And, you 721 00:26:47,630 --> 00:26:49,710 know, I mean, normally, I would say try 722 00:26:49,710 --> 00:26:51,950 to make it try to go there, dear 723 00:26:51,950 --> 00:26:54,190 listener, yourself, but I think unless you wanna 724 00:26:54,190 --> 00:26:55,329 camp out on the beach. 725 00:26:55,789 --> 00:26:58,190 And, and we have had some lovely weather 726 00:26:58,190 --> 00:27:00,345 recently, but, you know, it is in the 727 00:27:00,345 --> 00:27:01,164 North Sea, 728 00:27:01,785 --> 00:27:03,704 Northern Germany, so it could be a bit 729 00:27:03,704 --> 00:27:04,605 a bit chilly. 730 00:27:04,984 --> 00:27:06,105 Right. And, 731 00:27:06,585 --> 00:27:08,105 I mean, we have we have been doing 732 00:27:08,105 --> 00:27:10,184 lots of coverage of the International Year of 733 00:27:10,184 --> 00:27:11,565 Quantum Science and Technology 734 00:27:12,130 --> 00:27:13,349 in physics world. 735 00:27:13,730 --> 00:27:16,929 And, one thing that we've, that we've published 736 00:27:16,929 --> 00:27:18,769 very recently is a, 737 00:27:19,650 --> 00:27:20,869 a quantum briefing, 738 00:27:21,250 --> 00:27:23,990 which is chock full of some fantastic articles 739 00:27:24,690 --> 00:27:25,190 about, 740 00:27:25,809 --> 00:27:26,869 quantum physics. 741 00:27:27,375 --> 00:27:29,855 And it it has some flash fiction in 742 00:27:29,855 --> 00:27:31,855 it as well. It's a short story by, 743 00:27:32,414 --> 00:27:35,234 Kevlin Henney, who is a Bristol based, author 744 00:27:35,375 --> 00:27:36,914 amongst many other things. 745 00:27:37,615 --> 00:27:40,434 And he's he's looked at this famous voyage 746 00:27:40,575 --> 00:27:42,869 that, Heisenberg made to Helgoland, 747 00:27:43,170 --> 00:27:45,109 and he's come up with an alternative 748 00:27:46,609 --> 00:27:47,589 universe in which, 749 00:27:47,970 --> 00:27:49,670 Heisenberg didn't go there. 750 00:27:50,450 --> 00:27:52,369 And, you know, I suppose in in the 751 00:27:52,369 --> 00:27:53,430 spirit of the multiverse, 752 00:27:54,224 --> 00:27:55,984 has written about that. So can can you 753 00:27:55,984 --> 00:27:58,545 give us just a little preview of that 754 00:27:58,545 --> 00:28:01,184 story? Obviously, we want people to go and 755 00:28:01,184 --> 00:28:04,305 and read it. But, what what's Kevlin's premise 756 00:28:04,305 --> 00:28:04,964 on that? 757 00:28:05,505 --> 00:28:07,759 So so Kevlin is someone who is a 758 00:28:07,759 --> 00:28:09,920 physicist by training but works in the IT 759 00:28:09,920 --> 00:28:11,599 sector. And he was actually on our Physics 760 00:28:11,599 --> 00:28:13,279 World Stories podcast, so you can find out 761 00:28:13,279 --> 00:28:14,000 more from, 762 00:28:15,039 --> 00:28:17,140 last month. But, yeah, he 763 00:28:18,394 --> 00:28:21,115 is enjoys writing flash fiction, so he came 764 00:28:21,115 --> 00:28:22,514 up with this idea. I can't remember who 765 00:28:22,514 --> 00:28:24,095 it was, whether it was me or Tushner, 766 00:28:24,154 --> 00:28:26,234 our colleague, or him. This idea of an 767 00:28:26,234 --> 00:28:29,034 alternative universe where if Heisenberg hadn't been allowed 768 00:28:29,034 --> 00:28:30,414 to go to Helgorand 769 00:28:30,714 --> 00:28:32,335 and was had to stay in Gottingen, 770 00:28:33,130 --> 00:28:36,250 would that great event of discovering quantum mechanics 771 00:28:36,250 --> 00:28:38,089 have happened? So what he's he took took 772 00:28:38,089 --> 00:28:39,609 the idea and he's written it as a 773 00:28:39,609 --> 00:28:40,109 diary. 774 00:28:40,490 --> 00:28:42,490 So on the left hand side, he's got 775 00:28:42,490 --> 00:28:44,569 a diary, an imagined diary of what he'll 776 00:28:45,210 --> 00:28:46,190 Heisenberg did in Helgoland 777 00:28:46,595 --> 00:28:49,154 day by day. And on the right, he's 778 00:28:49,154 --> 00:28:51,555 kind of written a parallel diary of him 779 00:28:51,555 --> 00:28:54,195 staying at home and imagining him being frustrated 780 00:28:54,195 --> 00:28:55,575 and not being able to go. 781 00:28:56,355 --> 00:28:58,375 I did email Phil Ball and mention 782 00:28:58,674 --> 00:29:00,434 this to him, and he did actually say 783 00:29:00,434 --> 00:29:02,309 that he was interested in this idea of 784 00:29:02,309 --> 00:29:04,470 what we've done, but actually, he slightly poured 785 00:29:04,470 --> 00:29:06,390 cold water on it. He kind of thinks 786 00:29:06,390 --> 00:29:08,329 even if Heisenberg had never gone to Helgoland, 787 00:29:09,109 --> 00:29:11,029 he probably would have done this work anyway, 788 00:29:11,029 --> 00:29:12,009 just not on Helgoland. 789 00:29:12,470 --> 00:29:13,690 So it wasn't the magical 790 00:29:13,990 --> 00:29:15,930 Well hole in free sea air 791 00:29:16,294 --> 00:29:18,214 of Helgoland that Well, I think that's what 792 00:29:18,214 --> 00:29:19,654 he was implying in the email that he 793 00:29:19,654 --> 00:29:21,414 sent me that this would've it would've happened 794 00:29:21,414 --> 00:29:23,255 anyway. It would've been maybe would've been somewhere 795 00:29:23,255 --> 00:29:24,794 else or maybe a while later. 796 00:29:26,375 --> 00:29:27,894 But, yeah, it's a great little idea that 797 00:29:27,894 --> 00:29:29,320 he came up with of this. And so 798 00:29:29,320 --> 00:29:31,559 we've imagined it as if as if Kevlin 799 00:29:31,559 --> 00:29:33,640 Henney has discovered these notebooks. I mean, there 800 00:29:33,640 --> 00:29:35,420 there are no notebooks, but we've we've 801 00:29:35,799 --> 00:29:38,359 we've in the article, we've we've, laid it 802 00:29:38,359 --> 00:29:40,299 out as if it's a notebook. 803 00:29:40,920 --> 00:29:43,115 So it looks it looks quite realistic. It 804 00:29:43,115 --> 00:29:44,954 looks quite fun. So so, yeah, a clever 805 00:29:44,954 --> 00:29:47,134 little idea and, just a bit of fun, 806 00:29:48,075 --> 00:29:49,214 to sort of twist 807 00:29:50,394 --> 00:29:52,414 on old history, I think it's called. 808 00:29:52,954 --> 00:29:54,961 So, yeah, keep an eye out for that. 809 00:29:54,961 --> 00:29:57,574 Yeah. And and that is it's it's available 810 00:29:57,574 --> 00:29:59,897 for reading. The the quantum briefing can be 811 00:29:59,897 --> 00:30:02,220 found on the Physics World website, and I'll 812 00:30:02,220 --> 00:30:05,123 put an a link to it, in the 813 00:30:05,123 --> 00:30:07,965 notes for this podcast. It also, has an 814 00:30:07,965 --> 00:30:10,525 article by Margaret, a feature length article by 815 00:30:10,525 --> 00:30:11,025 Margaret 816 00:30:11,404 --> 00:30:13,585 about the quantum Zeno effect, 817 00:30:14,045 --> 00:30:14,605 which is, 818 00:30:15,164 --> 00:30:16,384 a sort of a fascinating 819 00:30:17,085 --> 00:30:18,144 quantum thing. 820 00:30:18,630 --> 00:30:21,269 And that that's actually the first quantum briefing, 821 00:30:21,269 --> 00:30:23,210 isn't it? There's there's gonna be a second 822 00:30:23,829 --> 00:30:26,230 quantum briefing that's going to be Not not 823 00:30:26,230 --> 00:30:28,070 quite a second we're gonna update this one 824 00:30:28,070 --> 00:30:29,210 with some extra articles. 825 00:30:29,990 --> 00:30:31,820 So this is a a digital magazine that 826 00:30:32,070 --> 00:30:34,125 so it's quite ease well, relatively easy to 827 00:30:34,125 --> 00:30:36,144 add in extra stuff. Right. Okay. 828 00:30:36,845 --> 00:30:38,764 There there were there are some limited printed 829 00:30:38,764 --> 00:30:40,524 copies in fact. We I'm gonna take a 830 00:30:40,524 --> 00:30:41,024 hundred 831 00:30:41,325 --> 00:30:43,404 in my suitcase. That's a hell go land. 832 00:30:43,404 --> 00:30:45,244 So anyone anyone listening, you know, get your 833 00:30:45,244 --> 00:30:47,005 hands on those. I'll be wandering around with 834 00:30:47,005 --> 00:30:49,380 these boxes with my suitcase trundling around the 835 00:30:49,380 --> 00:30:50,679 island, handing them out. 836 00:30:51,460 --> 00:30:53,220 But yeah. And also, yeah, the before we 837 00:30:53,220 --> 00:30:55,380 forget, there's the really great cover that we've 838 00:30:55,380 --> 00:30:56,099 got for it, 839 00:30:56,819 --> 00:30:58,179 which I know you were gonna come on 840 00:30:58,179 --> 00:30:59,240 to, which is by 841 00:31:00,964 --> 00:31:01,865 Tushner commissioned 842 00:31:02,244 --> 00:31:05,684 Felicity Inkpen, who's a scientist and artist who 843 00:31:05,684 --> 00:31:07,545 used to work So an artist called Inkpen. 844 00:31:07,765 --> 00:31:09,305 What what's that called? Nominative 845 00:31:10,005 --> 00:31:10,505 determinism? 846 00:31:10,884 --> 00:31:12,404 I think so. Yeah. Mind me out that 847 00:31:12,404 --> 00:31:14,244 wrong. Felicity. Yeah. It is a lovely it 848 00:31:14,244 --> 00:31:15,384 is a lovely cover. 849 00:31:15,710 --> 00:31:17,650 So what she's done is she 850 00:31:18,269 --> 00:31:20,430 it's called the the the painting is called 851 00:31:20,430 --> 00:31:20,930 Cubitt's 852 00:31:21,710 --> 00:31:22,210 Duality. 853 00:31:23,069 --> 00:31:25,150 So she it's a sort of, what she 854 00:31:25,150 --> 00:31:27,170 did is she took a tank of water 855 00:31:27,549 --> 00:31:30,075 and poured some colored dyes in and took 856 00:31:30,075 --> 00:31:32,894 lots of photographs and inspired from those pictures. 857 00:31:33,274 --> 00:31:35,755 She then painted an oil painting, and it 858 00:31:35,755 --> 00:31:36,974 kind of meant to symbolize 859 00:31:37,755 --> 00:31:39,054 wave particle duality. 860 00:31:40,154 --> 00:31:41,595 And we did that for the cover because 861 00:31:41,595 --> 00:31:43,274 I think we wanted something a bit different 862 00:31:43,274 --> 00:31:45,529 that's special for us and not just the 863 00:31:45,529 --> 00:31:46,029 usual 864 00:31:46,650 --> 00:31:48,569 standard stock pictures that, 865 00:31:49,529 --> 00:31:52,170 wouldn't perhaps have done the content justice. Yeah. 866 00:31:52,170 --> 00:31:54,170 Yeah. No. It it it really looks nice. 867 00:31:54,170 --> 00:31:57,404 Yeah. So, yeah, definitely look out for that. 868 00:31:57,565 --> 00:31:59,265 And if you happen to be on Helgoland, 869 00:32:00,045 --> 00:32:01,904 ask Matin for a for a copy. 870 00:32:02,205 --> 00:32:03,744 Now, Hamish, before we finish, 871 00:32:04,924 --> 00:32:07,404 you have been writing something quite interesting, a 872 00:32:07,404 --> 00:32:08,785 research update about 873 00:32:09,085 --> 00:32:09,585 neutrons 874 00:32:10,549 --> 00:32:13,750 and, which obviously these are subatomic particles without 875 00:32:13,750 --> 00:32:14,250 charge, 876 00:32:14,789 --> 00:32:16,470 but using it in a very unusual way 877 00:32:16,470 --> 00:32:18,490 to differentiate between counterfeit 878 00:32:19,429 --> 00:32:20,809 and genuine antique 879 00:32:21,109 --> 00:32:23,585 coins. So what are these coins, Hamish? Well, 880 00:32:23,585 --> 00:32:26,704 they're, they're Korean coins from the early nineteenth 881 00:32:26,704 --> 00:32:27,204 century. 882 00:32:27,664 --> 00:32:28,945 And, you know, if you if you're sort 883 00:32:28,945 --> 00:32:31,105 of familiar with old coins, they're that that 884 00:32:31,105 --> 00:32:32,085 sort of classic 885 00:32:32,625 --> 00:32:35,184 round coin with a square hole in the 886 00:32:35,184 --> 00:32:37,269 middle of it. You know, you that seems 887 00:32:37,269 --> 00:32:39,029 to be a common Didn't the Danish used 888 00:32:39,029 --> 00:32:41,109 to have coins like that? Oh, maybe they 889 00:32:41,109 --> 00:32:43,190 did. Maybe you'll find some on Helgoland Oh, 890 00:32:43,190 --> 00:32:43,669 yeah. 891 00:32:44,150 --> 00:32:45,750 Washing up on the beach. But the these 892 00:32:45,750 --> 00:32:47,049 are from Korea. 893 00:32:47,750 --> 00:32:49,369 And, yeah, some researchers 894 00:32:49,670 --> 00:32:52,089 in Korea and also in The US 895 00:32:52,555 --> 00:32:53,355 have used, 896 00:32:53,674 --> 00:32:55,615 a a a sort of a a novel 897 00:32:56,555 --> 00:32:59,914 technique using neutron scattering to tell the fake 898 00:32:59,914 --> 00:33:02,414 ones from the real ones. Yeah. 899 00:33:03,434 --> 00:33:05,934 And, well, how did they do that? Well, 900 00:33:06,910 --> 00:33:08,430 the the the they used two techniques. But 901 00:33:08,430 --> 00:33:10,109 the the technique that I found, 902 00:33:10,590 --> 00:33:11,490 most interesting 903 00:33:12,109 --> 00:33:12,609 is, 904 00:33:13,309 --> 00:33:15,809 they used the presence of hydrogen 905 00:33:16,269 --> 00:33:17,090 in the coins, 906 00:33:18,109 --> 00:33:19,650 to tell the difference between, 907 00:33:19,950 --> 00:33:22,545 an a genuine antique one and a sort 908 00:33:22,545 --> 00:33:25,424 of a more modern fake one that has 909 00:33:25,424 --> 00:33:26,164 just been 910 00:33:26,785 --> 00:33:29,125 chemically treated to look old. So the fakes, 911 00:33:29,345 --> 00:33:31,265 modern fakes pretending to look old. They weren't 912 00:33:31,265 --> 00:33:32,785 fakes from the time. Yeah. Yeah. They're yeah. 913 00:33:32,785 --> 00:33:34,704 They're modern fakes. They were people trying to 914 00:33:34,704 --> 00:33:35,765 sort of, Exactly. 915 00:33:36,660 --> 00:33:38,740 No. No. No. No. No. No. No. These 916 00:33:38,740 --> 00:33:40,740 are modern fakes. I suppose these coins are 917 00:33:40,740 --> 00:33:41,240 collectible. 918 00:33:41,700 --> 00:33:43,700 And it's it's interest I I found it 919 00:33:43,700 --> 00:33:45,720 interesting. I do have love for neutrons. 920 00:33:46,180 --> 00:33:48,580 And I I found it interesting because it's 921 00:33:48,580 --> 00:33:50,580 sort of a twist on how neutrons are 922 00:33:50,580 --> 00:33:51,640 normally used 923 00:33:52,075 --> 00:33:53,295 to study materials. 924 00:33:54,475 --> 00:33:56,234 Usually, you take a a beam and you 925 00:33:56,234 --> 00:33:59,535 scatter them from a sample, and the resulting 926 00:33:59,595 --> 00:34:01,375 diffraction pattern tells you 927 00:34:01,674 --> 00:34:03,914 about the structure of the sample. That's a 928 00:34:03,914 --> 00:34:04,654 very straightforward 929 00:34:05,500 --> 00:34:07,819 use of neutrons and Nobel prizes have been 930 00:34:07,819 --> 00:34:08,800 won for developing, 931 00:34:09,900 --> 00:34:11,119 those sort of techniques. 932 00:34:11,820 --> 00:34:13,980 But the thing about hydrogen is that it's 933 00:34:13,980 --> 00:34:16,400 a bad thing when it comes to neutrons. 934 00:34:16,780 --> 00:34:19,679 Hydrogen messes up this process because the proton 935 00:34:20,065 --> 00:34:22,405 that, you know, the nucleus within a hydrogen, 936 00:34:23,425 --> 00:34:25,045 is a very good incoherent 937 00:34:25,505 --> 00:34:29,204 scatterer of neutrons. And essentially, that means that, 938 00:34:29,824 --> 00:34:32,005 if there's lots of hydrogen in your sample, 939 00:34:32,065 --> 00:34:35,204 it blurs these patterns that you're looking for. 940 00:34:35,699 --> 00:34:36,199 And, 941 00:34:37,219 --> 00:34:39,859 in order to do neutron scattering experiments on 942 00:34:39,859 --> 00:34:41,400 hydrogen rich samples, 943 00:34:41,699 --> 00:34:44,280 researchers actually replace the hydrogen 944 00:34:44,739 --> 00:34:45,719 with deuterium. 945 00:34:46,019 --> 00:34:47,239 They call this deuteration. 946 00:34:48,824 --> 00:34:51,485 And they do that because deuterium, which is, 947 00:34:52,025 --> 00:34:55,164 a proton with a neutron, so helium hydrogen 948 00:34:55,224 --> 00:34:55,724 two, 949 00:34:56,425 --> 00:34:58,125 is not a good incoherent 950 00:34:58,425 --> 00:35:00,585 scatterer. So in the world of neutrons, you 951 00:35:00,585 --> 00:35:01,965 want to avoid hydrogen, 952 00:35:02,809 --> 00:35:03,789 at all cost. 953 00:35:04,730 --> 00:35:07,289 But in this new work, which was led 954 00:35:07,289 --> 00:35:08,510 by Youngju Kim 955 00:35:08,809 --> 00:35:11,929 and Daniel Hussey at, NIST, at the National 956 00:35:11,929 --> 00:35:14,684 Institute of Standards and Technology, and 957 00:35:15,085 --> 00:35:16,224 presence of hydrogen 958 00:35:16,525 --> 00:35:17,344 in coins 959 00:35:17,724 --> 00:35:20,204 was detected by, you know, sort of looking 960 00:35:20,204 --> 00:35:20,704 for 961 00:35:21,005 --> 00:35:22,144 this incoherent 962 00:35:22,445 --> 00:35:23,744 scattering of neutrons. 963 00:35:25,485 --> 00:35:26,925 So how did that work? I guess the 964 00:35:26,925 --> 00:35:29,085 neutrons travel through the coins, do they? And 965 00:35:29,085 --> 00:35:32,179 maybe the does the hydrogen block the neutrons 966 00:35:32,239 --> 00:35:33,119 more than the, 967 00:35:33,519 --> 00:35:35,940 the other ones? Yeah. That's exactly what happens. 968 00:35:36,719 --> 00:35:38,960 Beauty of neutrons is that they can travel 969 00:35:38,960 --> 00:35:41,300 through a lot of materials very easily. 970 00:35:41,840 --> 00:35:42,559 And so, 971 00:35:42,960 --> 00:35:45,039 the the the neutrons can travel through the 972 00:35:45,039 --> 00:35:45,539 metal 973 00:35:45,945 --> 00:35:48,585 of the coin very easily, but they're actually 974 00:35:48,585 --> 00:35:50,684 blocked, as you say, by by hydrogen. 975 00:35:51,224 --> 00:35:53,965 And this hydrogen is in inclusions 976 00:35:54,265 --> 00:35:55,724 of hydrogen rich 977 00:35:56,105 --> 00:35:58,364 materials that are created by corrosion. 978 00:35:59,199 --> 00:36:01,199 And it turns out that because the real 979 00:36:01,199 --> 00:36:02,420 coins are older, 980 00:36:03,119 --> 00:36:05,140 they have much deeper corrosion 981 00:36:05,599 --> 00:36:06,099 inclusions 982 00:36:06,800 --> 00:36:07,699 than the fakes. 983 00:36:08,000 --> 00:36:10,340 And though that much deeper corrosion 984 00:36:10,719 --> 00:36:11,840 is what, 985 00:36:12,565 --> 00:36:13,385 is revealed 986 00:36:13,765 --> 00:36:16,724 by the, by the neutron experiment. So even 987 00:36:16,724 --> 00:36:19,125 though the fakes have been corroded to look 988 00:36:19,125 --> 00:36:21,864 old, they they don't have these deep inclusions 989 00:36:21,925 --> 00:36:23,224 because that takes time. 990 00:36:23,765 --> 00:36:25,925 And, Oh, I see. So they actually corrode 991 00:36:25,925 --> 00:36:27,289 the fakes to make them look old, but 992 00:36:27,530 --> 00:36:29,849 Exactly. The real the real stuff has deeper. 993 00:36:29,849 --> 00:36:32,889 Has deeper deeper inclusions. Yeah. That's right. So 994 00:36:32,889 --> 00:36:34,250 that Hang on. Now they know what to 995 00:36:34,250 --> 00:36:36,170 do. So they're Well, yeah. That's the problem 996 00:36:36,170 --> 00:36:37,530 is that if, you know, if you if 997 00:36:37,530 --> 00:36:39,070 you make fake Korean coins 998 00:36:39,444 --> 00:36:40,105 and you 999 00:36:40,405 --> 00:36:43,364 read missed press releases or physics world, you're 1000 00:36:43,364 --> 00:36:44,744 you're you're on your way. 1001 00:36:45,125 --> 00:36:46,804 And Hang on. Is there a big market 1002 00:36:46,804 --> 00:36:48,804 for these fake coins? Is that Well, I 1003 00:36:48,804 --> 00:36:51,125 would imagine. I mean, you know, people do 1004 00:36:51,125 --> 00:36:52,424 like to collect coins. 1005 00:36:52,724 --> 00:36:53,704 So yeah. 1006 00:36:54,579 --> 00:36:56,760 Yeah. And and they they also used 1007 00:36:57,059 --> 00:36:59,780 another technique to look at at these coins, 1008 00:36:59,780 --> 00:37:01,400 and that's a a sophisticated 1009 00:37:01,699 --> 00:37:04,440 version of something called small angle scattering. 1010 00:37:04,900 --> 00:37:07,380 And small angle scattering is something that allows 1011 00:37:07,380 --> 00:37:08,519 you to look at 1012 00:37:08,894 --> 00:37:10,114 fairly big things 1013 00:37:10,414 --> 00:37:12,894 in a sample, so not the atomic structure, 1014 00:37:12,894 --> 00:37:14,515 but bigger structures 1015 00:37:14,894 --> 00:37:15,875 within a sample. 1016 00:37:16,414 --> 00:37:18,414 And what they did is they used the 1017 00:37:18,414 --> 00:37:19,554 small angle scattering 1018 00:37:19,934 --> 00:37:22,434 to look at tiny pores on the surfaces 1019 00:37:23,019 --> 00:37:25,579 of the coins. And these pores occur as 1020 00:37:25,579 --> 00:37:27,820 the coins age, you know, they they interact 1021 00:37:27,820 --> 00:37:28,720 with their environment. 1022 00:37:29,099 --> 00:37:31,260 Material is removed from the surface of the 1023 00:37:31,260 --> 00:37:31,760 coin. 1024 00:37:32,619 --> 00:37:33,519 And counterintuitively, 1025 00:37:34,140 --> 00:37:35,920 what they found is that the genuine 1026 00:37:36,539 --> 00:37:37,360 older coins 1027 00:37:37,815 --> 00:37:39,114 had smaller pores 1028 00:37:39,734 --> 00:37:42,214 than the fake coins. Fake coins had pores, 1029 00:37:42,214 --> 00:37:43,755 but the pores were much bigger. 1030 00:37:44,375 --> 00:37:46,375 Now you might not expect that to happen, 1031 00:37:46,375 --> 00:37:46,875 but 1032 00:37:47,734 --> 00:37:50,375 they believe the researchers believe that the reason 1033 00:37:50,375 --> 00:37:51,835 this happened is that 1034 00:37:52,349 --> 00:37:54,750 because the old coins have been buried actually, 1035 00:37:54,750 --> 00:37:56,530 I think in this case, they've been underwater 1036 00:37:57,150 --> 00:37:58,289 for a long time. 1037 00:38:00,269 --> 00:38:02,110 The the pores are produced, but then they 1038 00:38:02,110 --> 00:38:03,410 start to fill in 1039 00:38:03,869 --> 00:38:05,809 through other chemical processes. 1040 00:38:06,215 --> 00:38:07,275 And so the genuine 1041 00:38:07,655 --> 00:38:08,474 old coins 1042 00:38:09,175 --> 00:38:09,675 have, 1043 00:38:10,295 --> 00:38:11,675 have much smaller pores 1044 00:38:11,974 --> 00:38:13,735 than the new coins, which have been sort 1045 00:38:13,735 --> 00:38:14,394 of artificially 1046 00:38:15,494 --> 00:38:16,795 corroded or aged. 1047 00:38:17,094 --> 00:38:19,094 And so in in a sense, the neutrons 1048 00:38:19,094 --> 00:38:19,755 have revealed 1049 00:38:20,135 --> 00:38:20,635 two 1050 00:38:21,094 --> 00:38:21,594 signatures 1051 00:38:22,210 --> 00:38:23,349 of old coins. 1052 00:38:23,969 --> 00:38:24,849 And so now, 1053 00:38:25,250 --> 00:38:27,570 now these researchers are they're they're going back 1054 00:38:27,570 --> 00:38:29,670 and they're gonna look at a broader 1055 00:38:30,610 --> 00:38:33,329 sample of fake and real coins and and 1056 00:38:33,329 --> 00:38:35,954 and see if they can confirm this. But, 1057 00:38:36,195 --> 00:38:38,215 yeah, I thought this was a really interesting 1058 00:38:38,755 --> 00:38:40,375 use of neutron scattering. 1059 00:38:41,315 --> 00:38:43,155 You you I mean, you know, I I 1060 00:38:43,155 --> 00:38:44,994 I had the privilege of of working at 1061 00:38:44,994 --> 00:38:47,655 a a reactor where they did neutron scattering. 1062 00:38:47,760 --> 00:38:49,119 And, yeah, of course, you know, they were 1063 00:38:49,119 --> 00:38:52,079 looking at new magnetic materials and things like 1064 00:38:52,079 --> 00:38:54,960 that, but they're also very interested in, 1065 00:38:56,320 --> 00:38:58,099 you know, sort of industrial applications. 1066 00:38:59,039 --> 00:39:01,059 You know, they would look at bits of 1067 00:39:02,264 --> 00:39:04,444 a jet engine to look for 1068 00:39:05,144 --> 00:39:05,644 cracks 1069 00:39:06,105 --> 00:39:06,744 within the, 1070 00:39:07,704 --> 00:39:10,344 the turbine blades that are not evident from 1071 00:39:10,344 --> 00:39:11,005 the surface. 1072 00:39:11,304 --> 00:39:13,864 So, you know, neutron scattering is, you know, 1073 00:39:13,864 --> 00:39:16,424 there's lots of really interesting applications, and one 1074 00:39:16,424 --> 00:39:17,579 of them, I suppose, is 1075 00:39:17,980 --> 00:39:20,300 looking at, you know, antiquities and, 1076 00:39:20,860 --> 00:39:21,760 spotting fakes. 1077 00:39:22,619 --> 00:39:24,140 So yeah. But I was just trying to 1078 00:39:24,140 --> 00:39:25,820 imagine to to imagine if someone offers you 1079 00:39:25,820 --> 00:39:27,420 a fake Korean coin. You go, hang on 1080 00:39:27,420 --> 00:39:28,780 a minute. Let me just go down to 1081 00:39:28,780 --> 00:39:30,079 the, NIST in Colorado, 1082 00:39:30,695 --> 00:39:32,614 check check with these neutron people. Can can 1083 00:39:32,614 --> 00:39:34,454 I take my coin along to check it? 1084 00:39:34,454 --> 00:39:36,535 Yeah. Yeah. Yeah. Or or or will I 1085 00:39:36,614 --> 00:39:38,695 It's just in Maryland. Maryland. Or will I've 1086 00:39:38,695 --> 00:39:40,015 already bought it? And maybe I've already bought 1087 00:39:40,015 --> 00:39:41,255 it, and then I wasted my money. And 1088 00:39:41,255 --> 00:39:43,094 then I then I'm gonna be really disappointed 1089 00:39:43,094 --> 00:39:44,476 I'm gonna take it, and it works out 1090 00:39:44,476 --> 00:39:46,769 as Yeah. I mean, I think what these 1091 00:39:46,769 --> 00:39:49,250 researchers say in their papers that it's probably 1092 00:39:49,250 --> 00:39:52,710 more useful for people who do historical research. 1093 00:39:53,170 --> 00:39:53,670 Because, 1094 00:39:54,050 --> 00:39:55,750 you know, a lot of our understanding 1095 00:39:56,289 --> 00:39:59,329 of history comes from coins, and where coins 1096 00:39:59,329 --> 00:39:59,990 are found. 1097 00:40:00,965 --> 00:40:02,344 And so it'll allow, 1098 00:40:02,804 --> 00:40:03,304 historians 1099 00:40:04,005 --> 00:40:05,144 and I suppose archaeologists 1100 00:40:05,765 --> 00:40:06,585 to verify, 1101 00:40:07,844 --> 00:40:10,005 finds of coins and and and that sort 1102 00:40:10,005 --> 00:40:11,605 of thing. Yeah. So Do you know what? 1103 00:40:11,605 --> 00:40:12,965 I've been reminded of that feature we had. 1104 00:40:12,965 --> 00:40:14,585 Do you remember a few years ago about 1105 00:40:15,199 --> 00:40:16,739 studying Chinese porcelain 1106 00:40:17,359 --> 00:40:19,839 using optical microscopy to look for the inclusions 1107 00:40:19,839 --> 00:40:22,400 in the, glazing? Oh, right. Yeah. And that 1108 00:40:22,400 --> 00:40:25,440 again was for spotting fake fake Chinese vases, 1109 00:40:25,440 --> 00:40:27,119 which is a, you know, huge market for 1110 00:40:27,119 --> 00:40:28,019 that. Yeah. 1111 00:40:28,625 --> 00:40:30,464 Yeah. It is interesting. And I I suppose 1112 00:40:30,464 --> 00:40:32,164 at the end of the day, okay, 1113 00:40:32,625 --> 00:40:33,444 these counterfeiters, 1114 00:40:33,824 --> 00:40:34,804 they might know 1115 00:40:35,505 --> 00:40:38,304 that they need to put these inclusions in. 1116 00:40:38,304 --> 00:40:40,484 But unless they've got a neutral facility, 1117 00:40:41,585 --> 00:40:43,444 they won't know if they've done it properly. 1118 00:40:43,960 --> 00:40:46,119 So I suppose in principle, they could they 1119 00:40:46,119 --> 00:40:47,500 could improve their fakes. 1120 00:40:47,880 --> 00:40:48,280 But, 1121 00:40:48,760 --> 00:40:51,160 it it would be very difficult to, you 1122 00:40:51,160 --> 00:40:52,519 know, they might try to slip in a 1123 00:40:52,519 --> 00:40:53,500 research proposal 1124 00:40:55,239 --> 00:40:57,579 to, you know, to that mist reactor. 1125 00:40:57,960 --> 00:40:59,744 Hopefully, somebody would spot it. 1126 00:41:00,385 --> 00:41:03,345 Yeah. So that's neutrons and fake coins. And 1127 00:41:03,345 --> 00:41:05,265 you can find find out more about this 1128 00:41:05,265 --> 00:41:07,184 on the Physics World website. Just look for 1129 00:41:07,184 --> 00:41:07,845 the headline, 1130 00:41:08,305 --> 00:41:08,805 neutrons 1131 00:41:09,265 --> 00:41:09,765 differentiate 1132 00:41:10,224 --> 00:41:14,400 between real and fake antique coins. Thanks, Matin. 1133 00:41:14,780 --> 00:41:15,599 Thanks, Hamish. 1134 00:41:23,260 --> 00:41:25,019 I'm afraid that's all the time we have 1135 00:41:25,019 --> 00:41:26,320 for this week's podcast. 1136 00:41:26,735 --> 00:41:29,855 Thanks to Margaret Harris and Matin Durrani for 1137 00:41:29,855 --> 00:41:30,994 joining me today. 1138 00:41:31,375 --> 00:41:34,175 And a special thanks to our producer, Fred 1139 00:41:34,175 --> 00:41:34,675 Ailes. 1140 00:41:35,215 --> 00:41:37,155 We'll be back again next week.