1 00:00:08,480 --> 00:00:11,559 Speaker 1: Hey, Daniel, as a particle physicist, what's the one thing 2 00:00:11,680 --> 00:00:14,760 Speaker 1: you would most like to discover? If I could pick 3 00:00:14,880 --> 00:00:17,840 Speaker 1: just one thing to discover? Yeah, like go wild? What's 4 00:00:17,880 --> 00:00:20,959 Speaker 1: your biggest scientific ambition. Well that's a great question, but 5 00:00:21,120 --> 00:00:23,360 Speaker 1: it's not actually that hard to pick. I would want 6 00:00:23,400 --> 00:00:27,080 Speaker 1: to discover dark matter because it's such a big mystery. Yeah, 7 00:00:27,080 --> 00:00:30,160 Speaker 1: it's one of the biggest open questions in modern science, 8 00:00:30,200 --> 00:00:32,919 Speaker 1: and I personally really want to know the answer. Right, 9 00:00:32,960 --> 00:00:35,319 Speaker 1: But here's a catch. What have you discovered what it is? 10 00:00:35,560 --> 00:00:39,480 Speaker 1: But nobody believes you? Are you still interested? Oh? Man, 11 00:00:39,600 --> 00:00:43,280 Speaker 1: like a modern day physics Cassandra. That sounds a little 12 00:00:43,280 --> 00:00:45,560 Speaker 1: bit like torture. But you know, as long as I 13 00:00:45,640 --> 00:00:48,240 Speaker 1: know the answer to the questions about the universe, I 14 00:00:48,280 --> 00:00:50,360 Speaker 1: would still want to find out. So it's all about you. 15 00:00:51,880 --> 00:01:09,959 Speaker 1: Science is personal. Hi am or handmade cartoonists and the 16 00:01:10,000 --> 00:01:13,200 Speaker 1: creator of PhD comment. Hi, I'm Daniel. I'm a particle 17 00:01:13,240 --> 00:01:17,160 Speaker 1: physicist and I'm desperately seeking dark matter. How desperate are you, Daniel? 18 00:01:17,360 --> 00:01:20,440 Speaker 1: Not desperate enough to make up my data, but desperate 19 00:01:20,520 --> 00:01:23,119 Speaker 1: enough to consider almost anything. You're desperate enough to move 20 00:01:23,160 --> 00:01:26,320 Speaker 1: to Italy maybe to do your research. I do like 21 00:01:26,440 --> 00:01:29,160 Speaker 1: that black pasta to have over there, so called that 22 00:01:29,240 --> 00:01:34,000 Speaker 1: dark matter. Than yeah, it's called squid in tasta. Well 23 00:01:34,000 --> 00:01:38,040 Speaker 1: they've discovered something delicious at the very least. But welcome 24 00:01:38,040 --> 00:01:40,440 Speaker 1: to our podcast Daniel and Jorge Explain the Universe, a 25 00:01:40,560 --> 00:01:43,039 Speaker 1: production of our Heart Radio in which we take a 26 00:01:43,080 --> 00:01:47,040 Speaker 1: bite out of the tastiest intellectual questions of the universe. 27 00:01:47,160 --> 00:01:50,640 Speaker 1: We true, we swallow. We explain all of it to you. Sorry, 28 00:01:50,680 --> 00:01:53,240 Speaker 1: we serve it up on a dish and hope that 29 00:01:53,320 --> 00:01:55,559 Speaker 1: you slurp it all up so you can think about 30 00:01:55,600 --> 00:01:58,440 Speaker 1: the universe and everything in it. Because everything about the 31 00:01:58,520 --> 00:02:01,600 Speaker 1: universe is wondrous and hazing, and it makes us curious. 32 00:02:01,640 --> 00:02:04,080 Speaker 1: But it doesn't just make scientists curious. We think it 33 00:02:04,120 --> 00:02:08,040 Speaker 1: makes everybody curious. That curiosity is wonderful and we want 34 00:02:08,080 --> 00:02:10,920 Speaker 1: to cherish it and satisfy it by explaining to you 35 00:02:11,080 --> 00:02:13,520 Speaker 1: some of the mysteries of the universe. And there are 36 00:02:13,560 --> 00:02:15,720 Speaker 1: still a lot of mysteries out there. There are big 37 00:02:15,840 --> 00:02:18,120 Speaker 1: chunks of the universe we don't know anything about, and 38 00:02:18,160 --> 00:02:21,359 Speaker 1: there are big questions about the very nature of our 39 00:02:21,400 --> 00:02:24,840 Speaker 1: cosmos and where we came from, and also what is 40 00:02:25,000 --> 00:02:28,119 Speaker 1: even in it. That's right, Recently, scientists have cracked open 41 00:02:28,160 --> 00:02:30,239 Speaker 1: the universe and discovered that there's a lot of stuff 42 00:02:30,280 --> 00:02:32,919 Speaker 1: out there that we don't know, that we don't understand. 43 00:02:32,960 --> 00:02:35,680 Speaker 1: There are new kinds of stuff out there, and it 44 00:02:35,720 --> 00:02:39,000 Speaker 1: makes us desperately curious. What is it? Why is it? 45 00:02:39,120 --> 00:02:41,280 Speaker 1: Why is there so much more of it than our 46 00:02:41,440 --> 00:02:44,720 Speaker 1: kind of stuff? So many questions, so few answers. And 47 00:02:44,880 --> 00:02:48,080 Speaker 1: is it delicious? Also? It's a big question, and everybody's fine, 48 00:02:48,120 --> 00:02:49,840 Speaker 1: how much of it should you have on top of 49 00:02:49,840 --> 00:02:52,280 Speaker 1: your pasta? And can you put cheese on it? Are 50 00:02:52,320 --> 00:02:55,280 Speaker 1: there rules for what you can put parmes on cheese on? Absolutely, 51 00:02:55,320 --> 00:02:57,720 Speaker 1: you can put parmesan cheese on everything. That's the rule, 52 00:02:57,800 --> 00:03:00,000 Speaker 1: even sea food pasta. I feel like that's an unstage 53 00:03:00,000 --> 00:03:03,840 Speaker 1: it a rule that's a whole other podcast episode. We 54 00:03:03,840 --> 00:03:05,639 Speaker 1: can't get into that today. Man, We have to stay 55 00:03:05,639 --> 00:03:10,320 Speaker 1: on topic seafood matter, seafood matters. But anyways, a big 56 00:03:10,360 --> 00:03:12,960 Speaker 1: bite of the universe that we don't know anything about 57 00:03:13,360 --> 00:03:16,960 Speaker 1: is a big mystery called dark matter. Of all of 58 00:03:17,000 --> 00:03:19,440 Speaker 1: the energy and matter in the universe is something called 59 00:03:19,520 --> 00:03:21,880 Speaker 1: dark matter, but we don't know what it is, and 60 00:03:21,919 --> 00:03:23,920 Speaker 1: we would love to understand it. We would love to 61 00:03:23,960 --> 00:03:26,480 Speaker 1: break it apart and figure out isn't made out of 62 00:03:26,520 --> 00:03:29,280 Speaker 1: some tiny little particle we've never seen before. Is it 63 00:03:29,400 --> 00:03:32,280 Speaker 1: lots of different particles? Is it something else which isn't 64 00:03:32,320 --> 00:03:35,520 Speaker 1: even a particle. So physicists all over the world are 65 00:03:35,560 --> 00:03:38,520 Speaker 1: using lots of different techniques to try to isolate dark 66 00:03:38,560 --> 00:03:41,400 Speaker 1: matter and figure out what kind of particle it is. Yeah, 67 00:03:41,440 --> 00:03:44,440 Speaker 1: because it's sweating all around us, right like it's it's everywhere. 68 00:03:44,560 --> 00:03:47,080 Speaker 1: In fact, probably when you eat pasta you are taking 69 00:03:47,120 --> 00:03:50,240 Speaker 1: big bite fools of dark matter at the same time. 70 00:03:50,600 --> 00:03:52,840 Speaker 1: That's right, but fortunately your body doesn't digest it, so 71 00:03:52,880 --> 00:03:56,200 Speaker 1: you don't gain all of that mass. But yes, dark matter, 72 00:03:56,320 --> 00:03:59,320 Speaker 1: we think is all around us. It's part of the universe, 73 00:03:59,360 --> 00:04:02,520 Speaker 1: but it's not. And evenly through the universe it's clumped together, 74 00:04:02,920 --> 00:04:05,800 Speaker 1: just like our matter. So we think that our galaxy 75 00:04:05,880 --> 00:04:09,440 Speaker 1: is swimming in a massive halo of dark matter, and 76 00:04:09,480 --> 00:04:12,720 Speaker 1: that the Earth is flying through a wind of dark matter. 77 00:04:13,200 --> 00:04:15,880 Speaker 1: And so physicists are using lots of techniques to try 78 00:04:15,880 --> 00:04:18,680 Speaker 1: to discover this, looking at it colliding with itself in 79 00:04:18,720 --> 00:04:21,120 Speaker 1: the center of the galaxy. We're trying to make it 80 00:04:21,160 --> 00:04:25,159 Speaker 1: in underground collisions at the Large Hadron collider and also 81 00:04:25,240 --> 00:04:28,120 Speaker 1: we're trying to detect this dark matter wind. Yeah, everybody 82 00:04:28,160 --> 00:04:30,000 Speaker 1: seems to be looking for it, but it's really hard 83 00:04:30,000 --> 00:04:33,480 Speaker 1: because you can't touch it or see it, and so 84 00:04:33,520 --> 00:04:36,960 Speaker 1: far nobody has really got in a chest to figure 85 00:04:36,960 --> 00:04:39,080 Speaker 1: out what it is, or have they. It's been an 86 00:04:39,080 --> 00:04:42,679 Speaker 1: open puzzle for decades now in physics what is dark matter? 87 00:04:42,760 --> 00:04:45,200 Speaker 1: What is it made out of? And everybody knows that 88 00:04:45,200 --> 00:04:47,800 Speaker 1: the people who figure that out will go down in 89 00:04:48,000 --> 00:04:52,080 Speaker 1: history as having answered one of the biggest questions in physics. 90 00:04:52,520 --> 00:04:55,240 Speaker 1: And so it's definitely a big fat prize out there 91 00:04:55,279 --> 00:04:57,960 Speaker 1: waiting for somebody to win. Yeah, and in fact, there 92 00:04:58,080 --> 00:05:00,880 Speaker 1: is somebody out there who believe eves they've seen it 93 00:05:01,160 --> 00:05:03,800 Speaker 1: and maybe even know what it is, and in fact 94 00:05:03,800 --> 00:05:07,479 Speaker 1: they've been certain about this for about twenty years. That's right. 95 00:05:07,600 --> 00:05:09,400 Speaker 1: Of all the folks out there looking for dark matter, 96 00:05:09,520 --> 00:05:12,400 Speaker 1: there's a group in Italy that are very confident in 97 00:05:12,440 --> 00:05:15,839 Speaker 1: their signal they've seen something that they think can only 98 00:05:15,880 --> 00:05:19,400 Speaker 1: be explained by dark matter. Well, Italians being confident about 99 00:05:19,400 --> 00:05:23,600 Speaker 1: something Danna that feels like pretty on brand. Yeah, So 100 00:05:23,880 --> 00:05:27,159 Speaker 1: the big question is why doesn't anybody believe this experiment 101 00:05:27,240 --> 00:05:29,960 Speaker 1: and the results they found. So today on the podcast 102 00:05:29,960 --> 00:05:37,880 Speaker 1: will be tackling the question why doesn't anybody believe the 103 00:05:38,000 --> 00:05:41,800 Speaker 1: DAMA experiment. Now, Daniel, this is DAMA, d A m 104 00:05:41,920 --> 00:05:45,719 Speaker 1: A not Dharma experiment. Like in the TV series Lost, 105 00:05:45,960 --> 00:05:49,440 Speaker 1: I feel like maybe there's a conspiracy here, Maybe the 106 00:05:49,440 --> 00:05:52,240 Speaker 1: to are connected. Maybe Lost was actually about dark matter 107 00:05:52,400 --> 00:05:56,760 Speaker 1: the whole time. Maybe yeah, yes, the monster watch me 108 00:05:56,839 --> 00:05:58,839 Speaker 1: to ad have like this dark cloud, it could have 109 00:05:58,839 --> 00:06:00,679 Speaker 1: been dark matter, It could have been in dark matter. 110 00:06:00,800 --> 00:06:03,360 Speaker 1: They were physicists the whole time, and we finally put 111 00:06:03,360 --> 00:06:05,840 Speaker 1: it together right here on the podcast and unlocked the 112 00:06:05,880 --> 00:06:10,360 Speaker 1: mister Jack never had a chance. That's right now. It's 113 00:06:10,400 --> 00:06:14,359 Speaker 1: the DAMA experiment, and it's had several iterations. It's called Dama, 114 00:06:14,360 --> 00:06:17,320 Speaker 1: it's called Dama slash libra, but they're all fundamentally the 115 00:06:17,360 --> 00:06:21,279 Speaker 1: same experiment in the same location, seeing the same amazing 116 00:06:21,400 --> 00:06:25,080 Speaker 1: signal that looks like dark matter. But nobody seems to 117 00:06:25,120 --> 00:06:27,800 Speaker 1: believe that. The consensus in the particle physics community is 118 00:06:27,839 --> 00:06:31,520 Speaker 1: that DAMA has not discovered dark matter, and other experiments 119 00:06:31,560 --> 00:06:34,240 Speaker 1: continue to hunt for dark matter in lots of different ways. 120 00:06:34,680 --> 00:06:37,960 Speaker 1: So it's a fascinating question when one group sees something 121 00:06:37,960 --> 00:06:40,680 Speaker 1: but nobody else believes it. What do you do? Wow? 122 00:06:41,279 --> 00:06:43,960 Speaker 1: What does DAMA stand for? The d A comes from 123 00:06:44,080 --> 00:06:46,720 Speaker 1: dark and the m a comes from matter, so da 124 00:06:46,839 --> 00:06:49,919 Speaker 1: mash is just short for dark matter. You know, people 125 00:06:49,920 --> 00:06:52,440 Speaker 1: can't be bothered to say the whole name dark matter, 126 00:06:52,480 --> 00:06:56,280 Speaker 1: so they just squished it together into DAMA. Okay, they've 127 00:06:56,320 --> 00:06:59,960 Speaker 1: just appropriated the first two letters for the acronym. That's right, 128 00:07:00,160 --> 00:07:02,559 Speaker 1: and the follow up experiment will appropriate the other letters. 129 00:07:02,600 --> 00:07:07,839 Speaker 1: It will be alright. So these folks in Italy twenty 130 00:07:07,920 --> 00:07:11,600 Speaker 1: years ago claim they have found a signal for dark matter, 131 00:07:12,400 --> 00:07:14,800 Speaker 1: and they've been pretty confident about it, but nobody in 132 00:07:14,800 --> 00:07:17,320 Speaker 1: the field believed them. And I was wondering whether people 133 00:07:17,400 --> 00:07:20,239 Speaker 1: outside the field have followed this, if it's trickled through 134 00:07:20,280 --> 00:07:23,920 Speaker 1: into mainstream media, if people are aware of this incredible, 135 00:07:24,040 --> 00:07:27,520 Speaker 1: unexplained signal and a dark matter experiment, because usual Daniel 136 00:07:27,520 --> 00:07:29,360 Speaker 1: went out there into the wilds of the Internet to 137 00:07:29,400 --> 00:07:34,840 Speaker 1: ask people, why does nobody believe the DAMA experiment discovered 138 00:07:35,040 --> 00:07:37,160 Speaker 1: dark matter? So thank you to those of you who 139 00:07:37,160 --> 00:07:40,520 Speaker 1: are willing to speculate on a physics question without googling. 140 00:07:40,840 --> 00:07:44,280 Speaker 1: If you'd like to participate, and here your uninformed speculation 141 00:07:44,360 --> 00:07:47,400 Speaker 1: on the podcast, Please write to us two questions at 142 00:07:47,520 --> 00:07:50,400 Speaker 1: Daniel and Jorge dot com. Here's what people had to say. 143 00:07:50,640 --> 00:07:53,320 Speaker 1: I'm not sure I've never heard of this experiment before. 144 00:07:53,480 --> 00:07:57,680 Speaker 1: Then there are so many experiments right now and I'm 145 00:07:57,680 --> 00:08:02,200 Speaker 1: not sure I heard about this one. I don't know. 146 00:08:04,040 --> 00:08:07,960 Speaker 1: Um is it? Has there been no further evidence of 147 00:08:08,160 --> 00:08:11,240 Speaker 1: dark matter that's been found? Have they not been able 148 00:08:11,240 --> 00:08:13,840 Speaker 1: to replicate it? I imagine it's something like that, or 149 00:08:13,840 --> 00:08:15,840 Speaker 1: maybe they like look back at the results and we're like, no, 150 00:08:16,000 --> 00:08:19,560 Speaker 1: this could just be interference. Um, I don't I don't know. 151 00:08:20,000 --> 00:08:22,800 Speaker 1: I would assume that the discovery of dark matter would 152 00:08:22,840 --> 00:08:25,800 Speaker 1: be on par with the photo the first photo of 153 00:08:25,840 --> 00:08:28,800 Speaker 1: the black hole ever taken, and that was from Page News. 154 00:08:29,080 --> 00:08:33,480 Speaker 1: And because I haven't heard anything about dark matter being discovered, 155 00:08:34,000 --> 00:08:37,760 Speaker 1: that maybe they didn't discover it, there was noise in 156 00:08:37,800 --> 00:08:40,679 Speaker 1: the data, or they're still taking their time to calculate 157 00:08:40,679 --> 00:08:43,800 Speaker 1: the results. If the Deema experiment did discover a dark matter, 158 00:08:44,679 --> 00:08:48,400 Speaker 1: you think that we have more information about what it is, 159 00:08:48,720 --> 00:08:52,120 Speaker 1: all right? Not a lot of brand recognition for Doma. No, 160 00:08:52,760 --> 00:08:54,320 Speaker 1: I don't know. That means they should have chosen a 161 00:08:54,320 --> 00:08:57,120 Speaker 1: better name, or they just need a better pr team. 162 00:08:57,160 --> 00:09:00,400 Speaker 1: But because nobody in physics has really accepted their result, 163 00:09:00,440 --> 00:09:03,240 Speaker 1: it doesn't seem to have trickled out to the wider community. 164 00:09:03,400 --> 00:09:05,120 Speaker 1: I like this answer that somebody said, there are so 165 00:09:05,120 --> 00:09:07,560 Speaker 1: many experiments right now, I'm not sure I've heard about 166 00:09:07,600 --> 00:09:10,240 Speaker 1: this one, Like, do you feel like maybe you saturated 167 00:09:10,240 --> 00:09:13,960 Speaker 1: the market with acronym experiments. Oh, there are a lot 168 00:09:14,160 --> 00:09:17,200 Speaker 1: of dark matter experiments, you know, and they have crazy names. 169 00:09:17,400 --> 00:09:21,160 Speaker 1: There's Zenon, there's lux those LZ, this co signed, this cogent, 170 00:09:21,240 --> 00:09:24,600 Speaker 1: there's Zeppelin, this coupe, there's dark Side. These are just like, 171 00:09:24,640 --> 00:09:26,760 Speaker 1: you know, half of the dark matter experiments out there. 172 00:09:26,840 --> 00:09:29,720 Speaker 1: It's an enormous race. It's like a land grab. You know. 173 00:09:29,800 --> 00:09:33,120 Speaker 1: Everybody's rushing to figure out what dark matter is, knowing 174 00:09:33,160 --> 00:09:35,240 Speaker 1: that one of these groups might figure it out and 175 00:09:35,600 --> 00:09:38,200 Speaker 1: not only win a Noel Prize, but you know, answer 176 00:09:38,240 --> 00:09:41,440 Speaker 1: a deep question about the universe. So it's very tempting. 177 00:09:41,480 --> 00:09:44,240 Speaker 1: It's a very hot area of research. Yeah, and it's 178 00:09:44,280 --> 00:09:47,439 Speaker 1: a big part of the universe. It's twenty seven that's right. 179 00:09:47,480 --> 00:09:50,199 Speaker 1: If you add up all the energy in like a 180 00:09:50,320 --> 00:09:54,720 Speaker 1: random cube of space, then twenty seven percent of that 181 00:09:54,880 --> 00:09:58,600 Speaker 1: energy is devoted to making dark matter, whereas only five 182 00:09:58,720 --> 00:10:00,839 Speaker 1: percent of that energy is a the stuff you and 183 00:10:00,880 --> 00:10:03,520 Speaker 1: I are made out of, and stars and dust and 184 00:10:03,559 --> 00:10:05,760 Speaker 1: gas and most of the stuff that we think about 185 00:10:05,840 --> 00:10:08,840 Speaker 1: in the universe. It's just a tiny little fraction. So 186 00:10:08,920 --> 00:10:13,080 Speaker 1: discovering dark matter doesn't just like answer some abstract physics question. 187 00:10:13,160 --> 00:10:15,360 Speaker 1: It tells us what the universe is, because it's much 188 00:10:15,400 --> 00:10:18,439 Speaker 1: more than just what we're made at. Yeah, all right, 189 00:10:18,480 --> 00:10:21,559 Speaker 1: So these folks have discovered dark matter, or claim to 190 00:10:21,600 --> 00:10:24,480 Speaker 1: have discovered it, but nobody believes them. Daniel, Is that 191 00:10:24,600 --> 00:10:26,960 Speaker 1: like a night mer scenario for you as a scientist, 192 00:10:27,080 --> 00:10:29,880 Speaker 1: Like to discover something amazing and then have everybody think 193 00:10:29,880 --> 00:10:32,200 Speaker 1: that you're crazy. It's one of several nightmares, you know. 194 00:10:32,280 --> 00:10:35,840 Speaker 1: Other varieties of those nightmares are like you see something amazing, 195 00:10:36,000 --> 00:10:38,440 Speaker 1: you published something, it makes a big splash, and then 196 00:10:38,520 --> 00:10:41,280 Speaker 1: you realize that it was wrong. That's the kind of 197 00:10:41,280 --> 00:10:43,560 Speaker 1: thing that happened to the Opera experiment that claimed that 198 00:10:43,640 --> 00:10:46,400 Speaker 1: neutrinos were going faster than light, and then it turns 199 00:10:46,400 --> 00:10:49,320 Speaker 1: out they had miscalibrated because one of their cables wasn't 200 00:10:49,440 --> 00:10:52,120 Speaker 1: jiggled in the right way. They were Italian too, weren't 201 00:10:52,160 --> 00:10:56,840 Speaker 1: they They were also Italian, although you know that could 202 00:10:56,920 --> 00:11:00,360 Speaker 1: just be coincidence on not casting expersions on the Italian 203 00:11:00,360 --> 00:11:04,240 Speaker 1: physics community. Lots of wonderful Italian collaborators on the outlets 204 00:11:04,280 --> 00:11:07,160 Speaker 1: experiment with me. But yeah, that's one nightmare, and the 205 00:11:07,200 --> 00:11:09,719 Speaker 1: other one is that nobody reproduces your result, and so 206 00:11:09,880 --> 00:11:12,720 Speaker 1: nobody believes your result and you're left there with data 207 00:11:12,760 --> 00:11:15,240 Speaker 1: that you believe that you just can't convince your colleagues, 208 00:11:15,480 --> 00:11:19,560 Speaker 1: because remember, science is a human endeavor. It's by people 209 00:11:19,640 --> 00:11:21,599 Speaker 1: and four people, and in the end you have to 210 00:11:21,640 --> 00:11:24,480 Speaker 1: convince the community that what you've done holds up, that 211 00:11:24,520 --> 00:11:27,480 Speaker 1: you've uncracked something real about the universe and not just 212 00:11:27,520 --> 00:11:30,720 Speaker 1: an artifact of how you've done your experience. Yeah, I 213 00:11:30,720 --> 00:11:33,319 Speaker 1: feel like that's that's a similar nightmare for cartoonist. It's 214 00:11:33,320 --> 00:11:35,840 Speaker 1: like you write the perfect joke and nobody gets it. 215 00:11:37,320 --> 00:11:39,319 Speaker 1: Would I still be satisfied? Like, I think maybe I 216 00:11:39,320 --> 00:11:41,840 Speaker 1: would still be satisfied. I'd be like, yes, I wrote 217 00:11:41,880 --> 00:11:45,040 Speaker 1: the best joke, but everyone else is a fool. Well, 218 00:11:45,080 --> 00:11:47,080 Speaker 1: that's a good question for you as a cartoonist. Is 219 00:11:47,080 --> 00:11:50,240 Speaker 1: there any correlation between how popular our cartoon is and 220 00:11:50,240 --> 00:11:54,679 Speaker 1: how much you like. Alright, So Dama claims they saw 221 00:11:54,800 --> 00:11:57,560 Speaker 1: dark matter and measured it. So Daniel step us through it. 222 00:11:57,640 --> 00:12:00,680 Speaker 1: What exactly did they see? So what are doing is 223 00:12:00,720 --> 00:12:04,400 Speaker 1: they're looking for a tiny little particles of dark matter. 224 00:12:04,720 --> 00:12:07,720 Speaker 1: Now we don't know that dark matter is a particle, 225 00:12:08,000 --> 00:12:10,000 Speaker 1: but it's just sort of the best idea we have 226 00:12:10,280 --> 00:12:12,240 Speaker 1: is that matter is made of particles, and so we 227 00:12:12,280 --> 00:12:15,480 Speaker 1: figure maybe dark matter is also made out of dark 228 00:12:15,559 --> 00:12:19,560 Speaker 1: matter particles, some new kind of particle we haven't seen before. 229 00:12:19,920 --> 00:12:21,880 Speaker 1: Now we think that dark matter is made out of 230 00:12:21,960 --> 00:12:25,480 Speaker 1: matter because we see that it affects the rotation of galaxies. 231 00:12:25,840 --> 00:12:28,880 Speaker 1: Galaxies are spinning really really fast, and without dark matter 232 00:12:29,080 --> 00:12:32,640 Speaker 1: they would tear themselves apart and throw stars into interstellar space. 233 00:12:33,040 --> 00:12:35,520 Speaker 1: So we think dark matter is real. It's made of matter. 234 00:12:36,040 --> 00:12:37,880 Speaker 1: We're pretty sure that it's not made of any kind 235 00:12:37,880 --> 00:12:40,320 Speaker 1: of matter we're familiar with. It's not made out of 236 00:12:40,400 --> 00:12:43,280 Speaker 1: quarks or leptons, because if so, we would have seen 237 00:12:43,320 --> 00:12:45,240 Speaker 1: it already and it would have affected the way the 238 00:12:45,360 --> 00:12:48,280 Speaker 1: universe formed in very early moments. So we think that 239 00:12:48,400 --> 00:12:51,320 Speaker 1: dark matter has stuff to it. We think it's probably 240 00:12:51,360 --> 00:12:54,800 Speaker 1: made of particles. We think it's a new kind of particle. 241 00:12:55,280 --> 00:12:57,000 Speaker 1: But the thing that makes it hard to find is 242 00:12:57,040 --> 00:12:59,520 Speaker 1: that it doesn't really interact in the ways that we're 243 00:12:59,559 --> 00:13:02,720 Speaker 1: familiar with. Yeah, because everything that has matter that we 244 00:13:02,760 --> 00:13:05,360 Speaker 1: know about is a particle, right, Like, can you think 245 00:13:05,400 --> 00:13:08,040 Speaker 1: of a way in which something could have matter but 246 00:13:08,240 --> 00:13:11,839 Speaker 1: not like a particle or a particle field. Actually, there 247 00:13:11,840 --> 00:13:16,160 Speaker 1: are a set of really fascinating ideas about unparticle matter, 248 00:13:16,600 --> 00:13:19,520 Speaker 1: matter that's made us something that's smooth and continuous. We're 249 00:13:19,559 --> 00:13:21,400 Speaker 1: going to dig into that in a podcast in a 250 00:13:21,400 --> 00:13:24,280 Speaker 1: few weeks, which is really fascinating. But it's hard to 251 00:13:24,280 --> 00:13:27,200 Speaker 1: think about. It's harder to think about than particle matter. 252 00:13:27,720 --> 00:13:30,040 Speaker 1: And when you don't know what you're doing in physics, 253 00:13:30,080 --> 00:13:32,120 Speaker 1: what you do is you start with the familiar, and 254 00:13:32,200 --> 00:13:34,680 Speaker 1: until you've ruled that out as a possibility, you don't 255 00:13:34,679 --> 00:13:37,960 Speaker 1: really take steps into the weirder, crazier options. And so 256 00:13:38,000 --> 00:13:40,320 Speaker 1: we start with the simplest idea that, since everything we 257 00:13:40,360 --> 00:13:42,920 Speaker 1: know is made of particles, maybe dark matter is also 258 00:13:43,080 --> 00:13:45,880 Speaker 1: made of particles, but we don't actually know that. It's 259 00:13:45,880 --> 00:13:48,040 Speaker 1: like you have to check off the obvious first. Yeah, 260 00:13:48,200 --> 00:13:51,080 Speaker 1: you start with the simplest explanation. It's easiest, you know 261 00:13:51,160 --> 00:13:53,480 Speaker 1: how to do it. It makes the most sense, and 262 00:13:53,559 --> 00:13:55,440 Speaker 1: so you start there, you know. But we have a 263 00:13:55,520 --> 00:13:58,280 Speaker 1: variety of folks working in a variety of different ideas, 264 00:13:58,280 --> 00:14:00,480 Speaker 1: but this is sort of the main us. That's the 265 00:14:00,480 --> 00:14:04,040 Speaker 1: first time I hear that phrase on particle matter. What 266 00:14:04,160 --> 00:14:06,880 Speaker 1: did you just call it? Like smooth matter or creamy matter? 267 00:14:07,520 --> 00:14:09,520 Speaker 1: Creamy matter sounds like something I would like to put 268 00:14:09,559 --> 00:14:12,840 Speaker 1: on top of my pasta about dark creamy matter even better? 269 00:14:13,800 --> 00:14:15,840 Speaker 1: Oh yeah, that sounds like something my wife would study. 270 00:14:16,520 --> 00:14:18,679 Speaker 1: But the thing that we don't know about dark matter 271 00:14:19,120 --> 00:14:22,520 Speaker 1: is how to see it. Because dark matter doesn't give 272 00:14:22,560 --> 00:14:26,640 Speaker 1: off light, it doesn't reflect light. It's basically totally transparent 273 00:14:26,800 --> 00:14:28,520 Speaker 1: to matter. You might think of dark matter and think 274 00:14:28,520 --> 00:14:31,360 Speaker 1: of something black or dark that you couldn't see through, 275 00:14:31,680 --> 00:14:34,880 Speaker 1: but it's the opposite. It's something invisible. Life passes right 276 00:14:34,920 --> 00:14:37,840 Speaker 1: through it without interacting, except of course, that dark matter 277 00:14:37,880 --> 00:14:40,720 Speaker 1: has gravity, and so it can bend space and slightly 278 00:14:40,760 --> 00:14:43,240 Speaker 1: distort the path of light. Right, So dark matter doesn't 279 00:14:43,240 --> 00:14:46,880 Speaker 1: interact with us. Our devices are stuff in the usual 280 00:14:46,920 --> 00:14:50,520 Speaker 1: ways through electromagnetic forces. But people think that it may 281 00:14:50,560 --> 00:14:53,720 Speaker 1: interact with us through other forces like the weak force. Yeah, 282 00:14:53,920 --> 00:14:57,120 Speaker 1: we hope that dark matter has some way of interacting 283 00:14:57,160 --> 00:14:59,680 Speaker 1: with our kind of matter, not just because we want 284 00:14:59,680 --> 00:15:02,200 Speaker 1: to feel connected to dark matter, but because all of 285 00:15:02,200 --> 00:15:05,120 Speaker 1: our experiments are made of our kind of matter, and 286 00:15:05,160 --> 00:15:07,240 Speaker 1: so if we're gonna try to catch some dark matter, 287 00:15:07,520 --> 00:15:09,760 Speaker 1: that we have to build our experiments out of something 288 00:15:10,080 --> 00:15:13,680 Speaker 1: that matter will interact with. You Imagine like dark matter 289 00:15:13,760 --> 00:15:15,760 Speaker 1: is flying through the room and you're trying to catch one, 290 00:15:16,120 --> 00:15:18,880 Speaker 1: but you're using a catcher's mit that dark matter flies 291 00:15:19,000 --> 00:15:21,560 Speaker 1: right through. Now you have no chance to catch a 292 00:15:21,600 --> 00:15:25,160 Speaker 1: particle of dark matter. So we hope that dark matter 293 00:15:25,280 --> 00:15:28,280 Speaker 1: does have some kind of interaction with our kind of matter. 294 00:15:28,360 --> 00:15:31,160 Speaker 1: We don't know exactly what kind of interaction that would be. 295 00:15:31,400 --> 00:15:34,680 Speaker 1: We're pretty sure it's not electromagnetic. We know it doesn't 296 00:15:34,760 --> 00:15:37,960 Speaker 1: use the strong force. We're almost certain it doesn't use 297 00:15:38,000 --> 00:15:40,520 Speaker 1: the weak nuclear force. So we're hoping there might be 298 00:15:40,600 --> 00:15:44,080 Speaker 1: a new force, an undiscovered force, that connects dark matter 299 00:15:44,200 --> 00:15:46,640 Speaker 1: with our kind of matter. It's like trying to catch 300 00:15:46,640 --> 00:15:50,120 Speaker 1: a ghost exactly. It's trying to catch a tiny, tiny 301 00:15:50,120 --> 00:15:53,160 Speaker 1: little ghost with a super tiny little catcher's mit. Alright, 302 00:15:53,200 --> 00:15:55,880 Speaker 1: so then how did this DAMA experiment work? What are 303 00:15:55,920 --> 00:15:59,560 Speaker 1: they using to claim to have caught dark matter. So 304 00:15:59,560 --> 00:16:02,320 Speaker 1: there's a whole category of experiments looking for dark matter 305 00:16:02,360 --> 00:16:05,080 Speaker 1: that are called direct detection. And what they do is 306 00:16:05,080 --> 00:16:08,280 Speaker 1: they set up a big lump of material, usually very 307 00:16:08,360 --> 00:16:11,920 Speaker 1: quiet material that doesn't interact very much with things normally, 308 00:16:12,280 --> 00:16:14,520 Speaker 1: and they let it sit there underground under a bunch 309 00:16:14,560 --> 00:16:17,080 Speaker 1: of shielding, and they hope that a piece of dark 310 00:16:17,120 --> 00:16:20,320 Speaker 1: matter will fly through the Earth and bounce into a 311 00:16:20,440 --> 00:16:24,160 Speaker 1: molecule in their lump of stuff. And when that happens, 312 00:16:24,160 --> 00:16:26,240 Speaker 1: they'll get a little flash of light or in some 313 00:16:26,280 --> 00:16:29,400 Speaker 1: cases a wiggle of an electron. And so they've built, 314 00:16:29,440 --> 00:16:31,840 Speaker 1: you know, essentially a big catcher's mitt and they hope 315 00:16:31,880 --> 00:16:34,480 Speaker 1: that a piece of dark matter will bump into it 316 00:16:34,640 --> 00:16:36,920 Speaker 1: and give them a little signal. So that's the whole 317 00:16:37,000 --> 00:16:40,520 Speaker 1: category of these kinds of experiments. And people use different 318 00:16:40,600 --> 00:16:43,920 Speaker 1: kinds of material. Some use liquid zen on, some people 319 00:16:44,000 --> 00:16:48,480 Speaker 1: use super cool semiconductors. This experiment is using crystals, crystals 320 00:16:48,480 --> 00:16:51,920 Speaker 1: of sodium iodide, and so you put them on in 321 00:16:52,040 --> 00:16:53,880 Speaker 1: like a box and your hope is that the dark 322 00:16:53,880 --> 00:16:57,040 Speaker 1: matter goes through the box. But then somehow, you know, 323 00:16:57,080 --> 00:17:00,560 Speaker 1: it causes your crystalline sodium to spark somehow, Yeah, you're 324 00:17:00,600 --> 00:17:03,800 Speaker 1: hoping that dark matter can interact with the protons or 325 00:17:03,840 --> 00:17:07,879 Speaker 1: the neutrons inside the atoms of these crystals, and then occasionally, 326 00:17:08,080 --> 00:17:10,560 Speaker 1: one out of a trillion times, or ten trillion times, 327 00:17:10,600 --> 00:17:13,200 Speaker 1: or a hundred trillion times, it will bump into one 328 00:17:13,200 --> 00:17:15,719 Speaker 1: of those protons and give it a little boost. And 329 00:17:15,760 --> 00:17:19,199 Speaker 1: the reason they choose this sodium idied crystal is that 330 00:17:19,240 --> 00:17:21,920 Speaker 1: it has a special property. When it does get bumped, 331 00:17:22,160 --> 00:17:25,159 Speaker 1: it tends to resettle back into its old situation, and 332 00:17:25,160 --> 00:17:27,720 Speaker 1: it does so by giving off a little photon. So 333 00:17:27,760 --> 00:17:30,800 Speaker 1: as you say it sparks, and physics we call that scintillation, 334 00:17:31,119 --> 00:17:33,440 Speaker 1: So sends off a little photon and then you can 335 00:17:33,480 --> 00:17:36,720 Speaker 1: catch that with these photo multiplier tubes. So you're basically 336 00:17:36,720 --> 00:17:40,000 Speaker 1: looking at a dark crystal underground hoping to see a 337 00:17:40,040 --> 00:17:44,760 Speaker 1: flash of mine, sorry, scintillating. Daniel and so Doma claimed 338 00:17:44,760 --> 00:17:47,240 Speaker 1: that they've seen dark matter, that they have a signal 339 00:17:47,280 --> 00:17:50,080 Speaker 1: for dark matter, but nobody seems to believe them. So 340 00:17:50,200 --> 00:17:53,880 Speaker 1: let's dig into what they actually saw and why it's 341 00:17:53,880 --> 00:17:57,080 Speaker 1: so hard to accept. But first let's take a quick 342 00:17:57,080 --> 00:18:12,000 Speaker 1: break a right, Daniel, we're talking about the Dama experiment 343 00:18:12,000 --> 00:18:14,600 Speaker 1: in Italy who have been claiming for twenty years that 344 00:18:14,640 --> 00:18:17,960 Speaker 1: they found dark matter, but nobody believes them. And so 345 00:18:18,520 --> 00:18:22,040 Speaker 1: they they have a big vat of crystalline sodium underground, 346 00:18:22,160 --> 00:18:25,720 Speaker 1: shielded and they've seen it maybe interact with dark matter. 347 00:18:25,880 --> 00:18:28,199 Speaker 1: So what exactly have they seen? Yeah, so what they 348 00:18:28,240 --> 00:18:31,840 Speaker 1: see is really striking because what they're looking for are 349 00:18:31,880 --> 00:18:34,760 Speaker 1: these little flashes of light. But of course dark matter 350 00:18:34,800 --> 00:18:37,000 Speaker 1: is not the only thing that might give you those 351 00:18:37,040 --> 00:18:40,560 Speaker 1: flashes of light. You could have like radioactive decay in 352 00:18:40,600 --> 00:18:43,760 Speaker 1: the rock. This thing is underground in the Grand Sasso 353 00:18:43,880 --> 00:18:47,080 Speaker 1: mind in Italy, and you know, the rocks nearby can 354 00:18:47,160 --> 00:18:50,280 Speaker 1: have a little bit of radioactive decay or muans can 355 00:18:50,320 --> 00:18:52,560 Speaker 1: penetrate the rock is sometimes and get all the way 356 00:18:52,600 --> 00:18:54,760 Speaker 1: down to your experiment. So you have some sources of 357 00:18:54,800 --> 00:18:57,400 Speaker 1: background that are not dark mattered. Isn't it shielded? Don't 358 00:18:57,440 --> 00:19:00,119 Speaker 1: they put it behind big thick walls or something? And 359 00:19:00,160 --> 00:19:01,879 Speaker 1: first of all, they have buried it in this mind 360 00:19:01,960 --> 00:19:05,160 Speaker 1: under like you know, miles of marble and granite, which 361 00:19:05,200 --> 00:19:08,080 Speaker 1: is awesome shielding. But then yes, absolutely they have the 362 00:19:08,080 --> 00:19:11,320 Speaker 1: things surrounded by concrete and they have fiberglass. They do 363 00:19:11,400 --> 00:19:13,600 Speaker 1: their best to shield it, but you can't always shield 364 00:19:13,600 --> 00:19:17,240 Speaker 1: things completely perfectly, there will always be some level of background. 365 00:19:17,680 --> 00:19:19,840 Speaker 1: So what they do is they look for something that 366 00:19:20,000 --> 00:19:22,600 Speaker 1: only the dark matter could do, a signal that would 367 00:19:22,600 --> 00:19:24,919 Speaker 1: look different if it was dark matter or if it 368 00:19:25,000 --> 00:19:28,320 Speaker 1: was one of these normal everyday backgrounds. And the idea 369 00:19:28,359 --> 00:19:32,080 Speaker 1: they had is to look for seasonal variations, like in 370 00:19:32,080 --> 00:19:34,800 Speaker 1: in the fall, it tastes a little bit like pumpking spice, 371 00:19:34,960 --> 00:19:38,920 Speaker 1: and then in the winter it tastes. In the spring 372 00:19:38,960 --> 00:19:41,000 Speaker 1: it smells a little bit like flowers. No, they have 373 00:19:41,119 --> 00:19:43,719 Speaker 1: this idea of taking advantage of the fact that the 374 00:19:43,800 --> 00:19:47,480 Speaker 1: Earth is moving through the dark matter at different speeds, 375 00:19:47,960 --> 00:19:50,560 Speaker 1: and when we moved through the dark matter at higher speed, 376 00:19:50,760 --> 00:19:54,080 Speaker 1: they should see more dark matter interacting with their detector, 377 00:19:54,359 --> 00:19:56,639 Speaker 1: and when we moved through it at lower speed, they 378 00:19:56,680 --> 00:20:00,080 Speaker 1: should see less dark matter interacting with their detector. And 379 00:20:00,119 --> 00:20:02,680 Speaker 1: that's just because we're going around the Sun, and so 380 00:20:02,720 --> 00:20:05,560 Speaker 1: sometimes we're moving more with the dark matter and sometimes 381 00:20:05,560 --> 00:20:09,760 Speaker 1: we're moving more against the dark matter. It's kind of 382 00:20:09,800 --> 00:20:12,560 Speaker 1: like this old idea of the ether, kind of, isn't it. 383 00:20:12,640 --> 00:20:13,960 Speaker 1: You know? If we are in a big cloud of 384 00:20:14,040 --> 00:20:16,919 Speaker 1: dark matter and the Sun and the Earth is moving 385 00:20:17,119 --> 00:20:20,199 Speaker 1: through it as we go around the Sun. Then you know, 386 00:20:20,320 --> 00:20:22,680 Speaker 1: sometimes we'll see it going one way and then other 387 00:20:22,720 --> 00:20:25,840 Speaker 1: times we'll be seeing the dark matter fly by another way. Yeah, 388 00:20:25,880 --> 00:20:27,840 Speaker 1: it's very similar to the idea of the ether and 389 00:20:27,880 --> 00:20:30,080 Speaker 1: that there's sort of a rest frame. All right. We 390 00:20:30,119 --> 00:20:33,040 Speaker 1: don't know exactly where the dark matter is, but we 391 00:20:33,119 --> 00:20:36,600 Speaker 1: imagine it's pretty smoothly distributed through the galaxy. Again, we 392 00:20:36,640 --> 00:20:39,040 Speaker 1: don't know that it might have clumped, but dark matter 393 00:20:39,119 --> 00:20:41,760 Speaker 1: is very slow moving, and so we think it's pretty diffuse. 394 00:20:42,240 --> 00:20:44,640 Speaker 1: We think it's pretty much spread out. We also don't 395 00:20:44,680 --> 00:20:47,600 Speaker 1: know how fast it's rotating. We think it's rotating around 396 00:20:47,640 --> 00:20:49,919 Speaker 1: the center of the galaxy, just like our kind of 397 00:20:49,960 --> 00:20:53,320 Speaker 1: matter is. But regardless of how fast it's rotating, you 398 00:20:53,320 --> 00:20:56,840 Speaker 1: can imagine some rest frame for the dark matter. And 399 00:20:56,880 --> 00:20:59,320 Speaker 1: then the Earth is moving in that rest frame because 400 00:20:59,320 --> 00:21:02,240 Speaker 1: it orbits the Sun, and so some part of the 401 00:21:02,320 --> 00:21:04,840 Speaker 1: year it's moving through it faster than other parts of 402 00:21:04,840 --> 00:21:08,000 Speaker 1: the year. So their idea is, well, let's look for that. 403 00:21:08,359 --> 00:21:11,119 Speaker 1: If this is dark matter or not muans are crazy, 404 00:21:11,240 --> 00:21:14,080 Speaker 1: radioactive decay or something else, then we should see a 405 00:21:14,160 --> 00:21:17,760 Speaker 1: seasonal variation in our signal. We should see more interactions 406 00:21:17,800 --> 00:21:21,879 Speaker 1: in June than in December, because we're assuming that dark 407 00:21:21,920 --> 00:21:25,920 Speaker 1: matter kind of has a velocity, and sometimes we're going 408 00:21:25,960 --> 00:21:28,760 Speaker 1: against the current of dark matter and sometimes we're going 409 00:21:28,800 --> 00:21:31,000 Speaker 1: with the current. Yeah, well, you don't have to assume 410 00:21:31,000 --> 00:21:34,120 Speaker 1: that dark matter has a velocity with respect to the galaxy. 411 00:21:34,160 --> 00:21:37,640 Speaker 1: It's our velocity relative to the dark matter that's important. 412 00:21:37,760 --> 00:21:39,439 Speaker 1: So you can always just pick your rest frame. And 413 00:21:39,440 --> 00:21:41,320 Speaker 1: if you pick your rest frame as the dark matter, 414 00:21:41,800 --> 00:21:44,679 Speaker 1: then our velocity through that dark matter has to be 415 00:21:44,760 --> 00:21:47,760 Speaker 1: changing year to year because we're orbiting the Sun and 416 00:21:47,880 --> 00:21:50,439 Speaker 1: dark matter is not orbiting our Sun, right. But I 417 00:21:50,480 --> 00:21:52,320 Speaker 1: think you have to also account for the fact that 418 00:21:52,320 --> 00:21:56,040 Speaker 1: we're going around the galaxy, right, because if we were 419 00:21:56,040 --> 00:21:59,520 Speaker 1: just going around the Sun then and dark matter was static, 420 00:21:59,680 --> 00:22:03,080 Speaker 1: we would seed go the same speed by us. It 421 00:22:03,080 --> 00:22:05,120 Speaker 1: would just be in different directions. It's it's more about 422 00:22:05,119 --> 00:22:09,960 Speaker 1: the interactions with with our rotation around the galaxy to right. Yeah, 423 00:22:10,040 --> 00:22:11,680 Speaker 1: you can think about it that way, you know, think 424 00:22:11,720 --> 00:22:14,040 Speaker 1: about it like the Earth and the Sun are moving 425 00:22:14,040 --> 00:22:17,920 Speaker 1: in the same direction relative to the dark matter or 426 00:22:17,960 --> 00:22:20,280 Speaker 1: relative to the rest of the galaxy during part of 427 00:22:20,320 --> 00:22:22,720 Speaker 1: the year, and in the other part of the year 428 00:22:22,760 --> 00:22:25,200 Speaker 1: that you're moving the opposite direction. So the Sun is 429 00:22:25,240 --> 00:22:27,360 Speaker 1: moving around the galaxy in one direction and the Earth 430 00:22:27,440 --> 00:22:30,120 Speaker 1: is going the other way, because it's a different part 431 00:22:30,119 --> 00:22:33,240 Speaker 1: of its cycle around the Sun. And so these velocities 432 00:22:33,280 --> 00:22:35,199 Speaker 1: add up differently. Sometimes they add up to make a 433 00:22:35,320 --> 00:22:38,240 Speaker 1: larger velocity relative to the dark matter, and sometimes they 434 00:22:38,240 --> 00:22:40,600 Speaker 1: point in the opposite direction of each other, and so 435 00:22:40,640 --> 00:22:43,720 Speaker 1: they make a smaller velocity relative to the dark matter. 436 00:22:44,359 --> 00:22:46,400 Speaker 1: So like if you're just standing on Earth, you would 437 00:22:46,480 --> 00:22:50,200 Speaker 1: sort of see dark matter sometimes flow past year really 438 00:22:50,280 --> 00:22:54,320 Speaker 1: quickly and sometimes more slowly, like a dark matter wind. Yes, 439 00:22:54,400 --> 00:22:57,199 Speaker 1: just like a dark matter wind. And so that's the 440 00:22:57,280 --> 00:22:59,520 Speaker 1: idea is like let's look to see if there are 441 00:22:59,600 --> 00:23:03,680 Speaker 1: more dark matter interactions in June then in December, because 442 00:23:03,680 --> 00:23:06,760 Speaker 1: that seasonal variation would be what you expect to see 443 00:23:06,920 --> 00:23:11,440 Speaker 1: from dark matter, which has this seasonally varying velocity relative 444 00:23:11,480 --> 00:23:13,199 Speaker 1: to the Earth. And it has nothing to do with 445 00:23:13,240 --> 00:23:16,399 Speaker 1: pumpking spice or maybe we're shorts in the summer. Tip. Well, 446 00:23:16,400 --> 00:23:19,280 Speaker 1: you know, nobody understands the results of this experiment, and 447 00:23:19,320 --> 00:23:22,720 Speaker 1: so maybe it is just the cumulative effect of pumpkin spice, 448 00:23:22,760 --> 00:23:26,800 Speaker 1: lot pumping spice espressos because you know there in Italy, 449 00:23:27,160 --> 00:23:29,480 Speaker 1: all right, So they've seen a signal. Basically, what is 450 00:23:29,520 --> 00:23:32,480 Speaker 1: what you're saying is that they've seen a seasonal variation 451 00:23:32,920 --> 00:23:35,960 Speaker 1: in their detection of dark matter according to sort of 452 00:23:35,960 --> 00:23:39,000 Speaker 1: the motion of the Earth. So which might be like, hey, 453 00:23:39,080 --> 00:23:42,600 Speaker 1: maybe dark matter is there and it is seasonal. Yes, exactly, 454 00:23:42,640 --> 00:23:45,800 Speaker 1: they are seeing this seasonal variation. If you look at 455 00:23:45,800 --> 00:23:47,679 Speaker 1: a plot of their results, the sort of number of 456 00:23:47,720 --> 00:23:50,000 Speaker 1: sparks they see is a function of the day. Then 457 00:23:50,040 --> 00:23:52,280 Speaker 1: you see it goes up and it peaks in June, 458 00:23:52,359 --> 00:23:55,280 Speaker 1: and it falls down and it minimizes in December, and 459 00:23:55,320 --> 00:23:57,600 Speaker 1: then it goes back up again. And you know, they've 460 00:23:57,600 --> 00:24:00,680 Speaker 1: been running this experiment for years, which allows them to 461 00:24:00,720 --> 00:24:02,840 Speaker 1: see lots of these cycles. And so it's not just 462 00:24:02,920 --> 00:24:06,000 Speaker 1: like one little wiggle which could have been anything. It's 463 00:24:06,040 --> 00:24:08,960 Speaker 1: definitely a cycle, and it's definitely annual, and it definitely 464 00:24:09,040 --> 00:24:12,000 Speaker 1: peaks and dips in the right places. Wow. Yeah, they've 465 00:24:12,000 --> 00:24:14,960 Speaker 1: been seeing signals for fourteen years. Like it's not a 466 00:24:15,040 --> 00:24:18,000 Speaker 1: one time fluke that they see the pattern. It's like 467 00:24:18,000 --> 00:24:20,320 Speaker 1: they've they've been measuring this and it goes up and 468 00:24:20,359 --> 00:24:24,000 Speaker 1: down yearly for fourteen years. Yeah, for at least fourteen years. 469 00:24:24,040 --> 00:24:26,919 Speaker 1: They've had a few iterations of this experiment. They've upgraded this, 470 00:24:27,000 --> 00:24:29,960 Speaker 1: they've tweaked that, and so different plots have different numbers 471 00:24:29,960 --> 00:24:32,640 Speaker 1: of years on them. But you know, almost twenty years 472 00:24:32,640 --> 00:24:34,760 Speaker 1: ago they started seeing this signal. In the first few 473 00:24:34,800 --> 00:24:37,320 Speaker 1: years people were like, nah, keep taking data, we don't 474 00:24:37,320 --> 00:24:39,520 Speaker 1: believe it. But now they have these plots of just 475 00:24:39,600 --> 00:24:42,360 Speaker 1: like wiggle and wiggle and wiggle and wiggle, and it's 476 00:24:42,520 --> 00:24:45,000 Speaker 1: very unlikely that it's a fluke. You know, if you 477 00:24:45,080 --> 00:24:47,760 Speaker 1: do the calculation, what are the chances of seeing this 478 00:24:47,920 --> 00:24:51,000 Speaker 1: kind of wiggle from something which is actually flat, it's 479 00:24:51,119 --> 00:24:54,760 Speaker 1: very very small. The threshold for discovering particle physics is 480 00:24:54,880 --> 00:24:58,320 Speaker 1: five sigma, which means like, you know, one in millions 481 00:24:58,320 --> 00:25:01,239 Speaker 1: of chances of being a background in fluctuation. But they 482 00:25:01,280 --> 00:25:04,800 Speaker 1: have nine sigma, which is like almost unimaginable. So this 483 00:25:04,880 --> 00:25:08,719 Speaker 1: is definitely a signal something is happening here. The remaining 484 00:25:08,800 --> 00:25:12,560 Speaker 1: question is is it really dark matter? All right? So 485 00:25:12,600 --> 00:25:15,880 Speaker 1: they have fourteen years of data, it's a pretty clear 486 00:25:16,240 --> 00:25:19,359 Speaker 1: wiggle that there's dark matter, but nobody believes them. So 487 00:25:19,560 --> 00:25:22,320 Speaker 1: what's going on, Daniel? Do people just don't believe their data? 488 00:25:22,760 --> 00:25:25,239 Speaker 1: Are they suspicious? And is it that nobody has been 489 00:25:25,280 --> 00:25:27,880 Speaker 1: able to see it in the same way. What's going on, Well, 490 00:25:27,960 --> 00:25:29,800 Speaker 1: there's a lot of things going on here. Some of 491 00:25:29,800 --> 00:25:32,320 Speaker 1: them are technical and scientific, and some of them are 492 00:25:32,320 --> 00:25:36,639 Speaker 1: sort of sociological and maybe personal. Some people don't like pasta. 493 00:25:37,080 --> 00:25:40,639 Speaker 1: Everybody likes pasta. Some people just don't put parmesan on 494 00:25:40,680 --> 00:25:43,440 Speaker 1: their shrimp pasta, which is you know, unimaginable. That's a 495 00:25:43,560 --> 00:25:47,000 Speaker 1: no no, that's a yes yes for me anyway. One 496 00:25:47,080 --> 00:25:50,040 Speaker 1: problem is that they have not really shared the details 497 00:25:50,160 --> 00:25:52,840 Speaker 1: of their data. Like they show up at conferences, they 498 00:25:52,840 --> 00:25:56,000 Speaker 1: write papers, they show these results that look great, but 499 00:25:56,080 --> 00:25:58,639 Speaker 1: they haven't opened up their box to show us, like 500 00:25:58,680 --> 00:26:01,639 Speaker 1: the nuts and bolts how they analyze the data and 501 00:26:01,680 --> 00:26:04,280 Speaker 1: shared a lot of details. And as you can expect, 502 00:26:04,320 --> 00:26:07,240 Speaker 1: physicists want to see details. You can't just show up 503 00:26:07,280 --> 00:26:10,320 Speaker 1: with your one discovery plot and say, look, we discovered it, 504 00:26:10,400 --> 00:26:12,840 Speaker 1: let's all move on. People want to dig into it 505 00:26:12,880 --> 00:26:15,280 Speaker 1: and understand it and think about how to double check it. 506 00:26:15,640 --> 00:26:18,880 Speaker 1: And they've been pretty closed with their data, right. Well, 507 00:26:18,920 --> 00:26:20,760 Speaker 1: it used to be that people who are super closed, 508 00:26:20,760 --> 00:26:23,119 Speaker 1: but I think the more recent trend is for everyone 509 00:26:23,160 --> 00:26:25,440 Speaker 1: to just open up their you know, files and let 510 00:26:25,480 --> 00:26:28,360 Speaker 1: everyone sift through your numbers. Yeah, and you know, extraordinary 511 00:26:28,400 --> 00:26:31,840 Speaker 1: claims require extraordinary evidence, and so you have to like 512 00:26:31,960 --> 00:26:35,800 Speaker 1: respond to questions and give details when people ask you 513 00:26:35,840 --> 00:26:37,760 Speaker 1: send a paper in for a review, for example, the 514 00:26:37,800 --> 00:26:40,720 Speaker 1: reviewers can to ask for more experiments or additional plots, 515 00:26:40,720 --> 00:26:42,560 Speaker 1: because what they want to do is make sure this 516 00:26:42,640 --> 00:26:45,119 Speaker 1: is real, that it makes sense to them. Can't just 517 00:26:45,200 --> 00:26:48,280 Speaker 1: be one pretty plot has to reflect something true about 518 00:26:48,280 --> 00:26:51,640 Speaker 1: the universe, and so people want to consistent story, something 519 00:26:51,680 --> 00:26:53,679 Speaker 1: that tells them this is really dark matter and not 520 00:26:53,880 --> 00:26:57,080 Speaker 1: something else. So what's their case for not releasing the data? 521 00:26:57,280 --> 00:27:00,560 Speaker 1: Are they under audit or something? I don't know. It's 522 00:27:00,560 --> 00:27:02,600 Speaker 1: a bit of a cultural thing, you know. They show 523 00:27:02,720 --> 00:27:06,159 Speaker 1: up at conferences, and as one dark matter theorists described 524 00:27:06,200 --> 00:27:09,960 Speaker 1: to me, they seem aggressively uninterested in what other people 525 00:27:10,000 --> 00:27:12,480 Speaker 1: think about their data. I think you're saying they're too cool. 526 00:27:12,640 --> 00:27:15,199 Speaker 1: They believe their results, they're very confident in it, but 527 00:27:15,280 --> 00:27:18,440 Speaker 1: they haven't shared enough details for other people to really 528 00:27:18,440 --> 00:27:21,760 Speaker 1: gain confidence in their results. And so instead people have 529 00:27:21,800 --> 00:27:24,880 Speaker 1: had to turn to other experiments, which should be sensitive 530 00:27:24,920 --> 00:27:27,560 Speaker 1: to the same signal, to see if they can confirm right. 531 00:27:27,640 --> 00:27:30,679 Speaker 1: Because maybe another experiment that with a similar setup, like 532 00:27:30,720 --> 00:27:33,920 Speaker 1: with a vat of stuff waiting to interact with dark matter, 533 00:27:34,040 --> 00:27:37,240 Speaker 1: would also see like these seasonal spikes. Yeah, you would 534 00:27:37,240 --> 00:27:39,800 Speaker 1: expect so. And in fact, one of the other big 535 00:27:39,920 --> 00:27:42,560 Speaker 1: dark matter experiments in the world, the zeno On experiment, 536 00:27:42,880 --> 00:27:45,800 Speaker 1: is sitting in the same labs. Like they have this 537 00:27:45,880 --> 00:27:48,600 Speaker 1: big holid out space under this mountain to do these 538 00:27:48,680 --> 00:27:51,000 Speaker 1: kinds of experiments, and they gave part of it to 539 00:27:51,119 --> 00:27:53,840 Speaker 1: the Doma experiment and part of it to the Xenon experiment. 540 00:27:54,040 --> 00:27:56,720 Speaker 1: So the Xenon experiment is literally in the same place 541 00:27:56,760 --> 00:27:59,560 Speaker 1: as the Doma experiment. So if there's any issues with 542 00:27:59,640 --> 00:28:03,960 Speaker 1: like seasonal variations on temperature or something else, right, that's 543 00:28:03,960 --> 00:28:06,679 Speaker 1: the concerns that there might be some seasonal source of 544 00:28:06,760 --> 00:28:10,280 Speaker 1: background that they haven't accounted for. Zenon is in the 545 00:28:10,359 --> 00:28:13,000 Speaker 1: same place, it's in the same lab. They do not 546 00:28:13,240 --> 00:28:17,639 Speaker 1: see this seasonal variation they see, So nobody's seen this 547 00:28:17,720 --> 00:28:22,080 Speaker 1: seasonal variation. There's several of these dark matter experiments, but 548 00:28:22,160 --> 00:28:24,840 Speaker 1: nobody has seen this kind of variation with the year. 549 00:28:25,000 --> 00:28:27,760 Speaker 1: That's right, there's a huge variety of dark matter experiments. 550 00:28:27,800 --> 00:28:31,520 Speaker 1: They have different like active materials like liquid zenn versus 551 00:28:31,520 --> 00:28:34,440 Speaker 1: sodium idide crystals. They're in different places around the world, 552 00:28:34,520 --> 00:28:38,040 Speaker 1: they have different sensor technologies. Nobody has seen the results 553 00:28:38,080 --> 00:28:41,280 Speaker 1: that's consistent with what DAMA has seen, and so you 554 00:28:41,360 --> 00:28:43,880 Speaker 1: might ask, like, well, would they have seen these results? 555 00:28:44,040 --> 00:28:46,840 Speaker 1: Is it possible for dark matter to only interact with 556 00:28:46,880 --> 00:28:49,640 Speaker 1: this one kind of material and not the others? And 557 00:28:49,680 --> 00:28:53,000 Speaker 1: so people have built like boutique theories of dark matters 558 00:28:53,000 --> 00:28:55,800 Speaker 1: to try to explain this Dama experiment. Why DAMA would 559 00:28:55,800 --> 00:28:59,200 Speaker 1: see it but Xenon wouldn't. Maybe it only interacts with 560 00:28:59,240 --> 00:29:02,120 Speaker 1: neutrons and set of protons or prefers protons in one 561 00:29:02,200 --> 00:29:05,200 Speaker 1: arrangement to another kind of arrangement, But nobody has been 562 00:29:05,240 --> 00:29:08,200 Speaker 1: able to explain it. And in the meantime, people have 563 00:29:08,320 --> 00:29:11,440 Speaker 1: built copies of the Dama experiment that are essentially the 564 00:29:11,520 --> 00:29:15,560 Speaker 1: same technology, the same active material, the same kind of sensors, 565 00:29:15,720 --> 00:29:18,400 Speaker 1: but just in different locations to try to double check 566 00:29:18,520 --> 00:29:22,360 Speaker 1: DAMA really interesting. They've used like this crystalline sodium also, 567 00:29:22,720 --> 00:29:25,480 Speaker 1: and they've put it inside of a mine and and 568 00:29:25,600 --> 00:29:28,480 Speaker 1: do they see anything. They don't see anything yet. So 569 00:29:28,520 --> 00:29:31,880 Speaker 1: there's an experiment in South Korea called Cosigne, and I 570 00:29:31,960 --> 00:29:34,760 Speaker 1: have no idea what that stands for But they basically 571 00:29:34,800 --> 00:29:38,240 Speaker 1: have duplicated the DOMAS experiments set up, but they don't 572 00:29:38,240 --> 00:29:41,200 Speaker 1: see the results. Now, this is a difficult thing to do. 573 00:29:41,360 --> 00:29:43,840 Speaker 1: It takes years of data to say are we seeing 574 00:29:43,880 --> 00:29:46,640 Speaker 1: a flat line or are we seeing wiggles. So so 575 00:29:46,720 --> 00:29:48,600 Speaker 1: far they only have a couple of years of data 576 00:29:48,880 --> 00:29:52,000 Speaker 1: and they say their results are in quote severe tension 577 00:29:52,240 --> 00:29:55,400 Speaker 1: with the DAMA results, but they also admit that it 578 00:29:55,480 --> 00:29:57,960 Speaker 1: could be consistent with DAMA. They just don't have enough 579 00:29:58,040 --> 00:30:01,880 Speaker 1: data yet. So time will tell if Cosign sees a 580 00:30:01,920 --> 00:30:05,080 Speaker 1: wiggle or not. But so far the indications are that 581 00:30:05,160 --> 00:30:07,520 Speaker 1: they haven't interesting. They want to see it happen before 582 00:30:07,520 --> 00:30:11,760 Speaker 1: they co sign the certification. There, that's right, they want 583 00:30:11,800 --> 00:30:14,480 Speaker 1: to see their own cosign in the data. Let's see 584 00:30:14,480 --> 00:30:18,160 Speaker 1: their own wiggles. H alright. But still DOMA is pretty 585 00:30:18,160 --> 00:30:21,240 Speaker 1: confident about their result. DOMA is pretty confident in their results. 586 00:30:21,320 --> 00:30:24,040 Speaker 1: You know, they believe that it's dark matter. People have 587 00:30:24,160 --> 00:30:26,640 Speaker 1: thought about all sorts of other sources of background, like 588 00:30:27,160 --> 00:30:30,200 Speaker 1: maybe the rock heats up in the summer and it 589 00:30:30,280 --> 00:30:33,680 Speaker 1: gives off more radiation and that leaks into the experiment, 590 00:30:33,960 --> 00:30:35,640 Speaker 1: And they have all sorts of ways to monitor this 591 00:30:35,760 --> 00:30:38,000 Speaker 1: and they don't see that kind of thing. So physicists 592 00:30:38,000 --> 00:30:40,320 Speaker 1: in the community has been a lot of energy brainstorming 593 00:30:40,480 --> 00:30:44,680 Speaker 1: possible explanations for what might explain is other than dark matter, 594 00:30:44,960 --> 00:30:48,200 Speaker 1: more prosaic explanations, and so far they haven't figured out 595 00:30:48,240 --> 00:30:51,360 Speaker 1: anything that they can point to that says, here's why 596 00:30:51,520 --> 00:30:54,320 Speaker 1: DOMA is seeing this signal. It's not dark matter, it's 597 00:30:54,720 --> 00:30:57,160 Speaker 1: you know, growth of plants on the top of the 598 00:30:57,200 --> 00:30:59,880 Speaker 1: mountain is releasing something in June or something like that. 599 00:31:00,320 --> 00:31:02,840 Speaker 1: But nobody's found that explanation yet. All right, let's get 600 00:31:02,880 --> 00:31:06,800 Speaker 1: into what maybe DAMA is seeing in their signals of 601 00:31:06,960 --> 00:31:10,720 Speaker 1: dark matter and why nobody believes any of these. But 602 00:31:10,840 --> 00:31:22,560 Speaker 1: first let's take a quick break. All right, Daniel d 603 00:31:22,640 --> 00:31:25,320 Speaker 1: DAMA experiment has been seeing a dark matter signal for 604 00:31:25,480 --> 00:31:29,280 Speaker 1: fourteen years, but nobody believes them and nobody can replicate 605 00:31:29,360 --> 00:31:32,240 Speaker 1: the results. So what are some of the possibilities heres 606 00:31:32,480 --> 00:31:34,480 Speaker 1: of what they could be seeing. Do they have like 607 00:31:34,880 --> 00:31:37,840 Speaker 1: a wire that's not connected right but only once a year, 608 00:31:38,920 --> 00:31:41,240 Speaker 1: or is it could be the air conditioning in the 609 00:31:41,360 --> 00:31:43,640 Speaker 1: room that you know, in the summer it kicks up more, 610 00:31:43,800 --> 00:31:45,760 Speaker 1: or what could it be? So the sort of two 611 00:31:45,960 --> 00:31:50,800 Speaker 1: categories of possible explanations. One are non dark matter explanations right, 612 00:31:51,200 --> 00:31:55,080 Speaker 1: and ideas there are like they use nitrogen in their experiment, 613 00:31:55,240 --> 00:31:57,480 Speaker 1: but it also has a little bit of argon in it. 614 00:31:57,720 --> 00:32:00,800 Speaker 1: They surround the experiment with argon, and it could be 615 00:32:01,360 --> 00:32:04,920 Speaker 1: that some of that are gone has seasonal variations in it, 616 00:32:05,280 --> 00:32:08,640 Speaker 1: that is more activated during June than in December, based 617 00:32:08,720 --> 00:32:11,360 Speaker 1: on based on what how how would the argon know 618 00:32:11,600 --> 00:32:14,560 Speaker 1: what the season was? Well, it's not that an individual 619 00:32:14,880 --> 00:32:18,840 Speaker 1: argon adom knows the season or like celebrates Christmas. It's 620 00:32:18,880 --> 00:32:22,400 Speaker 1: that the amount of radio active aregon around the experiment 621 00:32:22,520 --> 00:32:25,920 Speaker 1: depends on the season. The contaminant we're interested in here 622 00:32:26,040 --> 00:32:29,560 Speaker 1: is are gone thirty seven, which is made when neutrons 623 00:32:29,680 --> 00:32:32,160 Speaker 1: hit calcium in the soil or are gone thirty six 624 00:32:32,280 --> 00:32:35,400 Speaker 1: in the atmosphere, and the neutron flux, the number of 625 00:32:35,480 --> 00:32:38,640 Speaker 1: neutrons coming in to make are gone thirty seven has 626 00:32:38,720 --> 00:32:42,719 Speaker 1: a seasonal variation due to the variation and atmosphere density, 627 00:32:42,760 --> 00:32:44,640 Speaker 1: which it determines like how many it make it all 628 00:32:44,680 --> 00:32:47,120 Speaker 1: the way down. But you know, people are really scratching 629 00:32:47,120 --> 00:32:50,240 Speaker 1: their heads trying to think of crazy explanations, because of course, 630 00:32:50,480 --> 00:32:53,320 Speaker 1: the folks and Dama are solid physicists, and they've taken 631 00:32:53,360 --> 00:32:55,600 Speaker 1: care of all the obvious effects that have as much 632 00:32:55,680 --> 00:32:58,120 Speaker 1: you know, climate controlling as they can manage in this 633 00:32:58,280 --> 00:33:00,600 Speaker 1: environment to try to isolate themselves from any sort of 634 00:33:00,640 --> 00:33:04,120 Speaker 1: seasonal variations. But you know, at the colliders were also 635 00:33:04,240 --> 00:33:07,440 Speaker 1: sensitive to really really tiny effects. The phases of the 636 00:33:07,600 --> 00:33:11,240 Speaker 1: moon affect the shape of the rock near Lake Geneva, 637 00:33:11,600 --> 00:33:14,840 Speaker 1: and that affects the bending of the accelerator because it's 638 00:33:14,920 --> 00:33:18,240 Speaker 1: under the rock, and people notice these things. What you 639 00:33:18,320 --> 00:33:22,120 Speaker 1: see title effects in your data. Absolutely, the train schedules 640 00:33:22,480 --> 00:33:25,959 Speaker 1: in Geneva affected the results of colliders in those tunnels, 641 00:33:26,000 --> 00:33:28,960 Speaker 1: and so we can be very sensitive to very small effects. 642 00:33:29,280 --> 00:33:31,880 Speaker 1: What how did how did the trains affect your the 643 00:33:31,960 --> 00:33:35,080 Speaker 1: particle closure? Is it like the vibrations of the trains 644 00:33:35,280 --> 00:33:38,040 Speaker 1: or just more people on campus at certain times. It's 645 00:33:38,080 --> 00:33:41,640 Speaker 1: really amazing. Actually it was the electricity from the trains. 646 00:33:42,080 --> 00:33:44,640 Speaker 1: Some of the extra current leaks down and made little 647 00:33:44,760 --> 00:33:48,680 Speaker 1: gentle magnetic fields which actually influenced the operation of the collider. 648 00:33:49,320 --> 00:33:53,160 Speaker 1: And so when you're hunting down tiny little explanations and 649 00:33:53,240 --> 00:33:56,040 Speaker 1: you're trying to separate the ideas from like dark matter 650 00:33:56,240 --> 00:33:59,640 Speaker 1: to other basic prosaic explanations. You've got to go all 651 00:33:59,720 --> 00:34:02,440 Speaker 1: the way down the list for really small effects. All right, 652 00:34:02,480 --> 00:34:04,800 Speaker 1: So what else could this signal they're seeing? What else 653 00:34:04,840 --> 00:34:07,520 Speaker 1: could it be? Could it be, you know, some other 654 00:34:07,680 --> 00:34:10,319 Speaker 1: kind of theory about how dark matter interact. It could 655 00:34:10,360 --> 00:34:12,680 Speaker 1: certainly be, like there could be other ways that dark 656 00:34:12,719 --> 00:34:14,960 Speaker 1: matter interacts. It could be that dark matter is something 657 00:34:15,080 --> 00:34:18,040 Speaker 1: weird that we hadn't imagined before, and that's why we're 658 00:34:18,040 --> 00:34:20,839 Speaker 1: seeing it only in these crystals but not in others. Now, 659 00:34:20,920 --> 00:34:23,360 Speaker 1: the cosine experiments and the other ones that are replicating 660 00:34:23,440 --> 00:34:26,239 Speaker 1: this make it pretty hard to follow that kind of 661 00:34:26,320 --> 00:34:29,440 Speaker 1: explanation because they're basically a copy of DAMA and they 662 00:34:29,560 --> 00:34:32,600 Speaker 1: don't see it. But put those aside, and let's say 663 00:34:32,920 --> 00:34:35,160 Speaker 1: maybe cosine and the other experiments that are trying to 664 00:34:35,200 --> 00:34:38,080 Speaker 1: replicate it just don't have enough data yet. People have 665 00:34:38,239 --> 00:34:40,879 Speaker 1: cooked up theories that try to explain why dark matter 666 00:34:40,960 --> 00:34:44,080 Speaker 1: interacts with sodium iodide more than it interacts with zenon, 667 00:34:44,239 --> 00:34:48,200 Speaker 1: for example, like dark maybe dark matter pre first Italians 668 00:34:48,560 --> 00:34:50,920 Speaker 1: or you know, less of vacation in Italy more than 669 00:34:51,000 --> 00:34:52,920 Speaker 1: it does in South Korea. Yeah, and it also has 670 00:34:52,960 --> 00:34:55,920 Speaker 1: to do with the mass because xenon is heavier, for example, 671 00:34:56,160 --> 00:34:58,960 Speaker 1: than other elements, and so dark matter is very very 672 00:34:59,080 --> 00:35:01,320 Speaker 1: low mass. If it doesn't have a lot of oomph 673 00:35:01,400 --> 00:35:03,520 Speaker 1: to it, then it might be that it's just harder 674 00:35:03,600 --> 00:35:05,960 Speaker 1: for it to push zen on than to interact with 675 00:35:06,320 --> 00:35:08,879 Speaker 1: sodium iodide. And so people have come up with these 676 00:35:08,920 --> 00:35:12,240 Speaker 1: theories of like very light dark matter, but those theories 677 00:35:12,239 --> 00:35:15,239 Speaker 1: are also hard to explain because DAMA builds a new 678 00:35:15,400 --> 00:35:18,480 Speaker 1: system in their experiment, one that should be sensitive to 679 00:35:18,560 --> 00:35:21,839 Speaker 1: sort of lower energy results, and they don't see any 680 00:35:21,960 --> 00:35:24,879 Speaker 1: difference in the low energy results and the original ones. 681 00:35:25,480 --> 00:35:28,040 Speaker 1: And if there was very very light dark matter, they 682 00:35:28,040 --> 00:35:31,000 Speaker 1: would expect to see a larger signal in these low 683 00:35:31,160 --> 00:35:34,600 Speaker 1: energy recoils, but they don't. So people have been a 684 00:35:34,680 --> 00:35:37,439 Speaker 1: lot of time trying to construct these fancy dark matter 685 00:35:37,560 --> 00:35:41,000 Speaker 1: theories that could explain DAMA as dark matter, but none 686 00:35:41,040 --> 00:35:43,800 Speaker 1: of them really hold water. So the consensus in the 687 00:35:43,880 --> 00:35:47,040 Speaker 1: dark matter community is that DAMA is not seeing dark matter. 688 00:35:47,080 --> 00:35:49,360 Speaker 1: They're seeing something else. We just don't know what it 689 00:35:49,520 --> 00:35:51,200 Speaker 1: is yet. I guess the problem too, is that, you know, 690 00:35:51,239 --> 00:35:53,360 Speaker 1: as we go around the sun, it's not just about 691 00:35:53,920 --> 00:35:56,480 Speaker 1: more sunlight or less sunlight. It's also kind of there's 692 00:35:56,480 --> 00:35:59,600 Speaker 1: other stuff going out there in space, right, absolutely, there 693 00:35:59,640 --> 00:36:02,480 Speaker 1: are very variations and like how many Muans strike the 694 00:36:02,560 --> 00:36:05,959 Speaker 1: Earth because Muans come to the Earth from cosmic rays 695 00:36:06,000 --> 00:36:09,080 Speaker 1: and not just from the Sun, but also from galactic sources, 696 00:36:09,440 --> 00:36:11,600 Speaker 1: like there are mus being created by other stars from 697 00:36:11,640 --> 00:36:14,320 Speaker 1: from the galactic center that hit the Earth, and so 698 00:36:14,560 --> 00:36:18,520 Speaker 1: that varies also with the seasons for similar reasons. And 699 00:36:18,719 --> 00:36:20,879 Speaker 1: so it could be that they're seeing some weird dawk 700 00:36:20,880 --> 00:36:24,279 Speaker 1: Off effect from these cosmic Muan seasons. It could be 701 00:36:24,360 --> 00:36:27,840 Speaker 1: that nobody's really nailed that down yet, all right, So 702 00:36:27,920 --> 00:36:31,400 Speaker 1: the consensus is that they're not seeing dark matter, but 703 00:36:31,480 --> 00:36:33,600 Speaker 1: how they told DAMA that they that everyone thinks so, 704 00:36:33,800 --> 00:36:37,960 Speaker 1: or is it's just sort of a like a background whispering, 705 00:36:38,080 --> 00:36:40,280 Speaker 1: Like I don't think they've seen it. DAMA is definitely 706 00:36:40,360 --> 00:36:44,160 Speaker 1: aware that their explanation is not accepted, but they are 707 00:36:44,320 --> 00:36:48,239 Speaker 1: very confident, you know, they are sure that their experiment 708 00:36:48,400 --> 00:36:51,200 Speaker 1: indicates the presence of dark matter particles in the halo. 709 00:36:51,640 --> 00:36:54,319 Speaker 1: There's a quote from the long time leader the experiment saying, 710 00:36:54,600 --> 00:36:58,719 Speaker 1: there is no alternative explanation for our signal. So they're 711 00:36:58,800 --> 00:37:03,360 Speaker 1: very confident. They are aware that nobody believes them, but 712 00:37:03,600 --> 00:37:06,960 Speaker 1: they're powering forward. You know, what do you think, Daniel, 713 00:37:07,120 --> 00:37:11,680 Speaker 1: Are you aggressively interested or aggressively uninterested in this result? 714 00:37:12,880 --> 00:37:15,120 Speaker 1: When I've heard about it, I was super excited. I 715 00:37:15,200 --> 00:37:18,080 Speaker 1: was like, what a beautiful signal, what a nice experiment. 716 00:37:18,480 --> 00:37:21,000 Speaker 1: I would love to believe it. But you know, before 717 00:37:21,040 --> 00:37:23,160 Speaker 1: you believe something like this, you really have to see 718 00:37:23,200 --> 00:37:26,320 Speaker 1: it replicated. Because we're not interested in one cute story 719 00:37:26,360 --> 00:37:29,080 Speaker 1: of an experiment that sees a cool wiggle. We're interested 720 00:37:29,120 --> 00:37:32,480 Speaker 1: in the actual story of dark matter. And if it's 721 00:37:32,480 --> 00:37:34,839 Speaker 1: a real story of science, you should appear in more 722 00:37:34,920 --> 00:37:36,800 Speaker 1: than one place. You should be able to see it 723 00:37:36,960 --> 00:37:39,399 Speaker 1: using more than one technique, or you should at least 724 00:37:39,440 --> 00:37:41,839 Speaker 1: be able to tell coherent story about why it's here 725 00:37:41,920 --> 00:37:44,560 Speaker 1: and not there. Because the universe we think is a 726 00:37:44,640 --> 00:37:47,120 Speaker 1: coherent story is that we should be able to pull 727 00:37:47,160 --> 00:37:49,320 Speaker 1: it apart by looking at it from different angles. And 728 00:37:49,440 --> 00:37:52,400 Speaker 1: this is so difficult to see that you really have 729 00:37:52,640 --> 00:37:54,400 Speaker 1: to see it in more than one place before you 730 00:37:54,480 --> 00:37:56,879 Speaker 1: believe it. Right. You don't want it to be weak 731 00:37:56,960 --> 00:38:00,880 Speaker 1: pasta right, that's right. And so there's an other experiment 732 00:38:01,000 --> 00:38:04,640 Speaker 1: being built in the southern hemisphere, in the Saber experiment, 733 00:38:04,920 --> 00:38:07,640 Speaker 1: and it's very similar to the Dama experiment, except again 734 00:38:07,680 --> 00:38:10,800 Speaker 1: it's in the southern hemisphere, and so it should have 735 00:38:11,080 --> 00:38:16,719 Speaker 1: the opposite seasonal related systematic uncertainties because it's cold when 736 00:38:16,840 --> 00:38:19,560 Speaker 1: Dama is warm, and it'll be warm when Dama is cold. 737 00:38:19,800 --> 00:38:22,440 Speaker 1: If it's not related to the dark matter, but if 738 00:38:22,480 --> 00:38:25,880 Speaker 1: it is, it should see the same seasonal changes, right, 739 00:38:25,880 --> 00:38:27,960 Speaker 1: because it's moving along. It's it's about the movement of 740 00:38:28,000 --> 00:38:30,799 Speaker 1: the Earth exactly, and so it's just another cross check, 741 00:38:30,920 --> 00:38:34,840 Speaker 1: like let's move all temperature related things off by six months. 742 00:38:35,120 --> 00:38:37,920 Speaker 1: The dark matter shouldn't change at all. So if they 743 00:38:37,960 --> 00:38:41,560 Speaker 1: see a signal and it's shifted, that suggests that it's 744 00:38:41,760 --> 00:38:44,960 Speaker 1: temperature seasonal variation thing. If they see a signal and 745 00:38:45,040 --> 00:38:47,759 Speaker 1: it's not shifted, then that removes a lot of the 746 00:38:47,800 --> 00:38:51,560 Speaker 1: possible explanations for temperature variations. It doesn't change things like 747 00:38:51,680 --> 00:38:54,560 Speaker 1: you know, cosmic muon seasons, but it helps us sort 748 00:38:54,600 --> 00:38:57,040 Speaker 1: of isolate what this might be, right, and did they 749 00:38:57,080 --> 00:38:59,640 Speaker 1: find anything. They're still building it and so we don't 750 00:38:59,680 --> 00:39:02,680 Speaker 1: know the results of the Saber experiment. It's being built 751 00:39:02,760 --> 00:39:06,080 Speaker 1: in a gold mine in Australia, and everybody is very 752 00:39:06,160 --> 00:39:09,040 Speaker 1: eager to see what that experiment has to say, all right, 753 00:39:09,120 --> 00:39:12,319 Speaker 1: So I guess the answer is stay tuned. I guess 754 00:39:12,400 --> 00:39:16,040 Speaker 1: nobody believes the DAMA experiment because it hasn't been replicated, 755 00:39:16,200 --> 00:39:18,600 Speaker 1: and it could still be other things that cause it 756 00:39:18,800 --> 00:39:22,200 Speaker 1: the signal. That's right, there's no coherent explanation in which 757 00:39:22,320 --> 00:39:25,520 Speaker 1: DAMA is seeing dark matter and somehow nobody else is 758 00:39:25,600 --> 00:39:28,320 Speaker 1: able to see it, and so the most likely explanation 759 00:39:28,440 --> 00:39:30,719 Speaker 1: is that it's some weird source of signal that they 760 00:39:30,800 --> 00:39:33,520 Speaker 1: haven't isolated yet. But it could still be. It could 761 00:39:33,560 --> 00:39:36,480 Speaker 1: be that there are pockets of dark matter where the 762 00:39:36,560 --> 00:39:38,719 Speaker 1: dark matter is interacting with some weird kind of matter 763 00:39:38,800 --> 00:39:41,680 Speaker 1: that only exists around the DAMA experiment in Italy for 764 00:39:41,800 --> 00:39:44,320 Speaker 1: some weird reason. But you have to have sort of 765 00:39:44,520 --> 00:39:47,720 Speaker 1: crazier and crazier thoughts to explain this and to explain 766 00:39:47,840 --> 00:39:50,120 Speaker 1: the lack of signal and all the other experience. I 767 00:39:50,680 --> 00:39:52,720 Speaker 1: guess it's it's sort of the charge for both sides 768 00:39:52,960 --> 00:39:56,000 Speaker 1: of people trying to prove this data, right, Like, it's 769 00:39:56,480 --> 00:39:58,759 Speaker 1: it's getting harder to come up with excuses, but it's 770 00:39:58,760 --> 00:40:02,080 Speaker 1: also getting harder to applicated. Yeah. Absolutely, but it's also 771 00:40:02,160 --> 00:40:04,719 Speaker 1: a fun puzzle if you're an experimentalist, and you'd like 772 00:40:04,840 --> 00:40:07,080 Speaker 1: to dig around in the data and understand where is 773 00:40:07,120 --> 00:40:08,840 Speaker 1: this coming from? Why is it look this way and 774 00:40:08,920 --> 00:40:11,080 Speaker 1: not the other way. It's not a deep mystery of 775 00:40:11,120 --> 00:40:13,239 Speaker 1: the universe, but it is a fun question to ask, 776 00:40:13,360 --> 00:40:15,440 Speaker 1: like what could be the source of this. It's a 777 00:40:15,680 --> 00:40:19,000 Speaker 1: nice little detective mystery, and the person who actually figures 778 00:40:19,040 --> 00:40:21,560 Speaker 1: it out eventually might not win the Nobel Prize, but 779 00:40:21,680 --> 00:40:26,160 Speaker 1: they will scratch longstanding itch in particle physics, a dark 780 00:40:27,760 --> 00:40:30,120 Speaker 1: a dark itch that really matters. All Right, We'll stay 781 00:40:30,200 --> 00:40:32,680 Speaker 1: tuned and maybe in the next couple of years we'll 782 00:40:32,760 --> 00:40:36,000 Speaker 1: hear news about whether it's a real or not, whether 783 00:40:36,080 --> 00:40:40,320 Speaker 1: they deserve the Nobel Prize, or just a nice dinner 784 00:40:41,040 --> 00:40:43,800 Speaker 1: with a nice glass of Italian one and plenty of 785 00:40:43,880 --> 00:40:46,680 Speaker 1: parmesan sprinkled on top. All right, thanks for joining us, 786 00:40:47,280 --> 00:40:57,440 Speaker 1: see you next time. Thanks for listening, and remember that 787 00:40:57,600 --> 00:41:00,360 Speaker 1: Daniel and Jorge explained The universe is a shin of 788 00:41:00,480 --> 00:41:03,800 Speaker 1: I Heart Radio or more podcast from my Heart Radio. 789 00:41:03,960 --> 00:41:07,480 Speaker 1: Visit the I Heart Radio, Apple Apple Podcasts, or wherever 790 00:41:07,640 --> 00:41:09,280 Speaker 1: you listen to your favorite shows.